Renal Diagnostics(Pyelogram,Urogram,Nephrogram,Cystourethrogram,Cystometry,DTPA Scan)

Increased dense nephrogramiRef:Diseases of the kidney & urinary tract By Robert W. Schrie 8/c p351; Grainger & Allison’s diagnostic radiology By Ronald G. Grainger, David J. Allison 3/e p1544]

• The diagnosis of papillary necrosis depends on the demonstration of calyceal and papillary abnormalities without associated parenchymal loss. The calyceal and papillary abnormalities fall into two groups:

1. Those that are characteristic of papillary necrosis

a.Tracks and horns of contrast medium arising _,from the calyceal fornices (representing necrosis around the papillary margin.)

b.Egg in a cup appearance (due to central necrosis producing central pool of contrast within the papillae)

c.   Ring shadow (Papillary sloughing produces a central lucent filling defect with a surrounding ring of contrast medium)

2. Those that are non-specific

The end result of papillary sloughing is clubbed, blunt or truncated calyces.

• Renal papillary necrosis refers to coagulative necrosis of the renal medullary pyramids and papillae brought on by several associated conditions and toxins that exhibit synergism toward the development of ischemia. Renal papillary necrosis may be localized or diffuse and unilateral or bilateral.
• Renal papillary necrosis can lead to secondary infection of desquamated necrotic foci, deposition of calculi, and/or separation and eventual sloughing of papillae, with impending acute urinary tract obstruction. Sinus like tracts and cavitations may be seen surrounding the sloughed papilla. Multiple sloughed papillae can obstruct their respective calyces or can congregate and embolize to more distal sites (eg, ureteropelvic junction, ureter, ureterovesical junction)
• Renal papillary necrosis is potentially disastrous and, in the presence of bilateral involvement or an obstructed solitary kidney, may lead to renal failure.
• Certain conditions have a known association with renal papillary necrosis, and the underlying mechanism of these conditions is ischemia, which ultimately leads to renal papillary necrosis.

– Analgesic abuse

– Obstruction of the urinary tract with infection

– Sickle cell disease

– Diabetes mellitus

Stress incontinence

Cystogram is used to evaluate bladder filling defects (tumors, diverticula) and bladder perforation.

Cystography and cystourethrography are important radiologic techniques for detecting vesicoureteral reflux and may be used in the workup of patients with urinary stress incontinence.

CT cystography (CT of the pelvis after the instillation of dilute contrast medium into the bladder) has been shown useful in the evaluation of traumatic bladder rupture.
                          
Ref: Gerst S.R., Hricak H. (2008). Chapter 6. Radiology of the Urinary Tract. In E.A. Tanagho, J.W. McAninch (Eds), Smith’s General Urology, 17e.

B i.e. Systemic hypertension

B i.e. Renal vein thrombosis

– Nonvisualization of kidney (or absence of nephrogram) occurs in complete renal ischemia secondary to occlusion of main renal artery, (global absence) or focal renal infarction/ischemia secondary to focal arterial occlusion or renal vein thrombosisQ or space occupying lesions (segmental absence).

–  Persistent dense nephrogram (both increasingly or immediate) is seen in systemic hypotension, severe dehydrationQ, renal artery stenosis, renal vein thrombosis, tubular obstruction & damage and urinary tract obstruction (eg ureteral obstruction)Q but not in systemic hypertension. Although hydronephrosis usually 1/t scalloped/shell i.e. non smooth rim nephrogramQ.

Ans. is b ie Endoscopic pyelotomy is contraindicated 

Endoscopic approaches (such as endoscopic pyelotomy or ballon dilatation) are used for the repair of PUJ obstruction.

Ans. is ‘c’ i.e., Horse shoe kidney 

Ans. is ‘b’ i.e., Polycystic kidney 

Ans. is ‘c’ i.e., Retrograde cystogram 

Ans. is ‘c’ i.e., Voiding Cystogram 

Voiding cystourethrography is the best method to visualize posterior urethra.

Remember,

Urethra can be imaged radiographically in two ways.

• Anterograde techniques —>       Best for visualization of posterior urethra. (This is done along with voiding cystourethrography or with voiding following

excretory urography)

• Retrograde technique                —>       Best for examining the anterior (penile) urethra (Contrast is injected through tip of urethra).

Answer is D (Radio-Renogram i.e. DTPA Scan)

Radiorenogram is the next best investigation of choice.

The next step would be to assess Renal function and the possible site of obstruction if that is the cause for anuria.

The choice lies between an IVP or a Radio-Renogram. Out of these two a Radio Renogram is a distinctly better option.

Imaging of the kidney and urinary tract have been greatly simplified by introduction of Radio nucleotide methods.

These are now fast Replacing radiocontrast studies like IVP.

Radionucleotide procedures are non invasive, highly sensitive and expose patients to less radiation.

Ans. B: Voiding cystourethrography

Perform VCUG and renal-bladder ultrasonography in any child with documented UTI before age 5 years, any child with pyelonephritis, and any male child with a symptomatic UTI.

A renal-bladder ultrasonography may be used to screen older children with UTI. If ultrasonographic findings are abnormal, conduct further workup studies with VCUG to rule out VUR.

During the initial workup in a patient with suspected reflux, perform the standard VCUG, which provides clear anatomic detail and allows accurate grading of the reflux degree. By filling and emptying the bladder several times (cycling) with the catheter still in the bladder, as described by Lebowitz, the yield of identifying VUR is clearly enhanced. The conventional cystography provides more anatomical accuracy than nuclear cystography; however, nuclear cystography is advantageous (used widely to monitor VUR) because of lower radiation exposure and increased sensitivity.

Ans. B: Micturating cysto urethrogram

Ans. Chronic pyelonephritis

Ans. Proximal convoluted tubules

Ans. Micturating cystourethrogram

Ans. Polycystic kidney

Ans. Micturating cystogram

Ans. Voiding cystogram