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W J Shih

Publications and source records attributed to W J Shih.

At least 37 records · Page 2Linked to original sources
PubMed2001

Localization of (99m)Tc HMDP in an extraskeletal myxoid chondrosarcoma: a case report.

Extraskeletal myxoid chondrosarcoma of the lower extremity is rare, and slowly progressive. The authors of this article present the case of a man with progressive enlargement of the right thigh that underwent bone scintigraphy. The bone images showed a diffuse, moderate increase in uptake in the swollen right thigh. Despite chemotherapy, the patient died 28 mo later. At autopsy, it was confirmed that he had extraskeletal myxoid chondrosarcoma of the right thigh, which had metastasized to the upper arms, left scapula, lungs, pleurae, and right lower quadrant of the abdomen. The myxoid chondroid matrix, a major feature of the extraskeletal myxoid chondrosarcoma, is thought to account for the localization of the bone-imaging agent.

Aged↗
PubMed2001

Visualization in the ipsilateral lymph nodes secondary to extravasation of a bone-imaging agent in the left hand: a case report.

Axillary or elbow lymph node visualization after subcutaneous infiltration of the bone-imaging agent on a routine bone scintigraphy has been reported. The prostate cancer patient in this case report underwent bone scintigraphy; in 3-h bone images, the lymph nodes in the wrist, elbow, and axillary regions were simultaneously visualized. This was caused by extravasation of the intravenous injection of bone-imaging agent in the dorsal part of the patient's hand.

Aged↗
PubMed2001

Brain SPECT artifacts in patients having metallic cranioplasty.

OBJECTIVE: Over the past few years, we have performed several brain SPECT studies on patients who have had previous head trauma that required metallic cranioplasty. Transaxial images showed clearly defined photon-deficient areas extending from the brain tissue into the area of the scalp. To investigate the extent and pattern of this type of artifact, SPECT brain phantom studies were performed and compared with the patient studies. METHODS: SPECT brain phantom studies were performed using various metallic sheets to simulate metallic plates that were used for cranioplasty. RESULTS: Phantom studies using lead to represent tantalum plates were similar to our patient studies; that is, the photon-deficient area in normal brain tissue extended into the area where normal scalp activity would be. There was also increased tracer activity at the periphery of the photon-deficient area that extended to where normal scalp activity would be. This was similar to the patient studies and was not present on the phantom studies done without any metallic sheets present. CONCLUSION: One would expect photon-deficient artifacts caused by radiopaque metallic plates in brain SPECT studies. The patient and phantom studies demonstrate that an increased tracer activity artifact is also present at the periphery of the photon-deficient area that extends into the area of the scalp. Knowing the appearance of this type of artifact caused by radiopaque metallic plates in brain SPECT studies could be beneficial, especially in cases with poor patient history and lacking radiographic correlation.

Aged↗
PubMed2001

Duodenogastric reflux on (99m)Tc-tetrofosmin myocardial SPECT mimics left ventricle inferior wall reverse redistribution and falsely decreases ejection fraction: a case report.

99mTc-labeled myocardial perfusion agents are excreted through the hepatobiliary system and can be used in the evaluation of the duodenogastric reflux that occurs during routine cardiac imaging. The resultant gastric activity can overlap the inferior wall of the left ventricle (LV) and can thus mimic reverse redistribution of the LV inferior wall on dual-isotope SPECT. We report a case of significant gastric activity, which leads to abnormally low LV ejection fraction and akinesis of the LV wall in addition to the appearance of reverse redistribution. This case report illustrates that care should be taken in the performance and interpretation of (99m)Tc-tetrofosmin SPECT in the presence of duodenal reflux. This condition could be mistaken for reverse redistribution in the inferior wall of the LV with concomitant underestimation of the LV and regional wall motion.

Aged↗
PubMed2000

Effect of cholesterol-lowering therapy on coronary endothelial vasomotor function in patients with coronary artery disease.

BACKGROUND: Improved endothelial function may contribute to the beneficial effects of cholesterol-lowering therapy. METHODS AND RESULTS: In this randomized, double-blind study, we compared the effect of 6 months of simvastatin (40 mg/d) treatment with that of placebo on coronary endothelial vasomotor function in 60 patients with coronary artery disease. Simvastatin lowered LDL-cholesterol by 40+/-12% from 130+/-28 mg/dL (P<0.001). Peak intracoronary acetylcholine infusion produced epicardial coronary constriction at baseline in both the simvastatin (-17+/-13%) and placebo (-24+/-16%) groups. After treatment, acetylcholine produced less constriction in both groups (-12+/-19% and -15+/-14%, respectively, P=0.97). The increase in coronary blood flow during infusion of the peak dose of substance P was blunted at baseline in both the simvastatin (42+/-50%) and placebo (55+/-71%) groups, reflecting impaired endothelium-dependent dilation of coronary microvessels. After treatment, the flow increase was 82+/-81% in the simvastatin group and 63+/-53% in the placebo group (P=0.16). CONCLUSIONS: Six months of cholesterol-lowering therapy has no significant effect on coronary endothelial vasomotor function in the study population of patients with coronary artery disease and mildly elevated cholesterol levels. These findings suggest that the effects of cholesterol lowering on endothelial function are more complex than previously thought.

