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Biomedical subjects

Y J Ho

Publications and source records attributed to Y J Ho.

At least 55 records · Page 3Linked to original sources
PubMed1999

Regional cerebral blood flow in patients with systemic lupus erythematosus.

Patients with systemic lupus erythematosus (SLE) with or without definite neuropsychiatric symptoms/signs were studied. Technetium-99m (Tc-99m) hexamethylpropylenamine (HMPAO) brain images were used to detect basal ganglion and cerebral cortex regional cerebral blood flow (rCBF) in patients with SLE with brain involvement. One hundred nine female patients with SLE were investigated using Tc-99m HMPAO brain images with fan-beam single-photon emission computed tomography (SPECT) and surface three-dimensional (3D) display. These patients were separated into 2 subgroups: group 1, 74 cases with definite neuropsychiatric symptoms/signs; and group 2, 35 cases without any neuropsychiatric symptoms/signs. Fan-beam SPECT demonstrated unilateral or bilateral hypoperfusion of basal ganglia or thalamus in 22% and 9% of patients in groups 1 and 2, respectively. Local hypoactivity anomalies were found in the brain cortex of 89% and 20% of patients in groups 1 and 2, respectively, using surface 3D display of the brain. In either group 1 or group 2 patients, parietal and frontal lobes are the most common areas and cerebellum and thalamus are the least common areas of brain involvement, respectively. This study suggests that in comparison with traditional brain imaging techniques, Tc-99m HMPAO brain imaging with fan-beam SPECT in combination with surface 3D display may provide objective information for detection of anomalies of rCBF in patients with SLE.

Adult↗
PubMed1999

Evidence for decreased salivary function in patients with reflux esophagitis.

It has been speculated that impaired salivary flow contributes to abnormal acid clearance of the esophagus in gastroesophageal reflux and results in reflux esophagitis (RE). To test this hypothesis, salivary functions were measured by quantitative salivary scintigraphies in patients with RE and in age- and sex-matched controls for comparison. Nineteen patients with RE and 36 healthy volunteers were enrolled in the study. After an intravenous injection of 5 mCi Tc-99m pertechnetate, sequential images of 1 min/frame were acquired for 30 min. The 1- and 15-min uptake ratios (UR) of the tracer in the four major salivary glands over the backgrounds were calculated. Saliva excretion was stimulated by 1 tablet of 200 mg ascorbic acid given orally 15 min after injection of the tracer, then the maximal excretion ratios (ER) of the four major salivary glands were calculated for the sialagogue stimulation. RE patients had lower values of 1st and 15th min UR and maximal ER than controls in the 4 major salivary glands. Poor salivary functions which represented a decrease in both UR and ER for patients with RE have been confirmed by quantitative salivary scintigraphy in this study.

Adult↗
PubMed1999

Using 99mTc-DTPA radioaerosol inhalation lung scintigraphies to detect the lung injury induced by consuming Sauropus androgynus vegetable and comparison with conventional pulmonary function tests.

Consuming Sauropus androgynus, a Malaysian plant, to reduce body weight began to become fashionable in Taiwan in 1994. According to some reports, people consuming this vegetable developed lung injuries. From July to November 1995, there were 81 nonsmoking women admitted to our hospital. Thirty-six cases had respiratory symptoms/signs and the remaining 45 had no symptoms/signs. We investigated these patients with pulmonary function tests (PFT) and technetium-99m DTPA radioaerosol inhalation lung scintigraphies (DTPA lung scan), a test to evaluate the lung ventilation and alveolar epithelial permeability. Eighteen patients had abnormal results in PFT, including obstructive type (n = 17), restrictive type (n = 5), and both (n = 4). There were 33 patients with abnormalities in DTPA lung scans, including unhomogeneous deposition of DTPA radioaerosols (n = 19), faster clearance of radioaerosols from lung (n = 26), and both (n = 12). Analyzing the results, we found that the patients with respiratory symptoms had a higher incidence of abnormal results of PFT and DTPA lung scans than the patients without respiratory symptoms (p < 0.05). Besides, we found that the DTPA lung scan was more sensitive than chest x-ray and PFT in detecting the lung injuries related to the consumption of S. androgynus (p < 0.05). Consuming S. androgynus can result in symptomatic or asymptomatic lung injuries, manifested as obstructive or restrictive ventilatory impairment, unhomogeneous radioaerosol distribution, and increased alveolar epithelial permeability. In addition, measurement of the 99mTc-DTPA clearance is the most sensitive test to detect the lung injuries caused by consuming S. androgynus.

