Imaging Studies of the GUT Flashcards
Function as interim kidneys for approximately 4 weeks, until the permanent kidneys develop
Mesonephros
- The pronephros regresses completely during
End of 4th Week
- the mesonephros degenerates during
End of 1st trimester (3rd month)
- This structure induces the development of the definitive kidney
Ureteric bud
- This structure forms the definitive kidney. It appears in the 5th week of development and becomes functional around 12th week
Metanephros
- The 2 components of metanephric system
Collecting system and Excretory System
- This system is derived from the Ureteric bud. It dilates to create the ureter, renal pelvis, major and minor calyces and collecting tubules.
Collecting system
- This system is derived from the metanephric blastema which forms the kidney’s functional unit.
Excretory System
- The cloaca which is a common chamber for gastrointestinal and urinary waste will be divided into two parts by the uro – rectal septum during___.
4th – 7th week of development
- The urinary badder is initially drained by the ____ which will later become the _____
Allantois; Urachus
- This is the remnant of the Urachus
Median Umbilical Ligament
- Indications for KUB X – ray
Kidney stones
Abnormal calcifications
Renal agenesis
- Limitations of KUB X -ray
Renal outline may be obscured by bowel gas
Radiation exposure
No functional information
Retained barium from other procedures that may interfere with visualization
- Radiographic study of the renal parenchyma, pelvicalyceal system, ureters, and urinary bladder. Largely replaced by CT urography.
Intravenous Urography
- Indications of Intravenous Urography
Check for normal function of kidneys
Check for anatomical variants or congenital anomalies
Check the Course of the Ureters
Detect and Localize a Ureteric Obstruction (Urolithiasis)
Assess for synchronous upper tract disease in those with bladder transitional cell carcinoma
- Fluoroscopic study of the lower urinary tract in which contrast is introduced into the bladder via a catheter
Voiding Cystourethrography
- Grade and corresponding manifestation of VUR
Grade I – VUR into a non – dilated ureter
Grade II – VUR into the upper collecting system without dilation
Grade III – VUR into dilated ureter and/or blunting of calyceal fornices
Grade IV – VUR into grossly dilated ureter
Grade V – Massive VUR, with significant ureteral dilation and tortuosity and loss of the papillary impression
- In performing renal ultrasound these parameters should be look out for
Kidney Size
Location
Renal Outline
Corticomedullary Differentiation
- T or F. In a normal ultrasound, the cortex appears hyperechoic (bright) while the medulla appears hypoechoic.
T
- Hydronephrosis would appear ____ in ultrasound
Calyceal Splitting.
In cases with distal obstruction proximal end of dilated ureter may be seen
- Calculi would appear as ____ in ultrasound
Echogenic (Bright) structures in distal acoustic shadowing
- Screening Modality of choice for Renal Artery Stenosis
Ultrasound
- Excellent cross-sectional imaging modality that provides functional information as well. Checks kidney function before contrast administration. Non – ionic contrast is preferred because of reduced side effects
CT Stonogram/Urogram
- Limitations of CT Stonogram/Urogram
Radiation Exposure
Expensive
Contrast Exposure
- Indications of CT Stonogram/Urogram
Renal Stone Disease
Renal/Bladder Massess
Trauma
- Renal Stone Disease present as ____ hematuria
Painful
- Renal/Bladder Masses present as _____ hematuria
Painless
- Becoming the gold standard for detection of renal calculi
Non – contrast CT
- This result from failure of the kidneys to ascend from the true pelvis into the lumbar region
Renal Ectopia
- Most common form of Renal Ectopia
Pelvic Kidney
- What condition is characterized by the fusion of kidneys at lower pole by a parenchymal or fibrous isthmus.
Horseshoe Kidney
- Horseshoe Kidney is associated with these conditions
Ureteropelvic junction obstruction, ureteral duplication, and genital tract anomalies.
- This is a non – neoplastic benign saclike structures containing fluid
Simple Renal Cyst
- Simple Renal Cyst is most commonly found in what area of the kidney
Renal Cortex; less commonly in parenchymal or parapelvic location
- Modality of choice for Renal Cyst
Ultrasound
- Pathognomonic Findings in Simple Renal Cyst
Spherical or slightly ovoid shape, homogenous internal structure and smooth margin
- Intravenous Pyelogram Findings of Simple Renal Cyst
Splaying of calices by smooth tumor
- The following would point to Atypical Cyst
Intracystic calcification and thickened wall
Higher viscosity of cyst fluid
Septa
Homogenous Internal Structure and Smooth wall
- These are classified under Complicated Cyst
Hemorrhagic Cyst –simple cyst secondarily affected by hemorrhage due to trauma or hemorrhagic diathesis
Infected Cyst - VUR, hematogenous infection
Ruptured Cyst
- This is a malignant epithelial tumor of the renal parenchyma usually arising in the renal poles
Renal Cell Carcinoma
- Modality of Choice for RCC
Biphasic CT/MRI after intravenous contrast administration
Ultrasound
- Pathognomonic Finding of RCC
Solid tumor of the renal cortex with rich vascular supply
Pseudocapsule
- Refers to the presence of calculi anywhere along the course of the urinary tract
Urolithiasis
- Most common stone
Calcium Oxalate
- Calcium – containing stones appear ___ on plain radiograph
Radiopaque
- Struvite (Triple phosphate) appear _____ on plain radiograph
Usually Opaque but variable
- Lucent Stones Include the following ____
Uric Acid, cystine, Indinavir Stones, Pure matrix stones
- Urolithiasis would present the following features in ultrasound
Echogenic Foci
Acoustic shadowing
Twinkle artifact on color Doppler
Color comet – tail artifact
