Urogenital imaging Flashcards
Where do the kidneys lie?
Retroperitoneal: paravertebral gutters of the posterior abdominal wall
What is the level of the left kidney hilum?
L1
What is the level of the right kidney hilum?
L1/2
What are the contents of the renal hilum?
Renal vein Renal artery Renal pelvis (ureter) Lymph Nerves Renal sinus fat
What conditions can be detected using USS of the kidneys?
Renal size Cortical scarring Doppler Distention of pelvicalyceal system Calculi Detection of renal abnormalities
When it a CT kidney indicated?
Vascular assessment
Characterizes most pathologies
Multiplanar
What type of CT is best to detect calculi?
No contrast
What part of the kidney is best seen with contrast?
Corticomedullary
What part of the renal tract is best seen when the contrast is being excreted?
Opacification of the renal collecting system and ureters
What is contrast induced nephropathy?
Condition in which an impairment in renal function occurs within 3 days following an IV administration of contrast medium in the absence of alternative aetiology
What are risk factors for contrast induced nephropathy?
Renal impairment +/- DM Dehydration Congestive heart failure LV ejection fracture Acute MI Nephrotoxic drugs
How can the risk of contrast induced nephropathy be reduced?
eGFR <60 pre contrast
What will an MRA renal angiogram show?
Abdominal aorta Right renal artery Left renal artery Aortic bifurcation Splenic artery Lumbar arteries
What is nephrogenic systemic sclerosis?
Severe systemic fibrosing disorder assoc with the exposure of gadolinium containing contrast media
Where does the ureter empty into the bladder?
Vesicoureteric junction
What are the 3 anatomical constrictions of the ureters?
Pelviureteric junction
Pelvic brim
Vesicoureteric junction
Where does the abdominal ureter run?
Medial aspect of psoas
Where does the pelvic ureter run?
Enters pelvis at bifurcation of common iliacs
Anterior and medial to SI joint
Turns medially at ischial spines to enter the posterolateral bladder
What is a CT urogram used for?
Assessing the collecting system, ureters and bladder
What is the structure of the bladder?
Pyramidal shaped organ when empty: Posteriorly is the base Anteriorly is the apex (behind pubic symphysis) Superior wall 2 inferolateral walls
Where do the ureters enter the bladder?
Posterolateral angles
What is the trigone?
Triangular smooth area of bladder between ureters and urethra
What covers the superior surface of the bladder?
Peritoneum
What lies inferolaterally to the bladder?
Obturator internus and levator muscles
What lies anterior to the bladder?
Pubic symphysis
What lies posterior to the bladder in females?
Anterior vagina and cervix
What lies posterior to the bladder in males?
Inferior prostate
What is required in a bladder ultrasound?
Full bladder
What can a bladder USS detect?
Volumetric measurement
Internal calculi
Wall irregularities
Diverticula
What is the gold standard to see a leak through a bladder wall tear?
Cystography
What is the gold standard for local staging of bladder wall tumours?
MRI
What is the gold standard for nodal and metastatic disease staging of the bladder?
CT
Describe the urethra in males
Bladder neck Prostatic urethra Membranous urethra Bulbous urethra Penile urethra
When is a urethrogram used?
Strictures
Trauma
Diverticula
What is the lymph drainage of the bladder?
Superolaterally to the external iliacs
Neck and fundus to the internal iliac, sacral and common iliiacs
What is the imaging of choice for the genitals?
USS for testes/scrotum, uterus, ovaries and prostate
When is a hysterosalpingogram used?
Infertility - tubal patency
Uterine anomalies
When is an MRI used?
Prostate cancer - local staging
Troubleshooting for adnexal/ uterine/ ovarian abnormalities not characterisable by USS
What can be seen on a scrotal USS?
Testicular parenchyma Head of epididymis Mediastinum testis Rete testis Appendix testis
What is the lymph drainage of the scrotum?
Superficial inguinal nodes
What is the lymph drainage of the testis?
Lumbar and para-aortic nodes
What causes renal colic?
Ureteric calculus
What can mimic renal colic?
Pyelonephriti (do USS to exclude ureteric obstruction)
Gynaecological (do USS to visualise uterine, ovarian and uterine tubal pathology)
Why is imaging done in renal colic?