Adolescent↗
PubMed1999

Acute paraquat intoxication: using nuclear pulmonary studies to predict patient outcome.

STUDY OBJECTIVES: Paraquat, a widely used herbicide, has been shown to cause severe and often fatal pulmonary fibrosis in humans and laboratory animals. Although paraquat is known to be directly cytotoxic to lung parenchyma, changes in routine lung scintigraphy results after acute paraquat intoxication have not been reported. The objective of this project was to investigate changes in lung ventilation (LV) and alveolar permeability (AP) in patients with paraquat intoxication, using 99mTc diethylenetriamine pentaacetate (DTPA) radioaerosol lung scintigraphy. DESIGN: Prospective, blinded study. SETTING: Nuclear medicine and toxicology departments in two university-affiliated teaching hospitals. PATIENTS OR PARTICIPANTS: Thirteen patients with acute paraquat intoxication were included in this study. Ten volunteers without acute paraquat intoxication were studied for comparison. MEASUREMENTS AND RESULTS: 99mTc DTPA aerosol inhalation and 99mTc macroaggregated albumin (MAA) perfusion lung scintigraphies were performed to determine LV, AP, and lung perfusion (LP). Five of the 13 patients (38%) had significant LV abnormalities; 3 of these 5 patients also showed abnormal LP. Of the 13 patients, 4 patients (31%) showed normal AP and survived. The remaining 9 patients (69%) showed abnormal AP and died. The mean values for AP were statistically different (p < 0.01) between survivor (0.72 +/- 0.16%) and nonsurvivor (1.52 +/- 0.40%) groups. Data from the normal volunteers and survival patients showed a 99mTc clearance slope < 1.00%. Data from patients who died showed a clearance slope > 1.00%. CONCLUSION: These results indicate that AP, measured by 99mTc DTPA aerosol inhalation lung scintigraphy, may help predict outcome in patients with paraquat intoxication.

Acute Disease↗
PubMed1999

Evaluation of regional cerebral blood flow with 99mTc-HMPAO in primary antiphospholipid antibody syndrome.

UNLABELLED: In this study, 99mTc-hexamethyl propyleneamine oxime (HMPAO) SPECT was used to evaluate the regional cerebral blood flow (rCBF) of the brain in patients with primary antiphospholipid antibody syndrome (PAPS). METHODS: Twenty-two women who were PAPS patients, aged 28-60 y, with mild neuropsychiatric manifestations and normal brain MRI findings were enrolled in this study. Brain HMPAO SPECT was performed to detect brain abnormalities. Meanwhile, serum anticardiolipin antibodies (ACA) and lupus anticoagulant (LA) were measured. RESULTS: HMPAO SPECT revealed hypoperfusion lesions in 16 of 22 (73%) PAPS patients. Cerebral cortex and cerebellum were the most and the least commonly involved areas, respectively. Eighteen of 22 (82%) and 14 of 22 (64%) patients had positive ACA and positive LA, respectively. ACA and LA results were related to HMPAO SPECT findings. CONCLUSION: HMPAO SPECT is a sensitive tool for detecting brain abnormalities in PAPS patients with only mild neuropsychiatric manifestations and normal brain MRI findings.

Adult↗
PubMed1998

Regional cerebral blood flow and glucose metabolism in Sjögren's syndrome.

