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Biomedical subjects

W J Shih

Publications and source records attributed to W J Shih.

At least 235 records · Page 13Linked to original sources

Extrarenal abnormalities in Tc-99m-DTPA renal blood flow studies.

We observed extrarenal abnormalities during renal flow scintigraphy and retrospectively reviewed 90 patient studies to determine the types and frequencies of such abnormal findings. For each routine Tc-99m-DTPA renal flow study, we obtained nine 2-second sequential images, which included the heart, abdominal aorta, spleen and kidneys. Eighty abnormalities, observed in 62 patients, were divided into three categories: aortic, 37 cases (aneurysms, ectasia, thrombosis, tortuosity, and abruptly decreased flow); splenic, 40 cases (enlarged, small, or absent spleen); and miscellaneous, 3 cases (hepatic arterialization and very slow circulation). Other correlative studies including Tc-99m sulfur colloid-spleen scintigraphy, ultrasonography (US), CT, aortography, and surgical and/or autopsy findings were available for corroboration in 56 of 80 lesions.

Adult↗

A multi-centre, double-blind randomized study to assess the efficacy and tolerance of sulindac versus placebo in the symptomatic treatment of patients with upper respiratory tract infection.

A multi-centre, double-blind, randomized, placebo-controlled study was carried out to compare the efficacy and tolerance of sulindac (200 mg twice daily) with placebo in the symptomatic treatment for 7 days of 312 adult patients with upper respiratory tract infection. Investigators and patients rated sulindac superior to placebo in the overall evaluations of response to treatment, but the differences were not significant. In general, patients treated with sulindac had greater mean decreases from baseline scores for individual signs and symptoms than did placebo patients. Fever was relieved better by sulindac than by placebo. The mean decrease from baseline pain scores was also greater in the sulindac group. More patients receiving sulindac reported clinical adverse experiences compared with those on placebo, the most common adverse experiences reported being in the digestive system.

Adult↗

Adult polycystic disease of kidneys: a potential cause of false-positive 67Ga images.

A 56-year-old man with adult polycystic disease of the kidneys complicated by renal failure, hypertension, and bacteremia underwent bilateral nephrectomy because the enlarged kidneys compromised his gastrointestinal function and respiratory capacity. A scan using 99mTc-methylene diphosphonate demonstrated nonfunctioning kidneys, bilaterally. An unusual radioactivity pattern in the bowel in 67Ga scintigraphy was due to extreme renal enlargement and should be kept in mind to avoid misinterpretation.

Abscess↗

Open rib biopsy guided by radionuclide technique.

When abnormally increased radioactivity is seen in a rib or ribs by bone imaging in a patient with suspected or known malignancy, it frequently is difficult to differentiate fracture from metastatic disease. Histological examination of the lesion is crucial for diagnosis, staging, and planning of therapy. To assess the value of external localization of the site or sites of abnormal uptake in a rib as a guide for open rib biopsy, 10 patients (7 men, 3 women; age range, 34 to 68 years) with known or suspected malignancy were studied. With reference to the oscilloscope image, a cobalt 57 marker was placed on the skin overlying the focus of increased uptake, and the area of increased activity was marked on the skin as a guide to surgical resection. Of ten resected ribs, four showed metastatic disease and five had fractures. (One patient underwent two external marking procedures and two surgical procedures.) Rib biopsy was not performed in 1 patient because prior to the surgical procedure, a small subcutaneous nodule adjacent to the skin marker was excised and confirmed to be carcinoma. Appropriate courses of management (operation, irradiation, chemotherapy) were taken after the biopsies. The surgeon responsible for the biopsy should be present during the skin-marking procedure, and the area beneath the scapula and the region adjacent to the spine should be avoided. Our results indicate that the technique is a very useful aid for approaching open rib biopsies more precisely.

Adenocarcinoma↗

Pyogenic liver abscess presenting as a "warm" lesion in Ga-67 scintigram. A potential pitfall in interpretation.

