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Biomedical subjects

W J Shih

Publications and source records attributed to W J Shih.

At least 199 records · Page 11Linked to original sources

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.

Adolescent↗

Cholescintigraphy in the detection of cholelithiasis: a review of 23 cases and a case report demonstrating the sequential evolution of the appearance of the gallbladder defect.

Cholescintigraphy of cholelithiasis has been reported as a defect or photon deficient area in the gallbladder. We present the case of a patient with gallstones whose cholescintigraphic study showed a sequential evaluation of the scan appearance from a defect, to a septation, a hole, and finally a filled-in appearance. Cholescintigrams and histopathologic findings after cholecystectomy of another 22 patients with cholelithiasis were also retrospectively reviewed. The results of the study concluded that: cholelithiasis is rarely demonstrated by cholescintigraphy and nonvisualization of the gallbladder may be due to acute or chronic cholecystitis associated with cholelithiasis.

Cholecystitis↗

111In-chloride thorax scintigraphic study for demonstration of pulmonary edema: canine model.

Pulmonary edema induced by injections of oleic acid was demonstrated using 111In-chloride lung/heart image in five anesthetized dogs. The anesthetized dogs were positioned under a gamma camera interfaced to a computer. After 111In-chloride IV injections, dynamic data were recorded at 1 frame/min before and after induced pulmonary edema. The computer generated the curve of the lung-to-heart activity ratio; the ratio rose from 0.5-0.6 at baseline to 0.85-1.5 at the end of the study in the dogs. At the end of each study, the removed lungs demonstrated edematous fluid, and a few red blood cells were seen in the alveoli. The results indicating pulmonary edema exhibited in the 111In-chloride lung-to-heart ratio obtained from a computerized gamma camera were compatible with the pathological result. Since 111In-chloride instantly binds to plasma transferrin, an excellent intravascular imaging agent, leakage of this tracer into alveoli indicates loss of membranous wall competence. Pulmonary edema, as in the adult respiratory distress syndrome, is sometimes difficult to diagnose; and this 111In-chloride lung-to-heart imaging technique may be potentially useful.

Animals↗

Assessment of left ventricular diastolic function: comparison of Doppler echocardiography and gated blood pool scintigraphy.

Although left ventricular diastolic filling patterns can be examined by both Doppler velocity recordings and gated blood pool scintigraphy, few data exist regarding a comparison of these techniques. Therefore, Doppler echocardiography and scintigraphy were compared in 25 patients. Pulsed Doppler echocardiography was performed using an apical four chamber view with the sample volume at the level of the mitral anulus. Doppler measurements included peak velocity of the early diastolic filling wave, time to peak early diastolic velocity from both end-systole and end-diastole, diastolic time period and diastolic integrated velocity (early, atrial and total). The cross-sectional area of the mitral anulus and the left ventricular end-diastolic volume were estimated from measurements made on the apical four chamber view. Scintigraphic measurements included normalized peak filling rate, time to normalized filling rate from both end-diastole and end-systole, diastolic time period and relative diastolic filling during early and atrial filling. Doppler echocardiography and scintigraphy compared favorably in assessment of fractional filling during early diastole (r = 0.84) and atrial systole (r = 0.85), ratio of early to atrial filling (r = 0.83), diastolic filling period (r = 0.94) and interval from end-diastole to peak early diastolic flow (r = 0.88). Normalized peak filling rate and time to normalized peak filling rate from end-systole did not correlate closely by these two techniques. The differences in normalized peak filling rate may be explained by difficulties in estimating mitral anulus cross-sectional area and left ventricular end-diastolic volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Progression of mediastinal tuberculosis and superior vena caval obstruction demonstrated by gallium-67 citrate and radiocolloid liver scintigraphy.

Most causes of superior vena caval (SVC) obstruction are caused by malignant mediastinal neoplasms, especially bronchogenic carcinoma. Less frequently SVC obstruction results from a non-malignant lesion such as mediastinal goiter or tuberculosis. We present a case of mediastinal tuberculosis which progressively enlarged as shown in consecutive Ga-67 citrate studies. As a result, SVC obstruction developed, exhibited by radionuclide SV Cavagram, and demonstrated "hot" spots in the radiocolloid scans.

Aged↗

Diffuse thoracoabdominal radioactivity seen in bone imaging.

