Abnormal diffusivity of normal appearing brain tissue in multiple sclerosis: a diffusion-weighted MR imaging study.

OBJECTIVE: To assess whether water diffusivity in normal appearing brain tissue including white and gray matter of multiple sclerosis (MS) patients shown by diffusion-weighted imaging (DWI) differs from normal individuals. MATERIAL AND METHOD: Conventional MRI and DWI were performed in 37 multiple sclerosis patients and 31 control subjects, matched for age and sex. Quantitative diffusivity values were obtained from variable locations of normal appearing white and gray matter from both hemispheres by using a standardized region of interest template. +/- 2. 9 x 10(-5) mm2/s and 85.90 x 10(-5) +/- 2.45 x 10(-5) mm2/s) than normal control subjects (NAWM: 73.46 x 10(-5) +/- 1.77 x 10(-5) mm2/s and NAGM: 82.90 x 10(-5) +/- 0.91 x 10(-5) mm2/s) with p-value < 0.0001. CONCLUSION: Water diffusivity was higher in all NAWM regions, deep gray matter regions, and some cortical gray matter region of MS patients than normal controls. DWI can quantify the presence and extent of MRI-undetectable pathology in the normal appearing brain tissue that were the disease burden.

Helical CT assessment on hilar cholangiocarcinoma: comparison value of arterial phase and portovenous phase correlation.

OBJECTIVE: To study the correlation between the findings of hilar cholangiocarcinoma in hepatic arterial phase and portal venous phase. Attention will focus on whether the arterial phase imaging shows more detail than portal phase imaging. MATERIAL AND METHOD: Descriptive study design with retrospective data collection in Srinagarind Hospital, Khon Kaen University. CT scans of the upper abdomen of 34 patients with pathologically proven hilar cholangiocarcinoma between 2002 and 2004 were reviewed for: (1) characteristic of the tumor; (2) adenopathy, (3) arterial involvement, (4) venous involvement, and (5) degree of biliary involvement on both the hepatic arterial and portal venous phases. RESULTS: The correlation was high for characteristics of the tumor, the tumor enhancement pattern, and detection of adenopathy, degree of biliary involvement, and arterial involvement, but low for portal venous involvement which the portal venous phase detected better than the hepatic arterial phase. CONCLUSION: In hilar type cholangiocarcinoma, the portal venous phase yielded the best findings. Furthermore, it showed all findings that were seen in the hepatic arterial phase. According to the present study, the authors suggest doing a pre-contrast study then a portal venous phase imaging for evaluation and diagnosis of hilar type cholangiocarcinoma. There is no necessity to perform hepatic arterial phase in hilar cholangiocarcinoma.

Ultrasound screening for Opisthorchis viverrini-associated cholangiocarcinomas: experience in an endemic area.

In Thailand, liver cancer is the most common malignancy in males and the third most common among females. In the Northeast region, cholangiocarcinoma (CHCA) is the prevalent type, with Opisthorchis viverrini (OV), an endemic liver fluke, being considered the cause. We evaluated the role of ultrasound (U/S) for cholangiocarcinoma screening as part of a larger cohort to characterize the linkage between liver fluke infestation and CHCA in Khon Kaen (Northeast Thailand). Most people (77%) had normal U/S findings while only 0.5% had suspected CHCA; thus, U/S should be used primarily for those with the highest risk, presenting symptoms and/or being OV positive.

ADC measurements in various patterns of multiple sclerosis lesions.

OBJECTIVE: To determine the difference of mean apparent diffusion coefficients (ADC) among different patterns of focal multiple sclerosis (MS) lesions, to compare mean lesion ADC between 2 clinical subgroups and to correlate mean lesion ADC with disability. MATERIAL AND METHOD: Thirty seven patients (26 with relapsing-remitting multiple sclerosis (MS) and 11 with secondary-progressive MS) underwent both conventional and diffusion-weighted MR imaging of the brain. After creating ADC maps, region identification was done by using b = 0 images and T2-weighted images. ADC values were measured for MS lesions and (NAWM). RESULTS: A total of 288 lesions were identified on the images. The mean ADC for the lesions was significantly higher than that of NAWM Hypointense T1 lesions (n = 221) had a significantly higher mean ADC than isointense T1 lesions (n = 67) in both nonenhancing lesions (n = 250) and enhancing lesions (n = 38). The enhanced rim of ring-enhancing lesions (n = 18) had lower ADC than the central nonenhanced portions. Confluent lesions (n = 62) had a substantially higher mean ADC than discrete lesion (n = 226). Mean lesion ADC of secondary progressive MS was significantly higher than relapsing remitting MS. No correlation between mean lesion ADC and (EDSS) score was found CONCLUSION: Quantitative diffusion-weighted imaging is useful to elucidate the heterogeneous pathological substrate of MS in different patterns of MS lesions, to differentiate 2 major clinical subgroups.

Selective transcatheter embolization for treatment of post-traumatic hepatic artery and portal vein pseudoaneurysms.

The authors report a case of post-traumatic hepatic artery and portal vein pseudoaneurysms caused by blunt abdominal trauma, with multiple organ injuries including liver laceration. Abdominal spiral CT, CDS and DSA were performed to confirm the diagnosis. Both pseudoaneurysms were treated successfully with selective transcatheter embolization.

Prostatic abscesses: radiographic findings and treatment.

OBJECTIVE: To analyze the medical images and therapeutic strategies in patients with prostatic abscesses. METHOD: From April 1999 to August 2002, 12 patients with prostatic abscesses at Srinagarind Hospital, Khon Kaen, Thailand were reviewed The average age was 47 years (range 29 to 75). Diagnostic procedures included analysis of midstream urine, abscess fluid for pathogens and medical imaging with TRUS, CT and MRI. Therapeutic options were transrectal ultrasound-guided drainage or conservative medical treatment. RESULTS: Almost all patients had predisposing diseases. All patients showed hypo-echoic masses, plus internal septation in 5 cases. Most lesions were located at the central gland. Their sizes ranged from 0.5 to 2.75 cm (average 1.51 cm) in diameter. The main pathogen was B. pseudomallei. On TRUS imaging, patients with melioidosis had one or more hypo-echoic areas with internal septation, thickened wall and surrounding multiple small daughter abscesses. All abscesses resolved within 4 weeks, with no difference in the duration of treatment, despite different sizes or pathogens. CONCLUSIONS: Transrectal ultrasonography is useful in the diagnosis of prostatic abscess as well as in the guidance for aspiration and the drainage of such abscesses. Our data showed sonographic patterns in prostatic abscess, especially with melioidosis.

Intramural duodenal hematoma: a case report and review of the literature.

One case of intramural duodenal hematoma following blunt abdominal injury is presented. The radiographic examinations included plain abdominal films, ultrasonography, upper gastrointestinal series, computerized tomographic (CT) scan and magnetic resonance imaging (MRI). The patient was examined by gastroscopy and treated conservatively as an in-patient for 1 month. He was symptom free at the 3-month follow-up.