Diffuse lung uptake of technetium-99m sulfur colloid in malaria

Diffuse lung accumulation of colloid was seen on liver-spleen imaging in a patient during the acute stage of vivax malaria. A repeat study was performed following successful therapy and showed complete disappearance of lung uptake. Possible mechanisms for this unusual observation are discussed, with the conclusion that this phenomenon is probably related to increased reticuloendothelial system activity, due to a malaria-induced increase in the pulmonary macrophages.     

Discordant uptake of technetium-99m DISIDA and technetium-99m sulfur colloid in an amebic abscess

Hepatobiliary imaging in a patient with an amebic abscess showed an early cold defect that later showed rim enhancement. A Tc-99m SC scan did not show prominent flow (making hepatoma unlikely) and showed the previously noted defect to appear larger and without rim enhancement. The differential damage to Kupffer cells and hepatocytes or edema may account for these findings. Amebic abscess should be included in the differential diagnosis of lesions that give increased Tc-99m IDA but cold Tc-99m SC images.     

Renal accumulation of technetium-99m sulfur colloid

A case of renal uptake in a routine technetium-99m sulfur colloid liver/spleen study is reported. The possible causes of uptake by the kidneys in view of the patient's previous history are discussed.     

Microautoradiographic study of technetium-99m colloid uptake by the rat liver

A new microautoradiographic technique was developed to study the distribution of 99mTc-labeled radiopharmaceuticals. Using a thick emulsion, it is possible to get microscopically visible tracks of internal conversion and Auger electrons. The liver uptake of microscopic particles has been thought to occur in Kupffer cells but no direct evidence has been provided for technetium colloids. Using this method, 99mTc-labeled colloids were clearly identified in Kupffer cells in the sinusoidal areas of liver. "Track" microautoradiography using a thick emulsion layer may be used on any frozen tissue sections and may provide an important tool to assess the biodistribution of 99mTc radiopharmaceuticals.     

Comparison of technetium-99m sulfur colloid and technetium-99m albumin colloid labeled solid meals for gastric emptying studies

A Tc-99m albumin colloid (Tc-AC) kit has been introduced as an alternative to Tc-99m sulfur colloid (Tc-SC) for liver-spleen imaging. Since there is no need for boiling, the use of Tc-AC reduces preparation time and manipulation. Tc-SC is one of the most commonly used radiopharmaceuticals for the labeling of solid-phase markers in gastric emptying studies. In vitro studies were performed to evaluate the labeling efficiency and stability in hydrochloric acid and in human gastric juice of intracellularly labeled chicken liver and scrambled eggs labeled with Tc-SC and Tc-AC. Gastric emptying studies also were performed on 20 healthy volunteers with both Tc-SC and Tc-AC labeled scrambled egg sandwiches. There was no significant difference between Tc-SC and Tc-AC in the labeling efficiency of chicken liver (98% +/- 1% for Tc-SC, 96% +/- 2% for Tc-AC) and scrambled eggs (92% +/- 2% for Tc-SC, 91% +/- 3% for Tc-AC). However, both Tc-SC and Tc-AC labeled scrambled eggs showed a lower stability than chicken liver, particularly in human gastric juice. Gastric emptying curves from both meals in 20 normal subjects were also similar, with a mean half-emptying time of 85 +/- 13 minutes and 87 +/- 16 minutes for the meals containing Tc-SC and Tc-AC respectively. Tc-AC is a reliable alternative to Tc-SC as a radiotracer for solid-phase gastric emptying studies.     

Splenic uptake of both technetium-99m diphosphonate and technetium-99m sulfur colloid in sickle cell beta (0) thalassemia

A 19-year-old black woman with sickle cell beta(0) thalassemia had experienced more than 100 hospital admissions for sickle cell crisis and aseptic necrosis of both femoral heads. Her spleen was enlarged threefold and accumulated both radiocolloid and bone-seeking agent on two occasions, demonstrating an exception to the rule in sickle cell anemia that spleens that take up bone-seeking agents demonstrate functional asplenia. In the context of fever, left upper quadrant pain, and splenomegaly, the pattern of calcification in the patient's spleen as revealed in ultrasound and CT studies suggested possible abscess and led to unnecessary splenectomy. The nuclear medicine studies did not support this diagnosis. Nuclear medicine physicians should not be misled by splenic findings of sickle cell thalassemia (and possibly of other heterozygous sickle cell disorders) that differ from those of the more familiar homozygous sickle cell anemia.     

