Normal brain development and aging: quantitative analysis at in vivo MR imaging in healthy volunteers.

PURPOSE: To quantitate neuroanatomic parameters in healthy volunteers and to compare the values with normative values from postmortem studies. MATERIALS AND METHODS: Magnetic resonance (MR) images of 116 volunteers aged 19 months to 80 years were analyzed with semiautomated procedures validated by means of comparison with manual tracings. Volumes measured included intracranial space, whole brain, gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). Results were compared with values from previous postmortem studies. RESULTS: Whole brain and intracranial space grew by 25%-27% between early childhood (mean age, 26 months; age range, 19-33 months) and adolescence (mean age, 14 years; age range, 12-15 years); thereafter, whole-brain volume decreased such that volunteers (age range, 71-80 years) had volumes similar to those of young children. GM increased 13% from early to later (6-9 years) childhood. Thereafter, GM increased more slowly and reached a plateau in the 4th decade; it decreased by 13% in the oldest volunteers. The GM-WM ratio decreased exponentially from early childhood through the 4th decade; thereafter, it gradually declined. In vivo patterns of change in the intracranial space, whole brain, and GM-WM ratio agreed with published postmortem data. CONCLUSION: MR images accurately depict normal patterns of age-related change in intracranial space, whole brain, GM, WM, and CSF. These quantitative MR imaging data can be used in research studies and clinical settings for the detection of abnormalities in fundamental neuroanatomic parameters.

Spatial attention deficits in patients with acquired or developmental cerebellar abnormality.

Recent imaging and clinical studies have challenged the concept that the functional role of the cerebellum is exclusively in the motor domain. We present evidence of slowed covert orienting of visuospatial attention in patients with developmental cerebellar abnormality (patients with autism, a disorder in which at least 90% of all postmortem cases reported to date have Purkinje neuron loss), and in patients with cerebellar damage acquired from tumor or stroke. In spatial cuing tasks, normal control subjects across a wide age range were able to orient attention within 100 msec of an attention-directing cue. Patients with cerebellar damage showed little evidence of having oriented attention after 100 msec but did show the effects of attention orienting after 800-1200 msec. These effects were demonstrated in a task in which results were independent of the motor response. In this task, smaller cerebellar vermal lobules VI-VII (from magnetic resonance imaging) were associated with greater attention-orienting deficits. Although eye movements may also be disrupted in patients with cerebellar damage, abnormal gaze shifting cannot explain the timing and nature of the attention-orienting deficits reported here. These data may be consistent with evidence from animal models that suggest damage to the cerebellum disrupts both the spatial encoding of a location for an attentional shift and the subsequent gaze shift. These data are also consistent with a model of cerebellar function in which the cerebellum supports a broad spectrum of brain systems involved in both nonmotor and motor function.

Abnormality of cerebellar vermian lobules VI and VII in patients with infantile autism: identification of hypoplastic and hyperplastic subgroups with MR imaging.

OBJECTIVE: Infantile autism is a neurobehavioral disorder that is widely believed to have etiologically distinct subtypes, including subtypes with a genetic basis, but no neuroanatomic evidence firmly supports this belief. To date, only one type of cerebellar abnormality has been identified in patients with autism: hypoplasia of the vermis and hemispheres. By using a large sample of autistic patients and healthy volunteers along with precise MR imaging and quantitative procedures, we sought to replicate previous reports of cerebellar vermian hypoplasia in autism and to identify additional subtypes of cerebellar abnormality. MATERIALS AND METHODS: Using MR technology, we imaged and measured posterior and anterior vermian regions in 50 autistic patients (2-40 years old) and 53 healthy control subjects (3-37 years old). The autistic patients had social, language, cognitive, behavioral, and medical history characteristics that were typical of the general autistic population. By using precise procedures for positioning and aligning MR slices, we obtained comparable MR images within and across subject groups. RESULTS: Statistical analyses showed two subgroups of autistic patients, one (86% of the patients) with findings consistent with vermian hypoplasia and another (12% of the patients) with evidence of vermian hyperplasia. The hypoplasia subgroup included 43 patients whose mean midsagittal area for vermian lobules VI and VII was 237 +/- 38 mm2, and the hyperplasia subgroup included six patients whose mean area was 377 +/- 12 mm2. Thus, the area of lobules VI and VII in the hypoplasia subgroup was 16% smaller than the mean area in the control subjects (282 +/- 42 mm2) (p < .0001), whereas that in the hyperplasia subgroup was 34% larger (p < .0001). Analyses showed that these two subtypes of vermian abnormalities were present across all ages of autistic patients studied. CONCLUSION: Two different subtypes of autistic patients can be identified on the basis of the presence of vermian hypoplasia or hyperplasia as seen on MR images. Possible origins for vermian hypoplasia include environmental trauma and genetic factors.

