Adult cerebral malaria: prognostic importance of imaging findings and correlation with postmortem findings

PURPOSE: To correlate imaging abnormalities, clinical features, and postmortem findings in patients with proved cerebral malaria. MATERIALS AND METHODS: Twenty-one patients aged 17-50 years with cerebral malaria consented to undergo transverse nonenhanced (10-mm sections) and contrast material-enhanced (8-mm sections in posterior fossa and 10-mm sections in supratentorial region) CT on admission (n = 21) and on day 10 (n = 6), with thin sections (5 mm) obtained in the area of abnormality. All CT scans were evaluated for diffuse cerebral edema, focal parenchymal abnormalities, and hemorrhage. CT findings were categorized as normal, diffuse cerebral edema, and edema with thalamic hypoattenuation without or with cerebellar hypoattenuation. Spearman rank correlation test was performed. RESULTS: Initial scans were normal in seven patients with mild disease (median Acute Physiology and Chronic Health Evaluation [APACHE] II score of 7, median Glasgow Coma Scale [GCS] score of 10), and all survived. Of eight patients with diffuse cerebral edema (GCS > or = 8; median APACHE II, 21), six survived. Cerebral edema with thalamic and cerebellar white matter hypoattenuation was seen in five patients. All had GCS score of 6 or less, median APACHE II score of 26, and multiorgan failure; none survived. One patient (GCS = 6) had thalamic hypoattenuation without cerebellar lesions. He survived with mild residual hemiparesis. Diffuse petechial hemorrhages were seen in the cerebrum and cerebellum at autopsy in all seven patients who died. These petechial hemorrhages were not visualized on CT scans. CT findings did not correlate with degree of parasitemia. CONCLUSION: CT findings correlate well with level of consciousness and severity of disease but underestimate the extent of disease at pathologic examination. A normal CT scan indicates a favorable outcome, whereas cerebellar hypoattenuation portends a poor outcome.     

Cerebrotendinous xanthomatosis: the spectrum of imaging findings and the correlation with neuropathologic findings

PURPOSE: To describe imaging findings and their neuropathologic correlate in patients with cerebrotendinous xanthomatosis (CTX). MATERIALS AND METHODS: Computed tomographic (CT) and magnetic resonance (MR) images in 24 patients with symptoms (mean age at time of imaging, 37 years; mean disease duration, 18 years) were reviewed for site and frequency of brain, spinal cord, and Achilles tendon involvement. Two patients died, and imaging findings were compared with postmortem neuropathologic findings. RESULTS: Apart from nonspecific supratentorial atrophy and deep white matter changes, more typical hyperintense lesions were seen on T2-weighted images in the dentate nucleus (in 79% of patients), globus pallidus, substantia nigra, and inferior olive and extended into adjacent white matter as disease progressed. In these locations, lipid crystal clefts and perivascular macrophages, neuronal loss, demyelination, fibrosis, and reactive astrocytosis were found at microscopic examination. Hypointensity was sometimes found on T2-weighted images in the dentate nucleus and was related to deposition of hemosiderin and calcifications. CT depicted fewer lesions; all had low attenuation, except for the calcifications. Spinal cord MR imaging revealed increased signal intensity in the lateral and dorsal columns on T2-weighted images. Achilles tendon xanthomas displayed intermediate signal intensity on T1- and T2-weighted images. CONCLUSION: The typical pattern of MR imaging findings reflects the classic histopathologic findings and should prompt the diagnosis of CTX.     

