Kidney Flashcards
- Oncocytosis is considered in a 50-year-old man with bilateral renal masses. Which is the single best answer regarding oncocytosis?
A. Account for 2% of all renal cortical tumours
B. Multifocality bilateralism and metachronous tumours occur together in 4-6%
C. In multifocal cases co-existent RCC is present in 50% of cases
D. Often have preserved renal function
E. The final diagnosis can be made on MR above
B. Multifocality bilateralism and metachronous tumours occur together in 4-6%
Co-existent RCC in 10% of cases. Due to diffuse bilateralrenal involvement patients with oncocytosis often presentwith abnormal renal function. Final diagnosis is by biopsy.
- In a 40-year-old woman with seizures and bilateral renal masses, with the appearance of multiple angiomyolipomas, which is the single best answer?
A. Sporadic solitary Angiomyolipoma (AML) have a female preponderance
B. Account for 50% of all renal AMLs
C. Are associated with tuberous sclerosis
D. Warrant treatment due to risk of bleeding when > 2cm
E. Are typically hypoechoic on US
C. Are associated with tuberous sclerosis
Those AML associated with tuberous sclerosis are multifocal, bilateral, larger and present in a younger age group. AML appear echogenic on US.
- Which is a cause of dilated calyx with wide infundibuli?
A. Hydrocalycosis
B. Structure secondary to calculus
C. Structure secondary to TB
D. Extrinsic compression by an artery
E. Post-obstructive uropathy
A. Hydrocalycosis
Answers B-E are causes with narrow infundibuli
- During MR of the spine a 2cm renal lesion is identifed at the upper pole cortex of the RK. The lesion is well-defned and is of high SI on T1 and T2 images. Ultrasound shows normal Doppler flow in the renal vein which is separate from the lesion, which is echogenic on US. The fndings are most likely to represent which of the following?
A. AML
B. Atypical cyst
C. Abscess
D. RCC
E. Lymphoma
A. AML
AML appears increased on S1 on T1+T2 and is echogenic onUS.
- Which of the following causes immediate faint persistent nephrogram on Intravenous Urogram (IVU)?
A. Renal vein thrombosis (RVT)
B. Acute obstruction
C. Acute hypotension
D. Acute tubular necrosis
E. Chronic obstruction
A. Renal vein thrombosis (RVT)
Acute glomerulonephritis, RVT and chronic severe ischaemia are all causes of immediate faint persistent nephrogram.
- Which is the cause of rim nephrogram?
A. Acute complete arterial occlusion
B. Acute ureteric obstruction
C. Polycystic kidney disease
D. Medullary sponge kidney
E. Acute pyelonephritis
A. Acute complete arterial occlusion
Acute complete arterial occlusion and severe hydronephrosis are causes of a rim nephrogram. B-E are causes of a striated nephrogram.
- A 45-year-old female with a six-month history of urinary tract symptoms undergoes CT showing an enlarged right kidney with a large staghorn calculus and hydronephrosis. The renal parenchyma is replaced by multiple confluent fluid-flled masses. Open nephrectomy histology from the right kidney reveals lipid laden foamy macrophages in combination with an inflammatory granuloma and a lymphoplasmocytic infltrate. What is the most likely diagnosis?
A. Renal lymphoma
B. Xanthogranulomatous pyelonephritis
C. Renal TB
D. Malakoplakia
E. Nephrocalcinosis
B. Xanthogranulomatous pyelonephritis
A rare form of low-grade chronic renal infection with progressive destruction of renal parenchyma, XGP is more common in women and in 50-60 age group. Most cases are diffuse. E.coli and P.mirabils are the most common organisms in these patients with UTI
- In a patient who had a right nephrectomy ten years ago for RCC, a 3cm lesion in the cortex of the lower pole of the left kidney is evaluated with MRI. This appears isointenseon the in-phase sequence and low SI on the opposed phase sequence. No other renal lesions are demonstrated. The renal veins appear normal. What is the most likely diagnosis?
A. Oncocytoma
B. Simple cyst
C. RCC
D. AML
E. Metastatic deposit
D. AML
Demonstration of fat within a renal mass on CT or MRI is diagnostic of AML.
- A patient informs you she has a medical condition prior to pelvic MRI for evaluation of a pelvic malignancy. Which of the following would contraindicate buscopan injection?
A. Hypertension
B. Angina
C. CABG 3 years ago
D. Myasthenia gravis
E. Multiple sclerosis
D. Myasthenia gravis
Antimuscarinics are contraindicated in myasthenia gravis (but may be used to decrease the muscarinic side effects of anticholinesterases), paralytic ileus, pyloric stenosis and prostatic enlargement. They should be used with caution in Down’s syndrome, GORD, diarrhoea, ulcerative colitis, acute myocardial infarction, hypertension, conditions characterized by tachycardia (hyperthyroidism, cardiac insuffciency, cardiac surgery), pyrexia, pregnancy and in individuals susceptible to angle closure glaucoma. HBB improves image quality and lesion visualisation in oncologic pelvic MR.
- In dynamic renal imaging:
A. The patient must not eat or drink for 6 hours prior to the test
B. Provides information on total and divided function only
C. Total divided renal function are evaluated in addition to rates of transit through parenchyma and outflow track
D. Diethylene triamine pentaacetic acid (DTPA) has the advantage of higher renal concentration than inulin
E. DTPA is excreted by glomerular fltration and tubular excretion
C. Total divided renal function are evaluated in addition to rates of transit through parenchyma and outflow track
This investigation requires a hydrated patient to lie supine with knees slightly flexed to reduce lumbar lordosis.
DTPA is handled the same way as inulin.
D and E are correct for MAG3
- A 3cm cystic lesion is seen on CT. Thickened septae are noted, with nodular areas of calcifcation, with solid non-enhancing areas. Which of the following Bosniak classifcation best describes the lesion?
A. I
B. II
C. IIF
D. III
E. IV
D. III
Class II have at least one thin septa traversing them (< 1mm) and they have an appearance of thin areas of mural calcification or fluid content with greater attenuation.
These lesions are benign however IIF with numerous class II features should be followed up.
Class III features as above are indicative of malignancy and biopsy or surgical exploration is necessary.
Type IV cystic lesions are clearly malignant.
- Which of the following indicates T2 disease in renal cell carcinoma?
A. Perinephric fat involvement
B. Tumour size > 2.5cm
C. Tumour involvement of renal vein
D. Tumour involvement of adrenal gland
E. IVC involvement
B. Tumour size > 2.5cm
Stage T2 disease is indicated when the tumour size is greater than 2.5cm
- Regarding lymphoma of the kidneys:
A. Multiple focal nodules appear hyperdense on CT
B. Involved kidneys are usually atrophic
C. Focal masses appear high signal on T1
D. Focal masses appear hyperintense on T2
E. CT may demonstrate sheet like diffuse infltration of perirenal tissues
E. CT may demonstrate sheet like diffuse infltration of perirenal tissues
Diffuse infltration leads to renal enlargement. Focal lesions have a characteristic usually low attenuation post-contrast on CT, low SI on T1 and hypo-isointense on T2.