Identify the calculus
Assess size and morphology of calculus
Detect associated ureteric obstruction
Identify additional asymptomatic calculi
What are the components of most calculi?
Calcium rich and are dense
What is the 1st line test done in suspected renal colic?
KUB x-ray - easy and may show a dense ureteric calculus
Only a minority of renal tract calculi are visible on KUB
How many x-rays will you get in a KUB x-ray?
Upper/ mid abdomen for kidneys and proximal ureters
Pelvis for distal ureters and bladder
What is the normal ureteric course?
Pass inferiorly over the psoas
Descend anterior to the tips of the lumbar transverse processes
Cross iliac bifurcation to enter pelvis
Pass posteromedially and enter the posterior aspect of the bladder
Where do ureteric calculi often get stuck?
Pelviureteric junction
Pelvic brim
Vesicoureteric junction
What can mimic ureteric calculi?
Phleboliths (calcification within a vein)
Lymph nodes
Uterine fibroids
Arterial calcification
What is the definitive test to diagnose a ureteric calculi?
Non-contrast CT
What is the follow up for renal colic?
KUB to check progress
What can cause macroscopic haematuria?
Calculi Infection Tumour (renal cell carcinoma) Urethritis/prostatitis Trauma Clotting disorders
How should macroscopic haematuria be investigated in those over 50?
CT urography (kidneys, collecting systems and ureters) Cystoscopy (bladder and urethra)
How should macroscopic haematuria be investigated in those under 50 be investigated?
Malignancy of bladder or ureters unlikely so:
US kidneys to detect calculi and renal parenchymal tumours
Cystoscopy for bladder TCC, calculi
CTU ONLY when Us or cystoscopy are normal
When is MR urography helpful?
Contrast allergy
Renal impairment
Pregnancy
What is the role of imaging in renal masses?
Confirm presence
Characterise as benign, indeterminate or malignant
Stage malignant masses
Is the risk of malignancy of a renal mass smaller than 3 cm high or low?
Low - managed conservatively
What are renal masses containing fat?
Angiomyolipomas
What are renal fluid density masses?
Cysts - uniform cysts are benign
What are complex cysts of the kidneys?
If contain solid areas or thick septa, often malignant
What are solid (non-cystic) tumours of the kidneys?
If over 3cm, malignant
What is used to stage a malignant renal tumour?
CT: extracapsular spread, involvement of adjacent organs, involvement of renal vein or IV
Nodal
Mets: lungs, bone
What can cause renal impairment?
Pre-renal: dehydration, hypotension, renal artery stenosis
Renal: parenchymal disease, drugs, toxins
Post-renal: obstruction
What is used to detect renal artery stenosis?
MR angiography
What is used to diagnose renal disease?
US to guide biopsy
What is used to diagnose post-renal disease?
US for hydronephrosis (often accompanies obstruction)
CT
What can cause a painful scrotum?
Epididymo-orchitis
Testicular torsion
Trauma
What can cause epididymo-orchitis?
Viral or bacteria
May be complicated by abscess formation or rarely ischaemia
The testis and/or epididymis is typically hypervascular on US
What can be seen on USS of testicular torsion?
Avascular - surgical emergency to prevent infarction
What can cause a painless scrotal swelling?
Hernia Varicocele Hydrocele Epididymal cyst Testicular tumour
What imaging modality is used in a painless scrotal swelling?
USS for spacial resolution of superficial soft tissue structures
What can be seen on USS of varicocele of the scrotum?
Dilated scrotal venous plexus on left side
Tortuous veins more than 2mm in diameter
What can be seen on USS of a hydrocoele?
Black anechoic fluid surrounding the testicle
What can be see on USS of an epididymal cyst?
Anechoic uni or multilocular cyst - typically arises within the epididymal head
What is used to assess renal injury due to trauma?
CT
What can be used to diagnose bladder trauma?
Cystography or CT
When is interventional radiology used for non-vascular issues?
Ureteric obstruction
Drainage of abscess or cyst
Biopsy of renal masses
Guided ablation of renal tumours
What vascular problems is interventional radiology used for?
RAS
Control of arterial bleeding sites
Varicocele embolisation
