Extensive extraosseous localization of bone imaging agent in a patient with renal failure and rhabdomyolysis accompanied by combined hypercalcemia and hyperphosphatemia.

Four sequential Tc-99m pyrophosphate (PYP) imaging studies were performed in a 28-year-old man with high fever and exudate pharyngitis associated with renal failure. Radiotracer localization in the left ventricle (LV), lungs, kidneys, and skeletal muscles were seen in two, initial imaging studies. In the second and third imaging studies, area of increase in activity was seen in the left-sided bowel. In studies done two months later (in the third study), the radioactivity in the skeletal muscles was no longer seen. Studies obtained nine months (in the fourth study) after the first imaging showed less radiotracer localization in the LV, lungs, and kidneys as compared to that seen in the initial study. Myocardial necrosis and microcalcification were proved by LV biopsy. The exact mechanism of extraosseous bone-imaging agent localization is unknown. However, this phenomenon may be related to renal failure, rhabdomyolysis, hypercalcemia, hyperphosphatemia, or elevated parathyroid hormone. The Tc-99m PYP imaging study is useful and sensitive in the detection of extraosseous tissue calcification and monitoring of the disease process.

Additional extrarenal abnormalities seen in Tc-99m DTPA renal flow study.

During 99mTc-DTPA renal flow studies, extrarenal abnormalities have been found to include aortic abnormalities (aneurysm, ectasia, thrombosis, and abruptly decreased flow), splenic abnormalities (enlarged, small, or absent spleen), hepatic arterialization, and very slow circulation. In addition to the above abnormal findings, we add three more extrarenal pathologies that may be concomitantly found with renal flow study: pleural effusion(s), malignancy of the abdomen, and anemia and/or skeletal metastases.

99m-Tc HMDP bone scintigraphic findings of gouty arthropathy of both hands: extending soft tissue uptake adjacent to the joints.

The 99mTc hydroxy methylene diphosphonate scintigraphic findings of both hands are correlated to the radiographic findings in a patient with a 30-year history of gouty arthropathy. Scintigraphic differentiation of the type of arthritis on the basis of uptake pattern is difficult. However, the findings of rheumatoid arthritis are confined to the joints and usually the involvement is symmetrical. With gout there is a tendency toward asymmetrical, bilateral, multifocal joint involvement with areas of intense abnormal uptake; because of the associated soft tissue swelling, the intense uptake usually extends beyond the involved joints.

Disorders of gallbladder function related to duodenogastric reflux in technetium-99m DISIDA hepatobiliary scintigraphy.

Controversy exists over the relation between gallbladder dysfunction and the propensity for duodenogastric reflux. To evaluate this, Tc-99m DISIDA hepatobiliary imaging studies in 120 patients were reviewed, excluding patients who had had cholecystectomy or subtotal gastrectomy before scintigraphy. Serial images were obtained at 5, 10, 15, 30, 45, and 60 minutes and up to 24 hours, if indicated, after intravenous injection of 5-10 mCi of Tc-99m DISIDA. Normally, the liver, bile ducts, gallbladder, common bile duct, and bowel are visualized sequentially. Reversal of the normal sequence of gallbladder (GB) and bowel visualization indicates GB dysfunction; nonvisualization of the GB reflects cystic duct obstruction or absent GB function. Duodenogastric reflux is identified by radiotracer localized in the area just below or immediately adjacent to the tip of the left hepatic lobe. The intragastric location of the tracer may be verified by oral administration of 300 uCi of Tc-99m sulfur colloid. Twenty-nine patients had duodenogastric reflux between 10 and 60 minutes after injection. Of the 29 patients, 22 had a nonvisualized gallbladder, four had reversal of appearance of GB and bowel activity, and three had a normal study. GB dysfunction or nonfunction is more frequently demonstrated when duodenogastric reflux is present than with normal gallbladder function (P less than 0.001). In conclusion, gallbladder malfunction is closely associated with duodenogastric reflux, an abnormality that may be diagnosed noninvasively by Tc-99m DISIDA hepatobiliary scintigraphy.

Scintigraphic findings in acute gangrenous cholecystitis.

Nine patients who had surgically proven acute gangrenous cholecystitis and Tc-99m DISIDA scintigrams were reviewed retrospectively. Three types of scintigraphic findings were presented: 1) nonvisualization of the gallbladder, three cases; 2) nonvisualization of the gallbladder plus a rim sign, two cases; and 3) nonvisualization of the gallbladder plus an enlarged photon deficient area corresponding to the gallbladder fossa, four cases. A rim sign or an enlarged gallbladder fossa reflect the direct spread of inflammation from the gallbladder into the liver, causing impaired hepatocyte function. An enlarged gallbladder fossa may represent a later stage of a rim sign. Presumably tracer excretion by hepatocytes is affected initially by the inflammatory process, followed by impairment of tracer concentrating ability. Since the gallbladder may be suspended occasionally by a mesentery and not in contact with the liver, the secondary signs may be absent in acute gangrenous cholecystitis.