Adult↗
PubMed2000

Resolution of Ga-67 citrate uptake in the left neck mass of Hodgkin's disease and reversion of double scoliosis of cervical-thoracic and lower lumbar vertebrae.

A 6-yr-old boy underwent a total body Ga-67 citrate imaging study because of a large mass of Hodgkin's lymphoma in the left neck and the left anterior chest wall region. The images showed intense uptake in the left neck extending anteroinferiorly to the left upper chest wall corresponding to the left neck and chest region. In addition, there was mild cervical-upper thoracic scoliosis with convexity to the right and mild scoliosis of the lower lumbar scoliosis with concavity to the left. After three cycles of chemotherapy, in the follow-up Ga-67 citrate total body images seven months after his first Ga-67 citrate imaging, the intense uptake in the left neck and the left upper chest wall had been resolved and the scoliosis of the cervical-thoracic and lower lumbar spine had also been reversed to normal. This case shows that a Ga-67 citrate imaging study is useful for first diagnosis and subsequent monitoring of the therapeutic effects in a follow-up imaging. Also Ga-67 citrate imaging provided evidence that the scoliosis had been reversed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Demonstration of Achilles tendon rupture by three phase bone scintigraphy and MRI.

A man with complaint of soreness in the right medial ankle underwent three-phase bone scintigraphy; the results of the study suggested chronic active osteomyelitis or cellulitis, he was on antibiotics and was not experiencing any improvement. MR imaging confirmed Achilles tendon rupture. This case illustrates that a positive three-phase study is non-specific disease entity.

Achilles Tendon↗
PubMed2000

Abnormally increased uptake in the palm and the thumb as the result of a bone imaging agent injection into the radial artery.

The "glove" phenomenon is caused by arterial injection of a bone-imaging agent into the antecubital fossa. The authors describe a patient who incidentally received an arterial injection of bone-imaging agent into the right distal radial artery near the wrist, which resulted in a "hot" palm and thumb. The phenomenon of hot palm and thumb can be explained by normal anatomic-physiologic blood flow after radial artery injection. The radial artery contributes the blood supply to the thumb through the dorsal metacarpal arteries of the first metacarpals, and the dorsal carpal branch of the radial artery, a branch of the interosseous artery, and dorsal carpal branch of the ulnar artery form the dorsal carpal rete. The normal vascular anatomic-physiologic dynamic constituted the mixture and dilution effects after the distal radial artery injection that resulted in hot areas limited to the palm and thumb of the hand on bone scintigraphy.

Aged↗
PubMed2000

Early appearance of the inferior vena cava in a Tc-99m red blood cell first-pass study: a sign of superior vena cava obstruction.

A man with small-cell carcinoma of the lung underwent a Tc-99m red blood cell gastrointestinal bleeding study because he had a tarry stool. In his first-pass study, there was early filling of the radiotracer in the middle and lower portion of the inferior cava; in addition, the study revealed a distorted and distended inferior vena cava along with an abdominal aortic aneurysm. Collateral circulation of the trunk was noted in the subsequent bloodpool images. A subsequent radionuclide superior vena cava study confirmed superior vena cava obstruction just above the entrance to the right atrium. Contrast-enhanced computed tomographic scans of the chest showed that the superior vena cava was compressed completely by the mediastinal tumor mass and that collateral circulation was present. Development of collateral circulation after superior vena cava obstruction in this patient allowed venous blood to return to the right atrium through the inferior vena cava. Thus, early filling of the inferior vena cava on radionuclide first-pass studies of the abdomen may serve as a sign of superior vena cava obstruction.

Adult↗
PubMed2000

Single SPECT measures of cerebral cortical perfusion reflect time-index estimation of dementia severity in Alzheimer's disease.

UNLABELLED: To determine the relationship between cerebral cortical blood flow loss and the temporal development of the dementia in Alzheimer's disease (AD), SPECT was studied in a cross section of AD patients with a broad range of impairment. METHODS: Thirty patients with a diagnosis of probable AD had their mini-mental state examination scores transformed into time-index values to give an estimation of dementia severity relative to the developmental time course. SPECT images were obtained using 99mTc-ethyl cysteinate dimer and a 3-head camera. Cortical surface perfusion was analyzed, including modified Talairach standardization, to obtain cortical elements from the convexity (each representing about 0.25 cm2 at the surface, 6.6-mm cortical depth) referenced to the mean perfusion of the full greater cerebellar hemisphere. These element ratios were analyzed (individually and by averages of estimated Brodmann's areas and brain regions) using linear regression with the time-index value. RESULTS: For individual posterotemporal and inferoparietal Brodmann's areas (21, 22 and 39, 40, respectively) the correlation coefficients between cortical perfusion ratios and dementia severity ranged between -0.67 and -0.78 (P < 0.001). Perfusion ratios from these regions declined 2.5%-4.2% for each estimated year of progression. Prefrontal area perfusion showed less association with severity. Perfusion in primary cortical regions had no significant association with dementia severity. CONCLUSION: Cerebral cortical perfusion loss is temporally related to development of dementia. The spatial pattern of high, significant correlations between cortical perfusion and dementia severity shows a regional distribution that corresponds closely to the distribution of AD pathology described in autopsy studies.

