OS 214 - Renal Module - Imaging of the KUB

Imaging of the KUB

OS 214 Renal Module Dr. Fragante

Exams 1 & 2, Lab Exam

05 March 2009 | Thursday of 8patty.nina.ad.aoo

Lecture Outline:

I. Introduction to KUB ImagingII. Renal Anatomical AbnormalitiesIII. InfectionsIV. Calculi and Obstructive UropathyV. Renal Parenchymal DiseasesVI. Urinary BladderVII. Adrenal GlandsVIII. Renal Vascular LesionsIX. Appendix

INTRO TO KUB IMAGING

Before using imaging modalities, make sure to perform a good history and physical examination (PE) first, as these will give you a working impression and guide you in choosing the appropriate modalities.

The different modalities used for visualizing the KUB are:

o X-ray filmo Intravenous pyelography (IVP)o Ultrasound (UTS)o Computerized tomography (CT) scan

Correlate imaging findings with renal function: serum BUN and creatinine results, urinalysis

Take note also of comorbidities, eg. diabetes mellitus, hypertension

A. KUB X-ray film Advise patient to have empty bowel (eg. take

Dulcolax first) to visualize the outlines of the kidneys and the psoas

Figure 1. Normal KUB film, showing the psoas lines and the outlines of the kidneys. Note that the right kidney (RK) is normally lower than the left (LK).

B. Intravenous Pyelography Series of films with contrast material to better

visualize the urinary system To see if there is retention of urine

Requirements for IVP1. Evaluate renal function

Get the serum BUN and creatinine to be assured that the contrast maaterial will be excreted

2. History Diabetes, HPM Inquire about the allergy history of the

patient to foresee allergic reactions to the contrast material that will be used

To know what to look for in IVP

Contrasts:o Ionic – hyperallergenic and hyperosmolar (so

may cause pain) but cheaper; gives a burning feeling when given intravenously

o Non-ionic – hypoallergenic and low osmolar but more expensive

IVP Procedure Scout film (no contrast yet) film 3 minutes after

contrast after 10 minutes during full bladder post-void (see Fig. 39 in appendix)

1. Plain Film/Scout Film Calcific densities stones Used as reference figure

2. Inject Contrast Material3. Film at 3 minutes

Kidneys and upper collecting systems visualized

The contrast in the cortex and the medulla is seen

4. Film at 5 minutes Visualize pelvis (collecting system and

ureters are opacyfying)]5. Contrast at 10 minutes

Contrast has reached the pelvocalceal system, ureters

This is the time to look for stones in these areas

6. Film at 15 minutes Whole abdomen profile Kidneys are still visualized Ureters are likewise opacified Bladder is starting to fill

7. Full bladder film at 20 minutes Full bladder has very smooth borders “dapat bilog na”

8. Post-void Film To check urinary retention < 50 cc You can still see some degree of

contrast in various areas of the GU system

C. Ultrasound

Figure 2. Sagittal (left) and tranverse (right) views of the kidney through ultrasonography. The outer hypoechoic area denotes the renal parenchyma, while the inner hyperechoic area denotes the renal pelvis (collecting system).

D. CT scan

RK LK

Psoas

lines

Imaging of the KUB




Has more detail than the other modalities, but more expensive, of course (see Fig. 38 in appendix).

Patient is scanned in the supine or decubitus position. Occasionally, a prone position may prove useful.

The best images are obtained with the patient’s respiration suspended; frequently, the end of partial or full inspiration brings the kidney to better view

Allows us to see cortex, medulla, and renal drainage

ANATOMICAL ABNORMALITIES

A. Ptotic Kidney Kidney is descended by at least two vertebrae levels;

during standing position Prone to having obstruction and infection

Figure 3. Ptotic right kidney – notice that it is almost completely at the level of the pelvis. Nasa House, MD. ‘tong condition na ‘to! Hehe.

B. Horseshoe Kidney, Pelvic Kidney Horseshoe kidney – lower poles of the kidneys are

connected malrotation of kidneyso Patients with this are prone to infections,

stones and malignancies Pelvic kidney – at the level of the pelvis already (even

if not during standing position); prone to UTI Pregnancy may be a problem: prone to

hydronephrosis and can make labor very difficult

Figure 4. Horseshoe kidney (left) and pelvic kidney (right).

C. Vesico-ureteral Reflux Urine goes back (reflux) to the kidneys; patients are

prone to nephritis Reflux increases risk for infection Results in dilatation of the collecting system

Figure 5. Vesiculo-ureteral reflux. Black arrows points to the reflux (right).