Diffusely increased radioactivity in the thoracoabdominal region (lower thorax and/or upper abdomen) occasionally has been observed when performing Tc-99m phosphonate bone studies. To assess the significance of activity in this finding, 1100 bone scintigrams were reviewed and the clinical data and other diagnostic imaging procedures were evaluated in these cases. With the exclusion of Tc-99m sulfur colloid liver-spleen scans 18 patients were found to have mild but diffuse increased radioactivity in the thoracoabdominal region either on the right or left. Clinical findings in these cases with abnormal uptakes were pleural effusions (six cases), hepatic colonic metastases (six cases), splenic metastases from bronchogenic carcinoma (one case), abdominal and peritoneal colonic metastases (one case), a massive metastatic squamous cell carcinoma (from lung) in the right lower chest (one case), and defective radiopharmaceuticals (three cases). Since the defective radiopharmaceuticals contained 5% of hydrolyzed reduced Tc-99m colloid by thin-layer chromatography, each of three patients received approximately 740 mu Ci of Tc-99m sulfur colloid. Factors to be considered in the interpretation of diffuse thoraco-abdominal activity from a bone agent should include splenic or hepatic metastases, a Tc-99m sulfur colloid splenic or hepatic metastases, a Tc-99m sulfur colloid study within the previous 24 hours, pleural effusion, faulty radiopharmaceuticals, and abdominal and peritoneal colonic metastases.

Abdomen↗

Ring-like uptake pattern of a skeletal imaging agent in a huge renal cell carcinoma.

A case of huge renal cell carcinoma with localization of a skeletal imaging agent is presented. Two unusual scintigraphic findings of bone agent localization in the tumor were observed: a ring-like configuration, and low-intensity uptake. The large ring-like appearance of the extraosseous radioactivity may reflect a bulky tumor with central necrosis and a less active calcification process.

Aged↗

False-positive radiocolloid liver image due to a subphrenic abscess.

A false-positive radiocolloid liver image can occur in various disease processes from extrinsic structures adjacent to the liver. A patient whose radiocolloid liver imaging showed an apparent photopenic area in the liver is presented; the abdominal CT demonstrated a low-density lesion located anterior to the liver, and at surgery the lesion was confirmed to be a right anterior subphrenic abscess.

False Positive Reactions↗

Incidental vertebral lesions identified during technetium-99m sulfur colloid liver-spleen imaging.

Three vertebral lesions, two compression fractures, and one metastasis in two patients, were incidentally demonstrated during Tc-99m sulfur colloid liver-spleen studies. Although the scintigraphic photon-deficient area could not be differentiated due to the metastasis and the compression fracture, the abnormal radiocolloid findings of vertebrae may lead to further studies using Tc-99m diphosphonate, Ga-67, radiographic studies, and/or biopsy.

Aged↗

Scintigraphic findings of multiple osteochondromas.

Multiple osteochondromas (hereditary multiple exostoses, diaphyseal aclasis, cartilagenous exostoses) are anomalies of bone development in which multiple cartilagenous exostoses grow out from the cortical surface, mainly involving ends of the long bones. While radiographic characteristics of multiple osteochondromas have been well documented, there is little information concerning the place of bone imaging in this disease. A patient with multiple osteochondromas whose skeletal scintigrams correlate with the concurrent radiographs is presented. Although there is no specific pattern scintigraphically, the abnormal, irregular increase in radioactivity at the end of the long bones may raise a possibility of this disease entity.

Adult↗

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.

Aged↗

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.

Humans↗

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.

Aged↗

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.

Adult↗

Localization of 99mTc-HMDP in hepatic metastases from colonic carcinoma.

To evaluate the significance and frequency of skeletal imaging agent localization in hepatic metastases from colonic carcinoma, scintigrams from 54 patients were retrospectively studied. Of 54 patients, 22 had hepatic metastases, and skeletal metastases were present in seven of 54. Six of the seven patients with skeletal metastases had concurrent hepatic deposits. Two patterns of bone agent localization in liver metastases occurred: diffuse and mild (10 patients) and ringlike in appearance (two patients). Twelve of the 22 patients had localization of skeletal imaging agent in hepatic metastases and extensive or large liver lesions. Concurrent serum calcium values for nine of 12 patients were reviewed; none had a high level of serum calcium. Among available plain films and /or CT scans of the abdomen for 21 of the 22 patients, only one patient with extensive colonic metastases had multiple calcifications shown on CT but not seen in plain films. The data indicate a high frequency of hepatic metastases in colon carcinoma (22/54, 40%) and a high frequency of skeletal imaging agent localization in the hepatic colonic metastases (12/22, 54.5%). Once skeletal metastases are observed, there are almost always hepatic metastases present (6/7). There was no relation between elevated serum calcium values and bone agent localization in hepatic deposits. The relation between skeletal imaging agent localization or radiographic calcifications and histopathology of colonic carcinoma was inconclusive. The presence of bone agent localization in a 99mTc hydroxymethylene diphosphonate (HMDP) bone study indicates colonic hepatic metastases that are substantially widespread and/or bulky.

Aged↗