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Adult T-cell leukaemia (ATL) is a T-cell lymphoid neoplasm caused by human T-cell leukaemia virus type I (HTLV-I). Radiological findings in central nervous system (CNS) involvement have not been well characterised. We reviewed the MRI of 18 patients with ATL who developed new neurological symptoms or signs, and pathology specimens from a 53-year-old woman who died of ATL. MRI findings were divided into three categories: definite, probable, and other abnormal. Definite and probable findings were defined as ATL-related. The characteristic findings were multiple parenchymal masses with or without contrast enhancement adjacent to cerebrospinal fluid (CSF) spaced and the deep grey matter of both cerebral hemispheres, plus leptomeningeal lesion. One patient had both cerebral and spinal cord lesions. Other abnormal findings in eight patients included one case of leukoencephalopathy caused by methotrexate. The histology findings consisted of clusters of tumour cells along perivascular spaces, and scattered infiltration of the parenchyma, with nests of tumour cells. Leptomeningeal infiltration by tumour spread into the parenchyma and secondary degeneration of the neuronal tracts was observed. MRI was useful for detecting CNS invasion by ATL and differentiating it from other abnormalities. The MRI findings seemed to correlate well with the histological changes.

Purpose: To date, there have been no systematic reports examining cerebral lymphomas with perfusion-sensitive MRI. We sought to determine the characteristics of perfusion-sensitive MRI of these tumors. Method: Five primary and three secondary cerebral lymphomas were analyzed. None of the patients had a history of AIDS. Various areas of relative cerebral blood volume (rCBV) within tumor were analyzed, and maximum CBV ratios (CBV[tumor/ contralateral]) were identified for evaluation. Results: In three primary and three secondary cerebral lymphomas, maximum CBV ratios were

Purpose The purpose of this work was to assess the changes of signal intensity on constructive interference in steady state (CISS) 3D Fourier transformation (3DFT) MRI after administration of Gd-DTPA and to evaluate the efficacy of contrast-enhanced CISS-3DFT MRI to depict the seventh and eighth cranial nerves affected by vestibular schwannomas. Method All scans were carried out on a 1.5 T MR unit. First, an experimental study was conducted to evaluate the changes in signal intensity of the CISS-3DFT sequence in relation to the concentration of contrast medium. Second, nine consecutive patients with 11 vestibular schwannomas underwent CISS-3DFT imaging before and after contrast agent administration. Signal intensities of the tumors and nerves were measured and compared between the pre- and postcontrast images. Visualization of the facial and cochlear nerves was rated on pre- and postcontrast CISS imaging independently. Results On the phantom study, the CISS-3DFT sequence showed a constant increase in signal intensity as the concentration of Gd-DTPA increased. The contrast between the nerves and tumors significantly increased after contrast agent administration (from 0.1 to 9.0 as mean contrast-to-noise ratio). The ability to depict the nerves was also significantly higher for postcontrast CISS-3DFT imaging than for precontrast. Conclusion Although the CISS-3DFT sequence offers similar contrast as other heavily T2-weighted sequences, the signal intensity of contrast-enhanced tumors increased on CISS-3DFT imaging. Contrast-enhanced CISS imaging was valuable for evaluating the seventh and eighth cranial nerves affected by vestibular schwannomas.

Our purpose was to evaluate the relationships between the ratio of maximum relative cerebral blood volume (rCBV) (rCBV ratio = rCBV[tumor]/rCBV[contralateral white matter]) and histologic and angiographic vascularities of gliomas using the gradient-echo echoplanar MR imaging technique. We also evaluated the usefulness of rCBV maps for grading gliomas.We examined 30 patients with histologically verified gliomas. Gliomas were classified as glioblastoma, anaplastic glioma with enhancement, anaplastic glioma without enhancement, and low-grade glioma. The maximum rCBV ratio of each glioma was compared with both histologic and angiographic vascularities, and the relationship between the maximum rCBV ratios and each type of glioma was established.The maximum rCBV ratios of the gliomas significantly correlated with both histologic and angiographic vascularities (p.001). Mean values and SDs of maximum rCBV ratios of each type of tumor were 7.32+/-4.39 for glioblastomas, 5.84+/-1.82 for anaplastic gliomas with enhancement, 1.53+/-0.75 for anaplastic gliomas without enhancement, and 1.26+/-0.55 for low-grade gliomas. The maximum rCBV ratios of the glioblastomas were significantly higher than those of the anaplastic gliomas without enhancement (p = .002) and the low-grade gliomas (p.001). The maximum rCBV ratios of the anaplastic gliomas with enhancement were higher than those of the anaplastic gliomas without enhancement and the low-grade gliomas, but the differences were not statistically significant (p = .08 and p = .03, respectively).The results of perfusion-sensitive MR imaging with gradient-echo echoplanar technique correlated with both histologic and angiographic vascularities.