INFECTIONS

A. Acute Pyelonephritis NORMAL findings in almost all various imaging

modalities! (daw, sabi sa lecture ni Ma’am…) Nuclear scan provides earlier detection Risk factor: stones

Figure 6. KUB film showing “acute pyelonephritis”. Left kidney is shown to be larger than the right.

Figure 7. Ultrasound (left) and CT scan (right) showing “acute pyelonephritis” (pointed by their respective arrows). Enlargement of the kidney is due to edema of inflammation. Areas of avascularity are due to toxic secretions which cause constriction

B. Chronic Pyelonephritis, Renal Abscess, Renal Tuberculosis Chronic pyelonephritis – may have cortical

irregularities or scarring Atrophied kidney and cortical abnormalities

o If not treated, renal abscess forms (2011 trans)

Imaging of the KUB




Figure 8. Cortical scarring, which can be a sign of chronic pyelonephritis. Distance at poles should not be differ by greater than 2 mm.

Figure 9. Ultrasound (left) and CT scan (right) showing renal abscess. In UTS the abscess is hypoechoic and in CT scan it is dark. It happens when you do not treat your chronic pyelonephritis.

Figure 10. KUB film (left) and CT scan (right) with foci of renal tuberculosis, shown by white arrows. Multiple calcific densities are seen.

CALCULI AND OBSTRUCTIVE UROPATHY

A. Stones and Calculi Uric acid stones – intake of beans, beer, meat, oats Calcium stones – from salty foods (junk food! Chippy!) Stones form in the calyx, then may go down to the

renal pelvis and then to the ureter (ouch…) For females: get calcium from milk, not calcium

tablets (2011 trans)

Staghorn calculi – stones can occupy an entire collecting system, conforming to the pelvocaliceal system (2011 trans); thus the “reindeer configuration”

Figure 11. Renal calculi, as shown by arrows (white calcified structures).

Figure 12. Staghorn calculi in both plain and contrast films.They can occupy a hole collecting system. They conform to the configuration of the pelvocaceal system.

Figure 13. Renal calculi as shown in UTS. The stones are hyperechoic, with shadowing behind them (2011 trans).

Plain Contrast

Patty, Nina, AD, Aoo : hi Jelly A’s! Hi JollyB’s! =)

Imaging of the KUB




Figure 14. CT-stonogram showing the stones. This is requested when X-ray is not enough (2011 trans).

Figure 15. Ureteral stones as seen in plain and contrast films using retrograde pyelography (RPG). Notice the discontinuation of the contrast because of obstruction by the stones.

B. Hydronephrosis There is dilatation of the collecting system because of

a chronic obstruction May be uni- or bilateral If not treated then there can be infection and then pus

formation

Figure 16. Hydronephrosis.

Figure 17. UTS showing hydronephrosis. Note the much-dilated pelvis, and the thinned out parenchyma. PCS – pelvicaliceal system; Ur – ureter.

C. Ureteral Stricture Stones and inflammation are more common causes

because can lead to fibrosis, leading to stricture

Figure 18. Ureteral stricture.

RENAL PARENCHYMAL DISEASE

A. Acute Renal Parenchymal Disease (2011 trans) Patients are edematous, ascetic because the

glomeruli are unable to filter Enlarged kidneys on UTZ Echogenic ball-like kidney

Figure 19. UTS showing acute renal parenchymal disease. The areas are hyperechoic because of inflammation.

B. Masses/Tumors and Cysts (2011 trans) Renal cysts – most common in the elderly

o Fluid-filled and can cause obstruction if large enough

o Seen as “fraying of the collecting system”o May cause obstruction

Renal tumors may metastasize to nearby organs such as the liver and spleen; first symptom is hematuria (painless)

ContrastPlain

Ur

PCS

pus/debris

Imaging of the KUB




Wilm’s tumor/nephroblastoma – more common in the pediatric population; may occupy the whole kidney; diffused, multiply masses

Diffuse malignancies – because of cancers like lymphomas

Figure 20. Cysts, as shown in IVP (left), UTS (upper right) and CT scan (lower right). Cysts in IVP are white.

Figure 21. Wilm’s tumor or nephroblastoma in UTS (left) and CT scan (right).

Figure 22. CT scan images showing renal cell carcinoma (left, with arrows) and organ metastases (LM – liver metastasis, SM – splenic metastasis).