Iodine-123 HIPDM brain imaging findings in subacute spongiform encephalopathy (Creutzfeldt-Jakob disease).

Decreased perfusion of the left frontal and left temporoparietal cortex has been shown in [123I] HIPDM planar and single photon emission computed tomographic images of a patient with Creutzfeldt-Jakob disease (CJD) that was proven by brain biopsy and subsequent autopsy. An EEG showed diffuse, periodic discharges most prominent to the left hemisphere. Concurrent head computed tomography (CT), nuclear magnetic resonance (NMR), and cerebral angiographic studies were negative. Abnormalities demonstrated by [123I]HPDM imaging and by EEG may represent changes in neurophysiological and neurochemical status while cerebral angiography, CT, and possibly NMR register only anatomic or structural lesions. Premortem diagnosis of CJD depends on brain biopsy; the availability of the [123I] HIPDM study may provide regional cerebral neurochemical and neurophysiological information, guiding or avoiding brain biopsy in the appropriate clinical setting.

Radionuclide gastric emptying studies in patients with anorexia nervosa.

To evaluate gastric emptying in anorexia nervosa patients, 26 patients (17 females, two males, ranging in age from 13 to 40 yr) with upper GI symptoms ingested 150-200 microCi [99mTc]triethelenetetraamine polysterene resin in cereal and were imaged in the supine position. Data were accumulated at 5 min intervals to obtain the gastric emptying time (GET). The results of the studies were divided into three categories: prolonged, 13 patients; rapid, 11; and normal 3. Twelve of 13 patients with prolonged GET were given 10 mg metoclopramide i.v. injections; nine of the 12 patients had a good response and three had no response. Five of the nine patients underwent metoclopramide therapy and four of the patients showed benefit from the therapy. One patient discontinued metoclopramide therapy because of somnolence. Although all patients had subjective symptoms of gastric dysfunction, our results indicated only 50% had objectively prolonged GET, and another 50% showed normal or even rapid GET. Therefore, this radionuclide study enables quantitatively objective documentation of gastric emptying, separation of those patients with rapid or normal GET from those with prolonged GET, thereby avoiding the possible side effects from metoclopramide medication, and prediction of effectiveness of metoclopramide therapy in patients with prolonged GET.

Extensive gastric varices demonstrated by technetium-99m red blood cell scintigraphy.

An alcohol abuse patient complicated by chronic pancreatitis had splenic vein thrombosis leading to gastric varices and underwent abdominal Tc-99m red blood cell scintigraphy. First pass study, sequential images up to 1 hour, and a 2.5 hour image showed abnormal radioactivity in the left side of the abdomen and midabdomen. In 24 hour images, the high level of activity in the left side persisted; in addition, there was accumulation of radioactivity in the cecum, ascending, transverse colon, the splenic flexure, and descending colon. A splenectomy was performed and during the surgical procedure, a large dilated vein in the greater omentum was noted. It is reemphasized that delayed imaging up to 24 hours is important when the results of earlier images are equivocal or negative.

Secondary lymphoma of the thyroid in 99mTc-pertechnetate scintigraphy.

We present markedly decreased radioactivity in the right on a 99mTc-pertechnetate thyroid image in a patient with secondary lymphoma of the thyroid. At autopsy, the right lobe of the thyroid was replaced by lymphoma tissue. Markedly decreased radioactivity on the images may be explained by lymphoma cell infiltration or replacement of thyroid tissue with a resultant attenuation effect as well as interference of the trapping mechanism of the thyroid folicular cell. While cold areas in a radionuclide scintigram may present difficulties in interpretation, a high index of secondary lymphoma suspicion should be made by a combination of the scintigraphic findings and history of malignant lymphoma.

Tc-99m labeled triethelene tetraamine polysterene resin gastric emptying studies in bulimia patients.

To evaluate gastric emptying in patients with bulimia, 20 patients (all women, ranging in age from 12 to 49 years) with upper gastrointestinal symptoms ingested 150-200 microCi 99mTc-triethelene tetraamine polysterene resin in cereal and had scintigraphy in the supine position. Data were accumulated at 5 min intervals to determine the gastric emptying time (GET). The results showed that the gastric emptying time was prolonged in 12 patients and decreased in 8. All 12 patients with prolonged emptying time were given 10 mg metoclopramide intravenously; 9 of these had a good response and 3 had no response. Although all patients had subjective symptoms of gastric dysfunction, the results indicate that about 60% had delayed and 40% had rapid gastric emptying. The findings of two extremes of gastric emptying time remain to be explained, however, this enables (a) objective documentation of gastric emptying as this technique (b) can separate those patients with rapid GET from those with prolonged GET, who might benefit from metoclopramide.

Incidentally evaluating the status of renal function in technetium-99m DISIDA hepatobiliary imaging.