We used constructive interference in steady state (CISS) 3D Fourier transform (3DFT) MRI data sets to obtain three-dimensional (3D) virtual MRI endoscopic views of the intracranial cerebrospinal fluid (CSF) spaces, processing them with a commercially available perspective endoscopic algorithm. We investigated the potential of the intracranial virtual MRI endoscopy applied to visualisation of the pathology in 13 patients with surgically confirmed trigeminal neuralgia (3), hemifacial spasm (3), acoustic neuroma (3), suprasellar germinoma (1), Langerhans cell histiocytosis (1), lateral ventricle nodules (1) and pituitary dwarfism (1). All images were acquired using a 1.5-T imager employing a circular polarised head coil. The CISS-3DFT data sets were transferred to a workstation for processing with the perspective endoscopic algorithm. Postprocessing for virtual MRI endoscopy was possible for all data sets. The lesions in 12 patients, and their complex anatomical relationships with the surrounding structures, were well seen on the 3D images. A small acoustic neuroma in the internal auditory meatus was not seen using virtual endoscopy. Although virtual MRI endoscopy has limitations, it provides 3D images which cannot be acquired using any other procedure.

To prospectively compare diffusion-tensor magnetic resonance (MR) imaging anisotropy measurements of white matter (WM) regions in early and late treatment groups of Krabbe disease patients treated with stem cell transplantation.The study was approved by the Institutional Review Board and was compliant with Health Insurance Portability and Accountability Act; informed consent was obtained from the families of all patients. Patients with early-onset Krabbe disease (four girls and three boys) underwent diffusion-tensor MR imaging before and after stem cell transplantation. Fractional anisotropy (FA) values from serial studies were compared in patients who underwent transplantation at less than 1 month (early group, two girls and one boy) and those who underwent transplantation at 5-8 months (late group, two girls and two boys). FA values were measured in the genu and splenium of the corpus callosum, the frontal WM, and the internal capsule; were compared with those of five age-matched children in the comparison group (normal MR images and no proved neurologic disease); and were expressed as a ratio. Images obtained after transplantation were evaluated at approximately 1 (n = 7), 2 (n = 6), 3 (n = 1), and 4 (n = 1) years.Before transplantation, mean FA ratios in the early group for all four WM regions ranged between 97% and 117%. At 1 year, mean FA ratios at all locations were either 92% or 93%. At 2 years after transplantation, mean FA ratios were between 83% and 92%. In one patient imaged at 3 years, the mean FA ratio was 97%; in another patient imaged at 4 years, the mean FA ratio was 77%. Before transplantation, mean FA ratios in the late group ranged between 55% and 74%. Mean FA ratios were between 37% and 50% at 1 year after transplantation and between 36% and 39% at 2 years.All patients had decreases in FA ratios over time. The early group had higher initial FA ratios and lower subsequent decreases, which may indicate amelioration of the dysmyelinating process.

Our aim was to review the MRI appearances of primary intracranial germ-cell tumours (GCT). We reviewed the MRI studies of 32 patients: 19 with germinomas, five with teratomas, one with an embryonal carcinoma, five with mixed and two with malignant nongerminomatous GCT. Eleven were in the pineal region, 12 suprasellar, five in the both sites, two in the basal ganglia and two in the corpus callosum. Contrast-enhanced images were available for 27 patients. The solid parts of GCT were nearly isointense with grey matter on both T1- and T2-weighted images. In seven patients with nongerminomatous GCT high-signal components were found on T1-weighted images, representing haemorrhage, high-protein fluid or fat. Cystic components were detected in 17 of 27 patients; eight germinomas and all nine nongerminomatous GCT had cysts. The solid components of germinomas enhanced homogeneously in eight cases and heterogeneously in 10, while all nongerminomatous GCT showed heterogeneous enhancement. MRI features tumours can facilitate correct diagnosis of GCT, including histological subtypes.