- Regarding metastatic sites of disease to the kidney:
A. Are frequently symptomatic
B. Usually occur from direct invasion
C. Haematogenous metastasis are usually > 3 cm
D. Are usually hypovascular on CT
E. Commonly calcify
D. Are usually hypovascular on CT
Metastases are usually small (< 3cm), multiple and confned to cortex.
The most common mode of spread is haematogenous.
Metastases tend not to invade the renal vein or calcify; they are more infltrative, less exophytic compared with renal cell carcinoma.
- Which of the following most favours RCC rather than TCC?
A. A central hypoechoic lesion on US
B. Intraluminal soft tissue mass in the calyx
C. Renal vein invasion
D. Infltration of renal sinus
E. Contrast outlining tumour in the pelvis
C. Renal vein invasion
In TCC inferior vena caval and renal vein invasion are uncommon
- Considering Squamous Cell Carcinoma (SCC) of the kidney:
A. Is the second most common tumour subtype affecting the kidney
B. Usually carries a better prognosis than RCC
C. Is usually indolent
D. Acute infection is involved in the aetiology
E. Renal calculi are present in most patients
E. Renal calculi are present in most patients
SCC of the kidney is a relatively rare condition. It carries a poor prognosis due to its aggressive nature. Both renal calculi and chronic infection have been implicated in its aetiology. Cross sectional imaging appearances are identical to those of TCC.
- Which is a cause of cortical rather than medullarynephrocalcinosis?
A. Acute cortical necrosis
B. Hyperoxaluria
C. Hypervitamosis D
D. Sarcoidosis
E. Renal tubular acidosis
A. Acute cortical necrosis
Acute cortical necrosis causes cortical nephrocalcinosis, whereas B-E are causes of medullary nephrocalcinosis
- Regarding hydronephrosis of pregnancy:
A. Left-sided dilated predominates
B. Occurs predominantly due to maternal hormones decreasing ureteric tone
C. Persists at most 3-4 days postpartum in most cases
D. Occurs in 90% of pregnant women by third trimester
E. Usually involves the entire length of the uterus
D. Occurs in 90% of pregnant women by third trimester
In most women dilatation disappears postpartum.
Resolution can take between a few days to several weeks.
Maternal hormones play a minor part.
Right-sided hydronephrosis is more common.
- Which is the most likely to cause bilateral small rather than large kidneys?
A. Medullary cystic disease
B. Multiple myeloma
C. PAN
D. Glycogen storage disease
E. Acute glomerulonephritis
A. Medullary cystic disease
Acute arterial hypotension, arteriosclerosis, nephrosclerosis and hereditary nephropathies including medullary cystic disease and Alport syndrome are all causes of bilateral small kidneys.
@# 47. A 50-year-old female undergoes CT for an echogenic lesion on ultrasound. Pre-contrast CT shows a lesion, which is well-defned and has increased attenuation (60HU). Postcontrast the lesion appears low in attenuation related to the surrounding parenchyma (61 HU). The diagnosis is:
A. Haemorrhagic renal cell carcinoma
B. Angiomyolipoma (AML) that has bled
C. Lymphoma
D. Haemorrhagic renal cyst
E. AML
D. Haemorrhagic renal cyst
A less than 10 HU increase post-contrast indicates benign hyperdense cyst. Other benign features include being sharply marginated and homogenous.
1) A patient who has no function in their native kidneys is found to have declining renal function 1 day after transplantation. A MAG3 renogram shows normal perfusion but diminished excretion. Which of the following processes is affecting the transplanted kidney?
a. acute rejection
b. chronic rejection
c. acute tubular necrosis
d. renal vein thrombosis
e. ciclosporin toxicity
c. acute tubular necrosis
Acute tubular necrosis is the commonest acute reversible cause of renal failure in the transplanted kidney and usually occurs within 24 hours. Of the complications of a transplanted kidney causing renal impairment, normal perfusion is seen in acute tubular necrosis, whereas renal vein thrombosis and transplant rejection have reduced perfusion accompanying the diminished excretion. Ciclosporin can cause a similar pattern of renal impairment but would be expected to occur 1 month after transplantation. Functional assessment of a transplanted kidney involves perfusion and excretion assessment with a MAG3 or DTPA renogram, MAG3 being the better test in transplant recipients with renal impairment. Doppler ultrasound resistive index measurement is also used, with a value of ,0.7 regarded as normal
2) A portal venous-phase CT of the abdomen and pelvis is performed in a 60-year-old man to investigate upper abdominal and back pain, which is attributed to features of pancreatitis on the scan. An incidental finding is of a rounded, renal lesion of diameter 3 cm, with average attenuation value of 80 HU and containing no significant component with a negative attenuation value on pixel densitometry. There are no previous images for comparison. What is the most likely diagnosis of the renal lesion?
a. angiomyolipoma
b. renal cell carcinoma
c. simple cyst
d. high-density cyst
e. infected cyst
b. renal cell carcinoma
A single portal venous phase CT is not the optimum image set to characterize renal parenchymal lesions. However, renal cell carcinoma is more commonly encountered than high-density cysts. Furthermore, carcinoma is most frequently found in men (2:1) aged over 50 years. Kidney neoplasms tend to have densities above 30 HU on an unenhanced CT and rise by more than 10–20 HU post-contrast, usually being above 70 HU in the portal phase.
4) A 55-year-old male has an ultrasound scan of the renal tract prompted by a single urinary tract infection. A kidney cyst of diameter 2 cm with a thin septum is seen. The septum has perceptible enhancement on CT. What is the most appropriate management from the choices below?
a. discharge with no follow-up
b. imaging follow-up
c. partial nephrectomy
d. nephrectomy
e. nephroureterectomy
b. imaging follow-up
An incidental, mildly complicated renal cyst has been uncovered. The Bosniak classification is a useful tool for evaluating cystic renal lesions, and guiding management. Simple cysts (Bosniak grade I) are thin walled, are of water density and have no enhancement. Minimally complicated cysts (grade II) may be clustered or septated, and have small curvilinear calcifications, a minimally irregular wall or high-density contents. Follow-up lesions (grade IIF) have perceptible enhancement of otherwise thin septations or are above 3cm in diameter with high-density contents. Surgical lesions (grade III) have thicker septa or walls, measurable enhancement, coarse irregular calcification and irregular margin, are multiloculated or can be a non-enhancing nodular mass. Clearly malignant lesions (grade IV) can have necrotic components, irregular wall thickening and enhancing solid elements.
9) CT scan of the chest, abdomen and pelvis is performed to stage a renal cell carcinoma. The tumour arises in, and is confined to, the upper pole of the left kidney with a maximum dimension of 5 cm. There is tumour thrombus in the left renal vein, inferior vena cava and right atrium. There are no enlarged lymph nodes and no metastases seen. According to the TNM classification what is the stage of the tumour?
a. T4 N0 M0
b. T2 N0 M0
c. T3a N0 M0
d. T3c N0 Mx
e. T3c N0 M0
e. T3c N0 M0
T1 and T2 renal cell carcinomas are limited to the kidney, and measure 7cm and .7cm respectively. T3 tumour extends beyond the kidney, into either the adrenal gland or perinephric tissues (T3a), the renal vein or vena cava below the diaphragm (T3b) or the vena cava above the diaphragm, or it invades the wall of the vena cava (T3c). T4 tumour invades beyond Gerota’s fascia. N1 or N2 nodal disease refers toinvolvement of a single regional node, or more than one regional node, respectively. Overall, T3c N0 M0 disease represents stage III disease.