During hepatobiliary imaging studies, approximately 9% of Tc-99m DISIDA normally is excreted via the kidney. In routine 2, 5, 10, 15, 30, 45, and 60-minute images, the kidneys and urinary bladder are best visualized at 5-10 minutes and after 10-15 minutes, respectively. Nonvisualization of the kidney and/or urinary bladder may indicate renal dysfunction. To evaluate this hypothesis, Tc-99m DISIDA hepatobiliary images of 63 patients were correlated with concurrent serum BUN and creatinine levels (measured within 24 hours of the hepatobiliary study). Serum creatinine and BUN values were normal in patients with renal visualization. In patients without renal visualization, 17 of 19 had abnormal BUN and creatinine levels. The values of BUN and creatinine were significantly elevated (P less than 0.001) in patients without renal visualization when compared with those showing renal visualization. One patient had visualization of a single kidney due to a nephrectomy; in another, persistent visualization was due to hydronephrosis. Nonvisualization of the kidneys and/or urinary bladder suggests abnormal renal function, and asymmetric renal activity raises the possibility of renal disease.

Intrathoracic abnormalities demonstrated by technetium-99m sulfur colloid imaging.

Since the scintillation camera enables us to include lower thorax in the views obtained during Tc-99m colloid imaging of the liver and spleen, intrathoracic pathology may be identified as relatively cold or hot areas in the thoracic cavity. Eighteen patients who underwent Tc-99m sulfur colloid imaging during a one-year period were found to have intrathoracic pathology demonstrated either as photopenic areas or as areas of increased radioactivity. These patients' clinical data and the results of other diagnostic modalities, including autopsy, were correlated with the Tc-99m images. The intrathoracic disease processes recognized were bacteremia, two cases; pleural effusion, two cases; lung pathology, one case; and cardiomegaly, 13 cases. With the Exception of two patients with bacteremia who had substantial radiocolloid sequestration by the lung, all the other patients had hepatic dysfunction. The presence of compromised hepatic function allows the visualization of intrathoracic abnormalities: photopenia suggesting pleural fluid collection or an enlarged cardiac silhouette (either photopenia or increased radioactivity occupying a large space in the anterior view to yield cardiothoracic ratio of greater than 50%). Therefore, Tc-99m sulfur during colloid liver-spleen imaging, patients with hepatic dysfunction may incidentally demonstrate intrathoracic pathology, especially cardiomegaly.

Flip-flop phenomenon in radiohippuran renal imaging. A sign of obstructive nephropathy.

In the dynamic radionuclide brain study, decreased flow in one cerebral hemisphere during the arterial phase followed by relatively increased radioactivity as compared with the contralateral hemisphere has been termed the flip-flop phenomenon, and reflects the development of collateral circulation to the affected side. In I-131 Hippuran renal imaging, relatively decreased activity in one kidney frequently is observed during the initial phase of the study, and is followed by a gradual increase of radioactivity in the late images when compared with the contralateral kidney. To evaluate the significance of this renal flip-flop phenomenon, the studies from 23 patients with these findings were retrospectively compared with the clinical data and findings from other diagnostic studies (CT, ultrasound, intravenous pyelogram, autopsy). Partial obstruction of the renal collecting system was found in all 23 patients. The causes were various malignant tumors in nine patients (colonic carcinoma, three patients; transitional cell carcinoma, three patients; prostatic carcinoma, two patients; seminoma, one patient), ureteropelvic obstruction in three patients, papillary necrosis in one patient, and ureteral fibrosis in one patient. The flip-flop phenomenon reflects asymmetric renal tubular function with decrease (prolonged parenchymal transit time) in the affected kidney as a result of ipsilateral obstruction of the collecting system, while contralateral renal function remains normal or relatively normal. The presence of the flip-flop phenomenon in an I-131 Hippuran renal study suggests the existence of some degree of collecting system obstruction that has persisted long enough to result in renal parenchymal damage.

Disappearance of Tc-99m HMDP tumor uptake in oat cell carcinoma after irradiation and chemotherapy.

Extraosseous localization of bone-seeking radiopharmaceuticals has been reported in various tumors, presumably on the basis of active calcium deposition in the tumors. We report a case of oat cell carcinoma in which the initial localization of Tc-99m-HMDP in the tumor disappeared after irradiation and chemotherapy. The disappearance of tracer uptake coincided with regression of the mass as seen in the chest radiograph. This finding may have potential application in determining tumor response to anticancer therapy.

Demonstration of pulmonary mass defect by iodine-123 N,N,N'trimethyl-N'[2-hydroxy-3-methyl-5-iodobenzyl]-1,3-propanediamine lung imaging.

A patient whose huge lung mass was demonstrated as a large defect on I-123 N,N,N'trimethyl-N'[2-hydroxy-3-methyl-5-iodobenzyl]-1,3-propanediamine (HIPDM) lung imaging is presented. I-123 HIPDM, a lipophilic agent, is designed for early detection of abnormal cerebral perfusion. Since up to 50% of the administered agent is accumulated and perhaps metabolized in the lung, the radiopharmaceutical may be potentially useful for detection of pathology of the lung in addition to evaluation of pulmonary amine metabolism.