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Several characteristic radiographic signs associated with various diseases are useful in neuroradiological practice; however, their clinical usefulness varies widely. This article presents some common signs and the associated pathological features, particularly those observed on computed tomography and magnetic resonance imaging or pathognomonic signs that are useful for accurate diagnosis, even in patients with rare diseases.

Background: Fingolimod (FTY) is an oral sphingosine-1-phosphate receptor modulator that reduces relapse and slows brain atrophy in multiple sclerosis (MS) patients. In addition, FTY has been shown to enhance remyelination in certain animal models., Objective: To analyze feasibility of a novel q-space Myelin Map imaging to monitor demyelination and remyelination under FTY treatment in MS patients., Methods: Treatment outcomes of 24 consecutive MS patients treated with FTY were analyzed. A longitudinal analysis of q-space Myelin Map imaging was performed in a subset of these patients., Results: During the treatment course (average of 16.1months), 10 patients (42%) exhibited improvement on the Expanded Disability Status Scale (EDSS) or maintained disability-free state ("optimal responders"). The average baseline age and EDSS score were significantly younger and milder in optimal responders compared to the rest of patients. A pilot longitudinal q-space Myelin Map study in 8 patients (including 4 optimal responders) showed that optimal responders tended to show signs of remyelination while exhibiting no newly evolved demyelinated lesions., Conclusion: FTY may improve disability in younger patients with milder MS, and absence of demyelination activity and presence of remyelination activity may in part be associated with such improvement. q-Space Myelin Map imaging is a clinically feasible modality to monitor demyelination and remyelination in MS patients., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Movement dysfunction in Parkinson's disease (PD) is caused by the degeneration of dopaminergic (DA) neurons in the substantia nigra (SN). Here, we established a method for voxel-based morphometry (VBM) and automatic tissue segmentation of the marmoset monkey brain using a 7-T animal scanner and applied the method to assess DA degeneration in a PD model, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated animals, with tyrosine-hydroxylase staining. The most significant decreases of local tissue volume were detected in the bilateral SN of MPTP-treated marmoset brains (-53.0% in right and -46.5% in left) and corresponded with the location of DA neurodegeneration found in histology (-65.4% in right). In addition to the SN, the decreases were also confirmed in the locus coeruleus, and lateral hypothalamus. VBM using 7-T MRI was effective in detecting volume loss in the SN of the PD-model marmoset. This study provides a potential basis for the application of VBM with ultra-high field MRI in the clinical diagnosis of PD. The developed method may also offer value in automatic whole-brain evaluation of structural changes for the marmoset monkey., (Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.)

The developmental anatomy of the brain is largely directed by neural-based cues. Despite this knowledge, the developmental trajectory of the primate brain has not yet been fully characterized. To realize this goal, the advance in noninvasive imaging methods and new brain atlases are essential. The common marmoset (Callithrix jacchus), a small New World primate, is widely used in neuroscience research. The recent introduction of transgenic techniques has enabled the marmoset to be used as a genetically modifiable primate model for brain development. Here, a magnetic resonance histology technique involving the use of ultra-high-resolution ex vivo magnetic resonance imaging (MRI) was performed to identify the developmental anatomy of the marmoset brain at different time points from gestational week 8 through to birth. The data allowed the generation of a multidimensional atlas of brain structures at different developmental stages. Furthermore, in utero MRI techniques were developed to noninvasively monitor brain development during the embryonic and fetal stages. The multidimensional atlas and the MRI tools developed herein are anticipated to further our understanding of the developing primate brain., (Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.)

Some fundamental technical aspects of magnetic resonance imaging (MRI) in evaluation of iron deposition were discussed. MRI is an imaging modality sensitive to iron deposition of the brain tissue. T(2) weighted imaging (T(2)WI), T(2) weighted imaging (T(2)WI), and susceptibility-weighted imaging (SWI) are particularly available for this purpose. They are different in sensitivity and availability, and should be used in the right places respectively. Susceptibility to iron deposition is also dependent on the strength of static magnetic field, which should be taken into account in the interpretation of the images.

