URINARY TRACT IMAGING🗸

Contrast X-rays

Computed Topography (CT) Scans

• CT Urography (also Radiolucent) >> Non-contrast CT (NCCT)

• Partial vs complete obstruction: Diuretic DTPA scan

Ureteric calculi

• Ureteric stone is generally vertically oval.

Renal Calculus

• A white area (right kidney) → right renal calculus
• Right kidney + psoas major muscle located posteromedially.

• On ultrasound → echogenic area + shadow behind it.
• Shadow → posterior acoustic shadowing.

• Dense calcification in the center of the pelvis is observed.

• This is the bladder stone or vesical calculus.

Hydronephrosis

• Left kidney
• gray color density → fluid.
• Enhancing rim → renal parenchyma.
• Rim sign seen in hydronephrosis.

• Calcium Ammonium Magnesium Phosphate.

• Associated with
• Proteus urinary tract infection.
• Parathyroid adenoma → Hypercalcemia → Calcium deposits in kidney

• Radio-opaque.

• "Coffin Lid" shaped.

• Formed in alkaline urine.

• Features
• Smooth surface, large size.
• takes up the shape of the pelvis and calyces.
• Calcification with lobulated appearance, i.e. parenchymal

• Coffin lu avathirikkan Maaninte (Staghorn) irachi thinnanam + Protein (Proteus) thinnanam→ Strong (Struvite) avanam

Putty kidney

• Cement (amorphous calcification) + lobulated appearance = parenchymal calcification

• Moth eaten calyces
• Earliest sign in the IVP for renal TB
• irregularity of the calyx.

• Later stages of TB

• → non-functional kidney and auto-nephrectomy.

• Sterile pyuria is seen in urinary TB.

Corkscrew and Beaded appearance

• Multiple ureteric strictures

Thimble bladder

• small, contracted bladder

• Heal with fibrosis
• bladder wall calcification

Investigations:

• Urine examination: Sterile pyuria (pus cells +, culture -).

• Confirmatory:
• ZN Staining of centrifuged 3 morning urine samples.

Note:

• If genital TB
• Genital swab for polymerase chain reaction (PCR) testing

B/L Nephrocalcinosis/ Medullary Nephrocalcinosis

• Lucent areas are observed between opaque areas.

• 2 causes
• A/w Hyperparathyroidism
• Medullary sponge kidney

• Functional kidney

• DMSA scan for scarring.

• It is incomplete calcification.

• In post-menopausal females
• calcific degeneration of uterine fibroid.

Acute pyelonephritis

• In acute pyelonephritis, the kidney is enlarged.

• In chronic pyelonephritis, the kidney is shrunken.

• Enlarged edematous kidney → Total / Focal

• A striated appearance is observed.

• Reduced areas of cortical vascularity on power Doppler

• Black areas
• Air is contained within the kidney and surrounding it.

• Organism: E.coli.
• Note: clostridium → emphysematous cholecystitis

• Common in immunocompromised, DM patients.

• Can turn fulminant and septic.

• IOC: CECT (gas in/around kidney).

• Management: Antibiotics + drainage.

Putty kidney

• Cement (amorphous calcification) + lobulated appearance = parenchymal calcification

• Moth eaten calyces
• Earliest sign in the IVP for renal TB
• irregularity of the calyx.

• Later stages of TB

• → non-functional kidney and auto-nephrectomy.

• Sterile pyuria is seen in urinary TB.

Corkscrew and Beaded appearance

• Multiple ureteric strictures

Thimble bladder

• small, contracted bladder

• Heal with fibrosis
• bladder wall calcification

Investigations:

• Urine examination: Sterile pyuria (pus cells +, culture -).

• Confirmatory:
• ZN Staining of centrifuged 3 morning urine samples.

Note:

• If genital TB
• Genital swab for polymerase chain reaction (PCR) testing

Ureterocele:

• IVU: "Cobra Head" or "Adder Head" sign.

• Cystic dilatation of ureteric terminal end.

• Surgery: Ureter reimplantation.

Weigert-Meyer Rule:

• Upper pole ureter:
• Ectopic insertion.
• Inferomedial to normal.

• Middle/lower pole ureter:
• Normal insertion.

Ectopic Sites:

• Male: Urethra.

• Female: Vagina (causes urinary dribbling).

Investigation:

Management:

• Ureter reimplantation.

Medullary sponge kidney appearance in IVP

• Paintbrush or bouquet of flowers appearance.

• Dilated collecting ducts / medullary ducts (Bellini ducts)

• A/w nephrocalcinosis and recurrent renal stones

Retroperitoneal fibrosis (Ormond's disease)

• Can compress ureters → hydronephrosis

• "Maiden Waist" deformity, medial indrawing of ureters.

