CT detection of infected synthetic grafts: preliminary report of a new sign.

The diagnosis of infected synthetic grafts is difficult using traditional radiographic techniques. In four cases, computed tomography demonstrated small pockets of gas in the clot around the grafts, a distinctive finding for an infected prosthesis. Further experience is required to determine whether this will prove to be a reliable diagnostic sign. The gas collections in infected grafts differ from normal gas in their multiplicity and occurrence more than 10 days after surgery.

Computed tomography of the gallbladder.

Computed tomography (CT) was used to study 79 patients with suspected gallbladder disease. First and second generation scanners were used to determine the efficacy of CT in detecting cholecystitis or cholelithiasis. Manifestations of gallbladder disease such as hydrops, opaque and nonopaque gallstones, chronic cholecystitis with thickened inflammatory walls, and secondary liver abscesses can be easily detected. It is a useful technique for individuals in whom the gallbladder has failed to opacity on oral cholecystography. The scanning method is described, and estimates of reliability are given including its accuracy, limitations, and place in the management of gallbladder disease, especially cholelithiasis. When conventional radiographic examinations or ultrasound fail to give definitive diagnostic information, CT can be a useful alternative with an overall diagnostic accuracy greater than 80%.

Accuracy of CT staging of bladder neoplasms using the gas-filled method: report of 21 patients with surgical confirmation.

CT staging of bladder neoplasms is a highly accurate procedure with a proven accuracy rate of 81% and a potential accuracy rate probably above 90%. At this institution, CT staging has become a routine procedure for all patients with bladder neoplasms prior to surgery or radiotherapy as well as to follow the progress of therapy. Staging of bladder carcinoma is performed by cystoscopy with biopsy, intravenous urography, and CT of the gas-filled bladder. Of 21 patients with surgical confirmation, 17 were correctly staged solely from the CT image. Overstaging in the four errors resulted from confusion produced by normal contiguous extravesical structures and by tangential viewing of the normal bladder wall. Negative contrast allowed precise demonstration of the morphology of the intravesical portion of the tumor.

Urological applications of computerized axial tomography.

Computerized tomography (CT scanning) of the chest and abdomen has been used as a diagnostic technique in more than 7,200 patients since 1974, 250 of whom had histological proved disorders of the genitourinary system and retroperitoneum. On the basis of this experience CT scanning has been found to be safe and effective, and offers certain advantages over conventional techniques. The number, extent and content of adrenal and renal mass lesions can be determined with relatively great accuracy. The presence and extent of metastases into the retroperitoneum, liver and chest often can be shown by CT scanning when other tests are negative. Placement of needles for aspiration, biopsy, injection of contrast medium or insertion of drainage tubes can be done accurately under computerized tomographic control. Air contrast scanning of the bladder can be of real help in staging bladder tumors, espically in obese patients. Computerized tomography in itself is non-invasive, carries a low radiation exposure comparable to other radiographic procedures and therefore, can, be valuable in following the course of patients with various diseases during and after therapy. While CT scanning will not replace other diagnostic procedures it should lead to a more judicious selection of potentially hazardous tests, such as angiography, aspiration and open biopsy.

CT demonstration of the splenic vein-pancreatic relationship: the pseudodilated pancreatic duct.

Cross-sectional anatomy of the splenic vein-pancreatic relationship is reviewed and correlated with findings on computed tomography. A layer of fat which is normally present between the splenic vein and the pancreas may simulate a dilated pancreatic duct. Distinct demonstration of the splenic vein as a structure separate from the pancreas was possible in 43 of 86 patients studied. An additional 25% of the patients had partial or indistinct demonstration of the splenic vein. Appreciation of this normal relationship on CT is imperative to avoid misinterpretation of the fat layer as a dilated pancreatic duct. In addition, the measured size of the pancreas may be falsely overestimated by addition of the splenic vein width if the intervening fat is not identified.

Computed tomography of localized adipose deposits presenting as tumor masses.

Computed tomography can reliably differentiate fat from other soft tissues. As a result of this property, adipose deposits presenting as tumors can be discriminated from neoplasms. Five examples are presented in which surgery was obviated by CT findings.

Computed tomography of gas-filled bladder: method of staging bladder neoplasms.

Current methods of staging bladder carcinoma have many disadvantages. A new method of staging bladder tumors employing computed tomography (CT) of the gas-filled bladder is presented. Representative cases are demonstrated. Direct visualization of the extent of the tumor and adjacent soft tissue structures is possible. CT scanning of the gas-filled bladder is a promising new method for staging bladder tumors and following their response to therapy.

CT detection and aspiration of abdominal abscesses.

Computed tomography (CT) is effective in detecting intraabdominal abscesses. Loculations of fluid and extraluminal gas are clearly localized in relation to other organs. Of 22 abscess in this series, CT successfully detected 20; comparative information with gallium, techneticum, and ultrasound scans is presented. In addition to localizing these collections, CT can be used to guide needle aspiration and drainage procedures. Three sizes of needles were used to aspirate specimens and/or provide drainage. This was accomplished successfully in 12 of 14 CT-guided procedures.

Determination of bone mineral content using CT scanning.

The usefulness and accuracy of CT scanning in the determination of bone mineral content is studied. The radius in 31 patients of both sexes and varying ages was examined using both the Norland-Cameron bone mineral analyzer and the CT scanner. There was reasonably good correlation (r=.72). Ten cadaver bones were then examined with CT scanning and were sent to the laboratory for calcium determination. These results indicate excellent correlation (r=.97). It is concluded that CT scanning represents the only practical and accurate in vivo method of bone mineral content determination.