10) A 30-year-old female has continued ipsilateral loin pain following surgery for pelviureteric junction obstruction. Ultrasound scan shows the renal pelvis to be less dilated than prior to surgery. MAG3 renogram is inconclusive with regard to the question of ongoing obstruction, and a Whitaker test is performed. The maximum pressure difference between the collecting system (antegrade) needle and the urinary catheter is found to be 10 cmH2O. What should the patient be advised regarding the findings of the Whitaker test?
a. this invasive test is also inconclusive
b. there is no evidence of pelviureteric junction or ureteric obstruction
c. there is ongoing pelviureteric junction obstruction
d. there is a second previously occult level of obstruction
e. the original diagnosis of pelviureteric junction obstruction is in doubt
b. there is no evidence of pelviureteric junction or ureteric obstruction
The Whitaker test is a pressure–flow study to evaluate ureteral obstruction or resistance in dilated non-refluxing upper tracts. Being invasive and time-consuming, it is usually performed only when excretory renograms are equivocal. A pressure difference of greater than 15cmH2O is abnormal.
15) An 80-year-old male has an IVU for unilateral loin pain. On the control film, the renal outline on the side of the pain is indistinct and enlarged. The same kidney has a staghorn calculus and shows no evidence of function following contrast injection. Which of the following is the most likely diagnosis?
a. xanthogranulomatous pyelonephritis
b. renal tuberculosis
c. hyperparathyroidism
d. hydatid cyst
e. carcinoma
a. xanthogranulomatous pyelonephritis
On the IVU, the features of xanthogranulomatous pyelonephritis are unilateral reniform enlargement, ipsilateral renal hypofunction and nephrolithiasis. The condition is probably produced by chronic lowgrade obstruction and chronic bacteriuria. Renal parenchyma is replaced by lipid-laden histiocytes causing renal expansion. This expansion can cause ‘stone fracture’ with obvious separation of the fracture fragments on plain film. Renal tube==rculosis causes dystrophic calcification that can be nodular, curvilinear or amorphous. The calcification is typically multifocal, involving other sites of the urinary tract, and there may be kidney scarring. Hyperparathyroidism causes medullary calcification. Six per cent of renal carcinomas have amorphous, irregular or occasionally curvilinear calcification, while hydatid cysts exhibit curvilinear or heterogeneous calcification
17) A 30-year-old male is investigated by renal tract ultrasound scan for renal impairment. Both kidneys are smooth in outline but enlarged. Which of the following diagnoses typically produces this pattern of renal enlargement?
a. autosomal dominant polycystic kidney disease
b. von Hippel–Lindau disease
c. sickle cell disease
d. metastases
e. nephroblastomatosis
c. sickle cell disease
Causes of bilateral smooth renal enlargement include diabetic nephropathy, acute glomerulonephritis, collagen vascular disease, vasculitis, AIDS nephropathy, leukaemia, lymphoma, autosomal recessive polycystic renal disease, acute interstitial nephritis, sickle cell disease, thalassaemia, acromegaly, amyloidosis, myeloma and acute urate nephropathy. When the bilateral renal enlargement is caused by masses, the differential diagnosis includes autosomal dominant polycystic disease, acquired renal cystic disease, lymphoma, metastases, Wilms’ tumours, tuberous sclerosis, von Hippel–Lindau syndrome, multiple oncocytomas and nephroblastomatosis
26) A 35-year-old female has investigations for episodic right loin pain. Ultrasound scan of the renal tract is unremarkable. A DMSA scan is performed with the patient sitting, and shows only 30% contribution to the total tracer activity from the right kidney. When the counts are repeated supine, the contribution from the right kidney is 50%. What is the most likely abnormality of the right kidney?
a. nutcracker kidney
b. nephroptosis
c. pelviureteric junction obstruction
d. ureteric calculus
e. vesicoureteric reflux
b. nephroptosis
Ptosis of the mobile kidney when erect can cause symptoms and underestimation of parenchymal DMSA uptake. Since the differential function may be a factor in considering removal of a kidney, the technique should account for the possibility of nephroptosis influencing the counts. A nutcracker kidney is a rare cause of left-sided loin pain and haematuria; it is caused by compression of the left renal vein between the aorta and superior mesenteric artery.
27) An 80-year-old male with a history of nephrectomy for renal cell carcinoma is found at follow-up to have a heterogeneously enhancing 25 mm lesion confined to his remaining kidney. No enlarged nodes or metastases are present. The lesion is biopsied and found to be an adenocarcinoma. The patient decides upon radiofrequency ablation as treatment. A CT scan 1 month after the ablation quantifies the average post-contrast enhancement of the tumour as 8 HU. Which of the following best represents the degree of success of the radiofrequency ablation?
a. failed
b. residual enhancing tumour requiring repeat ablation
c. residual enhancing tumour but no value in repeat ablation
d. successful
e. indeterminate
d. successful
The practice of radiofrequency ablation of renal tumours is emerging. Currently, CT 1 month after the procedure is used to assess treatment success. If enhancing prior to ablation, the tumour is regarded as ablated if there is ,10 HU rise in attenuation following contrast administration. Bulky persistent irregular peripheral enhancement is the commonest appearance of an incompletely treated lesion
30) A 65-year-old male being investigated for microscopic haematuria has an ultrasound scan, which suggests a 20 mm tumour in the cortex of the interpolar region of the left kidney. CT scan confirms an enhancing mass in the same location. On DMSA SPECT, this abnormality has good uptake. Which of the following is the most appropriate management?
a. no further action
b. biopsy
c. nephrectomy
d. image-guided drainage
e. chemotherapy
a. no further action
The abnormality described is prominent or hypertrophic cortex since it takes up DMSA, which in the kidneys is a parenchymal tracer. Renal cell carcinoma, cysts, abscess, haematoma, scar and infarct would be seen as photopenic areas on DMSA SPECT, if large enough.
