[en] This manual provides clinical interpretations of diagnostic imaging studies. It includes selected photographs and diagrams to illustrate major points presented in the text, and outline agents, procedures, physiology, pathophysiology, and clinical interpretation of diagnostic imaging studies

[en] Technetium-99m-labeled heat-damaged erythrocytes were evaluated as a spleen imaging agent in 14 patients. Spleen-to-liver deposition ratios were increased to such an extent that the liver was rarely visualized, and interference from the hepatic left lobe of the liver was eliminated. Information obtained was accurate and diagnostically adequate in various splenic involvements. This tracer appears to be one of the better spleen imaging agents presently available

[en] The reticuloendothelial system, including the spleen, subserves important immunologic functions. Loss of splenic function results in an increased incidence of severe bacterial infections and is accompanied by thrombocytosis. Several nephrotic children were noted to have remarkably high platelet counts and predisposition to bacterial infection with encapsulated organisms. We, therefore, investigated the splenic function of nine children with primary nephrotic syndrome and measured the phagocytic function of the spleen by sequestration of Technetium-99-labelled heat-treated autologous RBC, administered intravenously. Four children had decreased splenic function. Repeat studies performed in two of these children after remission of the nephrotic syndrome gave normal results. There were six episodes of bacterial infection (3 peritonitis, 1 septic arthritis, 1 cellulitis, and 1 Escherichia coli urinary tract infection) among the four patients with decreased splenic function. There were no episodes of bacterial infection among the five nephrotic children with normal splenic function. Nephrotic patients with decreased splenic function had significantly increased platelet counts (921,000 +/- 196,000; mean +/- SEM) compared to those with normal function (435,000 +/- 46,000; P less than 0.001). Our findings suggest the possibility that some nephrotic children may have decreased splenic function in association with increased susceptibility to bacterial infections

[en] These studies demonstrate the first application of Ru-97-DISIDA in human subjects. High quality images were obtained. Scintigraphic findings in patients with hepatobiliary disorders were consistent with the biodistribution data obtained in experinmental animals and with other imaging procedures and clinical findings. Administration of Ru-97-DISIDA I.V. and of a solid test meal labeled with Tc-99m-Sulfur Colloid allowed simulateneous detection and quantification of deodenogastric reflux and determination of the gastric emptying rate. This represents an advantage as compared to the currently used techniques which necessitate two separate studies if a solid meal is used, or would mandate a liquid meal for a simultaneous study. The excellent nuclear decay characteristics of Ru-97 (tl/2 69.6 h, gamma 216 keV, 86%, no betas) permit delayed study of the hepatobiliary system with considerably less radiation exposure than I-131 Rose Bengal and with a marked improvement in image quality. 5 refs., 3 figs., 3 tabs

[en] A 26-month-old girl with Kawasaki syndrome (mucocutaneous lymph node syndrome) is presented. Liver function studies were abnormal and sonographic examination revealed hydrops of the gallbladder. The Tc-99m DISIDA cholescintigraphy demonstrated both early and delayed nonvisualization of the gallbladder. A photopenic area was noted in and below the gallbladder fossa and there was medial and upward displacement of the common bile duct. It appears that Kawasaki syndrome may result in nonvisualization of the gallbladder by cholescintigraphy. Accordingly, this diagnosis should be added to the list of conditions associated with nonvisualization of the gallbladder by biliary scintigraphy

[en] This paper identifies pancreatic tumors with positron emission tomography (PET) using F-18 2-fluorodeoxyglucose (FDG). PET studies were performed in 13 patients with pancreatic tumors (11 adenocarcinomas; two islet cell tumors) using FDG. Data were acquired for 1 hour and in 14 contiguous 7-mm sections after attenuation correction. Suspicious areas were evaluated using quantitative techniques. In seven of 11 patients with adenocarcinomas, focal increase in FDG uptake correlated with pancreatic tumor shown on CT scans or MR images. Of the remaining four, one had a previous Whipple procedure, another had completed chemotherapy, and in two the tumor was out of the limited region imaged; in these four patients, liver metastases were identified in three

[en] The authors independently read planar and single photon emission CT (SPECT) images of the chest and abdomen obtained with In-111 ZCE-025 monoclonal antibody in 12 patients with colorectal carcinoma and elevated levels of carcinoembryonic antigen (CEA). These were compared with CT examinations in all patients and either intraoperative findings or extended clinical follow-up. True-positive concordance was achieved in 19 of 21 lesions. The In-111 study was more conclusive in five. There were four false-positive and two false-negative results. The author's experience suggests that ZCE-025 imaging, including SPECT and Tc-99m Microlite hepatic subtraction, may improve the accuracy of lesion detection in patients with colorectal carcinoma and high levels of CEA

[en] A simple procedural change for the synthesis of [¹⁸F]FDG has been used to recover [¹⁸O]water by direct distillation. The [¹⁸O]water thus recovered is reusable to produce [¹⁸F]fluoride without further purification. The recovery of [¹⁸O]water is reliable and our results are based on over 300 routine FDG preparations. The [¹⁸F]fluoride present in the target water is converted to potassium fluoride during the distillation and will be available for further reaction to complete the synthesis of FDG. The same procedure can be used to recover [¹⁸O]water in similar situations where [¹⁸F]fluoride is converted to potassium fluoride and in turn used to react with kryptofix for labelling other precursors. (author)

[en] Scintiangiography of xiphopagus conjoined twins following sequential i.v. injection of Tc-99m sulfur colloid revealed the size, configuration, and anatomic point of fusion of the twins' common liver prior to surgery. Cross circulation was determined to be non-significant by this approach. The technique is presented, compared to other methods, and the benefit of sequential hepatic scintiangiography for xiphopagus conjoined twins is reviewed

[en] The dedicated wipe test counter (DWTC) is a commercial geiger-counter type instrument especially designed for wipe test counting. All samples are counted under the same physical conditions within 0.3 cm from a 2-mg cm-2 mica end-window geiger tube of 1.27 cm in diameter. The counting capabilities of the DWTC were tested for different radioisotopes in common use in the nuclear medicine laboratory. Since most of the imaging agents are 99mTc-based radiopharmaceuticals, an experimental efficiency factor, J = 3 cpm kdpm-1, was determined for this radioisotope by the manufacturer and stored in the counting system for default use. In addition, the formulation for the counting time needed to achieve a measurement with adequate level of significance (two standard deviations) and a background measurement time of 20 min was programmed in the firmware of the DWTC. With these parameters, the counting time for a 99mTc wipe (threshold of 2000 dpm) becomes 1.88 min for a background level of 10 cpm. The counting time increases to 3.25 and 4.80 min for the respective background levels of 20 and 30 cpm while the threshold is kept the same. In practice, we were able to measure activities as low as 0.7 kdpm for 99mTc and 0.09 kdpm for 131I. Linearity was maintained for a wide range of activities for all tested radioisotopes. The DWTC was found to be simple to operate and satisfies all requirements for performing wipe tests in the nuclear medicine laboratory