Biomedical subjects

Chiao-Yun Chen

Publications and source records attributed to Chiao-Yun Chen.

9 recordsLinked to original sources

PubMed2006

Differentiation of gastric ulcers with MDCT.

It is important to differentiate malignant from benign gastric ulcers (GUs) because the early detection of malignancy offers the best prognosis and is essential for planning optimal therapy. However, the differential diagnosis between a malignant and benign gastric ulcer is sometimes difficult, and remains a great challenge. Recent advances in multidetector row-computed tomography (MDCT) with three-dimensional imaging software and multiplanar reformatted (MPR) images provide a potentially powerful tool for noninvasive gastric evaluation. Virtual gastroscopy (VG) is helpful in the detection and evaluation of GU in the same way as gastroscopy. In comparison with gastroscopy, VG images can depict abnormal endoluminal lesions with a wider field of view and they have no blind point because retrospective reconstruction is available. MPR images allow the radiologist to choose the optimal imaging plane to accurately evaluate the change of the gastric wall around the gastric ulcer avoiding partial volume averaging effects. This report describes the clinical usefulness of MDCT in differentiating malignant from benign GUs by using VG and MPR images.

Contrast Media↗

PubMed2006

Early response of hepatocellular carcinoma to transcatheter arterial chemoembolization: choline levels and MR diffusion constants--initial experience.

PURPOSE: To prospectively investigate the apparent diffusion coefficient (ADC) and choline levels measured at hydrogen 1 ((1)H) magnetic resonance (MR) spectroscopy, to monitor therapeutic responses of hepatocellular carcinoma (HCC) to transcatheter arterial chemoembolization (TACE). MATERIALS AND METHODS: Institutional review board approval was obtained, and all patients and control subjects provided informed consent. Histologically proved large HCCs (>3 cm in diameter) were evaluated in 20 patients (16 men and four women; mean age, 59 years; range, 34-80 years) before TACE and 2-3 days after TACE. A control group of eight adults (five men and three women; mean age, 43 years; range, 24-76 years) with normal livers was examined by using the same protocol. Hepatic choline levels were measured by means of an external phantom replacement method, quantifying the peak at 3.2 ppm at (1)H MR spectroscopy. ADCs were measured for all lesions. A Wilcoxon rank sum test was used to compare absolute choline concentrations and ADCs at baseline between HCCs and normal liver parenchyma. Changes in choline levels and ADCs in the tumors before and after TACE were analyzed by using the Wilcoxon signed rank test. RESULTS: The median preoperative choline level in patients with HCC (measured in 18 of the 20 patients) was 4.0 mmol/L (range, 0.0-17.2 mmol/L), which was significantly higher than that in patients with normal livers (n = 8) (median, 1.6 mmol/L; range, 0.0-2.1 mmol/L; P < .01). Among 18 patients with HCC, choline levels decreased significantly from before TACE to after TACE (P < .01). A significant increase in ADC from before TACE to after TACE in the 20 patients with HCC was also found (P < .01). CONCLUSION: Hepatic choline levels and ADCs may allow monitoring of therapeutic responses of HCC to TACE although larger, more definitive and quantitative studies with clinical end points are needed.

Adult↗

PubMed2006

Intramural duodenal hematoma and hemoperitoneum in anticoagulant therapy following upper gastrointestinal endoscopy.

OBJECTIVE: To report the unusual occurrence of intramural duodenal hematoma in a case on anticoagulant therapy, presenting as a complication of gastrointestinal endoscopy. CASE PRESENTATION AND INTERVENTION: A 74-year-old female patient developed nausea, vomiting and abdominal pain, and subsequently hypovolemic shock, 2 days after fiberoptic upper gastrointestinal endoscopy. The patient's international normalized ratio value was 2.7. A computed tomographic scan of the abdomen demonstrated duodenal wall thickening with intramural hematoma, as well as hematoma in the pararenal space and pelvic cavity. The patient was treated by conservative treatment that included correction of clotting abnormalities, blood transfusion, nasogastric decompression, hydration, and parenteral nutrition support. She resumed oral intake after 10 days of support treatment, recovering uneventfully. CONCLUSION: This case shows the possibility of development of an intramural duodenal hematoma in patients on anticoagulant therapy, without biopsies being taken.

Aged↗

PubMed2005

Neural correlates of impulsive-violent behavior: an event-related potential study.

Impulsive-violent offenders are often less capable of controlling their behavior. A cued Go/No-go task was used to test the hypothesis that impulsive-violent behavior reflects a deficit in the ability to inhibit prepotent responses and could be reflected in the measurement of event-related potentials. Results showed that the amplitudes of the N2 component at Fz reflected different degrees of inhibition in impulsive-violent offenders compared with matched controls. The N2 amplitude (No-go minus Go) was significantly lower in the impulsive-violent offenders than in matched controls. The amplitude of N2 increased when effort was required to withhold the Go intention. A smaller N2 amplitude was seen in offenders, suggesting difficulties with inhibition of prepotent behavior.

Adult↗

PubMed2005

Quantification of choline compounds in human hepatic tumors by proton MR spectroscopy at 3 T.

