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Multiple regression voxel-based morphometry analyses were used to examine the relationship between regional gray matter volumes and neurocognitive performance in 10 patients with amnestic mild cognitive impairment and 20 healthy age-matched controls. Cognitive functioning was assessed with seven standardized neuropsychological tests. Patients with amnestic mild cognitive impairment exhibited impaired cognitive performance (on the Mini Mental State Examination, tests of verbal fluency, verbal and spatial learning and memory, and visual-motor abilities) and reduced gray matter volume in the right temporal pole. Across all participants, better performance on several neuropsychological tests was associated with higher regional gray matter volumes. Voxel-based morphometry provides an operator-unbiased means to investigate volumetric differences, which may be related to impaired neuropsychological functioning.

This study demonstrates normal white matter structures of the supratentorial system revealed by diffusion tensor imaging. Their anatomic connections and functional significance are discussed in the context of the lesion-induced deficits reported in the literature, which may not fully represent the lesion-induced effects on the white matter function and may not be entirely specific to the tract discussed. Nevertheless, understanding the most common effects of lesions on the functional connectivity provides a framework that we can use in advanced neuroimaging studies, like diffusion tensor imaging, functional magnetic resonance imaging, and positron emission tomography, and in our daily clinical practice.

A 50-year-old patient with a 6-month history of progressive cognitive and motor disability is presented. There were no myoclonic jerks on examination and no periodic sharp waves by electroencephalography. Imaging showed high signal on T2-weighted scans in the basal ganglia and posterior limbs of the internal capsules, with no restricted diffusion and parenchymal volume loss. A brain biopsy was performed. Western blot analysis revealed a protease-resistant prion protein fragment (PrP7-8), the molecular hallmark of Gerstmann-Straussler-Scheinker disease.

Objective: To determine the incidence of dehiscence between the vestibular aqueduct and the jugular bulb on computed tomography (CT) scans and assess its implication as a cause of dizziness or hearing loss., Methods: Two hundred temporal bone CT scans were evaluated for the prevalence of dehiscence between the jugular bulb and vestibular aqueduct. Correlation of the imaging findings and clinical data was performed., Results: A total of 11.5% of patients had dehiscence of the jugular bulb with the vestibular aqueduct; 75% of these cases occurred on the right side and in the setting of a high jugular bulb. Nine (39.1%) of 23 patients with dehiscence had dizziness, and 11 (47.8%) had hearing loss. The correlation between the incidence of dizziness, hearing loss, and dehiscence was not significant., Conclusion: The incidence of a dehiscent jugular bulb with a vestibular aqueduct is 11.5%. The prevalences of vertigo and hearing loss associated with this finding are 39.1% and 47.8%, respectively. The depiction of dehiscent jugular bulb-vestibular aqueduct should be considered with caution as the sole cause of symptoms.

Scores on the University of Pennsylvania Smell Identification Test (UPSIT), as well as the numbers of MRI-determined plaques within the inferior frontal and temporal lobes, were obtained on three or four separate occasions in each of five MS patients over an 18- to 20-month period. A close association was observed, longitudinally, between the remission and exacerbation of plaque numbers and UPSIT scores, with more plaques reflecting lower UPSIT scores. These observations further support the hypothesis that olfactory loss in MS is associated with fluctuations in plaque numbers in central olfactory brain regions.

Purpose: The purpose of this study was to compare contrast-enhanced GRE and conventional SE (CSE) fat-suppressed T1-weighted techniques in the evaluation of head and neck lesions. A hybrid, opposed phase, frequency-selective, fat-suppressed fast multiplanar spoiled GRE (FMPSPGR) sequence was compared with a fat-suppressed CSE sequence., Method: Thirty-two patients with head and neck pathology were evaluated with both fat-suppressed CSE and FMPSPGR sequences. Regions of interest obtained by two viewers in consensus were used to establish contrast-to-noise (CNR) and signal-to-noise ratios for both sequences. Three neuroradiologists also independently reviewed the images for quality of fat suppression, lesion conspicuity, and potential pitfalls., Results: The CNR of the FMPSPGR sequence was superior to that of the fat-suppressed CSE sequence. Subjectively, all three reviewers rated the FMPSPGR sequence as having fat suppression equal to or better than that in the CSE sequence in 94% of cases. Imaging times for the FMPSPGR sequence were 60-75% faster than those for the CSE sequence., Conclusion: Enhanced imaging of the head and neck region using an opposed phase, fat-suppressed GRE sequence results in improved fat suppression compared with the CSE technique, with substantial savings in imaging time.

