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Diseases of the cerebral vasculature represent a heterogeneous group of ischemic and hemorrhagic etiologies, which often manifest clinically as an acute neurologic deficit also known as stroke or less commonly with symptoms such as headache or seizures. Stroke is the fourth leading cause of death and is a leading cause of serious long-term disability in the United States. Eighty-seven percent of strokes are ischemic, 10% are due to intracerebral hemorrhage, and 3% are secondary to subarachnoid hemorrhage. The past two decades have seen significant developments in the screening, diagnosis, and treatment of ischemic and hemorrhagic causes of stroke with advancements in CT and MRI technology and novel treatment devices and techniques. Multiple different imaging modalities can be used in the evaluation of cerebrovascular disease. The different imaging modalities all have their own niches and their own advantages and disadvantages in the evaluation of cerebrovascular disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

MR perfusion has shown abnormalities of affected WM in cerebral X-linked adrenoleukodystrophy, but serial data is needed to explore the import of such findings after hematopoietic stem cell transplantation. Our aim was to prospectively measure MR perfusion parameters in patients with cerebral adrenoleukodystrophy pre- and post-hematopoietic stem cell transplantation, and to correlate those measurements with clinical outcome.Ten patients with cerebral adrenoleukodystrophy prospectively underwent DSC-MR perfusion imaging at45 days pre- (baseline), 30-60 days post-, and 1 year post-hematopoietic stem cell transplantation. MR perfusion measurements in the 10 patients and 8 controls were obtained from the parieto-occipital WM, splenium of the corpus callosum, leading enhancing edge, and normal-appearing frontal white matter. MR imaging severity scores and clinical neurologic function and neurocognitive scores were also obtained. MR perfusion values were analyzed in the patients with cerebral adrenoleukodystrophy at each time point and compared with those in controls. Correlations were calculated between the pre-hematopoietic stem cell transplantation MR perfusion values and 1-year clinical scores, with P value adjustment for multiple comparisons.At baseline in patients with cerebral adrenoleukodystrophy, both relative CBV and relative CBF within the splenium of the corpus callosum and parieto-occipital WM significantly differed from those in controls (P = .005-.031) and remained so 1 year post-hematopoietic stem cell transplantation (P = .003-.005). Meanwhile, no MR perfusion parameter within the leading enhancing edge differed significantly from that in controls at baseline or at 1 year (P = .074-.999) or significantly changed by 1 year post-hematopoietic stem cell transplantation (P = .142-.887). Baseline Loes scores correlated with 1-year clinical neurologic function (r = 0.813, P.0001), while splenium of the corpus callosum relative CBV also significantly correlated with 1-year neurologic function scale and the neurocognitive full-scale intelligence quotient and performance intelligence quotient scores (r = -0.730-0.815, P = .007-.038).Leading enhancing edge measurements likely remain normal post-hematopoietic stem cell transplantation in cerebral adrenoleukodystrophy, suggesting local disease stabilization. Meanwhile, parieto-occipital WM and splenium of the corpus callosum relative CBV and relative CBF values worsened; this change signified irreversible injury. Baseline splenium of the corpus callosum relative CBV may predict clinical outcomes following hematopoietic stem cell transplantation.

Diseases of the cerebral vasculature represent a heterogeneous group of ischemic and hemorrhagic etiologies, which often manifest clinically as an acute neurologic deficit also known as stroke or less commonly with symptoms such as headache or seizures. Stroke is the fourth leading cause of death and is a leading cause of serious long-term disability in the United States. Eighty-seven percent of strokes are ischemic, 10% are due to intracerebral hemorrhage, and 3% are secondary to subarachnoid hemorrhage. The past two decades have seen significant developments in the screening, diagnosis, and treatment of ischemic and hemorrhagic causes of stroke with advancements in CT and MRI technology and novel treatment devices and techniques. Multiple different imaging modalities can be used in the evaluation of cerebrovascular disease. The different imaging modalities all have their own niches and their own advantages and disadvantages in the evaluation of cerebrovascular disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Purpose To determine if intracranial hemorrhages (ICH) are always hypointense on Susceptibility weighted imaging (SWI) and to determine the effect of T1-signal intensity on the appearance of ICH in SWI series. Methods SWI and T1-signal intensities of ICH were retrospectively studied in a series of patients. SWI signal intensities were statistically correlated with T1-signal intensities. Results In a series of 57 MRI scans from 40 patients, ICH was hypointense in 19, mixed-intensity in 21, and hyperintense in 17. Hyperintensity of ICH on SWI was significantly associated with increased T1 signal ( P Conclusion ICH can have a varied appearance on SWI.