• Causes:
• Idiopathic
• post-radiotherapy
• drug-induced (Methysergide).

• Management: DJ Stenting.

• Mnemonic: Purakil ninn (retroperioneal) DJ () kalikkunna Maid () ne Ormayundo (Ormond)

• Known as joining hands or handshake or flower vase appearance
• Has association with Turner's syndrome.
• IVU: "Flower Vase" or "Hand Shake" sign.
• Fuse at isthmus
• Inferior mesenteric Artery → Anterior to isthmus → Prevent ascent

Retrocaval ureter:

• Right ureter passes behind IVC.

• Hydronephrosis + hydroureter (of the proximal ureter)

• "Reversed J" or "FishHook" sign.

Renal Papillary Necrosis

• Signet ring appearance.

• Contrast is seen around the necrosed papilla.

Christmas or pine or fir tree appearance

• Seen in neurogenic bladder.

• The tone of the bladder is affected, causing a shape change from round to elongated.

• Multiple diverticuli are present.

Teardrop or pear shape or inverted pear shape appearance

• In an IVP image, the bladder appears to have a teardrop shape.

• A normal bladder is compressed by external forces, causing elongation.

• Causes include:
• Extrinsic compression of the bladder.
• Any pelvic cause.
• e.g., pelvic lipomatosis, pelvic abscess, pelvic hematoma, pelvic lymphadenopathy, pelvic vessel aneurysm.

Fetal skull calcification of the urinary bladder

• Seen in schistosomiasis.

• Bladder wall calcification

• Schistosoma haematobium resides in the vesical venous plexus of the bladder.

Imaging in PUV

• Management: Fulguration of the valve.

• Contrast flows out of the urethra.

• Features:
• Type of Hamartoma
• Benign,
• common in 5th-6th decade,
• origin from perivascular epitheloid cells (EPC).
• Neovascular tumor
• Only condition where fat is seen in kidney
• A/w Tuberous sclerosis complex (TSC).

• Clinical Features:
• Usually asymptomatic.

CECT (IOC)

• Fat → looks dirty black on CT.

• B/L angiomyolipomas
• A/w tuberous sclerosis.

• CECT (IOC).
• Solid enhancing lesion.
• Clear cell carcinoma is the most common.
• It is hyper-enhancing.

Xray

ADPKD

• On CT scan (Image 1), white bone is observed.
• Both kidneys are enlarged in size and have multiple cysts.

• On MRI (Image 2), black bone is observed.
• Both enlarged kidneys have multiple cysts.

• In IVP, initial or nephrogram phase:
• Multiple cysts do not take up the contrast,
• forming filling defects in the kidney.

• Spider leg appearance.
• d/t Splayed collecting system

• Swiss cheese appearance
• On nephrogram

ARPKD

• Striated appearance or sunray appearance of the kidneys.

• The kidney appears echogenic on ultrasonography.

Renal artery stenosis

• Affects the ostium.

• Young patient (without a family history of hypertension)

• 1st investigation is renal Doppler (Image 1)
• has a slow and blunted uptake.
• i.e. pulsus parvus et tardus waveform (Image 2)
• Normal renal artery has a quick upstroke.

• 2nd investigation is CT-angiography or MR-angiography.

• Gold standard procedure is digital subtraction angiography (DSA).

Fibromuscular dysplasia

• Beaded appearance.

• Seen in an MR-angiography.

• Indicates multiple strictures in the renal artery.

• Common in young adult females.

• Also presents with hypertension (similar to renal artery stenosis).



 

Adrenal adenoma

• The most common incidental adrenal lesion detected.

• Features:
• Fat-containing.
• Rapid wash-in and rapid wash-out of the contrast.

• Hounsfield unit (HU)
• Negative or <10 is considered → adrenal adenoma.
• If > 10 → take a delayed scan → shows ↑sed washout, s/o
• Low lipid Adrenal adenoma

Pheochromocytoma

• Lightbulb sign on T2 weighted MRI (T2W MRI).

• hyperintense in T2ZW MRI

• BIOPSY/FNAC → Contraindicated

Category	Investigation	Notes
Screening Test/ Initial	24-hour urine fractionated metanephrine. >> 24 hr urine VMA	Sensitivity and specificity: 98%.
Confirm → IOC/ Best investigation	Serum plasma free metanephrines	Most sensitive test 100% sensitivity.
Best / Radiological IOC	MRI abdomen.	Shows light bulb sign
IOC for Extra-adrenal Pheo	Gallium dotatate (DOTANOC) PET scan scan → detect somatostatin receptors / Tc 99 Dopa PET	Best for detecting metastasis/extra-adrenal sites
FOR METS	(Nucleotide scan) Metaiodobenzylguanidine (MIBG) scintigraphy	ㅤ
Localise Extra adrenal Pheo or mets	Radeon	ㅤ