Diffusion tensor MR imaging of high-grade cerebral gliomas

BACKGROUND AND PURPOSE: Optimizing high-grade glioma treatment requires the delineation of edematous and normal brain from tumor, perhaps by using potential differences in the absolute diffusion parameters of water. Our purpose was to determine whether mean diffusivity and diffusion anisotropic MR imaging data help in this differentiation. METHODS: Nine patients with high-grade cerebral glioblastoma underwent contrast-enhanced structural and diffusion tensor MR imaging before therapy. Tumor, edematous brain, and apparently normal white matter regions were determined on T2-weighted and contrast-enhanced T1-weighted structural images. Fractional anisotropy (FA) and were measured in each tissue type. Differences in these values among the tissue types were assessed with a standard analysis of variance. RESULTS: was highest in the necrotic tumor core (1825.38 +/-404.06) x 10(-6) mm(2)/s, followed by edematous brain (1411.23 +/- 322.31) x 10(-6) mm(2)/s, enhancing tumor core (1308.67 +/- 292.50) x 10(-6) mm(2)/s, enhancing tumor margin (1229.80 +/- 206.80) x 10(-6) mm(2)/s, and normal brain (731.53 +/- 35.21) x 10(-6) mm(2)/s. FA was highest in normal brain (0.47 +/- 0.08) and lowest in the necrotic core (0.09 +/- 0.03). was significantly different in enhancing tumor margins and edematous brain in all patients; FA was significantly different in only seven. These values were significantly different from those of normal brain in all cases in which they were measurable. CONCLUSION: values can be used to differentiate normal white matter, edematous brain, and enhancing tumor margins. Diffusion anisotropic data added no benefit to tissue differentiation. Further studies are required to determine if a value that corresponds to the limit of tumor invasion can be identified.     

Multimodal imaging in cerebral gliomas and its neuropathological correlation

Introduction

Concerning the preoperative clinical diagnostic work-up of glioma patients, tumor heterogeneity challenges the oncological therapy. The current study assesses the performance of a multimodal imaging approach to differentiate between areas in malignant gliomas and to investigate the extent to which such a combinatorial imaging approach might predict the underlying histology.

Methods

Prior to surgical resection, patients harboring intracranial gliomas underwent MRIs (MR-S, PWI) and ¹⁸F-FET-PETs. Intratumoral and peritumoral biopsy targets were defined, by MRI only, by FET-PET only, and by MRI and FET-PET combined, and biopsied prior to surgical resection and which then received separate histopathological examinations.

Results

In total, 38 tissue samples were acquired (seven glioblastomas, one anaplastic astrocytoma, one anaplastic oligoastrocytoma, one diffuse astrocytoma, and one oligoastrocytoma) and underwent histopathological analysis. The highest mean values of Mib1 and CD31 were found in the target point “T’ defined by MRI and FET-PET combined. A significant correlation between NAA/Cr and PET tracer uptake (−0.845, p < 0.05) as well as Cho/Cr ratio and cell density (0.742, p < 0.05) and NAA/Cr ratio and MIB-1 (−0761, p < 0.05) was disclosed for this target point, though not for target points defined by MRI and FET-PET alone.

Conclusion

Multimodal-imaging-guided stereotactic biopsy correlated more with histological malignancy indices, such as cell density and MIB-1 labeling, than targets that were based solely on the highest amino acid uptake or contrast enhancement on MRI. The results of our study indicate that a combined PET-MR multimodal imaging approach bears potential benefits in detecting glioma heterogeneity.     

Gd-EOB-DTPA-enhanced MR imaging findings of hepatocellular adenoma: correlation with pathological findings

We report a case of a 28-year-old woman with hepatocellular adenoma and correlate findings of pathology and magnetic resonance (MR) imaging with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) enhancement. In the hepatobiliary phase, the peripheral region of the tumor that corresponded with proliferating hepatocytes with steatosis showed slight hypointensity compared with the surrounding liver parenchyma, and the central region of the tumor that corresponded with cellular areas showed isointensity.     

