Chun Jen Hsueh

Brain Injury After Acute Carbon Monoxide Poisoning: Early and Late Complications

OBJECTIVE The purposes of this article are to illustrate the variable CT and MRI features of carbon monoxide-induced brain injury and to discuss the underlying pathogenesis. CONCLUSION Carbon monoxide can produce different patterns of brain injury in the acute and delayed stages. CT and MRI are valuable in the delineation of disease extent and helpful for understanding the pathophysiologic mechanisms.

Salivary Glands: Echo-Planar versus PROPELLER Diffusion-weighted MR Imaging for Assessment of ADCs

PURPOSE To compare the image distortion and the quantification variation in parotid gland apparent diffusion coefficients (ADCs) on periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) versus echo-planar diffusion-weighted (DW) magnetic resonance (MR) images and to investigate the relationship between parotid gland ADC and parotid gland fat content. MATERIALS AND METHODS This prospective study was approved by a local institutional review board. Written informed consent was obtained from all 33 enrolled healthy volunteers (15 men, 18 women; mean age, 36.4 years +/- 11.8 [standard deviation]). All participants underwent 1.5-T non-fat-saturated and fat-saturated PROPELLER DW MR imaging as well as 1.5-T nonaccelerated and twofold-accelerated echo-planar DW MR imaging. Image distortion on the DW images was qualitatively scored, and parotid ADC was quantitatively analyzed. The correlation between parotid ADC and parotid fat content was evaluated by using linear regression analysis. Wilcoxon signed rank and t tests were used for statistical analysis, with Bonferroni correction applied for multiple comparisons. RESULTS Echo-planar DW images showed distortion, which was completely eliminated on the PROPELLER DW images. The mean parotid ADCs measured with non-fat-saturated PROPELLER (0.670 x 10(-3) mm(2) +/- 0.149), nonaccelerated echo-planar (0.892 x 10(-3) mm(2) +/- 0.128), twofold-accelerated echo-planar (1.088 x 10(-3) mm(2) +/- 0.124), and fat-saturated PROPELLER (1.307 x 10(-3) mm(2) +/- 0.217) DW imaging differed significantly from one another (P < .001 for all comparisons). Parotid ADC had a significant negative correlation with parotid fat content (x) measured at non-fat-saturated PROPELLER DW imaging: ADC = -0.0087x + 1.1173 (r = 0.80, P < .001). CONCLUSION PROPELLER DW imaging pulse sequences can yield distortion-free images for parotid ADC measurements and enable quantitative evaluation of the relationship between parotid ADC and parotid fat content. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2531082228/-/DC1.

Diffusion-tensor MR imaging for evaluation of the efficacy of hyperbaric oxygen therapy in patients with delayed neuropsychiatric syndrome caused by carbon monoxide inhalation

The purpose of this study is to assess the efficacy of hyperbaric oxygen therapy (HBOT) in patients with delayed neuropsychiatric syndrome (DNS) caused by carbon monoxide (CO) inhalation using diffusion tensor magnetic resonance (MR) imaging and neuropsychological test. Conventional and diffusion tensor brain MR imaging exams were performed in six patients with DNS immediately before and 3 months after the HBOT to obtain fractional anisotropy (FA) values. Six age‐ and sex‐matched normal control subjects also received MR exams for comparison. Mini‐Mental State Examination (MMSE) was also performed in patients immediately before and 3 months after the HBOT. A significantly higher mean FA value was found in control subjects as compared with the patients both before and 3 months after the HBOT (P < 0.001). The mean FA value 3 months after the HBOT was also significantly higher than that before the HBOT in the patient group (P < 0.001). All of the patients regained full scores in the MMSE 3 months after the HBOT. Diffusion tensor MR imaging can be a quantitative method for the assessment of the white matter change and monitor the treatment response in patients of CO‐induced DNS with a good clinical correlation. HBO may be an effective therapy for DNS.

Volume-Dependent Overestimation of Spontaneous Intracerebral Hematoma Volume by the ABC/2 Formula

Background: Although the ABC/2 formula has been widely used to estimate the volume of intracerebral hematoma (ICH), the formula tends to overestimate hematoma volume. The volume-related imprecision of the ABC/2 formula has not been documented quantitatively. Purpose: To investigate the volume-dependent overestimation of the ABC/2 formula by comparing it with computer-assisted volumetric analysis (CAVA). Material and Methods: Forty patients who had suffered spontaneous ICH and who had undergone non-enhanced brain computed tomography scans were enrolled in this study. The ICH volume was estimated based on the ABC/2 formula and also calculated by CAVA. Based on the ICH volume calculated by the CAVA method, the patients were divided into three groups: group 1 consisted of 17 patients with an ICH volume of less than 20 ml; group 2 comprised 13 patients with an ICH volume of 20 to 40 ml; and group 3 was composed of 10 patients with an ICH volume larger than 40 ml. Results: The mean estimated hematoma volume was 43.6 ml when using the ABC/2 formula, compared with 33.8 ml when using the CAVA method. The mean estimated difference was 1.3 ml, 4.4 ml, and 31.4 ml for groups 1, 2, and 3, respectively, corresponding to an estimation error of 9.9%, 16.7%, and 37.1% by the ABC/2 formula (P<0.05). Conclusion: The ABC/2 formula significantly overestimates the volume of ICH. A positive association between the estimation error and the volume of ICH is demonstrated.