UNLABELLED: Involvement of the brain is one of the most important complications of Sjögren's syndrome (SS). However, diagnosis of brain involvement in SS patients is difficult due to the lack of effective imaging methods. In this study, we compared two updated brain imaging modalities, 18F-2-fluoro-2-deoxy-D-glucose (FDG) PET and 99mTc-hexamethyl propyleneamine oxime (HMPAO) SPECT, in SS patients with neuropsychiatric manifestations, to detect glucose metabolism of the brain and regional cerebral blood flow. METHODS: Sixteen primary female SS patients with normal brain MRI findings were enrolled in this study. RESULTS: Technetium-99m-HMPAO SPECT findings were abnormal in 13 (81%) patients. Parietal and temporal lobes were the most common areas of brain involvement. Fluorine-18-FDG PET findings were abnormal in 3 (19%) patients. Temporal lobes were the most common areas of brain involvement. CONCLUSION: We conclude that brain HMPAO SPECT has better correlation with clinical manifestations than brain FDG PET or CT/MRI.

Adult↗
PubMed1997

A clinical study on physiological response in electroacupuncture analgesia and meperidine analgesia for colonoscopy.

Fifty-nine patients underwent consecutive colonoscopic examination with premedication of electroacupuncture analgesia (EA) were compared with conventional meperidine analgesia (MA) in pain relief and changes of neurotransmitters in serum. The results showed that analgesic efficacy of both groups were the same but with less side effects in the EA group (P < 0.01) especially in regard to dizziness. Serum concentration of beta-endorphin in both groups has a similar curve change at 4 different phases during colonoscopy. Serum concentration of epinephrine, norepinephrine, dopamine and cortisol showed no significant difference between these two groups. The analgesic effect of EA and MA during colonoscopic examination may be closely related to beta-endorphin production in serum.

Acupuncture Analgesia↗
PubMed1996

Hepatic angiomyolipoma: a report of two cases.

Two cases of rare hepatic angiomyolipoma are reported. Both represented with slight abdominal discomfort. The first patient complained of abdominal fullness, and had a normal physical examination and laboratory data. The second came with epigastralgia. Tenderness over right upper quadrant was noted and positive hepatitis B antigen was found. Ultrasound demonstrated hyperechoic hepatic lesion in both. Although diagnosis of hepatic angiomyolipoma was suspected by the radiological findings of ultrasound, CT, MRI, and angiography, it was confirmed by the histological presence of three mesenchymal components: abundant vessels, mature fat cells and smooth muscle cells. For fear of the coexistence of hepatocellular carcinoma, especially given the high prevalence area of Taiwan, surgical intervention was recommended if liver function permitted. Successful treatment was achieved by hepatic resection in both cases.

Adult↗
PubMed1994

CT of sebaceous adenoma of the parotid gland.

We report a large sebaceous adenoma of the parotid gland. CT showed soft-tissue mass in the lateral portion of the adenoma corresponding to the histologic finding of proliferation of sebaceous glands and fibrous stromal tissue. There were numerous fatty cysts (-65Hu). Some of the cystic component ruptured, and CT demonstrated leaking of fatty material into the parapharyngeal space.

Adenoma↗
PubMed1994

Comparison of five modalities in localization of primary aldosteronism.

BACKGROUND: The best response to surgical treatment of primary aldosteronism occurs in patients with an aldosterone-producing adenoma (APA), so pre-operative localization of the lesion is necessary. METHODS: A comparison was made of five localizing modalities-computed tomography (CT) of the adrenal gland, magnetic resonance imaging (MRI), dexamethasone suppression-131I-19-cholesterol adrenal scintiscan (DS, NP-59 adrenal scan), adrenal venography (venography) and adrenal venous sampling for aldosterone content (AVS) in 22 patients (12 women, 10 men) with primary aldosteronism; all had undergone operative confirmation within the past 9 years. The age at diagnosis ranged from 27 to 67 years (mean: 39.7). RESULTS: Unilateral adrenalectomy resulted in normal blood pressure without medication in 63.6% (14/22), and in improvement in 36.4% (8/22). Correct localization of the lesion was obtained in 95% (20/21) by CT, 100% (7/7) by MRI, 80% (12/15) by DS,NP-59 adrenal scan, 100% (6/6) by AVS and 78% (7/9) by venography. CONCLUSIONS: This experience would advocate CT of the adrenals as the initial means of localizing an APA on an outpatient basis because it is comfortable, safe, inexpensive and gives immediate results. The major role of MRI in the evaluation of adrenal adenoma should be complementary to CT. DS, NP-59 adrenal scan can be an adjuvant method for localization if CT scan results are not definitive. Adrenal venous catheterization with blood sampling for aldosterone content could be reserved for patients whose biochemical finging suggests the presence of an APA, and for whom CT or MRI of the adrenals and DS, NP-59 adrenal scan are inconclusive.

