William A. Fajman

Radionuclide angiography of the liver and spleen. Noninvasive method for assessing the ratio of portal venous to total hepatic blood flow and portasystemic shunt patency.

Radioactivity verus time curves were generated for the first pass of technetium-99m pertechnetate through the left ventricle, kidneys, spleen and liver, after a 20 mCi peripheral intravenous bolus injection. The rate of change of radioactivity in these organs before recirculation is proportional to blood flow through the organ. The hepatic perfusion index, defined as the ratio of portal flow to total hepatic blood flow, was correlated with the angiographic grade of portal perfusion. The hepatic perfusion index in seven normal subjects was 66.0 +/- 3.4 percent (mean +/- standard error of the mean), and in 22 cirrhotic patients with decreasing angiographic perfusion of grades 1 to 4 the index was 54 +/- 4.6, 37 +/- 2.6, 17 +/- 4.7 and 3 +/- 1.1 percent, respectively. The correlation between the calculated perfusion index and the angiographic grade of portal flow was highly significant (p less than 0.001). The passage of radionuclide through the spleen differed before and after shunt surgery in patients with portal hypertension. The slope to height ratio, based on the downslope of the splenic curve, was significantly greater (p less than 0.01) in the shunted patients and provided a simple index for assessing shunt patency.

An unusual cause of an isolated, focal splenic defect demonstrated by liver-spleen scintigraphy

Metastatic involvement of the spleen is uncommon. Lymphoma is the most common cause of primary and secondary malignant lesions of the spleen, whereas splenic metastases from carcinoma are rare and usually occur in a setting of concomitant carcinomatosis with melanoma, breast, ovary and lung accounting for the principal primary tumors. We report a case of an isolated, focal splenic defect demonstrated by Tc-99m-sulfur colloid scintigraphy which was the only visual evidence of metastatic adenocarcinoma of the colon. To our knowledge this unusual cause of a focal splenic defect on liver-spleen scintigraphy has not been previously described.

Clinical Experience with the Radioisotope Varicocele Scan as a Screening Method for the Detection of Subclinical Varicoceles

The association of varicoceles and subfertility has been well documented. Although varicoceles remain the most common surgically correctable cause of male infertility the diagnosis of small varicoceles remains a challenge. We evaluated 40 men with an isotope blood pooling scan. Seven volunteers served as either positive or negative controls. Complete correlation between physical findings and the isotope scan was found. The 6 patients with obvious clinical varicoceles and a stress pattern on semen analysis all had positive scans. The 18 patients with a stress pattern and who were clinically suspected of having a varicocele all had positive scans. Of 9 patients evaluated for infertility with a stress pattern but no clinical evidence of varicocele 6 had positive scans. We believe that the isotope scan will prove to be a useful procedure in the detection of nonpalpable varicoceles in selected subfertile men.

Is there need for thoracic spine radiographs following a negative chest CT in trauma patients

Abstract. The purpose of this study was to assess the need for conventional radiographs of the thoracic spine for routine clearance of trauma patients in whom chest CT has revealed no spinal trauma. The study was in the form of a retrospective review of trauma patients over the previous five years who underwent conventional radiographs of the thoracic spine following a chest CT that revealed no spinal trauma. Two hundred thirty-five trauma patients were found to have undergone conventional thoracic spine series following a chest CT that showed no spinal trauma. In 234 of the cases, the thoracic spine series was also negative. In one case, the thoracic spine series revealed mild anterior compression of the T7 vertebral body. This injury was stable and required no specific intervention. CT of the chest is an adequate evaluation of the thoracic spine in trauma patients who require routine thoracic spine clearance, making subsequent conventional radiographs of the thoracic spine unnecessary.

Early enhancing lesion seen on computed tomography consistent with focal nodular hyperplasia.

A 65-year-old man was referred to the nuclear medicine department after a finding suggesting hemangioma was observed incidentally. SPECT and planar images of the abdomen using labeled red blood cells did not show any foci of abnormal uptake. Further imaging with sulfur colloid showed uptake in the region of the lesion seen on computed tomography (CT), a finding suggestive of a benign liver lesion, most likely focal nodular hyperplasia.