The quantification of choline-containing compounds (Cho) in hepatic tumors by (1)H MR spectroscopy (MRS) is of great interest because such compounds have been linked to malignancy. In this study, a practical external phantom replacement method for the absolute quantification of hepatic metabolites is demonstrated. We performed experiments at 3 T using a body coil, and used an external phantom containing choline chloride for calibration. We first tested the quantification strategy to confirm its suitability in vivo using a phantom of known concentration and normal brain tissue. The results obtained after coil loading and T(1) and T(2) effects were corrected for were consistent with the known concentration and previously published values. To demonstrate its feasibility, we applied the technique to liver studies conducted on five normal volunteers and four patients with hepatocellular carcinoma, and one patient (also in the latter group) who had undergone post-transcatheter arterial chemoembolization (TACE). The Cho concentrations in the four patients were estimated to be 3.4, 6.3, 7.4, and 14.0 mM, respectively. These values are substantially higher than those obtained from the healthy volunteers (1.3 +/- 0.9 mM (mean +/- SD)). The results indicate that the proposed method is accurate and requires fewer tedious procedures for MRS; therefore, it may be a promising technique for evaluating response to treatment in liver cancer.

Brain↗

PubMed2005

Primary mesenteric lipoma causing closed loop bowel obstruction: a case report.

Primary mesenteric lipoma is rare, with fewer than 50 cases described in English-language literature, and those causing bowel obstructions are even more uncommon. The long stalk of the lipoma that caused secondary volvulus and rapid ischemic change in our patient is worth reporting because of its rarity and distinctive picture in emergency abdominal computed tomography.

Female↗

PubMed2004

Biliary cystadenocarcinoma associated with atrophy of the left hepatic lobe and hepatolithiasis mimicking intrahepatic cholangiocarcinoma: a case report.

Biliary cystadenocarcinoma and its benign counterpart, biliary cystadenoma, are rare hepatic cystic tumors arising from the hepatobiliary epithelium. We report the case of a 68-year-old Taiwanese woman who presented initially with acute cholangitis. A series of imaging studies including abdominal ultrasound, computerized tomography, endoscopic retrograde cholangiopancreatography, and percutaneous transhepatic cholangiography showed bilateral intrahepatic duct (IHD) and common bile duct (CBD) stones with IHD and CBD dilatation, and an ill-defined tumor within the atrophied left hepatic lobe. The patient underwent surgical resection of the tumor and choledocholithotomy. The pathologic diagnosis was biliary cystadenocarcinoma. We review this rare disease entity and discuss its unusual radiologic features mimicking intrahepatic cholangiocarcinoma.

Aged↗

PubMedDate not supplied

Effect of intravenous gadolinium-DTPA on diffusion-weighted magnetic resonance images for evaluation of focal hepatic lesions.

OBJECTIVE: Diffusion-weighted imaging (DWI) is usually performed before administration of intravenous contrast agents. Repetition of DWI is occasionally necessary after contrast administration, but the effects of contrast material on DWI and apparent diffusion coefficient (ADC) values in the abdomen have not yet been fully examined. The purpose of this work is to assess whether administration of gadolinium-based contrast material significantly affects DWI and ADC values at the focal hepatic lesions. METHODS: The results of DWI at 3.0 T (Signa VH3; GE Medical Systems, Milwaukee, WI) were examined in 20 patients (age range: 33-86 years, mean age = 68 years) who were evaluated by means of a hepatic protocol at our hospital. Among the 20 patients studied, a total of 57 lesions were detected. Diffusion-weighted imaging was obtained using single-shot echo planar imaging with a b value of 500 s/mm. Patients were injected with 0.1 mmol/kg gadopentetate dimeglumine. The signal-to-noise ratio (SNR) of the liver and the hepatic lesions was examined, and the contrast-to-noise ratio (CNR) of each lesion was evaluated. In addition, the ADC values calculated from the DWI were compared before and after administration of contrast agent. The statistical significance of differences between precontrast and postcontrast administration was determined by use of a paired t test. RESULTS: The SNR and CNR of the DWI were not significantly different before and after administration of contrast agent. The ADC values tended to decrease after administration of contrast agent for each focal hepatic lesion and the liver, although they did not reach statistical significance. CONCLUSION: There was no significant difference before and after administration of contrast agent in the SNR or CNR of DWI. This indicates the feasibility of postcontrast DWI as a substitute for an unsuccessful precontrast-enhanced study in clinical practice.

Adult↗

PubMedDate not supplied

Ionic versus nonionic paramagnetic contrast media in differentiating between postoperative scar and recurrent disk.

BACKGROUND AND PURPOSE: In theory, ionic solutes diffuse more slowly in cartilage than do nonionic solutes. We tested the hypothesis that the contrast ratio between scar and recurrent disk fragment on MR images is greater after IV administration of an ionic rather than a nonionic contrast medium when a clinical dose is used. METHODS: Twenty patients who had recurrent lumbar disk herniation were enrolled in this study. The enhancement of epidural scar and recurrent disk fragment was measured at 5, 25, 40, and 50 min after IV injection of ionic and nonionic contrast media (0.1 mmol/kg) RESULTS: The enhancement was consistently and significantly higher for scar than for recurrent disk fragment, although the contrast ratio between scar and recurrent disk fragment decreased between 5 and 50 min after the administration of each contrast medium. No significant difference was shown between ionic and nonionic contrast media in the enhancement of recurrent disk fragment at 5, 25, 40, and 50 min after injection. The contrast ratio between scar and recurrent disk fragment was not a significant difference at 5, 25, and 40 min after administration of both contrast media. At 50 min, the contrast ratio between scar and recurrent disk fragment was 1.32 +/- 0.41 with ionic contrast medium and 1.20 +/- 0.56 with nonionic contrast medium. The difference was significant. CONCLUSION: The contrast ratio between scar and recurrent disk fragment is affected by the timing of the imaging. Images obtained immediately after the injection of each contrast medium showed a greater contrast ratio than did delayed images. In addition, with the ionic medium, this difference was greater than with nonionic medium at 5, 25, 40, and 50 min after injection and that difference reached statistical significance at 50 min.

Cicatrix↗