CT and MR imaging findings of xanthogranulomatous cholecystitis: correlation with pathologic findings

The aim of this study was to evaluate CT and MRI findings in xanthogranulomatous cholecystitis (XGC) and to correlate the imaging findings with various pathologic parameters. The study included 13 patients with histopathologically confirmed XGC. The CT (n=13) and MRI (n=5) obtained in these patients were evaluated retrospectively. On CT, low-attenuation areas in the wall of XGC correlated with foam and inflammatory cells or necrosis and/or abscess in XGC. Areas of iso- to slightly high signal intensity on T2-weighted images, showing slight enhancement at early phase and strong enhancement at last phase on dynamic study, corresponded with areas of abundant xanthogranulomas. Areas with very high signal intensity on T2-weighted images without enhancement corresponded with necrosis and/or abscesses. Luminal surface enhancement (LSE) of gallbladder wall represented preservation of the epithelial layer. The early-enhanced areas of the liver bed on dynamic CT and MR images corresponded with accumulation of inflammatory cells and abundant fibrosis. Our results indicate that CT and MRI findings correlate well with the histopathologic findings of XGC.     

Susceptibility-based imaging of glioblastoma microvascularity at 8 T: correlation of MR imaging and postmortem pathology

BACKGROUND AND PURPOSE: Imaging methods are currently being optimized in an attempt to assess and monitor angiogenesis in vivo. The purpose of this investigation was to determine whether areas of apparently increased tumor vascularity, as identified on 8-T gradient-echo (GE) imaging of a known glioblastoma multiforme (GBM), corresponds to foci of increased microvascularity on histopathologic analysis. METHODS: We performed postmortem in situ, high-resolution GE 8-T MR imaging of the brain in a 53-year-old woman with GBM. Ten histopathologic specimens in the region of the tumor bed were studied by using hematoxylin-eosin and reticulin stains. MR and histopathologic results were assessed and compared for microvascular size and density. RESULTS: 8-T GE images showed small, penetrating vessels in the gray matter and white matter. The images, however, were partly inhomogeneous as a result of local magnetic field inhomogeneities adjacent to the skull base and aerated paranasal sinus structures. 8-T MR images demonstrated serpiginous areas of signal intensity loss, which were thought to represent areas of increased microvascularity. Areas of lower microvascularity in the tumor bed corresponded to areas of lower vascularity on histopathologic sections with smaller vessel diameters. There was concurrence between vascular size predicted by histopathologic analysis and 8-T MR imaging in nine of nine biopsy samples. Vascular density agreed in seven of nine biopsy samples. CONCLUSION: Our pilot data suggest that microvascularity in GBM can be identified by use of high-resolution, GE, 8-T MR imaging.     

Human fascioliasis: MR imaging findings of hepatic lesions

Our objective was to describe MR imaging findings of liver lesions in human fascioliasis. The MR imaging of the liver was performed in 29 patients with fascioliasis. Seventeen patients were women and 12 were men, with a mean age of 47.5 years (age range 17–75 years). Hepatic lesions were grouped into five types based on their signal characteristics. Three patients had normal imaging findings. One or more lesions were observed in the other 26 patients. The lesion types and the frequency of appearances were as follows: hyperintensity of the liver capsule on T2-weighted images (n=16, 55.2%); ill-defined slightly hyperintense areas on T2-weighted images (n=18, 62.1%); lesions which were hypointense on T1-weighted and hyperintense on T2-weighted images (n=10, 34.5%); hypointense on T1-weighted images and centrally hypo- or hyperintense, surrounded by peripherally less hyperintense area on T2-weighted images (n=4, 13.8%); and hypointense foci or ill-defined hypointense areas on T1- and T2-weighted images (n=10, 34.5%). We describe the MR imaging features of the disease. Our findings may help the differential diagnosis in which fascioliasis should be added to the list. Electronic Publication     

Hepatocellular carcinoma: correlation of MR imaging and histopathologic findings.