There are few reports of MR imaging findings following psychosurgery. Here, we report the findings of 3T MR imaging of the sequelae of stereotactic subcaudate tractotomy (SST). Rostral atrophy is noted on conventional imaging. Diffusion tensor (DT) tractography demonstrated no communicating white matter tracts between the inferior frontal lobes, which appeared normally as thick fibre bundles in age-matched controls. DT tractography provides a unique tool for the evaluation of sequelae of ablative psychosurgical procedures.

Purpose: To establish normative magnetic resonance diffusion tensor imaging (MRDTI) data in the pediatric optic nerve and compare to pathologic conditions both intrinsic and extrinsic to the anterior optic nerve pathway. Materials and Methods: A retrospective analysis of MRDTI at 3.0T in children ages 0–18 with both normal imaging studies and with pathologic conditions either arising from the optic nerves or exerting mass effect on the anterior optic pathways was performed. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were obtained within the posterior part of the intraorbital optic nerves. Statistical analysis compared normal controls to optic pathway lesions. Results: Lesions intrinsic to the optic nerve including septo-optic dysplasia and optic nerve glioma demonstrated statistically significant reductions in FA and increases in ADC values. There was no statistically significant difference in FA or mean diffusivity between the normal controls and patients with lesions extrinsic to the optic nerve but exerting mass effect on the visual pathway. Conclusion: MRDTI is a feasible technique for evaluating the optic nerves in pediatric patients. It may play a role in presurgical planning by demonstrating integrity of the visual pathway in patients with resectable lesions, allowing for minimization of morbidity associated with vision loss. J. Magn. Reson. Imaging 2010;32:76–81. © 2010 Wiley-Liss, Inc.

Septo-optic dysplasia (SOD) refers to a heterogeneous group of midline brain developmental anomalies, with optic nerve hypoplasia (ONH) being one of the morphologic correlates of the condition. Traditionally, ONH has been diagnosed on fundoscopic exam. Conventional MRI is used in cases of suspected ONH to identify associated brain abnormalities and to compare findings to the fundoscopic exam. Advances in magnetic resonance diffusion tensor imaging (MRDTI) permit in vivo, noninvasive, quantitative characterization of the entire visual pathway at 3.0 T. To investigate the feasibility of MRDTI at 3.0 T in children with SOD to evaluate the entire visual pathway. MRDTI at 3T was performed in two children with SOD and seven age-matched controls. Manual region-of-interest analysis was used to evaluate the tensor metrics of the optic nerves. Deterministic tractography was used to evaluate the tensor metrics of the optic radiations. The SOD patients demonstrated a significant decrease in anisotropy and increase in mean diffusivity of the optic nerves and radiations compared to the control subjects. This study demonstrates the feasibility of MRDTI to evaluate the entire visual pathway in children, and it demonstrates pre- and post-chiasmatic diffusion tensor abnormalities in SOD patients.

Background/Aims: As a preoperative planning tool, conventional magnetic resonance (MR) imaging may have limited value in differentiating tumors from white matter tracts. MR diffusion tensor imaging (MRDTI) has become a useful tool for evaluating white matter tracts in relation to surrounding structures and has been used in surgical planning for brain tumors involving white matter. We investigated the use of DTI of the optic nerves in surgical planning for pediatric suprasellar tumors. Methods: We present findings in 10 pediatric control patients and 2 cases of pediatric suprasellar tumors in which a routine 6-direction DTI of the brain was performed at 3 T. Postprocessing permitted the study of the diffusion tensor parameters, as well as the tractography, of the optic nerves. Results: The control patients demonstrated the optimization of the technique and permitted the quantitation of fractional anisotropy and apparent diffusion coefficient values. The tumor cases demonstrated the utility of optic nerve DTI to differentiate between optic nerves and suprasellar/chiasmatic brain tumors. Conclusions: A routine 6-direction DTI of the pediatric brain at 3 T permits a detailed DTI study of the optic nerves. Optic nerve tractography can be used to aid in the evaluation and treatment of pediatric brain tumors in the area of the optic chiasm.

Stroke-like migraine attacks after radiation therapy (SMART) syndrome has a characteristic clinical presentation and postcontrast T1WI MRI appearance. Susceptibility-weighted imaging (SWI) may help distinguish SMART from other disorders that may have a similar postcontrast MRI appearance. The MRI examinations of four patients with SMART syndrome are described herein, each of which included SWI, FLAIR, DWI, and postcontrast T1WI on the presenting and follow-up MRI examinations. In each, the initial SWI MRI demonstrated numerous susceptibility hypointensities