Figure 23. UTS (left) and CT scan (right) showing diffuse malignancies (eg. lymphomas).

URINARY BLADDER

Normal filled UB: very smooth borders, like a balloon Normal post-void UB: not more than 50cc of urine left;

if more than 50cc, then UB is more prone to infection

Figure 24. Normal filled UB (left and middle) and normal post-void UB (right).

A. Cystolithiasis (2011 trans) Stones of the UB; calcific, rounded/ovoid opacity that

have the same density as bone and may look like eggs

Capacity of UB is decreased; there may also be reflux Patient becomes more prone to cystitis Usually lamellated; lamellae represent times of

deposition, just like in “tree rings” Mves with changes in position Uually smooth borders but can be mulitlobulated

Figure 25. Plain and contrast films showing cystolithiasis.

LM

SM

Plain Contrast

Imaging of the KUB




Figure 26. UB calculi with blood clots, as shown in UTS.

B. Prostatic Enlargement with Chronic Bladder Obstruction/Cystitis

Figure 27. Enlargement of the prostate, leading to UB obstruction and cystitis.

Patients have poor stream due to retention UTZ is used to evaluate prostate

C. Emphysematous Cystitis Characterized by infection of UB and UB wall with

gas-forming organisms (2011 trans); thus, there is air outlining the wall of the bladder

“Mickey Mouse” appearance because of diverticula

D. Chronic Cystitis UB may become fibrotic, and have vesico-ureteral

reflux Can lead to chronic renal parenchymal disease

E. Contracted Bladder UB capacity approximately only 20cc; “one drink of

iced tea, ihi na agad” Treated with bladder augmentation (2011 trans);

“neobladder”, attached to ileal segment

Figure 28. Emphysematous cystitis. Note the outline of ai in the UB wall (shown by arrows) and the “Mickey Mouse” appearance (UB Div – UB diverticula).

Figure 29. Chronic cystitis: with vesico-ureteral reflux (VUR), as shown in contrast film (left), and with thickened bladder wall (white lining of the UB located in the center), as shown in CT scan (right).

Figure 30. Normal findings in UTS (top images), compared to findings of cystitis in UTS (bottom images). The normal UB has smooth walls, while the cystitic UB has rough edges.

Figure 31. Contracted bladder.

F. Post-traumatic Bladder Extrophy UB not only descends, but goes out (2011 trans) There is widening of the symphysis pubis; also, there

is bilateral dilatation of the collecting systems (also ureters)

Due to pelvic fractures, motorcycle accidents, horseback riding

May involve urethras in males (2011 trans)

Enlarged prostate

UB Div

UB Div

VUR

Imaging of the KUB




Figure 32. Bladder extrophy. The ureters are dilated, and the symphysis pubis widened.

G. UB Malignancy There is a change from “full moon” to “half/crescent

moon” UB wall may be eaten up (2011 trans) Risk factor: smoking and alcohol intake Most common: transitional cell CA

Figure 33. UB malignancy as shown in CT scan (left) and contrast film (right), where the “crescent moon” is very evident.

ADRENAL GLANDS

A. Adrenal Gland Hyperplasia

Figure 34. CT scans showing normal adrenal gland (left) and hyperplastic adrenal gland (right).

B. Pheochromocytoma Tumors of the adrenal medulla, resulting in increase

in catecholamine production Hypertension is one manifestation As opposed to adrenal gland hyperplasia,

pheochromocytoma look like round masses; in the

former, the original shape is somewhat retained (2011 trans)

Figure 35. Pheochromocytoma, as seen in UTS (left) and CT scans (right).

RENAL VASCULAR LESIONS

Renal angiography – used for visualizing the vascular tree of the kidneys; aside from locating lesions, this is also used in screening for organ transplants

o Philippines has one of the highest rates of kidney transplantation

Figure 36. Normal renal angiogram.

Figure 37. The left angiogram shows renal artery stenosis, while the right angiogram shows the effect of stenting (no more stenosis).

Before Stenting After Stenting

Imaging of the KUB




APPENDIX Figure 38. CT scans of the normal kidney.

Figure 39. Series of IVP contrast films: scout film (no contrast yet, left), 3 minutes after injection (top middle), after 10 minutes (top right), full bladder (bottom right) and post-void bladder (bottom middle).

Scout

film

3 min

10 mins

Full bladderPost-void

OS 214 - Renal Module - Imaging of the KUB

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