Parietal lobe abnormalities detected with MR in patients with infantile autism.

OBJECTIVE: Infantile autism is a neurologic disorder that severely disrupts the development of many higher cognitive functions. The most consistent abnormal neuroanatomic findings in autism are loss of Purkinje neurons in the posterior cerebellum as detected by autopsy studies and hypoplasia of the posterior cerebellar vermis and hemispheres as detected by in vivo neuroimaging. Evidence of developmental arrest has also been detected in limbic structures in autopsy studies of autistic patients with mental retardation. Neither in vivo neuroimaging nor autopsy studies of autistic persons have reported abnormalities in the cerebrum. Because the cerebrum mediates many higher cognitive functions, such as social communication, language, abstract reasoning, planning, and organization, that are known to be deficient in patients with autism, a closer examination of the neuroanatomy of the cerebrum in infantile autism is warranted. MATERIALS AND METHODS: MR images of 21 healthy autistic patients (6-32 years old) were mixed with MR images of control subjects and reviewed on four separate occasions by a neuroradiologist for any neuroanatomic abnormalities. Autism was diagnosed on the basis of criteria for autism as defined by the Diagnostic and Statistical Manual of Mental Disorders, and the autistic patients did not have any other concurrent neurologic disorders. To control for systematic bias in judging the type and location of abnormalities in the autistic population, three control groups were used: a normal control group of 12 subjects, a control group of 23 nonautistic patients with a variety of brain abnormalities for the first review, and another control group of 17 nonautistic patients for the second review. Control patients with brain abnormalities were selected from patients' files on the basis of MR findings of a variety of brain abnormalities. All MR images were coded for anonymity, randomly mixed, and examined by a neuroradiologist blinded to the purpose of the study and to the group membership of each subject. All normal and abnormal findings seen on the MR images of each subject were described on a standard form listing all major brain structures to ensure an examination of each structure in turn. To test for reliability, three subsequent reviews were performed by the same neuroradiologist. RESULTS: Parietal lobes were abnormal in appearance in 43% (9/21) of autistic patients. Cortical volume loss in the parietal lobes was seen in seven autistic patients; in four of these cases, cortical volume loss extended either into the adjacent superior frontal or occipital lobe. Additional abnormalities detected with MR in these nine patients included white matter volume loss in the parietal lobes (three patients) and thinning of the corpus callosum, especially along the posterior body (two patients). Abnormalities were bilateral. The mesial, lateral, and orbital regions of the frontal lobes; temporal lobes; limbic structures; basal ganglia; diencephalon; and brainstem were normal in all autistic patients. No abnormalities were found in the 12 normal control subjects. The control subjects with neurologic abnormalities had various abnormal findings consistent with their medical conditions. CONCLUSION: Our results indicate that the parietal lobes are reduced in volume in a portion of the autistic population. Possible origins for this localized cerebral abnormality include early-onset altered development and late-onset progressive atrophy.

Cerebellar and cerebral abnormalities in Rett syndrome: a quantitative MR analysis.

Rett syndrome is a neurodegenerative disease of young girls that begins in early childhood with autismlike behavior and loss of language skills, and progresses with marked deterioration of the motor system in the second decade of life. The purpose of this study was to determine if neuroanatomic changes detected with MR imaging could help to explain the clinical presentation and progression of signs and symptoms in these patients. Accordingly, computer-assisted planimetry was used to measure various dimensions of cerebral, cerebellar, and brainstem structures on sagittal and transverse MR images of 13 patients with Rett syndrome and 10 healthy volunteers. Dimensions of the cerebrum, basal ganglia, cerebellum, and brainstem were measured on transverse images. Areas of cerebellar vermian lobules, the fourth ventricle, the pituitary gland, and the corpus callosum were measured on sagittal images. Fourteen dimensions and areas were measured in each patient and each control subject; according to two-tailed Student's t tests, all but two values were significantly smaller in the patients with Rett syndrome than in control subjects. Graphing the measurements against age by using simple linear regression revealed progressive cerebellar atrophy without evidence of atrophy of the brainstem or cerebrum. Our results indicate that patients with Rett syndrome have global hypoplasia of the brain and progressive cerebellar atrophy increasing with age. Cerebellar atrophy with age may contribute to the deterioration of the motor system seen in older patients with Rett syndrome.