Prominent gaseous distension of bowel causing false-positive technetium-99m sulfur colloid liver scintigram

A Tc-99m sulfur colloid liver scan carried out shortly after a prolonged upper gastrointestinal endoscopy demonstrated two concave indentations along the inferior border of the liver and increased space between the left lobe of the liver and the spleen. These abnormalities, simulating compression by an extrinsic mass, were caused by air introduced endoscopically into the gastrointestinal tract. Eight days later, a repeat radiocolloid scan was normal. There should be awareness that gaseous distension of the bowel and stomach may result in a false-positive radiocolloid liver scan. Correlation with abdominal radiographs may avert such misinterpretation.     

A simplified method of assessing hemodynamics in technetium-99m sulfur colloid liver imaging

A total of 204 Tc-99m sulfur colloid hemodynamic studies of the liver taken at 5-second intervals were evaluated. The time when the gradually increasing activity in the liver becomes equal to the reducing activity in the heart pool is defined as the relative half clearance time (RHCT) of cardiac activity to the liver. The RHCT was measured in each scan and was correlated with clinical information, liver function tests, and static scan findings. Normal RHCT was established to be in the range of 40 +/- 20 seconds. This study indicates that the RHCT truly reflects the functional status of the hepatic blood flow as well as the phagocytic activity of the Kupffer cells of the liver when cardiac function is normal. A prolonged RHCT may indicate the presence of a parenchymal disease of the liver or cardiac failure with hepatic congestion, or both. The longer the RHCT, the more severe the pathologic condition of the liver, provided that cardiac function is normal.     

Tc-99m colloid lung uptake in a rare case of toxoplasmosis with liver involvement

Intensive lung accumulation of colloid (Tc-99m phytate) was demonstrated in a child suffering from acquired toxoplasmosis with a rare manifestation of severe liver damage. The possible mechanism and clinical importance of colloid lung concentration in this case is briefly discussed, including a review of the literature on this subject.     

Comparison of technetium-99m sulfur colloid and in vitro labeled technetium-99m RBCs in the detection of gastrointestinal bleeding

Twenty-seven paired Tc-99m sulfur colloid (SC) and Tc-99m RBC studies were evaluated for the detection of GI bleeding. The only two positive Tc-99m SC studies had positive early Tc-99m RBC studies as well. There were 15 other positive Tc-99m RBC studies (three during the first hour) and these were associated with normal Tc-99m SC scans. Approximately 70% of the positive Tc-99m RBC studies occurred after 1 hour. Tc-99m RBCs should be the initial test in patients with GI bleeding.     

Diffuse lung uptake of technetium-99m tin colloid in heat stroke. Case report

Diffuse lung uptake of Tc-99m tin colloid during liver scanning was found in a patient with heat stroke. Slightly increased splenic uptake was present, but bone marrow uptake was not. A repeat liver scan seven days after the initial scan showed no lung uptake.     

Pleuroperitoneal communication in a patient with right pleural effusion and ascites diagnosed by technetium-99m sulfur colloid imaging

A 55-year-old man with an 11-year history of intermittent right pleural effusions had continued fevers and a large right transudative pleural effusion. Minimal ascites was noted by ultrasound examination. A communication between the thorax and intraperitoneal cavity was established by radionuclide examination of the chest and abdomen. Tc-99m sulfur colloid was injected into the peritoneal cavity, and imaging at 1 and 4.5 hours confirmed passage from the peritoneal to the pleural cavity. Repeated attempts to sclerose the pleural cavity failed to decrease the transudative accumulations. The patient was subsequently treated with the placement of a LeVeen shunt.     

Quantitative evaluation of postembolized splenic tissue using technetium-99m sulfur colloid

Tc-99m sulfur colloid scans were used to quantitate the percent of residual splenic tissue after partial splenic embolization (PSE) performed for the treatment of hypersplenism in 17 renal transplant patients. A liver-spleen phantom was designed which simulated the human liver and spleen configuration to evaluate the technique. This phantom contained a solution of tc-99m sulfur colloid, which allowed precise quantities of the spleen phantom volume to be displaced using lucite pseudo-emboli. After each lucite embolus, computer images of the spleen phantom were collected and analyzed in the same manner used for the transplant patients. Correlation of the actual volume displaced or embolized with the computer estimated values was 0.996 (P less than 0.001). This technique was superior to both CT and MRI, which were more difficult to perform and less precise in measuring a decrease in postinfarction functioning splenic tissue.