34) A 35-year-old male with autosomal dominant polycystic kidney disease has been shown on CT to have, among the innumerable renal cysts, several high-density cysts. Which of the following MRI sequences would be most useful in detecting a renal cell carcinoma among haemorrhagic or proteinaceous cysts?
a. T1W
b. T2W
c. T1W post-gadolinium
d. T1W fat-suppressed post-gadolinium
e. T1W post-gadolinium with pre-contrast T1W signal subtracted
e. T1W post-gadolinium with pre-contrast T1W signal subtracted
The cornerstone of diagnosis here is the post-contrast enhancement of renal cell carcinoma. To identify this among the high T1 signal of haemorrhage or protein within cysts, it is ideal to subtract the precontrast T1 signal. Fat suppression will not remove the distracting high signal from mildly complicated cysts. Risk of renal cell carcinoma is increased in adult polycystic renal disease when in renal failure. Hence caution may be required since at certain levels of renal impairment the use of MRI contrast is not advised
38) An adult male patient who has been taking over-the-counter analgesics regularly for years has an IVU for ureteric colic. No radioopaque calculi are seen on the control film. With contrast in the renal calyces, they are noted to be club shaped on the side of the pain. On the same image, there is a triangular filling defect in the renal pelvis. The colic is most likely to be caused by which of the following?
a. radio-opaque stone
b. radiolucent stone
c. sloughed papilla
d. blood clot
e. transitional cell carcinoma
c. sloughed papilla
Predisposing factors to papillary necrosis include diabetes mellitus, analgesic nephropathy/abuse, sickle cell disease, pyelonephritis, obstructive uropathy, tuberculosis, trauma, cirrhosis, coagulopathy and renal vein thrombosis. None of the other options easily explains the club-shaped calyx. Blood clots from renal or tumour haemorrhage do cause ureteric colic but tend to elongate along the pelvis and ureter
40) A 38-year-old man presents with a classic history of ureteric colic. Plain abdominal film is unremarkable, and CT KUB shows ureteric dilatation and periureteric stranding down to the vesicoureteric junction on the side of the pain. No radio-opaque calculi are seen on the CT scan. Ultrasound examination shows a tiny, densely echogenic focus within the bladder wall, at the same vesicoureteric junction. For which of the following conditions is the patient most likely to be receiving treatment?
a. diabetes mellitus
b. asthma
c. HIV
d. gastro-oesophageal reflux
e. headaches
c. HIV
While around 10% of renal and ureteric stones are radiolucent on plain film, almost all are opaque on CT. One exception is the tiny radiolucent calculi formed in patients on protease inhibitors such as indinavir used in the treatment of HIV/AIDS
50) A 60-year-old male has an ultrasound scan of the renal tract for renal colic. There is an echo-free, thin-walled structure in the renal sinus with posterior acoustic enhancement and dilatation of the major calyces. A CT KUB (unenhanced) does not add to this appearance, but a 10-minute delayed, contrast-enhanced CT shows that the calyces are obstructed while the renal pelvis is not dilated but stretched over the non-enhancing sinus abnormality. What is the most likely diagnosis?
a. sinus lipomatosis
b. parapelvic cyst
c. pelviureteric junction obstruction
d. transitional call carcinoma
e. renal cell carcinoma
b. parapelvic cyst
The main differential diagnosis for a parapelvic or renal sinus cyst is hydronephrosis. Such cysts may present with pain due to obstructive caliectasis, but rarely cause hydronephrosis. They are found in 1.5% of autopsies and represent 4–6% of all renal cysts. A distinction is made in this question between renal and ureteric colic, the former symptom located to the loin and the latter more typically being loin to groin.
71) A 60-year-old female who has declined intervention for a renal angiomyolipoma of diameter 6 cm presents with flank pain, hypotension and tachycardia. In this scenario, which of the following is likely to account for the presentation?
a. torsion of the angiomyolipoma
b. haemorrhage from the angiomyolipoma
c. rupture of the angiomyolipoma
d. leak from the non-aneurysmal abdominal aorta
e. nephroptosis
b. haemorrhage from the angiomyolipoma
Angiomyolipomas are benign hamartomatous tumours that can occur in the kidneys. They contain fat, smooth muscle and abnormal blood vessels. Eighty per cent are sporadic and occur most often in females aged 50–80 years. Twenty per cent of patients with angiomyolipomas have tuberous sclerosis. Retroperitoneal bleed is the most significant complication and can be catastrophic. The risk increases with size of the lesion due to increased abnormal vasculature. Haemorrhage occurs because of large tortuous vessels and aneurysms. Embolization is performed for symptomatic (flank pain) angiomyolipomas, those that have bled at any size, and prophylactically when over 4cm.
81) A 70-year-old man with previously diagnosed, bilateral renal calculi is seen with fever, rigors and left loin pain. Ultrasound scan shows a dilated left renal collecting system. Which of the following is the most management?
a. oral antibiotics with outpatient follow-up
b. urinary catheter, intravenous antibiotics and admission to hospital
c. left nephrostomy and antibiotics
d. bilateral nephrostomy
e. intramuscular anti-spasmodics
c. left nephrostomy and antibiotics
Pyonephrosis secondary to an obstructing calculus is the likely diagnosis. Percutaneous nephrostomy is indicated for temporary or permanent relief of an obstructed urinary system (malignant or benign obstructive uropathy), pyonephrosis, renal stones, iatrogenic ureteric injury, transplant kidney ureteric obstruction, and vesicovaginal fistula. A ‘onestab’ puncture technique or Seldinger technique can be used. For any procedures where urinary infection is suspected or in stone disease, prophylactic antibiotics are mandatory – for example, 80mg gentamicin or 750mg cefuroxime. Clotting must also be checked and if necessary corrected. The major complication rate is around 3% while minor complications occur in around 15%. Major complications are septicaemia, blood loss requiring transfusion, pleural or abdominal viscera puncture, or transcolonic approach. Minor complications include retroperitoneal urine extravasation, clot colic from macroscopic haematuria and tube complications. Tube complications include catheter dislodgement, blockage, leaking, kinking and fracture.
84) A 60-year-old man has a 4 cm rounded mass arising within the right kidney. It has heterogeneous, strong post-contrast enhancement. Calcification is also evident within the tumour. Which of the following features of this renal mass would favour the diagnosis of renal cell carcinoma over angiomyolipoma?
a. marked vascularity
b. calcification
c. fat within the tumour
d. round morphology
e. hyperechogenic on ultrasound scan
b. calcification
Angiomyolipoma should not have calcification whereas it is seen in 10% of renal cell carcinomas. Both these tumours can be hypervascular. The cornerstone of diagnosis of an angiomyolipoma is identifying fat on CT or MRI; however, fat has been reported in renal cell carcinoma, and peripheral or renal sinus fat can become trapped in any large renal tumour
95) A portal venous phase abdominal CT scan of a 65-year-old man demonstrates an ill-defined, rounded area 4 cm in diameter within a kidney. It is heterogeneous but predominantly of attenuation value above 70 HU. It contains small dense calcific foci. Which additional feature suggests that the lesion is more likely to be a renal cell carcinoma than a transitional cell carcinoma of the collecting system?
a. thickened indurated pelvicalyceal wall
b. central location of the tumour with centrifugal expansion that compresses renal sinus fat
c. renal parenchymal invasion with renal contour preservation
d. renal vein thrombus
e. further mass arising from the urinary bladder wall
d. renal vein thrombus
Differentiation of renal cell from transitional cell carcinoma is helpful for planning surgical treatment since transitional cell carcinoma of the renal collecting system requires the more extensive surgical procedure of nephroureterectomy. Renal vein thrombus is seen with renal cell carcinoma while all other options given are features of transitional cell carcinoma of the kidney. Delayed contrast CToffers a pyelographic phase on which collecting system, ureter and bladder filling defects are clearly demonstrated. A urothelial field effect can occur, resulting in multiple transitional cell carcinomas throughout the renal tract. Renal cell carcinoma, as it expands, tends to distort the renal outline and is more likely to be peripheral and exophytic
94) A diabetic patient with long-standing mild renal impairment requires an angiogram, and it is decided that iodinated contrast will be used. Which of the following is most likely to prevent the patient from developing contrast-induced nephropathy?