Contribution of the cerebellum to neuropsychological functioning: evidence from a case of cerebellar degenerative disorder.

A detailed neuropsychological evaluation was performed on a patient with an idiopathic cerebellar degenerative disorder. Significant deficits were found in verbal and nonverbal intelligence, verbal associative learning, and visuospatial skills. These deficits were not readily explained by motor control difficulties. In contrast to the patient's moderately impaired language abilities, he was severely impaired on a test of verbal fluency and demonstrated mild naming deficits. Severe cerebellar parenchymal volume loss was demonstrated by magnetic resonance examination. Supratentorial structures showed only minimal posterior parietal and occipital sulcal prominence. On neurological examination, this patient had signs of severe involvement of the cerebellar systems and mild-to-moderate dysfunction of the corticospinal tract. As is characteristic of patients with cerebellar degeneration, there was neurophysiological evidence of subclinical involvement of auditory and somatosensory pathways at the level of the brain stem. Since relatively little cerebral cortical atrophy was noted in this patient, these findings suggest that an intact cerebellum is important for normal cognitive functions.

Absence of magnetic resonance imaging evidence of pontine abnormality in infantile autism.

In vivo studies involving magnetic resonance imaging and studies of neuropathologic specimens have shown that autism is most consistently associated with developmental hypoplasia of the neocerebellum. We investigated whether the cerebellar hypoplasia was accompanied by gross structural abnormalities in the major input (cerebrocerebellar) and output (cerebrorubral) pathways to the cerebellum by measuring the area of the ventral pons (including the pontine nuclei and the transverse fibers) and the midbrain on midsagittal magnetic resonance images in 34 autistic and 44 subjects. The area of the entire pons and several regions of interest within the midbrain (including the superior and inferior colliculi) were also determined with midsagittal magnetic resonance images. We found no significant difference between measurements of the pons and midbrain in autistic and control subjects. Our data show no evidence of gross anatomic abnormalities in the input and output pathways to the cerebellum in autism, a finding that is consistent with previous studies of neuropathologic specimens; rather, the reduced size of the neocerebellum in autism appears to be the result of maldevelopment within the cerebellum itself.

Spinal cord tumors: gadolinium-DTPA-enhanced MR imaging.

To assess the utility of gadolinium-DTPA (Gd) and of MR imaging in the evaluation of spinal cord tumors, ten consecutive patients were prospectively evaluated. T1-proton density-, and T2-weighted images were obtained in sagittal or axial planes. T1-weighted images were obtained before and after intravenous administration. Five tumors were within the cervical spinal cord; 3 neoplasms were within the thoracic cord; 1 neoplasm extended from the cervical to the thoracic cord and 1 neoplasm extended from the cervical cord to the conus medullaris. Four tumors were ependymomas; 3 were astrocytomas; 1 was an hemangioblastoma, and 1 was a metastatic malignant peripheral nerve sheath tumor. The remaining patient died prior to spinal surgery and no autopsy was obtained. Of the precontrast sequences, tumors were best evaluated using T1-weighted images. Abnormal findings included cord widening, presence of a tumor mass, intratumoral or other associated cyst(s), and hemorrhage. Nevertheless, T1-weighted images obtained following the administration of GD were superior relative to all other pre- and post-contrast sequences for defining tumor margins, characterizing cyst(s) and delineating tumor masses. Based primarily on their appearance on post-contrast T1-weighted images, tumor-associated cysts could be subcategorized into 3 types: intratumoral cysts (found within the contrast-enhancing soft tissue mass); nonenhancing extratumoral cysts (found eitherrostral or caudal to the enhancing tumor mass); and enhancing extratumoral cysts (having an enhancing wall or containing an enhancing nodule).(ABSTRACT TRUNCATED AT 250 WORDS)

Neonatal schizencephaly: comparison of brain imaging.

