Occult gastric bleeding demonstrated by bone scan and Tc-99m-DTPA renal scan.

A patient is described who had coagulopathy and clinically intermittent gastrointestinal bleeding. The bleeding site was clearly shown on renal and bone imaging performed at a time when the patient was considered clinically to have stopped bleeding. A bleeding gastric ulcer was subsequently demonstrated by radionuclide and contrast angiography, and at surgery.

Computed tomography diagnosis of right aortic arch with an aberrant left innominate artery.

A patient whose chest computed tomography scan demonstrated a right-sided aortic arch with an aberrant retroesophageal left innominate artery is reported. There have been only isolated case reports of this developmental variation of the arch and great vessels. The demonstration of this anomaly by computed tomography scanning has never been previously reported.

Clinical application of computerized axial tomography (CAT) scanning of calcaneus fractures.

CAT scanning of calcaneal fractures with the 30 degree coronal or the transverse plane provides useful information not available on conventional roentgenograms. Joint alignment, displacement of fragments, and the integrity of the medial wall are key factors in deciding whether surgical reconstruction is indicated and what surgical approach to use--medial, lateral, or both. Examples of such information obtained on eight patients with calcaneal fractures is reported comparing CAT scan results to conventional roentgenograms. CAT scans can be used also with the foot immobilized in a cast.

A complication following Kimray-Greenfield filter insertion.

The Kimray-Greenfield inferior vena cava filter, which is used to prevent pulmonary embolization from the pelvis and lower extremities, has a high patency rate and a low complication rate. In one patient, however, thrombus formation at the apex of the filter during introduction resulted in the filter's failure to open completely so that the entire width of the cava in the transverse diameter was not occluded. This potential complication may be avoided by keeping the introduction time to a minimum and by constantly infusing a heparin solution through the side port of the insertion device while it is in the vena cava.

CT detection of retroperitoneal gas associated with gas in intervertebral disks.

Three cases are presented with computed tomographic evidence of gas in retroperitoneal soft tissues in association with the so-called "vacuum phenomenon" (Knutsson sign) in lumbar disks. We review the explanations of Knutsson sign and offer an explanation of how extradiscal gas can occur in association with it.

Interobserver discrepancies in distance measurements from lumbar spine CT scans.

Lumbar spine computed tomographic (CT) scans of 10 patients were examined independently at two levels by five experienced radiologists. At each level the minimum midline sagittal diameter was measured, and at each intervertebral space the left foramen was measured for its minimum diameter. Statistically significant differences were found between the measurements of different observers, differences that in a number of cases could have led to disagreement over whether or not stenosis was present. There were reasonably strong correlations between different observers' readings of midline sagittal diameters but generally not of foraminal diameters. Reasons for discrepancies between observers in spine CT measurements are reviewed briefly.

Pyogenic sacroiliitis. An absolute indication for computerized tomographic scanning.

Pyogenic sacroiliitis (PSI) resulted from direct injection of a foreign substance, pumice, in a 32-year-old woman and was complicated by iliopsoas abscess. The symptoms of PSI are unspecific, and similar complaints may accompany such conditions as herniated disc and arthritis. Results of physical examination may be misleading, especially if movements that stress the sacroiliac joint are omitted. Early roentgenograms are normal and rarely aid in the diagnosis. Scintiscanning with gallium and technetium may indicate an inflammatory pelvic focus. These methods lack specificity, however, and may underestimate the extent of disease. The computerized tomographic (CT) scan was effective in detecting interosseous gas with an associated soft tissue abscess. It also proved invaluable in precisely delineating the location and extent of the lesion in and around the sacroiliac joint, facilitating use of the most expeditious surgical approach. Through follow-up CT studies the course and end results of therapy can be objectively determined.