Seventy-two histologically proved nodular hepatocellular carcinomas (HCCs) were studied with magnetic resonance (MR) imaging at 1.5 T. Capsules were present in 56 of the 72 tumors. Thirty-seven capsules were depicted on T1-weighted spin-echo MR images, and 16 were depicted on T2-weighted MR images. Visualization was dependent on thickness and structure of the capsules. Of the 72 tumors, 36 had a mosaic pattern. A mosaic pattern was visualized in 12 of the 36 tumors on T1-weighted images and in 27 of the 36 tumors on T2-weighted images. Six tumors were determined to be histologic grade 1, and all were hyperintense on T1-weighted images, regardless of whether intracellular fat deposits were present. Four of the six grade 1 tumors were isointense on T2-weighted images. In contrast, grades 2 and 3 tumors had various signal intensities on T1-weighted images and most were hyperintense on T2-weighted images. Twenty-one of 32 tumors (66%) with focal areas of increased signal intensity on T2-weighted images had intratumoral dilated sinusoids at histologic examination.     

Familial arteriopathic leukoencephalopathy: imaging and neuropathologic findings.

We present the clinical, imaging, and neuropathologic data for a family with an autosomal dominant, nonhypertensive, progressive cerebral arteriopathy and leukoencephalopathy. Clinical presentation was characterized by progressive dementia, gait abnormalities, and, in some, Parkinson-like symptoms. MR abnormalities, consisting of white matter T2 hyperintensities and cystic-appearing T1 hypointensities, were present in seven family members. The basal ganglia also showed cystic abnormalities. Neuropathologic examination in two cases revealed numerous lacunar infarctlike lesions, extensive demyelination, and widespread hyalinization of arteriolar walls with karyolysis and granular deposits within the media. These findings appear to constitute further evidence of a genetically determined arteriopathic leukoencephalopathy.     

MR imaging of soft-tissue hemangiomas: correlation with pathologic findings

Soft-tissue hemangiomas have been described in MR imaging, but a histopathologic correlation to better understand the MR appearance has not been reported. Five patients with intramuscular soft-tissue hemangiomas were imaged in orthogonal planes on a 1.5-T system with spin-echo (SE) short-TR/TE sequences (600/20) and long-TR/TE sequences (2500/20-80). Complete intact surgical specimens were obtained, and gross and histopathologic findings were compared with MR findings. A striated-septated configuration with a high signal intensity on long-SE sequences (TE greater than 75 msec) correlated with endothelial-lined vascular channels separated by fibrous and/or fatty linear strands. An awareness of the morphologic MR pattern of soft-tissue hemangiomas may aid in recognition of these lesions.     

Postoperative fluid-attenuated inversion recovery MR imaging of cerebral gliomas: initial results

Fluid-attenuated inversion-recovery (FLAIR) imaging has shown to be a valuable imaging modality in the assessment of intra-axial brain tumors; however, no data are available about the role of this technique in the clinically important postoperative stage. The purpose of this study was to evaluate the diagnostic potential of FLAIR MR imaging in residual tumor after surgical resection of cerebral gliomas. Fifteen patients with residual cerebral gliomas were examined within the first 18 days after partial surgical resection of cerebral gliomas. The imaging protocol included T1-weighted spin echo, T2- and proton-density-weighted fast spin echo, and FLAIR imaging with identical slice parameters. T1 and FLAIR were repeated after contrast media application. Detection and delineation of residual tumor were the primary parameters of the image analysis. Additionally, the influence of image artifacts on the image interpretation was assessed. On FLAIR images residual signal abnormalities at the border of the resection cavities were observed in all patients, whereas T2- and T1-weighted images present residual abnormalities in 13 of 15 and 10 of 15 patients, respectively. The FLAIR imaging was found to be superior to conventional imaging sequences in the delineation of these changes and comparable to contrast enhanced T1-weighted imaging in the delineation of residual enhancing lesions. Because of protein cell components and blood byproducts within the resection cavity, FLAIR imaging was unable to suppress the cerebrospinal fluid (CSF) in 4 patients. After the decomposition of proteins and blood, CSF could again be completely suppressed and residual or recurrent tumors were clearly identified. Our preliminary study has shown that FLAIR may be a valuable diagnostic modality in the early postoperative MR imaging after resection of cerebral gliomas due to its better delineation of residual pathologic signal at the border of the resection cavity. It should therefore be integrated into the early and/or intraoperative MR imaging protocol.     