Schizencephaly is a regional disturbance of cerebral hemisphere formation occurring at 3-5 months gestation; neonatal presentation is uncommon. Three neonates with schizencephaly were evaluated with cranial ultrasonography (US), unenhanced computed tomography (CT), and magnetic resonance imaging (MRI) examinations. Common findings in US, CT, and MRI include parasylvian and midline clefts, size asymmetries of the basal ganglia and thalamus, cerebral parenchymal volume loss, ventriculomegaly, ventricular diverticula, and absence of the septum pellucidum. MRI and CT were superior to US in detecting calcification, gyral and sulcal abnormalities, and parasylvian clefts. MRI alone demonstrated homolateral absence of the sylvian vasculature, small medullary pyramids, low position of the fornix, and the thinning of the corpus callosum. Although US appears adequate as a screening test, MRI best defines the precise pathoanatomic findings of neonatal schizencephaly and allows for the prediction of neurologic outcomes in affected newborns.

Cortical atrophy and cognitive performance in infantile nephropathic cystinosis.

A group of children and adolescents with infantile nephropathic cystinosis underwent cognitive testing and were examined for cortical atrophy using magnetic resonance imaging or computed tomography. Ten of 11 patients demonstrated cortical atrophy. A consistent pattern of lower cognitive performance was found in patients with greater atrophy; however, only the relationship between atrophy and short-term memory approached statistical significance. In addition, evidence for greater impairment of visual memory than of other cognitive functions was observed. This latter observation did not appear to be related to the degree of atrophy.

Magnetic resonance imaging in the evaluation of vitreoretinal disease in eyes with intraocular silicone oil.

Media opacification in eyes filled with silicone oil makes the evaluation of recurrent retinal detachment difficult. Ultrasonography through silicone oil is subject to significant imaging artifacts. We performed magnetic resonance imaging on six patients with unilateral intravitreal silicone oil to determine if the technique would detect detached retina and subretinal oil. All patients had undergone pars plana vitrectomy with silicone oil injection for proliferative vitreoretinopathy; five patients had encircling solid silicone scleral buckles. In five patients the media were clear, and ophthalmoscopic findings were correlated with magnetic resonance findings. Four patients had recurrence of inferior retinal detachment; magnetic resonance imaging demonstrated subretinal oil in three of these patients. One patient had a concentric, shallow, anterior retinal detachment; magnetic resonance scanning demonstrated a globular hyperintensity suggestive of subretinal oil. In the sixth patient, who had an opaque cornea, magnetic resonance imaging suggested that the retina was attached preoperatively; this was confirmed at subsequent surgery. A chemical shift artifact was helpful in defining the contour of retinal detachments and the presence of subretinal oil by outlining the silicone oil within the eye.

Magnetic resonance imaging of the hippocampal formation and mammillary nuclei distinguish medial temporal lobe and diencephalic amnesia.

Studies of circumscribed amnesia have been a useful source of information about the organization of human memory functions. In an effort to obtain neuroanatomical information about the patients being studied, we have used 2 high-resolution protocols for imaging the human brain with magnetic resonance (MR). One provides images of the hippocampus, permitting visualization of the hippocampal formation in considerable detail. The second provides images of the mammillary nuclei. Four amnesic patients with alcoholic Korsakoff's syndrome had abnormally small mammillary nuclei that were barely detectable by MR in most cases. The temporal lobe, hippocampal formation, and parahippocampal gyrus were of normal size. In a second group of 4 (non-Korsakoff) amnesic patients, the opposite findings were obtained. The hippocampal formation was markedly reduced in size in the absence of a detectable change in the size of the temporal lobe. By contrast, the mammillary nuclei, though somewhat reduced in volume, were considerably larger than in the patients with Korsakoff's syndrome. The anatomical findings for individual patients generally corresponded to the severity of their memory impairment. The results show that neuroimaging techniques can distinguish between patients with diencephalic and medial temporal lobe amnesia. These techniques can therefore provide useful information about the crucial issue of patient classification, and they set the stage for exploring possible quantitative and qualitative differences between patients.

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.

Temporal lobe ganglioglioma in refractory epilepsy: CT and MR in three cases.

