Effect of instrument diameter on the depth of penetration of fiberoptic sigmoidoscopes

Newer fiberoptic sigmoidoscopes tend to have smaller diameter insertion shafts than older models. The extent to which this diameter affects how deeply an instrument can be inserted into the colon and the frequency with which sigmoidoscopes of different diameters could reach more proximal areas of the colon was evaluated. Instrument diameter did not influence the length of the sigmoidoscope shaft that could be introduced into the patient. However, when fully inserted to 60 cm, the 12-mm diameter sigmoidoscopes viewed significantly less of the sigmoid and descending colon than did the 16-mm diameter sigmoidoscopes. This lesser degree of anatomic depth of penetration has direct implications for the diagnostic capabilities of smaller diameter instruments.

Parapelvic lymph cyst in a renal allograft mimicking hydronephrosis: CT diagnosis

Lymphoceles are common complications of renal transplantation and usually arise between the bladder and the transplant kidney. A rare case of a parapelvic lymphocyst in a renal allograft is presented that sonographically mimicked hydronephrosis but was correctly diagnosed by CT.

Extramedullary hematopoiesis in the adrenal glands: CT characteristics

A patient with agnogenic myeloid metaplasia was discovered by CT to have bilateral asymmetric adrenal enlargement. A CT guided needle biopsy demonstrated extramedullary hematopoiesis. The CT and cytological findings are presented.

Nuclear medicine evaluation of focal fatty infiltration of the liver

Focal fatty infiltration of the liver (FFIL) occasionally may be mistaken as metastatic disease, primary liver malignancy, or other space-occupying lesions on CT or ultrasound studies, especially if there is significant mass effect. In these confusing cases, Xe-133 liver imaging has been advocated for confirmation of FFIL, since such studies have been reported to be sensitive and specific. The authors present results of four Xe-133 and four Tc-99m sulfur colloid scans in six patients with FFIL. Xe-133 imaging was found useful for diagnostic confirmation in only one patient and was misleading in the other three. Routine liver-spleen imaging was a more reliable method of confirmation, since no focal defects were found in any of the patients.

Pitfalls of computed tomography in diagnosis of discitis

Sixteen patients with discitis from January 1980 through December 1983 underwent 18 CT scans for initial evaluation. In six scans the study produced a false negative result (sensitivity 63%, 11/16). In three of these six the scan was performed at the wrong disc level, and in three the error was interpretive. During the same time period 6 patients had a CT diagnosis of discitis which proved incorrect (positive predictive value 63%), three of which had fractures, two had normal post discectomy changes, and one had a neuropathic arthropathy. These studies were reviewed in a blinded fashion along with 30 CT scans of post operative patients without clinical or laboratory evidence of discitis. The CT findings in the discitis patients were: (a) anterior paravertebral soft tissue swelling with obliteration of paravertebral fat planes, (b) fragmentation or erosions of vertebral end plates, and (c) paravertebral fluid collection (abscess). Both (a) and (b) were seen in 13/15 patients, (a) alone in 1/15, (b) alone in 1/15, and all three (a, b, c) in 2/15. The CT scan is diagnostic of discitis in those with all three findings. In those patients with only (a) or both (a) and (b), the CT can be suggestive of discitis in the proper clinical setting when correlated with plain film findings: however, these CT findings are also observed in other conditions. Involvement of the spinal canal by inflammatory mass was seen in 6/16 patients with discitis. Low attenuation (hypodensity) of the affected disc was not observed.

Assessment of primary gynecologic malignancies: comparison of 0.15-T resistive MRI with CT

Thirty-eight patients with gynecologic malignancies (ovarian, cervical, and endometrial carcinoma) underwent computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen and pelvis. Results of these studies were compared with each other as well as with clinical staging and surgical findings when possible. CT and MRI correctly staged 64% (nine of 14) of patients with cervical carcinoma. In patients suspected of residual or recurrent disease, CT and MRI were each correct in 75% (15 of 20), four of the errors being due to inability to distinguish inflammation or radiation changes from recurrent tumor. CT and 0.15-T resistive MRI are of equal value in screening for residual or recurrent disease and as an adjunct to clinical staging; further advances in MRI technology may alter this impression.

The triangle sign: a CT sign of intraperitoneal fluid

Ninety-four abdominal CT examinations of 91 patients with intraperitoneal fluid were reviewed, and in 25 scans (27%) triangular fluid collections were found within the leaves of the mesentery or adjacent to bowel. In a control group of 30 patients without CT evidence of intraperitoneal fluid, no triangular densities were identified. Triangular fluid collections were visualized in a higher percentage of patients when the quantity of intraperitoneal fluid was moderate to large, IV contrast was given, good bowel opacification was obtained, the amount of mesenteric fat was moderate to large, and the abdominal CT examination included cuts through the pelvis. A triangular fluid collection was reproduced in a cadaver by intraperitoneal infusion of saline. Percutaneous needle aspiration confirmed that the saline collection was responsible for the CT findings. The CT appearance of this new triangle sign is demonstrated.

Computed tomographic diagnosis of pancreatic pseudoaneurysm

Hemorrhagic complications of pancreatic pseudocysts are potentially life threatening. This case, definitively diagnosed by bolus CT study, demonstrated pseudoaneurysm formation within a pancreatic pseudocyst.

CT diagnosis of fracture of the coracoid process of the scapula

A case of fracture of the coracoid process of the scapula is presented in which the findings were not apparent on plain films. CT demonstrated the fracture, and the absence of soft tissue mass suggested a remote traumatic etiology rather than metastatic disease. The findings were confirmed surgically and pathologically.

Comparison of NMR and CT imaging in the evaluation of metastatic retroperitoneal lymphadenopathy from testicular carcinoma

Twenty-five patients with nonseminomatous germ cell carcinoma of the testis underwent CT and nuclear magnetic resonance (NMR) of the retroperitoneum followed by radical retroperitoneal lymph node dissection for surgical proof of metastatic disease. Computed tomography correctly predicted the presence or absence of adenopathy in 88% and assigned the correct stage in 84%. Nuclear magnetic resonance had comparable figures of 84 and 80%. Computed tomography appeared superior to NMR in detecting other abdominal abnormalities, although these were few in number. Nuclear magnetic resonance is nearly equivalent to CT in staging retroperitoneal lymphadenopathy from testicular cancer and may surpass CT following technical advances and the introduction of oral contrast agents.

Perirenal pancreatic pseudocysts: diagnostic management

Three cases of pancreatic pseudocysts involving the kidney are presented in which clinical findings or diagnostic imaging favored intrinsic renal disease. Correct diagnosis was established in all cases by sonographically guided cyst aspiration with amylase determinations on the cyst fluid. In addition, laboratory studies ruled out infection, a well known complication of pancreatic pseudocysts. The findings were instrumental in guiding clinical management and insuring correctly timed and properly guided surgical intervention. It is concluded that any patient with a fluid collection in the kidney region may have a pancreatic pseudocyst even without a clear-cut history of pancreatitis or trauma. Fine-needle aspiration is safe and efficacious, and laboratory analysis of cyst fluid should always include amylase determination, in addition to bacteriologic and cytologic evaluation, even if serum amylase is normal.