Diffuse pulmonary ossification detected by bone scanning with Tc-99m hydroxymethylene diphosphate

Diffuse pulmonary ossification (DPO) is a rare pathologic finding of heterotropic bone formation within the lungs. It has been associated with mitral stenosis, chronic left ventricular failure, interstitial fibrosis, metastatic breast cancer, pulmonary amyloidosis, histoplasmosis, and chronic busulfan therapy. This patient represents a case associated with Placidyl use.

Splenic Infarction at Low Altitude in a Child with Hemoglobin S-C Disease

We describe a 15-year-old black boy with hemoglobin S-C disease living in Atlanta (altitude 1,034 ft), with no prior history of aircraft or mountain travel, who developed splenic infarction. The clinical picture was characterized by severe left upper quadrant abdominal pain, fever, splenomegaly, and hematologic and scintigraphic evidence of functional asplenia. The diagnosis was suggested by liver/spleen scintigraphy and further confirmed by ultrasonography and computerized tomography (CT) of the spleen. Treatment consisted of analgesics, intravenous fluids, and short-term antibiotic therapy. The child recovered without sequelae.

Portal venous-total hepatic flow ratio by radionuclide angiography☆

Quantitating portal perfusion of cirrhotic liver is important to surgeons preoperatively selecting shunt ‘procedures and postoperatively evaluating the results of shunting. The ideal method for measuring the portal fraction of total hepatic flow should be noninvasive, technically suitable for widespread use, and accurate in the presence of hepatocellular disease [3]. At the present, there are no methods that fulfill all these criteria. Portal perfusion has not been satisfactorily evaluated in the awake human subject because of difficulty evaluating the dual blood supply to the liver, impaired extraction capacity of diseased liver, and the anatomic inaccessibility of the portal vein. Shunt procedures are performed to control variceal hemorrhage. However, an unacceptably high incidence of disabling hepatic encephalopathy has been reported following total or nonselective shunts. Selective shunts (distal splenorenal shunts) have the lowest incidence of postoperative encephalopathy and are as effective as total shunts for preventing recurrent variceal hemorrhage. [ 93, Recently, however, several papers have questioned the efficacy of selective shunting maintaining portal perfusion in the years

False positive V/Q imaging in pulmonary contusion.

Pulmonary contusion and embolism are frequent complications of trauma. The radionuclide imaging finding of pulmonary embolism, a segmental ventilation/perfusion mismatch, has been documented in the literature to occur in pulmonary contusion, without, however, excluding concurrent pulmonary embolus by arteriography. The authors report a case of ventilation/perfusion mismatch due to pulmonary contusion with normal pulmonary arteriography.

Apparent change in cardiac geometry during single-photon emission tomography thallium-201 acquisition: a complex phenomenon

We investigated the frequency and extent of changes in heart position and geometry independent of body motion during stress single-photon emission tomography (SPET) thallium-201 myocardial perfusion imaging. Following an exercise treadmill test, patients had a 22.1-min SPET acquisition which was followed immediately by a static image acquisition for 1 min with the camera position identical to the first view of the SPET study. Point sources were placed on the body to monitor patient motion. Cardiac motion was assessed by an approach which mimicked a cross-correlation technique applied to cardiac count profiles along the horizontal and vertical directions from the first view of the SPET study and the static image. A large percentage (87.5%) of cases had some degree of horizontal or vertical motion. Pixel shifts in cardiac position of ≧2 pixels (12 mm) occurred in 60% of patients. In 37% of patients who moved the cardiac motion was consistent with simple translation of the heart and thus amenable to correction using proposed SPET motion-correction programs. The peak heart rate achieved during stress and the ratio of the heart rate immediately before SPET acquisition to the resting heart rate were determined to be independent predictors of patient motion during SPET acquisition. Cardiac motion changes were minimal at (13.3 ±2.2) min after cessation of exercise. The implications of these findings for the accuracy of SPET 201Tl require further investigation.