Role of advanced MR imaging modalities in diagnosing cerebral gliomas

The objective of this study was to evaluate the potential role of newly developed, advanced magnetic resonance (MR) imaging techniques (spectroscopy, diffusion and perfusion imaging) in diagnosing brain gliomas, with special reference to histological typing and grading, treatment planning and posttreatment follow-up. Conventional MR imaging enables the detection and localisation of neoplastic lesions, as well as providing, in typical cases, some indication about their nature. However, it has limited sensitivity and specificity in evaluating histological type and grade, delineating margins and differentiating oedema, tumour and treatment side-effects. These limitations can be overcome by supplementing the morphological data obtained with conventional MR imaging with the metabolic, structural and perfusional information provided by new MR techniques that are increasingly becoming an integral part of routine MR studies. Incorporation of such new MR techniques can lead to more comprehensive and precise diagnoses that can better assist surgeons in determining prognosis and planning treatment strategies. In addition, the recent development of new, more effective, treatments for cerebral glioma strongly relies on morphofunctional MR imaging with its ability to provide a biological interpretation of these characteristically heterogeneous tumours.     

Reliability of computed tomography: correlation with neuropathologic findings.

Findings on cranial computed tomography (CT) were correlated with autopsy findings in 58 cases with 129 lesions to determine CT reliability. When only CT scans of good quality were considered, there were no false positive cases. The number of false negative studies varied directly with lesion size: one of 42 lesions larger than 2.5 cm; four of 12 lesions between 1.5 and 2.5 cm; 12 of 15 between 0.5 and 1.5 cm; and all 21 of those smaller than 0.5 cm. Lesion size was undetermined in the remaining 18 casesbecause of the nature of the disease. While the series is small, these results suggest that the current detector threshold for CT may be in the range of 0.5-1.5 cm, although smaller lesions may be seen if there is substantial surrounding edema.     

Abnormalities of the brain in AIDS patients: correlation of postmortem MR findings with neuropathology

The ability of MR to detect CNS lesions in AIDS patients was evaluated by postmortem scanning of 10 formalin-fixed brains. Nine patients had premortem mental status changes and five had focal neurologic deficits. The brains were imaged and sectioned in corresponding planes. MR images showed atrophy in eight of the 10. All grossly identified lesions and areas of MR abnormality were histologically evaluated. Areas of infarction and necrosis associated with cytomegalovirus (CMV) or Toxoplasma gondii were seen as foci of increased signal intensity. Severe ventriculitis and focal gliosis were also visible by MR. Neither CT nor MR was able to detect diffuse CMV- or HIV-associated microglial nodules. Dementia without focal neurologic signs correlated best with the presence of diffuse microglial nodules at pathology. Our results demonstrate the usefulness of correlating postmortem MR imaging with neuropathology, and the relevance of postmortem findings to the interpretation of MR images in living patients.     

Deep white matter infarction: correlation of MR imaging and histopathologic findings

Focal and confluent areas of periventricular hyperintensity have been reported on magnetic resonance (MR) images in 30% of patients over 60 years of age. In order to better understand the pathologic basis of these lesions, the authors studied 14 formalin-fixed brains with MR imaging. Multiple focal areas of hyperintensity were identified in the periventricular white matter in three of the 14 brains studied (21%). Subsequent gross and microscopic pathologic examination of both hyperintense and normal-intensity areas was performed on 87 tissue sections. The larger lesions were characterized centrally by necrosis, axonal loss, and demyelination and therefore represent true infarcts. Reactive astrocytes oriented along the degenerated axons were identified at distances of up to several centimeters from the central infarct. This is called isomorphic gliosis and is associated with increased intensity on T2-weighted images that increases the apparent size of the central lesion.