a. prior administration of acetylcysteine
b. thorough hydration of the patient
c. oral fluid restriction
d. concurrent diuretic administration
e. use of high-osmolar contrast medium
b. thorough hydration of the patient
A significant contribution to the evidence base used to guide practice in contrast-induced nephropathy (CIN) comes from the NEPHRIC study group. The trial was a randomized, prospective, double-blind, multicentre study performed in 17 centres in Denmark, France, Germany, Spain and Sweden, and consisted of 129 patients. CIN is acute renal impairment with an absolute increase in serum creatinine of at least 0.5mg/dl (44.2 mmol/l) or a relative increase of at least 25% from baseline. A rise of 1mg/dl is less frequently used as the definition. CIN usually peaks on day 2 or 3 following iodinated contrast injection, with a return to baseline within 2 weeks. Return to baseline is not always seen. Low-osmolar iodinated contrast media have a low rate of CIN in the general population – less than 2%. In patients with increased risk of CIN due to diabetes mellitus or pre-existing renal impairment, this rate rises significantly. It has also been shown that low-osmolar contrast causes less CIN than high-osmolar (order of 1800 mosmol/kg water) contrast in high-risk patient groups. No difference in CIN rate is observed in lowrisk groups when iso-osmolar is compared with low-osmolar contrast agents. The NEPHRIC study group shows that in people with diabetes or those with renal impairment having iliofemoral or coronary angiography there is a reduced rate of CIN when using iso-osmolar iodinated contrast as opposed to low-osmolar contrast medium. Osmotic diuresis causing increased sodium load to the distal nephron, with consequent increased medullary work, possible hypoxia and volume depletion giving rise to activation of vasoregulatory hormone systems, is suggested as the reason for the findings. Vigorous hydration is encouraged as perhaps the most important measure to try to avoid CIN. There is evidence both supporting and rejecting the nephroprotective effect of the free radical scavenger acetylcysteine when given before the iodinated contrast media
96) An adult male is initially investigated for abnormal liver function tests. Eventually, the diagnosis of Stauffer’s syndrome is pronounced. What are the likely CT findings?
a. liver mass in keeping with hepatocellular carcinoma with renal metastases
b. renal mass in keeping with renal cell carcinoma with liver metastases
c. renal mass in keeping with renal cell carcinoma and hepatosplenomegaly without focal hepatic or splenic lesions
d. hepatosplenomegaly and bilateral renal enlargement without focal lesions in any of these organs
e. renal mass in keeping with renal cell carcinoma with a pancreatic head metastasis
c. renal mass in keeping with renal cell carcinoma and hepatosplenomegaly without focal hepatic or splenic lesions
Stauffer described a syndrome of nephrogenic hepatopathy in which a renal cancer without liver metastases causes hepatosplenomegaly and abnormal liver function. Renal cell carcinoma paraneoplastic phenomena include erythrocytosis and hypercalcaemia.
97) A clinical trial of a novel chemotherapy agent for renal cell carcinoma is being undertaken. The response of the primary tumour and nodal and distant metastases will be assessed according to the RECIST criteria. On axial imaging, the long axis of every lesion present on the pre-treatment scan has decreased on the post-treatment CT. However, the patient has progressive disease. Which additional feature from the list below would explain this?
a. the improvement in the summed long axes of five lesions is not more than 30%
b. a new site of disease is identified
c. the lesions have not all disappeared
d. sustained improvement was not proven by a repeat CT at 4 weeks
e. the improvement in the summed products of bidimensional measurements is not more than 50%
b. a new site of disease is identified
Two criteria are commonly used for assessing cancer response to treatment: WHO and RECIST. The latter stands for Response Evaluation Criteria in Solid Tumours, and it is this tool that is usually used in treatment trials. The WHO criteria compare a summed area product (longest axial dimension multiplied by the longest axial dimension perpendicular to this). RECIST sums the longest axial dimension and compares this across scans. Complete response for both criteria is disappearance of disease, confirmed at 4 weeks. A partial response according to the WHO is 50% or more reduction in the summed area product following treatment and confirmed at 4 weeks. RECIST requires a 30% or greater decrease in the summed longest diameters, confirmed at 4 weeks. Progressive disease is defined as a 25% increase in summed area product for the WHO criteria and a 20% increase in summed longest diameter according to RECIST. Progressive disease also results from the appearance of any new site of disease. Stable disease reflects changes of magnitude that do not achieve partial response or progressive disease
5 A 28 year old man presents with loin pain and dipstick positive haematuria. A CT KUB is arranged for further investigation. Which of the following statements is not correct regarding this investigation?
(a) It is now the initial investigation of choice
(b) lndinavir related calculi are not well seen
(c) Urate caltuli are well visualised
(d) Nephrocalcinosis may result in a false positive examination
(e) The ‘comet tail’ sign confirms a ureteric calculus rather than phlebolith
(e) The ‘comet tail’ sign confirms a ureteric calculus rather than phlebolith
lndinavir and pure matrix calculi are the only types of stone not well visualized on CTKUB. The ‘soft tissue rim’ sign refers to circumferential thickening of the ureteric wall around a calculus as opposed to the ‘comet tail’ sign which is seen around phleboliths.
11 A 30 year old man presents with bilateral loin pain. KUB shows coarse granular calcification widely distributed in the region of the renal pyramids. US shows increased echogenicity of the renal pyramids with some posterior acoustic shadowing. Which of the following is least likely?
(a) Alport syndrome
(b) Medullary sponge kidney
(c) Milk-alkalr syndrome
(d) Hyperparathyroidism
(e) Renal tubular acidosis
(a) Alport syndrome
Medullary nephrocalcinosis has a wide differential diagnosis, but options (b), (d) and (e) account for 70% of cases. Other causes include papillary necrosis and drugs such as Frusemide. Alport syndrome (hereditary chronic nephritis) typically gives rise to cortical calcificatio
13 A 60 year old man presents with biliary colic. At US an incidental finding of a well-demarcated 5 cm mass of low echogenicity is noted arising from the right kidney. CT confirms a renal mass with a central low attenuation scar. MRI shows the mass to be hypointense on T1W and hyperintense on T2W with enhancement after i.v. gadolinium administration, although the central scar enhances less well than the remainder of the mass. What is the likeliest diagnosis?
(a) Renal cell carcinoma
(b) Oncocytoma
(c) Transitional cell carcinoma
(d) Hamartoma
(e) Metastasis
(b) Oncocytoma
In addition to the above findings, a ‘spoke-wheel’ appearance at angiography and a photopaenic area on 99mrc-DMSA scan may be seen.