In the Ga-67 scintigram, most pyogenic liver abscesses appear to be areas of high radiotracer concentration; rarely photon-deficient lesions may also occur. We present a 58-year-old man with sepsis and hepatic abscess, demonstrated by a Tc-99m BIDA study and a computerized tomogram of the body, showing homogenous radiogallium uptake throughout the liver in the Ga-67 images. To avoid missing such a "warm" lesion, it is emphasized that abdominal Ga-67 scintigrams for localization of a focal inflammatory lesion should be done along with Tc-99m sulfur colloid or Tc-99m BIDA scintigraphy.

Gallium Radioisotopes↗

Demonstrating alcoholic cirrhosis of the liver by Tc-99m BIDA scintigram.

Six patients with decompensated cirrhosis of the liver underwent Tc-99m BIDA studies. All demonstrated 1) persistently high blood pool activity in the heart, lung, and soft tissue, 2) slow hepatic tracer uptake, 3) prolonged liver-to-bowel transit time, and 4) visualization of an enlarged spleen. Four of the six patients demonstrated evidence of ascites and in one patient there were visible collateral veins of the abdomen. These findings are due primarily to hepatic dysfunction and retaining Tc-99m BIDA in blood pool because of Tc-99m BIDA exclusively hepatic excretion and little or no alternative renal excretion. All six Tc-99m sulfur colloid studies were performed concomitantly. Except for bone marrow uptake and reversal of the normal liver-spleen ratio of radioactivity, the imaging abnormalities observed with Tc-99m BIDA were similar to those seen by Tc-99m SC. It is concluded that with Tc-99m BIDA studies, three of six abnormal findings, as described, suggest a decompensated stage of cirrhosis of the liver.

Humans↗

Unusual persistence of Tc-99m MDP uptake in the incisional scar after thoracotomy.

Postoperative scar is one of the causes of extraosseous localization of Tc-99m phosphonate bone agents. Usually, an incisional scar will not be visualized in a Tc-99m phosphonate skeletal image two weeks after surgery. A case is reported with an unusually persistent localization of radiotracer in the scar of a thoracotomy seen in three consecutive bone images done beyond two weeks postoperatively. This patient suffered from "pulmonary insufficiency" before and after the thoracotomy. The abnormal radiotracer localization in the scar is presumably related to his pulmonary insufficiency, with resulting relatively delayed wound healing.

Aged↗

Diagnostic imaging in mediastinal thyroid tumor.

Various diagnostic imagings in nine patients with mediastinal goiters were presented. The clinical manifestations of these patients were various, from totally asymptomatic to severe dyspnea. Six of the nine patients underwent surgical intervention, three were follicular adenomas and three were nodular goiters. A chest radiograph (positive in seven out of nine patients) provided the most valuable initial localization of a goiter mass to the anterior, middle, or posterior compartment. Esophagograms (performed in four patients) showed compression of esophagus by the mediastinal mass. I-131 scintigraphy (performed in seven patients) was capable of detection of functional (in three patients) vs nonfunctional status of thyroid status (in four patients). Angiography (performed in five patients), characterized by anatomic continuity with cervical thyroid gland, calcifications, well-defined border of masses and/or contrast enhancement, offered important roles to direct a diagnosis of intrathoracic goiter. The computed tomography becomes increasingly important because all mediastinal goiters are not radioiodine avid.

Adenoma↗

Abdominal halo in Tc-99M DISIDA hepatobiliary scintigraphy: a sign of massive ascites.

An abdominal halo was demonstrated in a Tc-99m di-isopropyl imminodiacetic acid (DISIDA) hepatobiliary scintigram of a patient with a long history of alcohol abuse and liver disease complicated by massive ascites. This halo was not observed in the concurrent Tc-99m sulfur colloid study. Large amounts of ascitic fluid floated the liver, the bowel and the mesentery in the central abdomen forming an abdominal halo, a band-like clear zone around the abdominal organs. Severe hepatic dysfunction, resulting in prolongation of the blood pool phase in the Tc-99m DISIDA study, will cause exaggeration of this finding. When an abdominal halo is seen it should be considered a sign of massive ascites.

