Diagnostic ultrasound ( PDFDrive )

334 PART II Abdominal and Pelvic Sonography
A
B
C
FIG. 9.35 Infectious Cystitis. (A) Transverse decubitus sonogram
reveals bladder wall thickening (arrowheads) with pseudopolyp
formation (arrows). (B) Bladder malacoplakia. Transverse sonogram
shows a mucosal-based mass with focal invasion of the prostate gland.
(C) Cystitis glandularis. Transverse sonogram shows a solid papillary
mass.
FISTULAS, STONES (CALCULI),
AND CALCIFICATION
Bladder Fistulas
Bladder istulas can be congenital or acquired. Causes of acquired
istulas include trauma, inlammation, radiation, and neoplasm.
Fistula from the bladder to the vagina, gut, skin, uterus, and the
ureter may occur. Vesicovaginal istulas are most oten related
to gynecologic or urologic surgery, bladder carcinoma, and
carcinoma of the cervix. Vesicoenteric istulas typically occur
as a complication of diverticulitis or Crohn disease. Vesicocutaneous
istulas result from surgery or trauma. Vesicouterine
istulas are a rare complication of cesarean section. Vesicoureteral
istulas are also rare and usually occur ater hysterectomy. 81
All these istulas are diicult to identify directly by sonography
because the tracts are oten thin and short. Occasionally, linear
bands of varying echogenicity may be seen. 82,83 If the bladder
communicates with gut, vagina, or skin, an abnormal collection
of gas may be seen in the bladder lumen. At ultrasound, this
appears as a nondependent linear echogenic focus with distal
dirty shadowing. Palpation of the abdomen during scanning
may cause gas to percolate through the istula, enhancing its
detection 83 (Fig. 9.36D). For depicting oten short vesicovaginal
istulas, color Doppler sonographic low jets may be shown with
diluted microbubble contrast agents in the bladder. 84
Renal Calculi
Renal stones are common, with a reported prevalence of 12%
in the general population. 85 Stone disease increases with advancing
age, and white men are most oten afected. From 60% to 80%
of calculi are composed of calcium. 86 Multiple predisposing
conditions, including dehydration, urinary stasis, hyperuricemia,
hyperparathyroidism, and hypercalciuria, may result in
renal calculi, but no cause is identiied in most patients. Caliceal