20 A patient is diagnosed with a 4 cm right upper pole renal cell carcinoma. Staging investigations demonstrate tumour thrombus in the renal vein extending into the IVC, but no local lymphadenopathy and no evidence of distant metastases. What is the Robson staging of this tumour?
(a) Stage II
(b) Stage Illa
(c) Stage lllb
(d) Stage Ille
(e) Stage IV
(b) Stage Illa
Stage I includes tumours that are confined entirely to the kidney. Stage II tumours invade the perinephric fat or adrenal gland on the same side. Stage Illa tumours extend into the renal vein or the IVC. Stage lllb tumours involve local LNs. Stage Illc combines stages Illa and lllb. Stage IV tumours describes those with distant metastases.?
21 A 24 year old with known ureteric reflux disease in childhood presents with loin pain. KUB shows an extensive calculus involving the lower pole and interpolar calyces. What is the likeliest composition of the stone?
(a) Magnesium ammonium phosphate
(b) Xanthine
(c) Cysteine
(d) Urate
(e) Calcium oxalate
(a) Magnesium ammonium phosphate
70% of staghorn calculi are composed of magnesium ammonium phosphate (struvite stones). The remainder are cysteine or urate stones. These large calculi are often seen in patients with a history of recurrent infections.
34 With regards to a 99mTc-MAG3 renogram, which of the following statements is incorrect?
(a) The pure blood flow phase lasts for 2 minutes
(b) The uptake phase should be measured 60-120 secs after tracer administration
(c) The peak of the curve represents the maximum activity in the kidney .
(d) Frusemitle should be administered in the presence of dilatation.
(e) A renal tumour would cause a photopaenic area within the kidney
(a) The pure blood flow phase lasts for 2 minutes
The pure blood flow phase is the first phase of the examination and lasts up to 40 secs (equivalent to an arterial phase study).
45 A 35 year old woman presents with a history of loin pain. CT shows a large perinephric haematoma. She cannot recall any significant trauma other than whilst playing with her child. Which of the following is the least likely cause?
(a) Multicystic dysplastic kidney
(b) Renal cell carcinoma
(c) Autosomal dominant polycystic kidney disease
(d) Polyarteritis nodosa
(e) Angiomyolipoma of the kidney
(a) Multicystic dysplastic kidney
Occult RCC, polyarteritis nodosa, ADPKD and angiomyolipoma are well recognized causes of perinephric haematoma after innocuous trauma. MCDK do not typically bleed externally into the perinephric space.
47 A 32 year old woman undergoes an IVU which demonstrates bilateral striated nephrograms. Which of the following is least likely?
(a) Tamm-Horsfell proteinuria
(b) Hypotension
(c) Amyloidosis
(d) Acute pyelonephritis
(e) Medullary sponge kidney
(c) Amyloidosis
Striated nephrograms are transiently seen in acute extra-renal obstruction along with hypotension and intratubular obstruction. Other causes of bilateral striated nephrograms include rhabdomyolysis and cystic renal disease. Causes of a (usually) single striated nephrogram include renal contusion and renal vein thrombosis
49 A 50 year old man is found to have an incidental renal lesion. On unenhanced CT, the lesion is 2 cm, round, homogeneous, well defined, without calcification and situated in the upper pole of the right kidney. It has an attenuation of 60 Hounsfield units, which after the administration of intravenous contrast medium increases to 69 HU. Which of the following is the likeliest diagnosis?
(a) Renal cell carcinoma
(b) Lipid poor angiomyolipoma
(c) Renal oncocytoma
(d) Simple cyst
(e) Metanephric adenoma
(d) Simple cyst
Although most cysts are of low attenuation, by far the commonest cause of an otherwise benign appearing, non-enhancing (<10 HU increase), hyperattenuating (normal renal parenchyma approximately 40 HU on unenhanced CT) lesion is a hyperdense cyst containing proteinaceous material. Lipid poor angiomyolipomas are a rare (3-4%) subset of angiomyolipomas.
@#e 1 A 52 year old man presents with loin pain and microscopic haematuria. KUB reveals no abnormality. A CT KUB demonstrates a 7 mm mid-ureteric calculus. What is the most likely composition of the calculus?
(a) Calcium phosphate
(b) Calcium oxalate
(c) Urate
(d) Xanthine
(e) Cystine
(c) Urate
Although both xanthine and urate stones are radiolucent, urate stones are much more common. Cystine stones are mildly opaque. Calcium oxalate and calcium phosphate stones are radio-opaque
5 A frail 72 year old diabetic woman has serum creatinine measurements which are persistently at the upper end of the normal range. A nuclear medicine clearance scan is requested for a more accurate estimate of glomerular filtration rate. Which of the following tracers would be most appropriate?
(a) 51 Cr-EDTA
(b) 99mTc-DMSA
(c) 99mTc-Glucoheptonate
(d) 99mTc-HIDA
(e) 99mTc-MAG3
(a) 51 Cr-EDTA
GFR is a commonly accepted standard measure of renal function. It can be measured by tracers that are cleared exclusively by glomerular filtration, the most common being 51 Cr-EDTA (the.standard radiopharmaceutical in Europe) and 99mTc-DTPA (more common in the USA).
8 A 52 year old man is referred for a renal US as part of an investigation for proteinuria. US shows a 2 cm round, well-defined right upper pole cystic lesion. At CT, the lesion demonstrates internal hairline-thin septae and barely perceptible enhancement after the administration ofintravenous contrast medium. Which of the following statements is true?
(a) This is a Bosniak IV lesion
(b) This lesion should be surgically excised
(c) This lesion should be followed-up
(d) This is a Bosniak I lesion
(e) Bosniak classification can be defined on US
(c) This lesion should be followed-up
The Bosniak classification is a CT classification of cystic renal lesions. Bosniak I are simple cysts, Bosniak II are minimally complicated cysts. Bosniak llf (lesionE1 that should be followed-up) have hairline thin septae and subtle wall enhancement or are intrarenal lesions >3 cm with high density content. Bosniak Ill cysts are complicated lesions with irregular thickened septae, measurable enhancement and coarse irregular calcification. These should be treated surgically. Bosniak IV lesions are clearly malignant with a large necrotic component, irregular wall thickening and solid enhancing elements.
13 Which of the following are not radiological signs of renal artery stenosis?
(a) Delayed appearance of contrast material on IVU
(b) Notching of proximal ureter on IVU
(c) Spectral broadening and flow reversal on Duplex US
(d) Decreased density of contrast material on IVU
(e) Tardus/ parvus waveform on Duplex US
(d) Decreased density of contrast material on IVU
An increase in density of contrast material is seen on IVU due to relative increased water reabsorption. Other IVU signs include delayed washout of contrast medium and lack of distension of the collecting system. US findings include peak Renal artery:Aortic velocity >3.5, absence of blood flow during diastole, no detectable Doppler signal in a visualized renal artery, loss of early systolic peak and a resistive index <0.56.