Objective: To evaluate the incidence of facial nerve stimulation from cochlear implants and to better define the segment of nerve being stimulated and the causes of stimulation., Study Design: Retrospective patient case review and a temporal bone dissection study., Setting: A tertiary care setting., Patients: All patients given a cochlear implant at the Hospital of the University of Pennsylvania. This encompassed only adult patients., Intervention: All patients had surgical insertion of either a 3M single channel, Nucleus 22-channel, or CLARION multichannel cochlear implant., Main Outcome Measures: Demonstration of facial nerve stimulation with a cochlear implant and determination of affected electrodes; measurement of electrode location and distances between the labyrinthine segment of the facial nerve and the cochlea in temporal bone dissections: and determination of the relationship between the labyrinthine facial nerve and the cochlea using computed tomography evaluation., Results: The overall incidence of facial nerve stimulation using all three devices was 14% (8 of 58). Otosclerosis and otosyphilis appear to be predisposing conditions to stimulation. The mid-cochlear electrodes, located near the labyrinthine facial nerve, appear to cause stimulation of the VIIth nerve most commonly. Computed tomographic evaluation of the bone between the labyrinthine fallopian canal and the cochlea may provide some indication of potential facial nerve problems., Conclusion: Facial nerve stimulation from the use of cochlear implants is more prevalent in patients with otosclerosis and otosyphilis. The labyrinthine segment of the facial nerve is the most likely area being stimulated in most patients. Preoperative computed tomographic evaluation may be beneficial in determining the possibility of this problem.

Objective: Our goal was to assess whether significant secondary atherosclerotic changes from radiation can be detected on SE MR of the neck., Materials and Methods: Pre- and postradiation MR scans of 16 patients with head and neck malignancies were studied randomly, independently, and blindly by two readers to determine the frequency of narrowing of the carotid arterial lumen and obliteration of the carotid space within the carotid sheath., Results: Interval narrowing of either the common, internal, or external carotid artery lumen was seen in 108 of 192 (56%) of vessels evaluated on postradiation MR scans compared with preradiation studies. The differences in the grades of vessel luminal diameter were statistically significant (p < 0.05 for one reader and p < 0.0001 for the other reader). Among the 16 patients, 3 patients had vessels with a critical degree of stenosis, newly appearing on postradiation scans. Seven of 16 patients had diffuse obliteration of the planes within the carotid space., Conclusion: The incidence of accelerated atherosclerosis from therapeutic radiation may be greater than expected in nonirradiated patients. Magnetic resonance scans are an effective, noninvasive method for this type of follow-up.

Superficial siderosis of the central nervous system (CNS) is a rare but ultimately fatal disorder characterized by progressive hearing loss, ataxia, and dementia. Symptoms are caused by the deposition of hemosiderin in the CNS as a result of recurrent or persistent extravasation of blood into the cerebrospinal fluid. Sites most commonly involved include the cerebellum, brain stem, and eighth cranial nerve. In the past, diagnosis was most often made at autopsy, and this may account for the lack of reported cases in the otolaryngologic literature and the presumed rarity of the disorder. Now, diagnosis is confirmed by characteristic magnetic resonance imaging findings and treatment is targeted toward the source of bleeding. The diagnosis of superficial CNS siderosis should be entertained in all patients presenting with sensorineural hearing loss and ataxia.

Magnetic resonance imaging was employed to evaluate soft palate function in four normal volunteers and four patients with surgically repaired cleft palate, using a GE Signa clinical scanner at 1.5 T and a custom designed receive coil with a sensitivity profile encompassing from the nasopharynx to the larynx. Midsagittal images were obtained using spoiled gradient recalled acquisition at steady state while the subject phonated the following sounds: (a) MMM, (b) SSS, (c) DAH, and (d) EEE. An image at rest with normal breathing was also obtained. The soft palate and its relationship to the airway and the posterior pharyngeal wall were clearly visualized in all cases. Phonation of the prescribed sounds demonstrated the normal range of soft palate motion. The images also depicted the ability of the soft palate to divert airflow to the nasopharynx. Interpretation of functional MRI may be of value in evaluation of surgical results, guidance of speech therapy, and surgical planning in the cleft palate patient. This noninvasive alternative to conventional methods of visualization provides advantages in resolution, repeatability, and patient comfort.