Abdomen↗

Sequential early and delayed myocardial 99mTc pyrophosphate scans: evaluation of diffuse myocardial uptake.

Of 114 pyrophosphate (PPi) myocardial studies, eleven were selected to assess the significance of diffuse uptake observed in the images obtained early (2-3 h) following injection and compared with delayed scintigrams at 6-24 h. From the results of the late studies the patients were divided into two groups; those with no or minimal residual activity in the delayed study (five cases) and those with approximately the same intensity of delayed scans as in the early study (six cases). No significant abnormalities in cardiac enzymes or the EKG (obtained within 24 h) were noted in the patients of the first group. Cardiac enzymes, EKG abnormalities, indicating myocardial damage, or decreased radionuclide LVEF dysfunction were found in the patients of second group. We concluded that a late image is required in a case of diffuse PPi myocardial uptake in the early image, and myocardial damage may be present if there is persistently diffuse uptake of PPi in the late image.

Diphosphates↗

Massive splenomegaly with multiple defects in a chronic myelogenous leukemia demonstrated by 99mTc-sulfur colloid scintigraphy.

A 99mTc-sulfur colloid liver-spleen scintigram of a 78-year-old woman with a painful, large mass in the left upper quadrant of the abdomen revealed massive splenomegaly with multiple areas of absent radioactivity. Splenectomy was performed and the removed spleen, weighting 2,010 g, was confirmed to contain acute and old infarcts with leukemic cell and megakaryocyte infiltration.

Aged↗

Discordant Tc-99m sulfur colloid and In-113m chloride blood pool images in patients with acute amebic liver abscess.

Using combined Tc-99m sulfur colloid and In-113m chloride eluate imaging, studies from 32 patients with proven amebic liver abscess were analyzed. The results revealed good perfusion of the amebic lesion in three, poor perfusion in 11, and absent perfusion in 18. These results appear to depend on abscess size and age. Images with In-113m seem to be better than those with Tc-99m sulfur colloid in depicting amebic liver abscess during antiamebic therapy. Overall, the In-113m images provide more precise information concerning abscess size and shape.

Acute Disease↗

Discordant 99mTc sulfur colloid and 67Ga-citrate scintigrams in Aspergillus splenic abscesses.

A 43-year-old man with acute undifferentiated leukemia developed high fever and stomatitis followed by severe abdominal pain after completion of a first course of chemotherapy. A 99mTc-sulfur colloid (SC) scan showed multiple, irregular defects in an enlarged spleen. A 67Ga-citrate scan showed uniform tracer distribution except for a large defect in the upper portion of the spleen. The size of the spleen in the 67Ga-scan was much larger than in the SC scan. At surgery an abscess cavity was found between the spleen and the greater gastric curvature with multiple smaller abscesses on the splenic capsule and throughout the splenic parenchyma. A hematoma was present in the upper pole of the spleen. The disparate splenic size and seemingly discordant distribution patterns of tracer in the 99mTc- and 67Ga-scans were fully explained by histopathological study of the surgically resected spleen.

Abscess↗

Extraosseous localization of 99mTc-MDP in ganglioneuroblastoma.

A 2 1/2-year-old boy with a posterior mediastinal ganglioneuroblastoma was evaluated by bone scintigraphy using 99mTc-DMP and showed a marked increased uptake in the tumor mass. Although a routine chest X-ray and body CT scan failed to demonstrate calcification, X-ray examination of the removed tumor specimen revealed small scattered calcification. The proposed mechanisms of the radiopharmaceutical localization in benign and malignant tumors other than calcification/mineralization are discussed. Regardless of the mechanism, localization of a bone scanning agent in a tumor provides a rapid, simple, and noninvasive means of demonstrating tumor size, configuration, and the relation of the surrounding structures to the tumor.

Bone and Bones↗