16 A 63 year old man with a history of renal calculi presents with a 4 month history of unilateral flank pain, weight loss and fever. Renal US shows loss of cortico-medullary differentiation, with hypoechoic dilated calyces with an echogenic rim and multiple hypoechoic masses with low level internal echoes replacing much of the renal parenchyma. CT confirms a 1 cm calculus in the renal pelvis and multiple lowattenuation masses within the kidney. Angiography shows displacement of segmental arteries around an avascular masses. What is the likeliest diagnosis?
(a) Candida pyelonephritis
(b) Renal sarcoma
(c) Chronic renal infarction
(d) Multilocular renal cell carcinoma
(e) Xanthogranulomatous pyelonephritis
(e) Xanthogranulomatous pyelonephritis
XGP is a chronic granulomatous infection in chronic renal obstruction with progressive macrophage infiltration of the renal parenchyma. Fungal renal infections can cause pyelonephritis with fungal balls. Renal sarcoma typically presents with an infiltrative and expansile mass. Mutilocular RCC is a type of a cystic RCC
17 A 50 year old metformin-controlled diabetic man presents with renal colic. His serum creatinine is 90 μmol/L. Initial CT KUB is equivocal and the decision is made to administer i.v. contrast medium. Which of the following is incorrect?
(a) Contrast induced nephropathy (CIN) is usually transient
(b) The single most important risk factor for CIN is pre-test GFR
(c) High osmolar contrast media are more nephrotoxic than low osmolar contrast media
(d) The patient should stop his metformin for 48 hours after the examination
(e) The patient should be well hydrated prior to the examination
(d) The patient should stop his metformin for 48 hours after the examination
If the serum creatinine is within the normal range, or the estimated GFR is >60 ml/min, then metformin need not be stopped. If these are abnormal then discussion with the clinical team is required.
23 A 50 year old woman develops microscopic haematuria and is referred for an IVU. This demonstrates bilateral bulbous cavitation of the papillae with streaks of contrast material extending from the fornix parallel to the axis of the papillae and diminished density of the nephrogram. In addition, small filling defects are seen in the renal calyces. Which of the following is most likely to account for these findings?
(a) Sickle cell disease
(b) Analgeslc nephropathy
(c) Renal vein thrombosis
(d) Christmas disease
(e) Hepatic cirrhosis
(b) Analgeslc nephropathy
These are the IVU signs of papillary necrosis. There is a wide differential diagnosis for these appearances including diabetes mellitus, SCD, obstructive uropathy, and pyelonephritis. Overall, diabetes is the most common cause, but analgesic nephropathy is particularly common in middle-aged females.
24 A 35 year old man presents with night sweats and weight loss. CT examination shows multiple enlarged lymph nodes in the thorax and abdomen with homogeneous, ill defined masses in the kidney. A diagnosis of renal lymphoma is suspected. Which of the following statements is incorrect?
(a) Renal involvement is more common in NHL than Hodgkin’s disease
(b) Primary renal lymphoma is less common than secondary renal lymphoma
(c) It is more commonly bilateral than unilateral
(d) Enhanced through transmission is commonly seen on US
(e) Avid enhancement after contrast medium administration is seen on CT
(e) Avid enhancement after contrast medium administration is seen on CT
Renal lymphoma typically occurs in B-Cell non-Hodgkin’s lymphoma, where it is the second most common organ involved after the haematopoietic and reticulo-endothelial systems. Primary renal lymphoma is uncommon as the normal kidney does not contain significant amounts of lymphoid tissue. Intra-renal lymphoma appears as an ill-defined, homogeneous mass on CT which enhance poorly relative to the surrounding parenel
26 A 30 year old woman presents to the emergency department hypotensive and unwell. CT shows retroperitoneal blood which is arising from a 6 cm renal mass. The mass is well defined and on unenhanced imaging has a mean density of -5 HU. What is the most likely diagnosis?
(a) Renal oncocytoma
(b) Renal cell carcinoma
(c) Renal angiomyolipoma
(d) Renal liposarcoma
(e) Renal lipoma
(c) Renal angiomyolipoma
Renal AML is a benign tumour containing fat, smooth muscle and thick-walled blood vessels. They can bleed (50-60% of AMLs > 4cm bleed spontaneously), and can cause haemorrhagic shock (Wunderlich syndrome). Fat on non-contrast CT in the absence of calcification is virtually diagnostic. They can be associated with tuberous sclerosis (in 80% of TS patients), VHL, and NF
32 A 26 year old man is involved in an RTA, and falls from his motorcycle at 60 mph. On arrival in the emergency department he is alert and mobile with a blood pressure of 115/72 and a pulse rate of 60/min. He complains of mild discomfort over his left lower rib cage. A urine sample demonstrates rose coloured urine. Which of the following is the most appropriate next step?
(a) Renal ultrasound
(b) Admit for observation and image should he deteriorate
(c) Contrast enhanced CT of the abdomen
(d) IVU
(e) Renal angiography
(c) Contrast enhanced CT of the abdomen
With a high velocity injury and frank haematuria, CT is the investigation of choice. 25% of patients with frank haematuria and blunt trauma have a significant renal injury. Normotensive patients with microscopic haematuria have a significant renal injury in <0.2%.
40 A 54 year old man presents with microscopic haematuria. CT shows a 3 cm renal mass containing flecks of calcification and which demonstrates heterogeneous enhancement with i.v. contrast medium. What is the likeliest diagnosis?
(a) Oncocytoma
(b) Angiomyolipoma
(c) Lymphoma
(d) Transitional cell carcinoma
(e) Renal cell carcinoma
(e) Renal cell carcinoma
RCC is by far the commonest malignant renal tumour. 10% of these tumours calcify
41 Regarding the anatomy of the normal kidney, which of the following statements is true?
(a) The renal arteries typically have three divisions
(b) The column of Bertin is isoechoic to renal cortex
(c) The column of Bertin represents the fusion of the embryological anterior and posterior kidneys
(d) The right renal artery typically arises at the level of the L3 intervertebral disc
(e) The left renal artery is usually longer and lower than the left
(b) The column of Bertin is isoechoic to renal cortex
The column of Bertin is an area of focal cortical hyperplasia, typically seen between the upper and interpolar region. It has the imaging characteristic of renal cortex. Its main clinical significance is that it can be mistaken for a renal tumour. Both renal arteries usually have two divisions. The renal arteries typically arise at the L1/L2 level. The right renal artery is usually longer and lower than the left.
43 With regards to 99mTc-DTPA in renal imaging, which of the following statements is incorrect?
(a) It has a rapid extravascular, extracellular distribution
(b) It is cleared mainly by tubular secretion
(c) It undergoes 5-10% plasma protein binding
(d) Good post test hydration and frequent voiding reduce radiation dose
(e) It is useful in providing information relating to GFR
(b) It is cleared mainly by tubular secretion
It is mainly cleared by glomerular filtration hence its utility as a GFR agent. It is useful in assessing the degree of obstructive uropathy. 99mTc-MAG3 is cleared by tubular secretion and is the agent of choice in patients with renal insufficiency as it is not GFR dependent.
61 A 3 year old child born to an HIV positive mother is found to have bilateral enlarged kidneys on ultrasound. Which of the following conditions is least likely?