Three patients (ages 5, 16 and 21 years) with chronic, refractory, partial epilepsy and temporal lobe ganglioglioma were evaluated for surgical treatment. Noncontrast CT revealed a low attenuation, cystic temporal lesion in 2 patients. One neoplasm demonstrated focal calcification and temporal altrophy, while the other had mass effect and surrounding edema. Contrast enhancement of the mass was seen in one instance. Non-contrast and post-contrast CT were completely normal in the remaining patient. MR was abnormal in both patients in which it was performed (including the patient with a normal CT examination). Lesions were hyperintense on T2W inmages and iso-to-hypointense on T1W images when compared to normal parenchyma. Regions of calcification were missed on standard spin-echo sequences. Continuous video EEG monitoring captured habitual partial seizures in all patients; focal onset correlated with tumor location in each instance. Intraoperative electrocorticography corroborated the EEG results. Two of three patients underwent gross total resection. Pathologic features were characteristic of ganglioglioma in all instances. All patients have been seizure-free postoperatively [mean follow-up: 16 months (range 13-18 months)] and without evidence of tumor recurrence. Although ganglioglioma is an unusual cause of refractory temporal lobe epilepsy, our short term follow-up suggests excellent outcome with both partial and gross total resection.

Intracranial ependymoma and subependymoma: MR manifestations.

In order to provide a detailed description of the MR appearance of intracranial ependymoma, the MR examinations of 12 patients (10 with ependymomas and two with subependymomas) were reviewed and correlated with operative and pathologic reports. Three of 10 ependymomas were intraventricular, two were intraparenchymal, and five were transependymal, extending from CSF spaces into parenchyma. Both subependymomas were intraventricular. Solid ependymomas and subependymomas were iso- to hypointense relative to normal white matter on T1-weighted images and hyperintense on proton-density- and T2-weighted images. Foci of signal heterogeneity within solid neoplasms represented methemoglobin, hemosiderin, necrosis, calcification, and encased native vessels or tumor vascularity. Gd-DTPA-enhanced images in two patients differentiated enhancing tumor from surrounding nonenhancing edema and from surrounding normal brain parenchyma. Cystic neoplasms had sharply defined, round or oval margins and uniform signal intensity equivalent to or slightly hyperintense relative to CSF. Tumor-associated calcification was not demonstrated readily by MR. Sagittal and coronal images were valuable in assessing the amount of intraventricular tumor and route of extension. We conclude that the MR differentiation of ependymomas and subependymomas from other gliomas is provided most reliably by the location and morphology of the tumor and not by differences in signal intensity. The typical ependymoma arises within the fourth ventricle as a solid mass with heterogeneous signal intensity. A propensity for spread is seen along the CSF pathways via the foramina of Magendie and Luschka and the aqueduct of Sylvius. Supratentorial ependymomas may be periventricular in location and have cystic components. The two subependymomas in our series were solid, intraventricular tumors with relatively homogeneous signal intensities.

Encephalitis caused by human immunodeficiency virus: CT and MR imaging manifestations with clinical and pathologic correlation.

To determine the computed tomographic (CT) and magnetic resonance (MR) imaging manifestations of central nervous system (CNS) infection by the human immunodeficiency virus (HIV), the authors analyzed the results of imaging of the CNS in 24 patients with HIV encephalitis confirmed at autopsy. Careful pathologic correlation demonstrated that neither CT nor MR imaging enabled detection of microglial nodules with multinucleated giant cells, the hallmark of HIV encephalitis seen in all 24 affected patients. The most common abnormality observed on images of the CNS was atrophy, demonstrated in 18 patients. Demyelination and vacuolation of white matter tracts accompanying severe HIV infection caused hypoattenuation on CT scans and hyperintensity on T2-weighted MR images. These lesions had no mass effect. MR imaging was more sensitive than CT in the detection of lesions caused by HIV or other superimposed infectious agents. Although it is often difficult to attribute any radiologic appearance to a single etiologic agent in patients with acquired immunodeficiency syndrome, the combination of atrophy and symmetric, periventricular or diffuse white matter disease suggests HIV encephalitis.

The cerebellum: 3. Anatomic-MR correlation in the coronal plane.