Aged↗
PubMed2000

Estimating the long-term effects of storage at -70 degrees C on cholesterol, triglyceride, and HDL-cholesterol measurements in stored sera.

We estimated the effects of long-term storage at -70 degrees C on serum total cholesterol, HDL-cholesterol, and triglycerides in specimens that had been stored for up to 7 years. These estimates were made using measurements in serial specimens collected from the placebo control group of the Air Force/Texas Coronary Atherosclerosis Prevention Study over a period of approximately 5 years. We compared the group means for pairs of serial specimens taken at 6- and 12-month intervals, assuming that (a) a negligible placebo effect occurred between the serial specimen pairs; (b) in the absence of storage effects, the variation in the group means would reflect only normal biological variation and would not materially affect the group means for the serial specimens; (c) any systematic changes in these group means would reflect storage-related changes; and (d) storage-related changes are cumulative, i.e., the overall changes for a given storage period are the sum of the changes during previous storage periods. We observed average decreases of 2.0% per year for total cholesterol over 7 years and 2.8% per year in triglycerides for the first 5 years. HDL-cholesterol decreased by 1.3% per year, but this change was not statistically significant. This approach may be useful for estimating storage-related changes for studies in specimens stored for a period of years and for which stability data may not be available.

Blood Specimen Collection↗
PubMed2000

Spontaneous subcapsular and intrarenal hematoma demonstrated by various diagnostic modalities and monitored by ultrasonography until complete resolution.

A patient with acute right abdominal pain and nausea underwent various diagnostic imaging studies, including ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), technetium-99m DTPA renal study, and contrast arteriogram. The 99mTc renal study showed a linear photopenic area along the lateral cortical aspect of the right kidney and a focal cortical defect in the left kidney. These lesions corresponded to the findings of US, CT, MRI, and contrast angiography. Because of a suspected malignant mass, a CT-guided aspiration biopsy of the right kidney was performed that resulted in bloody fluid without malignant cells. The patient's condition was diagnosed as intrarenal and subcapsular renal hematoma. The patient was treated conservatively and followed up with CT and US studies. Sequential CT and US demonstrated gradual reduction of the size of the hematoma, and complete resolution was confirmed by US 1.5 years later. As long as underlying pathology can be ruled out, conservative management of spontaneous renal subcapsular hematoma is recommended.

Aged↗
PubMed2000

Urinary extravasation and leakage after renal transplantation: a case report.

OBJECTIVE: This case report illustrates urinary extravasation and leakage after renal transplantation, as documented by nuclear medicine renal imaging. The extravasation and leakage were identified only on images acquired after the patient voided. The surgical wound site dressings were found to contain radioactive contamination as well.

Adult↗
PubMed2000

Synergistic effects of clinically achievable concentrations of 12-O-tetradecanoylphorbol-13-acetate in combination with all-trans retinoic acid, 1alpha,25-dihydroxyvitamin D3, and sodium butyrate on differentiation in HL-60 cells.

Our recent studies demonstrated that 12-O-tetradecanoylphorbol-13-acetate (TPA) has pharmacological activity for the treatment of acute myelocytic leukemia patients. In the present study, we investigated the potential synergistic effect of all-trans retinoic acid (RA), 1alpha,25-dihydroxyvitamin D3 (VD3), and sodium butyrate (NaB) on TPA-induced differentiation in HL-60 human promyelocytic leukemia cells. The cells were treated once with these agents for 48 h or treated every 24 h for 96 h. Treatment of HL-60 cells once with TPA, RA, VD3, or NaB for 48 h resulted in concentration-dependent growth inhibition and cell differentiation. At clinically achievable concentrations, TPA (0.16 nM) increased the number of adherent cells and RA (0.1-1 microM) increased the number of nitroblue tetrazolium (NBT)-positive cells. The combinations of TPA (0.16 nM) with RA (0.1-1 microM), VD3 (1 nM), or NaB (100 microM) for 48 h synergistically increased differentiation as measured by the formation of adherent cells (P < or = 0.01). Moreover, cells treated with various combinations of low concentrations of TPA, RA, VD3, and NaB every 24 h for 96 h resulted in a further decrease in cell growth and an increase in differentiation. At clinically achievable concentrations, the strongest stimulation of differentiation was achieved in cells treated with a "cocktail" that combined TPA, RA, VD3, and NaB. The synergistic effect of combinations of TPA with RA or NaB at clinically effective concentrations on HL-60 cell differentiation suggests that the combination of these agents may improve the therapeutic efficacy of TPA for the treatment of acute promyelocytic leukemia (APL) patients. A differentiation "cocktail" that combines TPA, RA, VD3, and NaB may provide an even more effective strategy for improving the therapeutic efficacy of TPA and RA.

Anesthetics, Intravenous↗