(a) ADPKD
(b) Obstructive pelvic mass
(c) HIV nephropathy
(d) Medullary cystic disease
(e) Lymphoma
(d) Medullary cystic disease
Medullary cystic disease appears either as a juvenile (rapidly progressive) or as an infantile form. It is characterised by the presence of bilateral small kidneys with numerous small cortico-medullary cysts which give an appearance of increased parenchymal echogenicity, with loss of the corticomedullary junction. Although rare, ADPKD can present in this age group.
63 A 50 year old woman presents with vague left sided· abdominal pain. KUB demonstrates no renal tract calcificationbut an enlarged left renal outline is noted. Which of the following is not part of the differential diagnosis?
(a) Cervical carcinoma
(b) Nephrotic syndrome
(c) Pyelonephritis
(d) Congenital duplication
(e) Renal artery dissection
(e) Renal artery dissection
Renal artery dissection causes the affected kidney to decrease in size due to arterial insufficiency. Ureteric obstruction with hydronephrosis can be a presenting feature of cervical cancer.
65 A 25 year old woman presents with a 6 month history of debilitating right loin pain. IVU and arteriography show a vascular impression on the superior infundibulum with secondary dilatation of the upper pole calyx. Which of the following is the likeliest diagnosis?
(a) Fraley’s syndrome
(b) Cavernous haemangioma
(c) Bartter syndrome
(d) Bardet-Biedel syndrome
(e) Alport syndrome
(a) Fraley’s syndrome
Fraley’s syndrome is rare, comprising superior infundibular narrowing due to a crossing vessel causing significant loin pain. It is more common in young women and on the right side. If symptomatic surgery is indicated.
69 A 30 year old man is involved in a high speed RTA. At contrast enhanced CT, he is noted to have a laceration in the upper pole of his right kidney extending through the corticomedullary junction into the collecting system with extravasation and surrounding haematoma. According to the American Association for the Surgery of Trauma guidelines, how would you categorise this injury?
(a) Grade I
(b) Grade II
(c) Grade Ill
(d) Grade IV
(e) Grade V
(b) Grade II
Grade I refers to contusion or non-expanding subcapsular haematoma and is the commonest type.
Grade II refers a laceration less than 1cm deep without extravasation.
Grade III describes a laceration more than 1 cm deep without extravasation.
Grade IV refers to the above or alternatively to a segmental renal artery or vein injury with contained haematoma.
Grade V refers to a shattered kidney or to renal pedicle injury
75 A 35 year old man undergoes renal transplantation. On the 1st post operative day he becomes oliguric. Doppler ultrasound shows an enlarged, generally hypoechoic graft with diffusely diminished cortical perfusion, decreased systolic ri~e time and a plateau like reversal of diastolic flow. Which of the following is the likeliest diagnosis?
(a) Normal day 1 post transplant changes
(b) Renal allograft necrosis
(c) Renal vein thrombosis
(d) Renal artery stenosis
(e) Arteriovenous fistula
(c) Renal vein thrombosis
Renal/iliac vein thrombosis occurs in up to 5% of cases. If it occurs in the immediate post-operative period it is usually due to endothelial injury at the anastomosis site or extrinsic compression. An absence of venous flow can also be observed with Doppler US.
- A 23 year old female has a renal ultrasound scan for recurrent urinary tract infections. The only abnormality detected is a 3 cm hyperechoic mass in the upper pole of the left kidney. She subsequently undergoes CT which shows the lesion to have an average HU of –10. Which of the following is the most likely diagnosis?
a. Renal cell carcinoma
b. Transitional cell carcinoma
c. Renal lymphoma
d. Angiomyolipoma
e. Renal abscess
- d. Angiomyolipoma
The finding of fat attenuation values within a renal lesion on CT is diagnostic of angiomyolipoma. This is a benign tumour that is typically hyperechoic on ultrasound and of high signal on T1-weighted MR due to fat. It does not enhance post-gadolinium, in contrast to renal cell carcinoma, which usually does enhance
- A 65 year old male has a renal ultrasound scan for right flank pain which demonstrates a 7 cm solid mass within the right kidney with a hypoechoic centre. Subsequent CT scan of the chest, abdomen and pelvis reveals the lesion to have a low-attenuation central scar. There is no renal vein invasion or evidence of malignancy elsewhere in the body. Which of the following is the most likely diagnosis?
a. Lymphoma of the kidney
b. Transitional cell carcinoma
c. Collecting duct tumour
d. Oncocytoma
e. Nephroblastoma
- d. Oncocytoma
The features described are typical of renal oncocytoma. Oncocytoma is a tubular adenoma that is very rarely malignant. They are often asymptomatic even when large. The central scar is typical and is due to haemorrhage and infarction of the tumour having outgrown its vascular supply. Radiological differentiation from renal cell carcinoma can be very difficult and percutaneous needle biopsy is unreliable. Nephrectomy is therefore often indicated
- A 45 year old male is diagnosed with renal cell carcinoma and is being worked up for curative nephrectomy. Which one of the following imaging modalities would you advise as being the most accurate at ruling out malignant renal vein invasion?
a. Doppler ultrasound
b. B-mode ultrasound
c. CT
d. MRI
e. PET-CT
- d. MRI
MRI is superior to the other imaging modalities listed at ruling out renal vein invasion. CT is still very accurate (reported as high as 96%), but MR has the advantage of being able to accurately differentiate benign from malignant thrombus. MR offers no advantage in detecting nodal disease, however, and patients being considered for curative surgery should undergo staging CT of the chest, abdomen and pelvis. PET does not have a specific role for detecting renal vein invasion
- A 71 year old male undergoes renal CT for characterisation of a cystic renal mass. Which one of the following five features would classify the lesion as a Bosniak III lesion?
a. Lack of enhancement
b. Septation
c. Minimally irregular wall
d. Curvilinear calcification
e. Uniform wall thickening
- e. Uniform wall thickening
The Bosniak classification groups cystic renal lesions into one of four categories based on CT/MR appearances. The differentiation between groups II and III is important as group II are typically ‘follow-up lesions’ and group III are ‘surgical lesions’. Features of a Bosniak III lesion include irregular thickened septa, measurable enhancement, coarse irregular calcification, multiloculation, nodularity, uniform wall thickening and margin irregularity
- A 36-year-old labourer working on a building site falls 15 feet from scaffolding on his back onto a wheelbarrow. He is catheterized in the resuscitation room and is noted to have gross haematuria. Which of the following CT findings are consistent with a grade 4 renal injury?
A. Renal artery avulsion.
B. Shattered kidney.
C. Deep laceration to the collecting system.
D. Subcapsular haematoma.
E. Parenchymal contusion
- C. Deep laceration to the collecting system.
Renal injuries are classified into five grades of severity by the American Association for the Surgery of Trauma (AAST), with approximately 80% classified as grade 1 (Table 4.1). Most significant injuries manifest as haematuria and no significant urinary tract injury occurs in the absence of gross haematuria and shock. In addition, most significant renal trauma is associated with additional visceral injury.