Adrenal Glands↗
PubMed1993

Disseminated tuberculomas in spinal cord and brain demonstrated by MRI with gadolinium-DTPA.

Intramedullary tuberculoma is rare, and there has been no report of concurrent intramedullary and intracerebral tuberculomas. We report a 30-year-old man with miliary tuberculosis of the lung. He suffered sudden paraplegia due to tuberculomas in the thoracic spinal cord and MRI showed more tuberculomas in the cervical spinal cord, brain stem, and cerebral and cerebellar hemispheres. The tuberculomas were isointense on the T1-weighted images, and hyperintense on the T2-weighted images; there was marked enhancement with intravenous gadolinium-DTPA. All the tuberculomas were very small 1 year after antituberculous chemotherapy.

Adult↗
PubMed1993

Myelography, CT and MRI in leukaemic infiltration of the lumbar theca.

A 25-year-old woman with acute lymphoblastic leukaemia, while in remission, developed paraparesis, with faecal and urinary incontinence. CT demonstrated increased density of the lumbar theca and enlargement of the nerve roots. Myelography showed complete obstruction below the L3 level. MRI showed increased signal intensity in the lumbar sac on T1 weighting, and the cauda equina enhanced with gadolinium-DTPA. Lymphoblasts were seen in the lumbar spinal fluid. After chemotherapy, these abnormalities resolved, as did the paraparesis and incontinence.

Adult↗
PubMed1993

Magnetic resonance imaging of cerebral hemiatrophy.

Twenty-one cases of cerebral hemiatrophy were studied using 1.0 T magnetic resonance imaging (MRI). In addition to showing the generalized decrease in volume of the cerebral hemisphere, three patterns of cerebral hemiatrophy were noted: pattern I, diffuse cortical and subcortical atrophy (six cases):pattern II, diffuse cortical atrophy associated with expanded porencephalic cysts (10 cases); pattern III, old infarction with necrosis in the territory of the middle cerebral artery (five cases). Pattern I and pattern II were believed to have resulted from hypoxic-ischemic encephalopathy with subcortical leukomalacia (SCL). In all 21 cases, MRI also showed Wallerian degeneration, hyperintensive signals in the posterior limb of the internal capsule on the T2-weighted images, and unilateral atrophy of the cerebral peduncle as far as the pyramid of the medulla oblongata. Structural changes such as thickness of the calvarium, dilatation of the ipsilateral side of the frontal and ethmoid sinus, and reduced size of the middle cranial fossa, were found in 13 cases. Thus, MRI is a useful method of examination in the diagnosis of cerebral hemiatrophy as it has the ability to highlight changes in the cerebral hemisphere, basal ganglion, thalamus and brainstem as well as highlighting bony structural changes.

Adolescent↗
PubMed1993

[The chemical shift imaging of liver].