We studied the spectroscopic appearance of radiation-induced myelinolysis in cats to understand the characteristics of proton MR spectroscopy of demyelinating disorders. Eight cats received 5,000 rads to a 1.5 x 1.5 cm area of the right cerebral hemisphere. Eight to 9 months after irradiation, a gross area of abnormal postcontrast enhancement and/or high MR signal intensity was detected in the irradiated hemisphere of six of the eight cats. Proton spectra of a 1.0 cm3 voxel in the affected region demonstrated depressed N-acetyl aspartate/creatine-phosphocreatine and N-acetyl aspartate/choline-containing compound peak ratios compared with the contralateral non-irradiated brain in all cats. Elevated amino acid resonances in the 2.0-2.5 ppm range were not consistently seen in irradiated zones of the brain with pathologic findings of demyelination. In vivo proton MR spectroscopy may show differences between irradiated brain and nonirradiated brain even when histopathologic lesions are not apparent yet.

The purpose of this study was to compare CT and MR for the detection of cervical disk herniations. Nineteen patients suspected of harboring degenerative disk disease of the cervical spine underwent thin contiguous section CT myelography (CTM) and thin contiguous section three-dimensional Fourier transform (3DFT) gradient echo MR at 67 disk levels. Blinded readings of a high intensity CSF MR technique for the presence or absence of disk herniation were performed by three neuroradiologists. The intraobserver CT-MR concordances ranged from 84 to 89%. Using CTM as the paragon test, MR demonstrated a sensitivity of 79-91% and a specificity of 82-88% for disk herniation. Mean MR-CT concordance (86%) was nearly equivalent to that of CT-CT intraobserver concordance (88%). When consensus readings were considered, the MR-CT concordance (91%) was slightly higher than that of CT-CT intraobserver concordance (88%). We conclude that thin section 3DFT gradient echo MR with high intensity CSF is a reliable method to screen for degenerative disk disease in the cervical spine, since the agreement between MR and CTM is comparable with the intraobserver agreement of CTM.

Twenty spinal studies to rule out cord compression using a multicoil array system were compared with the 20 consecutive previous studies in which a 5 x 11 inch flat plate coil (5 x 11 FPC) was used on the same 1.5 T MR scanner. The multicoil studies averaged 53 min shorter overall (105 min with the 5 x 11 FPC versus 52 min with multicoil). The reduction in scan time was maximal in studies when Gd-DTPA was administered (76 min reduction) or when the results showed noncompressive epidural disease or intramedullary disease (78 min). Scan quality was diagnostic in all examinations, and lesion localization was superior with the multicoil. The multicoil system substantially reduces scan times when whole spine studies are performed.

Forty patients with positive CSF cytology for subarachnoid dissemination of neoplasms were examined by magnetic resonance (MR) imaging for the detection of intracranial or intraspinal CSF metastases. The MR evidence of cerebral leptomeningeal metastases was noted in 12 of 54 unenhanced (22.2%) and 7 of 20 (35%) gadolinium-enhanced studies. However, in only 2 of the 20 (10%) gadolinium-enhanced scans did the enhanced brain images alone demonstrate the presence of CSF seeding. Four of 29 (13.8%) unenhanced studies of the spine and 6 of 16 (37.5%) gadolinium-enhanced spine studies were positive for neoplastic deposits on the spinal nerves or cord. Magnetic resonance without and with gadolinium enhancement was most likely to be positive in studies of patients with a non-CNS primary malignancy (16/51 = 31.4%) and least accurate with lymphoma or leukemia (1/18 = 5.6%). Although gadolinium administration increases the ability of MR to detect leptomeningeal metastases (particularly in the spine), the overall sensitivity of unenhanced and enhanced MR examinations is low (19.3 and 36.1%, respectively) in patients with proven cytological evidence of neoplastic seeding.

A case of rhinocerebral mucormycosis evaluated by magnetic resonance (MR) imaging is presented, with inflammatory changes in the paranasal sinuses and orbit. Extension of the infection into the cavernous sinus, with cavernous sinus thrombosis and internal carotid artery narrowing, was well demonstrated on pre- and postgadolinium MR images. Infarctions in the anterior choroidal artery distribution suggested intracranial invasion of basal arteries, and watershed distribution infarctions attested to the tenuousness of flow through a narrowed cavernous carotid artery. Magnetic resonance effectively demonstrated the wide array of findings possible in rhinoorbitocerebral mucormycosis.