''Gender gap'' in multiple sclerosis: magnetic resonance imaging evidence

The authors evaluated the gender difference in the magnetic resonance imaging characteristics of the lesions occurring in the brain of 413 multiple sclerosis (MS) patients. Men had fewer contrast-enhancing lesions (P = 0.01), but a higher proportion of lesions evolving into 'black holes' (P = 0.001), when compared with women. Thus, our data indicate that men with MS are prone to develop less inflammatory, but more destructive lesions than women. This study results provides support for a modulation of the MS pathological changes by gender.     

Mycetoma of the calf

 Actinomycetous infections typically involve either the head and neck or the extremities following a traumatic implantation. Classic clinical associations are draining sinus tracts. This case report describes the pathologic and MR findings of a relatively acute mycetomatous process involving the soft tissues. Pathologic findings in this case included an occasional granule composed of gram positive, thin branching elements. These and other findings were consistent with actinomycetes bacterium infection. The discussion centers around the use of MR, both with and without gadolinium, in evaluating this type of granulomatous infection. Infiltration of the adjacent subcutaneous tissues was easier to appreciate on both the T1-weighted images without gadolinium and the T1-weighted images with gadolinium when compared to the T2-weighted images. Signal characteristics as described in this case report may suggest a granulomatous process.     

Dynamic gadolinium-enhanced MRI in the detection of spinal arteriovenous malformations

Arteriovenous fistulae and malformations (AVFs and AVMs) of the spinal cord are rare, potentially treatable causes of progressive disability. Although a variety of MRI abnormalities has been described, the diagnosis rests on the findings on selective spinal angiography.Collecting T2^*-weighted MR images during the passage of a gadolinium bolus gives information about perfusion and blood volume. We carried out dynamic MRI in seven patients with vascular abnormalities (5 dural AVFs, 1 intramedullary AVM, 1 cryptic angioma) and in two patients without an AVM. High resolution T1- and T2-weighted sagittal images of the whole spinal cord were first obtained using a multiarray receiver coil. Sagittal radiofrequency spoilt gradient echo images (GE34/25, flip angle 10⁰) were then obtained during bolus injection of gadolinium-DTPA. Abnormalities were seen in all seven patients with AVFs or AVMs. In the patient with an intramedullary AVM and four of the five with dural AVFs transient signal reduction was seen within the perimedullary venous plexus during passage of the bolus. The findings correlated well with those from selective spinal angiography. We conclude that dynamic MRI offers a useful adjunct to angiography and may localise an arteriovenous shunt when conventional MRI fails to do so. In combination with high-resolution imaging of the entire spinal cord the technique may make myelography redundant; it is simple, well tolerated and can be carried out without significant time penalty.     

Leukemia clusters around nuclear facilities in Britain

He bas been retained for the defense by British Nuclear Fuelsplc in two suits in which leukemia and non-Hodgkin's lymphoma have been alleged to result from radiation exposures due to the operation of the nuclear reprocessing plant at Sellafield. This paper has been sent to the senior authors of the papers reporting clusters of leukemia or other malignancy in the vicinity of nuclear facilities in Britain and their comments invited. Subject to considerations of space and CCC style, these comments will be published as submited.     

Perfusion imaging by a flow-sensitive alternating inversion recovery (Fair) technique: Application to functional brain imaging

Perfusion is a crucial physiological parameter for tissue function. To obtain perfusion-weighted images and consequently to measure cerebral blood flow (CBF), a newly developed flow-sensitive alternating inversion recovery (FAIR) technique was used. Dependency of FAIR signal on inversion times (TI) was examined; signal is predominantly located in large vessels at short TI, whereas it is diffused into gray matter areas at longer TI. CBF of gray matter areas in the human brain is 71 ± 15 SD ml/100 g/min (n = 6). In fMRI studies, micro- and macrovessel inflow contributions can be obtained by adjusting TIs. Signal changes in large vessel areas including the scalp were seen during finger opposition at a TI of 0.4 s; however, these were not observed at a longer TI of 1.4 s. To compare with commonly used BOLD and slice selective inversion recovery techniques, FAIR and BOLD images were acquired at the same time during unilateral finger opposition. Generally, activation sites determined by three techniques are consistent. However, activation of some areas can be detected only by FAIR, not by BOLD, suggesting that the oxygen consumption increase couples with the CBF change completely. Relative and absolute CBF changes in the contralateral motor cortex are 53 ± 17% SD (n = 9) and 27 ± 11 SD ml/100 g/min (n = 9), respectively.     

MR imaging of the brain in patients with hepatic form of Wilson''s disease

The aim of this study was to detect the sites and frequency of possible lesions by brain magnetic resonance imaging (MRI; 1,5T) in a group of 16 neurologically asymptomatic patients with hepatic form of Wilson's disease (WD; seven untreated and nine under treatment). Abnormal MR findings of the brain were found in 75% of patients. Lesions in brain parenchyma were detected in all untreated, drug-naive patients and in 44% of treated patients. Abnormal signal in globus pallidus, putamen, and caudate nucleus was revealed in 86, 71 and 71% of treated and in 33, 33 and 22% of untreated patients, respectively. In five of eight patients with putaminal pathology (62.5%) and in four of seven patients with caudate nuclei involvement (57%), only proton density 2-weighted sequence (PDW) exhibited sensitivity for lesion detection, with both T1W and long echo T2W sequences being insensitive. This superiority of PDW sequence was even more pronounced in the group of untreated patients in whom 80% of putaminal pathology was visible exclusively on this sequence. The lower frequency of lesions in the group of treated in comparison with untreated patients indicated that they might be reversible in the course of chronic chelating therapy.     

Optic nerve injury demonstrated by MRI with STIR sequences

We studied nine patients with optic nerve injury associated with closed head trauma by magnetic resonance imaging (MRI) with short inversion time inversion recovery (STIR) sequences on 11 occasions from 4 days to 14 years after the injury: three studies were within 17 days and eight over 4 months to 14 years. MRI revealed abnormal high signal in 10 of the 11 injured nerves. MRI 4 days after the injury showed no abnormality.     

磁共振尿路成像对泌尿系疾病的诊断价值

目的评价磁共振尿路成像(Magneticresonanceurography,MRU)对泌尿系疾病的诊断价值。方法对36例泌尿系疾病患者进行MRU检查,并结合临床手术、病理资料和其他影像学资料进行回顾性分析。结果36例患者中,均有MRU阳性结果,3例肾盂、肾盏癌,4例前列腺癌,8例前列腺增生症,2例输尿管癌定性、定位明确;9例肾盂、输尿管移行段梗阻定位明确,定性有帮助;10例输尿管下段梗阻中6例诊断明确,4例未能确诊。结论MRU在泌尿系疾病的诊断中,对肿瘤的定位、定性参考价值较高,对尿路梗阻定位诊断有价值,对定性诊断帮助有其局限性。     

MR appearances of urinary bladder in amyloidosis associated with multiple myeloma

Amyloidosis led to thickening of the urinary bladder wall, with hypointensity in T2-weighted images, which was distinguished from multiple myeloma involvement. Received: 3 April 1995/Accepted: 7 August 1995