Tissue characterization of different pathologies of the liver can be achieved by differences of relaxation time on changing of pulse sequences in magnetic resonance imaging (MRI). The usefulness of MRI for detection of liver disease is limited when the pathological change is subtle. Chemical shift is a fundamental characteristics in nuclear magnetic resonance (NMR). Chemical shift imaging (CSI) in MRI is based on the different Larmor frequency of proton in water and fat; and therefore it was able to enhance the effectiveness of pathology. For this study, Dixon's method was used to detect liver pathologies and compare its detectability with conventional pulse sequences. Forty cases were enrolled for study; they included 5 health volunteers, 15 hepatomas, 1 cholangiocarcinoma, 5 metastatic hepatic tumors and 14 fatty livers. In hepatic tumors, the lesion number, tumor margination and lesion-to-liver contrast in images were read and analyzed. Signal intensities, signal-to-noise ratio and contrast-to-noise ratio were compared, after measurement, from stored data. In fatty livers, the relative change of signal intensities in different areas of the liver in in-phase and out-phase images were compared with the back muscle and spleen to find where the fatty metamorphosis happened. CSI in spin echo or gradient echo pulse sequences was found to be adequate and valuable for detecting fatty liver, when compared with conventional MRI. CSI not only identified the extension of disease itself but also characterized the fatty change in liver parenchyma. Though CSI affords no further advantages than conventional pulse sequences for detection of hepatic tumors, occasionally, when the image quality of the conventional pulse sequences is not satisfactory or equivocal in lesion detection, the use of CSI might be attempted.

Fatty Liver↗
PubMed1993

Detection of renal allograft dysfunction with color Doppler flow ultrasound.

Thirty-six color Doppler flow (CDF) ultrasound studies were performed on 28 allograft kidneys to assess the capability of this technique in diagnosing transplant dysfunction through morphology and Doppler spectra. The composite score obtained from ultrasound images showed no statistical significance. Quantitative studies with Pulsatility Index (PI) and Resistive Index (RI) after localization of the arcuate, interlobar, segmental and main renal arteries by CDF revealed significant differences between normal functioning graft kidneys and the group of acute rejection, as well as the group of acute tubular necrosis (ATN) (P < 0.05). No apparent change was demonstrated in patients with chronic rejection. When PI was greater than 1.60 or RI was greater than 0.80, the transplant kidney was more likely to be rejected, though possibility of ATN should be considered. RI was easier to calculate, and correlated better than PI with the serum creatinine level. CDF expedited the Doppler spectrum study.

Adult↗
PubMed1992

Transcatheter arterial chemoembolization for hepatocellular carcinoma.

The factors relating to the duration of survival were analyzed for 329 cases of hepatocellular carcinoma (HCC) treated by transcatheter arterial chemoembolization (TACE) between January 1, 1983, and December 31, 1990. The cumulative survival value obtained was slightly higher but not statistically significantly higher in these 329 cases as compared with the 129 cases reported in 1989. This improvement was probably attributable to careful selection of the patients on the basis of the clinical Child's status and to improvement of the superselective angiotechnique used in the present study. The overall cumulative 1-, 2-, and 3-year survival values in this series were 50%, 25%, and 15%, respectively. The median duration of survival was 12.7 months (Kaplan-Meier method). The 1-, 2-, and 3-year survival values determined for 190 patients in Child's group A, for 95 patients in Child's group B, and for 44 patients in Child's group C were 60%, 30%, and 20%; 35%, 20%, and 10%; and 35%, 20%, and 10%, respectively. Analyses were also carried out according to the tumor's type and size, the integrity of the tumor capsule, and the patency of the portal vein. Our results disclosed that a better outcome in terms of the median survival period and the survival value was favored by the following factors: a single lesion measuring less than 5 cm in diameter, an intact capsule, a patent portal vein, and a good clinical status. It is also essential that all patients who have undergone TACE be periodically evaluated by ultrasonography, CT, and angiography to determine whether repeated chemoembolization is necessary.

Adult↗
PubMed1992

MRI of sequela of transverse myelitis.

A 4-year-old boy developed acute paraplegia, associated with sensory impairement and bowel and urinary dysfunction after an URI. MRI showed diffuse hyperintensity in T2WI in the spinal cord below the T6 level. Acute transverse myelitis was diagnosed based on the clinical presentations and MRI findings. The patient had poor recovery and two months later, a follow-up MRI disclosed a severe diffuse atrophic change of the spinal cord in the affected segment.

Acute Disease↗