Thin (5-mm) coronal high-field (1.5-T) MR images of four human brain specimens and 14 normal volunteers were correlated with myelin-stained microtomic sections of the specimen cerebella. The primary white-matter tracts innervating several hemispheric (posterior quadrangular, superior, and inferior semilunar, gracile, biventer, tonsil) and vermian (declive, folium, tuber) lobules are oriented perpendicularly to the coronal plane of section and are shown well on proton-density-weighted (long TR/short TE) and T2-weighted (long TR/long TE) spin-echo images, which provide excellent contrast between gray and white matter. Several of the surface sulci and fissures of the cerebellar hemispheres (including the superior posterior, horizontal, secondary, and posterolateral fissures) also course perpendicular to the coronal plane and are depicted well on T1-weighted (short TR/short TE) and T2-weighted images, which maximize contrast between CSF and parenchyma. The opportunity for side-to-side comparison of the hemispheres is a distinct advantage of the coronal view. Nevertheless, more obliquely oriented surfaces (preculminate, primary, inferior posterior, inferior anterior, and intrabiventral fissures) and deep hemispheric structures (primary white-matter tracts to central, anterior quadrangular, and floccular lobules) may be obscured by volume-averaging in the coronal plane; moreover, much of the finer anatomy of the vermis is depicted poorly. The constant surface and deep anatomy of the cerebellum revealed on coronal images in normal volunteers encourages detailed mapping. MR imaging in the coronal plane should be especially useful in identifying, localizing, and quantifying normal and abnormal morphologic differences between the cerebellar hemispheres.

Leptomeningeal metastasis: a comparison of gadolinium-enhanced MR and contrast-enhanced CT of the brain.

We evaluated 14 consecutive patients with leptomeningeal metastasis prospectively, using both T1-weighted (T1W) gadolinium-DTPA-enhanced MR (Gd-MR) and contrast-enhanced CT (CE-CT). Thirteen had positive CSF cytology; the remaining patient had an atypical CSF lymphocytosis and primary CNS lymphoma. The patients (8M/6F) ranged in age from 8 to 70 years (median, 42 years). Tumor histology included 3 systemic and 2 primary CNS lymphomas, 3 breast carcinomas, 2 leukemias, 1 malignant schwannoma, 1 small cell lung cancer, 1 prostate cancer, and 1 melanoma. Both imaging methods demonstrated parenchymal volume loss equally well in all patients. Gd-MR revealed abnormal enhancement of meninges or parenchyma in 10 patients, including all 5 patients with positive CE-CT. Neither technique revealed any foci of abnormal enhancement in 4 patients. Gd-MR was superior to CE-CT in demonstrating and quantifying enhancing subarachnoid and parenchymal nodules in 6 patients and in demonstrating sulcal, dural, cisternal, tentorial, and ependymal enhancement. Our findings indicate that T1W Gd-MR is the preferred imaging modality in leptomeningeal metastasis and suggest that CE-CT is unnecessary.

The cerebellum: 3. Anatomic-MR correlation in the coronal plane.

Thin (5-mm) coronal high-field (1.5-T) MR images of four human brain specimens and 14 normal volunteers were correlated with myelin-stained microtomic sections of the specimen cerebella. The primary white-matter tracts innervating several hemispheric (posterior quadrangular, superior, and inferior semilunar, gracile, biventer, tonsil) and vermian (declive, folium, tuber) lobules are oriented perpendicularly to the coronal plane of section and are shown well on proton-density-weighted (long TR/short TE) and T2-weighted (long TR/long TE) spin-echo images, which provide excellent contrast between gray and white matter. Several of the surface sulci and fissures of the cerebellar hemispheres (including the superior posterior, horizontal, secondary, and posterolateral fissures) also course perpendicular to the coronal plane and are depicted well on T1-weighted (short TR/short TE) and T2-weighted images, which maximize contrast between CSF and parenchyma. The opportunity for side-to-side comparison of the hemispheres is a distinct advantage of the coronal view. Nevertheless, more obliquely oriented surfaces (preculminate, primary, inferior posterior, inferior anterior, and intrabiventral fissures) and deep hemispheric structures (primary white-matter tracts to central, anterior quadrangular, and floccular lobules) may be obscured by volume-averaging in the coronal plane; moreover, much of the finer anatomy of the vermis is depicted poorly. The constant surface and deep anatomy of the cerebellum revealed on coronal images in normal volunteers encourages detailed mapping. MR imaging in the coronal plane should be especially useful in identifying, localizing, and quantifying normal and abnormal morphologic differences between the cerebellar hemispheres.