Acute putaminal necrosis and white matter demyelination in a child with subnormal copper metabolism in Wilson disease: MR imaging and spectroscopic findings

Wilson disease (WD) that manifests solely with acute and severe neurological damage in the absence of hepatic disease and Kayser–Fleischer ring of the cornea is rare and difficult to diagnose at the acute setting. This report describes unusual diffusion and proton spectroscopic magnetic resonance (MR) imaging findings in a 12-year-old boy with WD who presented with hemichorea and subnormal copper metabolism. The MR imaging findings of lactate accumulation, decrease of N-acerylaspartate/creatinine (NAA/Cr) ratio and markedly increased apparent diffusion coefficient (ADC) value of the asymmetrical edematous putaminal lesions in the early stage were suggestive of acute necrosis with anaerobic metabolism of glucose leading to poor clinical outcome at follow-up.

Parasellar solitary fibrous tumor of meninges: magnetic resonance imaging features with pathologic correlation.

Solitary fibrous tumor (SFT) is a benign mensenchymal neoplasm of spindle-cell origin. The authors report the case of a 50-year-old man with SFT arising from the meninges of the left parasellar region with cavernous sinus involvement. The tumor was demonstrated isointense on T1-weighted and heterogeneously hypointense on T2-weighted magnetic resonance imaging (MRI) with strong contrast enhancement. The preoperative MRI diagnosis was meningioma or hemangiopericytoma. Pathological study revealed an SFT that stained positive immunohistochemically for CD34 and vimentin.

Primary hemangiopericytoma of the tibia: MR and angiographic correlation

Abstract The Magnetic Resonance Imaging (MRI) appearances of primary osseous hemangiopericytoma (HPC) have been rarely described. We report on a 46-year-old Chinese man with primary osseous HPC of the right tibia. The characteristic vascular distribution of this tumor, presenting with a ”spoke-wheel” appearance on MR images and with angiographic correlation, is described. Although not pathognomonic, this MR appearance may be an important finding in suggesting the diagnosis of osseous HPC.

T2-enhanced tensor diffusion trace-weighted image in the detection of hyper-acute cerebral infarction: Comparison with isotropic diffusion-weighted image

BACKGROUND AND PURPOSE Although isotropic diffusion-weighted imaging (isoDWI) is very sensitive to the detection of acute ischemic stroke, it may occasionally show diffusion negative result in hyper-acute stroke. We hypothesize that high diffusion contrast diffusion trace-weighted image with enhanced T2 may improve stroke lesion conspicuity. METHODS Five hyper acute stroke patients (M:F=0:5, average age=61.8+/-20.5 y/o) and 16 acute stroke patients (M:F=11:5, average age=67.7+/-12 y/o) were examined six-direction tensor DWIs at b=707s/mm(2). Three different diffusion-weighted images, including isotropic (isoDWI), diffusion trace-weighted image (trDWI) and T2-enhanced diffusion trace-weighted image (T2E_trDWI), were generated. Normalized lesion-to-normal ratio (nLNR) and contrast-to-noise ratio (CNR) of three diffusion images were calculated from each patient and statistically compared. RESULTS The trDWI shows better nLNR than isoDWI on both hyper-acute and acute stroke lesions, whereas no significant improvement in CNR. Nevertheless, the T2E_trDWI has statistically superior CNR and nLNR than those of isoDWI and trDWI in both hyper-acute and acute stroke. CONCLUSIONS We concluded that tensor diffusion trace-weighted image with T2 enhancement is more sensitive to stroke lesion detection, and can provide higher lesion conspicuity than the conventional isotropic DWI for early stroke lesion delineation without the need of high-b-value technique.

Diffusion-Weighted Magnetic Resonance Imaging of Spontaneous Venous Infarction and Cortical Hemorrhage Complicating Dural Arteriovenous Fistula

Dural arteriovenous fistula (DAVF) is an abnormal arteriovenous shunt that occurs in the dura matter within or near a dural sinus. The clinical manifestations vary. The authors report herein a rare case of type III DAVF presenting with coexisting intracranial hemorrhage (ICH) and venous infarction evidenced by computed tomography (CT) and diffusion‐weighted magnetic resonance imaging. Conventional angiography proved that the right middle meningeal artery and the occipital artery supplied the DAVF, with direct drainage into the cortical veins and superior sagittal sinus.

Work-related Musculoskeletal Disorders among Medical Staff in a Radiology Department

Background: The aim was to investigate the association between musculoskeletal disorders (MSD) and work-related risk factors in the medical staff in a single radiology department. Methods: The study was conducted in a radiology department with 107 staff members. A self-administered, modified Nordic Musculoskeletal Questionnaire was used to determine work practices, work descriptions, prolonged postures and movements, and body pain. Ninety-seven questionnaires (93.3% response) were returned for analysis. Results: The majority of respondents (77.3%) reported at least one episode of body pain during the previous year. Less than half (44.3%) of respondents were able to have time off during work shifts, and 42.3% worked more than eight hours per shift. Pain in the neck or shoulder (61.9%) was the most common complaint. There was a lower incidence of body pain for staff members who could arrange at least some time off during the work shift than for staff unable to do so. Conclusions: MSD among staff in the radiology department were related to work posture and movement. Time off taken during a work shift appeared to be a protective factor lowering the incidence of pain in all parts of the body.