Neuroradiology 0028-3940

Oppenheim, C.; Dormont, D.; Hasboun, D.; Bazin, B.; Samson, S.; Lehéricy, S.; Baulac, M.; Marsault, C.

doi: 10.1007/s002340050786pmid: 10450838

We report a retrospective analysis of MRI in 206 patients with intractable seizures and describe the findings in bilateral mesial temporal sclerosis (MTS) on fast spin-echo (FSE) and fast fluid-attenuated inversion-recovery (fFLAIR) sequences. Criteria for MTS were atrophy, signal change and loss of the digitations of the head of the hippocampus. In patients with bilateral MRI signs of MTS, correlation with clinical electro, volumetric MRI data and neuropsychological tests, when available, was performed. Bilateral MTS was observed in seven patients. Bilateral loss of the digitations and signal change on fFLAIR was seen in all seven. In three, bilateral atrophy was obvious. In two patients, mild bilateral atrophy was observed and in two others, the hippocampi were: asymmetrical, with obvious atrophy on only one side. Volumetric data confirmed bilateral symmetrical atrophy in five patients, and volumes were at the lowest of the normal range in the other two. The EEG showed temporal abnormalities in all patients, unilateral in five and bilateral in two. All patients had memory impairment and neuropsychological data confirmed visual and verbal memory deficits; two patients failed the Wada test on both sides. High-resolution T2-weighted FSE and fFLAIR sequences allow diagnosis of bilateral MTS, which has important therapeutic and prognostic implications.

Mittal, T. K.; Halpin, S. F. S.; Bourne, M. W.; Hourihan, M. D.; Perkins, T.; Sun, Y.; Tan, S.

doi: 10.1007/s002340050787pmid: 10450839

MRI is limited by movement artefact, even with current imagers, when examining a restless or claustrophobic patient. We prospectively analysed the images of 92 patients produced by a single-shot fast spin-echo (SSFSE) pulse sequence and compared them with conventional (FSE) and reduced-time fast spin-echo (RT-FSE) techniques, with regard to lesion detection and movement artefact in brain imaging. Images obtained in each case were independently reviewed and scored for overall diagnosis, number of lesions detected, and movement artefact. FSE showed 1217 lesions, RT-FSE 1137, and SSFSE 1044. This discrepancy arose mainly in patients with multiple sclerosis or small-vessel disease, since with SSFSE we were less able to separate small, adjacent low-contrast lesions than with FSE. Arbitrary movement scores were 36, 25 and zero respectively. There were, however, no clinically significant differences in overall diagnosis between the three techniques. SSFSE thus proved a reliable, fast, accurate method for obtaining T2-weighted images, and may be of particular use in the restless, claustrophobic or obtunded patient.

Cellerini, M.; Mascalchi, M.; Mangiafico, S.; Ferrito, G. P.; Scardigli, V.; Pellicanò, G.; Quilici, N.

doi: 10.1007/s002340050788pmid: 10450840

MRI and phase-contrast MR angiography (PC MRA) were obtained in 13 patients with angiographically confirmed intracranial dural arteriovenous fistulae (DAVF). Three- and two-dimensional PC MRA was obtained with low (6–20 cm/s) and high (> 40 cm/s) velocity encoding along the three main body axes. MRI showed focal or diffuse signal abnormalities in the brain parenchyma in six patients, dilated cortical veins in seven, venous pouches in four with type IV DAVF and enlargement of the superior ophthalmic vein in three patients with DAVF of the cavernous sinus. However, it showed none of the fistula sites and did not allow reliable identification of feeding arteries. 3D PC MRA enabled identification of the fistula and enlarged feeding arteries in six cases each. Stenosis or occlusion of the dural sinuses was detected in six of eight cases on 3D PC MRA with low velocity encoding. In six patients with type II DAVF phase reconstruction of 2D PC MRA demonstrated flow reversal in the dural sinuses or superior ophthalmic vein.

Cotter, D.; Miszkiel, K.; Al-Sarraj, S.; Wilkinson, I. D.; Paley, M.; Harrison, M. J. G.; Hall-Craggs, M. A.; Everall, I. P.

doi: 10.1007/s002340050789pmid: 10450841

We compared two methods of estimating the volume of 10 formalin-fixed brains using MRI. MRI was performed and total brain volume was then assessed using two distinct techniques: a stereological point-counting technique based on the Cavalieri principle, and an edge-tracing technique. The total brain volumes obtained using these two techniques were similar and correlated closely with each other (r = 0.97). Both methods could be optimised to a similar degree while maintaining the coefficient of error at an acceptably low level. However, the stereological assessment of brain volume required between 20 min and 30 min per brain, depending on the number of points per sampling grid, compared with 1 h per brain using the planimetric method. Thus, while planimetric and stereological approaches yield very similar results, the stereological method has the advantage of greater speed and, therefore, efficiency.