A first-pass, contrast-enhanced three-dimensional (3D) magnetic resonance (MR) angiography with short acquisition time was performed for three consecutive cases with suspected spinal arteriovenous fistula (AVF). This MR technique demonstrated the feeding arteries and draining veins of the spinal dural AVF, and was very useful for the definite diagnosis of the lesions as a disease with arteriovenous shunt. With this MR technique, we could localize the feeding artery and shunt before conventional angiography. J. Magn. Reson. Imaging 2000;12:949–952. © 2000 Wiley-Liss, Inc.

Purpose: To investigate the MR dynamic patterns of neurohypophyseal germ cell tumors (GCTs) for differential diagnosis of infundibular diseases affecting young people. Material and Methods: Eleven patients with neurohypophyseal GCTs underwent dynamic MR studies with T1-weighted spin-echo (SE) or turbo SE techniques. Other infundibular lesions, including adenohypophysitis (n=3), Langerhans' cell histiocytosis (LCH, n=2), and 1 hemangioblastoma from von Hippel-Lindau disease, were also evaluated. Serial images were obtained every 15 s (turbo SE) or 30 s (SE technique) for 240 s after rapid injection of contrast medium. The dynamic patterns were analyzed quantitatively with the contrast medium enhancement ratio. Results: On dynamic MR images, GCTs typically showed a gradual enhancement increase with a peak between 105 s and 180 s, while two showed a relatively rapid increase. LCH and hemangioblastoma showed a dynamic pattern similar to GCTs, while adenohypophysitis demonstrated a sharp rise and a steeper wash-out with an obvious peak before 90 s. Conclusion: Typical dynamic pattern of GCTs was the gradual enhancement increase without wash-out. Dynamic MR imaging can distinguish GCTs from adenohypophysitis, but is not useful for differentiation from LCH.

The degree of tumor malignancy generally correlates to tumor grade, and the direct measurement of tumor vasculature is desired. Dynamic susceptibility contrast magnetic resonance imaging can provide relative cerebral blood volume and, therefore, is one of the most reliable methods to evaluate tumor vasculature in vivo. Tumor vessel size is extremely variable due to complex tumor angiogenesis, and the gradient-echo echo-planar imaging (GE-EPI) technique, which is sensitive to the total vascular bed, is well suited for this purpose. As many studies have shown, dynamic susceptibility contrast magnetic resonance imaging is more useful for grading glioma than conventional magnetic resonance imaging. We found that this technique can also provide supplementary information to differentiate between malignant lymphoma and glioma because the absence of tumor neovascularization of malignant lymphoma leads to low rCBV, which is in contrast to those of malignant gliomas. Indeed, this technique can be used for the differentiation of extra-axial tumors such as between meningioma and neurinoma. Recently, this technique has been focused toward determining the stereotactic biopsy site, monitoring the embolization of effect in meningioma, or evaluation of treatment effects after radiation therapy. However, the value of tumor rCBV is affected by many conditions such as the T1 relaxivity effects of gadolinium in the extravascular space. To establish the usefulness of this technique, further examination will be needed.

PURPOSE: To compare qualitatively and quantitatively the contrast of brain lesions detected with fluid-attenuated inversion-recovery (FLAIR) and intermediate-weighted sequences at magnetic resonance (MR) imaging. MATERIALS AND METHODS: In this prospective study, 47 patients suspected of having a brain lesion underwent MR imaging with FLAIR, intermediate-weighted, and T2-weighted sequences. Qualitative assessment was performed of lesion conspicuity, detection, overall image artifact, and additional clinical information. Contrast and contrast-to-noise ratio (CNR) were calculated between lesions and the normal brain or cerebrospinal fluid (CSF). RESULTS: FLAIR images were equal to intermediate-weighted images for overall lesion conspicuity and detection but were associated more often with image artifacts. Lesion-to-background contrast was significantly higher on FLAIR than on intermediate-weighted images. FLAIR images failed to demonstrate multiple sclerosis (MS) plaques located in the basal ganglia and brain stem. CONCLUSION: Although FLAIR images provided additional information in some cases, they did not have distinct advantages over intermediate-weighted images. When cases of MS are evaluated, intermediate-weighted images are preferable to FLAIR images. Except in cases of MS, either FLAIR or intermediate-weighted sequences should be added to T2-weighted sequences at MR imaging.