Deasy, N. P.; Jarosz, J. M.; Sarraj, S. Al; Cox, T. C. S.

doi: 10.1007/s002340050790pmid: 10450842

The intrasphenoid form of basal cephalocele is uncommon. We describe the clinical, CT and MRI findings in two cases presenting in middle age with persistent cerebrospinal fluid rhinorrhoea. Emphasis is placed upon the imaging findings which aid in discrimination of intrasphenoidal cephalocele from more common causes of a sphenoid sinus mass.

Nakagawa, N.; Katayama, T.; Makita, Y.; Kuroda, K.; Aizawa, H.; Kikuchi, K.

doi: 10.1007/s002340050791pmid: 10450843

Spinocerebellar ataxia type 6 (SCA6) is an autosomal dominant, slowly progressive cerebellar ataxia without multisystem involvement. We report a 57-year-old woman with genetically confirmed SCA6 who showed clinical features of olivopontocerebellar atrophy. Conventional T2-weighted and FLAIR MRI demonstrated high signal in the middle cerebellar peduncles, in addition to mild atrophy of the pons and cerebellum.

Uggowitzer, M. M.; Kugler, C.; Groell, R.; Lindbichler, F.; Radner, H.; Sutter, B.; Ranner, G.

doi: 10.1007/s002340050792pmid: 10450844

Metastasising chordomas are extremely rare and only four cases with drop metastases have been reported. We report a patient with an intracranial chondroid chordoma, typically involving the clivus, treated by repeated resection, percutaneous transluminal embolisation and radiosurgery. During follow-up with MRI asymptomatic intradural drop metastases were observed throughout the spine, with transgression of the intervertebral foramen, forming a “dumbbell”.

Bilgen, I. G.; Yunten, N.; Ustun, E. E.; Oksel, F.; Gumusdis, G.

doi: 10.1007/s002340050793pmid: 10450845

We present the radiological features of a 42-year-old man with long-standing inactive ankylosing spondylitis (AS), demonstrating that arachnoiditis is a cause of a cauda equina syndrome (CES) in this disease. CT showed a dorsal arachnoid diverticulum causing scalloped erosion of the laminae, and punctate and curvilinear dural calcification. MRI revealed adhesion and convergence of the cauda equina dorsally into the arachnoid pouch, causing the dural sac to appear empty canal. To the best of our knowledge, dural calcification on CT is a new finding in AS, which may be related to the CES. Our findings support the hypothesis that chronic adhesive arachnoiditis with subsequent loss of meningeal elasticity may be the main cause of CES in AS.

Yoon, H.-K.; Kim, S. S.; Kim, I. O.; Na, D. G.; Byun, H. S.; Shin, H. J.; Han, B. K.

doi: 10.1007/s002340050794pmid: 10450846

Childhood meningeal tumours are uncommon and mostly meningiomas. We reviewed the histological and radiological findings in meningeal tumours in six children aged 12 years or less (four benign meningiomas, one malignant meningioma and one haemangiopericytoma). Compared to the adult counterpart, childhood meningiomas showed atypical features: cysts, haemorrhage, aggressiveness and unusual location. MRI features varied according to the site of the tumour, histology, haemorrhage, and presence of intra- or peritumoral cysts. Diagnosis of the extra-axial tumour was relatively easy in two patients with meningiomas, one malignant meningioma and one haemangiopericytoma. MRI findings strongly suggested an intra-axial tumour in two patients with benign meningiomas, because of severe adjacent edema. Awareness of the variable findings of childhood meningiomas and similar tumours may help in differentiation from brain tumours.

Otsuka, H.; Harada, M.; Mori, K.; Hisaoka, S.; Nishitani, H.

doi: 10.1007/s002340050795pmid: 10450847

Histological abnormalities of the brain in autism have been investigated extensively. We studied metabolites in the hippocampus-amygdala (HA) region and cerebellum. We examined the right HA region and left cerebellar hemisphere of 27 autistic patients 2–18 years old, 21 boys and 6 girls and 10 normal children 6–14 years old, 4 boys and 6 girls, using the STEAM sequence. This sequence was used to minimise the influence of relaxation times. The N-acetyl aspartate (NAA) concentration was significantly lower (P = 0.042) in autistic patients than in normal children (9.37 and 10.95 mM, respectively). There was no significant difference in other metabolites. The correlation coefficient (r value) of NAA between the HA region and cerebellum was 0.616. The decreased NAA concentration may be due to neuronal hypofunction or immature neurons. The NAA concentration in the HA region and cerebellum may be related, because of neuronal circuits or networks.