Study Design: Magnetic resonance imaging (MRI) study on degeneration of the thoracic spine in asymptomatic subjects., Objective: To investigate the incidence of degenerative MRI findings of the thoracic spine in asymptomatic subjects and to identify factors related to the degeneration of the thoracic discs., Summary of Background Data: Studies on age-related degenerative changes of the thoracic spine are scarce., Methods: Ninety-four asymptomatic Japanese volunteers (48 men and 46 women, mean age of 48.0 +/- 13.4 years) underwent MRI of the thoracic and cervical spine and filled the questionnaire regarding life styles. The items evaluated on MRI using a numerical grading system were (1) decrease in the signal intensity of the intervertebral discs (DSI), (2) posterior disc protrusion (PDP), (3) anterior compression of the dural sac (ACD), and (4) disc space narrowing. Association between each degenerative MRI finding and several factors, including age, sex, smoking, sports, body mass index, and degeneration of cervical spine was investigated., Results: Forty-four (46.8%) patients demonstrated positive degenerative MRI findings at 1 or more thoracic intervertebral levels. The percentage of the subjects with positive MRI findings was 37.2% in DSI, 30.9% in PDP, 29.8% in ACD, and 4.3% in disc space narrowing. The percentages of all MRI findings increased with aging. In 85 (90.4%) patients, degenerative MRI findings were positive in the cervical spine. DSI was significantly associated with age (odds ratio, 11.21, 95% confidence interval, 2.70-46.5), PDP with age (3.44, 1.02-16.61), smoking (4.94, 1.55-15.71) and presence of PDP in the cervical spine (4.25, 1.01-17.92), and ACD was associated with smoking (3.99, 1.28-12.44)., Conclusion: Degenerative changes in the thoracic spine on MRI was observed in approximately half of the asymptomatic subjects, whereas their incidences were less frequent than those in the cervical spine. Factors significantly associated with degenerative changes in the thoracic spine included age, smoking, and degeneration in the cervical spine.

Background: We conducted a prospective long-term follow-up study to assess associations between magnetic resonance imaging (MRI) findings and changes in clinical symptoms, as well as factors relating to the prognosis of symptoms., Methods: A total of 133 patients with acute whiplash injury between 1993 and 1996 participated in this follow-up study. They underwent neurological examinations by spine surgeons and second MRI scans of the cervical spine were obtained. They also filled out a questionnaire regarding cervical symptoms and the accident details. The items evaluated by MRI were (1) a decrease in the signal intensity of the intervertebral disc; (2) anterior compression of the dura and the spinal cord; (3) posterior disc protrusion; (4) disc space narrowing; and (5) foraminal stenosis. Relations between the presence/absence of degenerative changes on MRI, accident details, and patients' symptoms were assessed by calculating the adjusted odds ratio (OR)., Results: Progression of some degenerative changes was recognized on MRI in 98.5% of the 133 whiplash injury patients, and clinical symptoms diminished in more than a half of the 133 patients. There were no statistically significant associations between MRI findings and changes in clinical symptoms. The prognosis for neck pain tended to be poor after accidents with double collisions (rear-end collision followed by frontend collision) [adjusted OR 5.83, 95% confidence interval (CI) 1.15-29.71] and accidents with serious car damage (2.87, 1.03-7.99). The prognosis for stiff shoulders tended to be poor in women (2.83, 1.23-6.51); and the prognosis for numbness in the upper extremities tended to be poor after accidents with serious car damage (3.39, 1.14-10.06)., Conclusions: This study demonstrated that progression of degenerative changes of the cervical spine on MRI was not associated with clinical symptoms during the 10-year period after whiplash injury.

Purpose: To investigate whether diffusion-tensor tractography (DTT) of neuronal fibers is useful for delineating the configuration of the neuronal fiber trajectories in the primate visual pathway, including the well-developed optic chiasm, in comparison with tract tracing at manganese-enhanced magnetic resonance (MR) imaging., Materials and Methods: The handling methods used for all the animals in this study were approved by the institutional committee for animal experiments. Diffusion-tensor MR imaging was performed in four healthy common marmosets, and in two of these animals, manganese-enhanced MR imaging tract tracing was performed by using a 7.0-T MR imaging unit. The visual pathways were quantitatively investigated in terms of the manganese distribution observed on the manganese-enhanced MR images. The images obtained with DTT and manganese-enhanced MR imaging tract tracing were qualitatively compared, and the features of the visual pathway were verified through fusion of the reconstructed images obtained by using these two modalities., Results: DTT provided information regarding the neuroanatomic features of the marmoset visual pathway and revealed the bilateral branching patterns of the typical primate retinogeniculate pathways, although several incorrectly tracked fibers were noted. The distribution of manganese on the manganese-enhanced MR images revealed bilateral innervation of the retinal projections and depicted the layered internal structure of the lateral geniculate nuclei bilaterally, depending on the ocularity of each layer. These morphologic findings were consistent with those of previous histopathologic studies., Conclusion: The findings of this preliminary study raise the possibility that DTT is useful for visualizing the neuronal fiber trajectories in primate visual pathways., Supplemental Material: http://radiology.rsnajnls.org/cgi/content/full/249/3/855/DC1., (RSNA, 2008)

Prior to surgery or endovascular therapy for the lower extremity varicose veins or deep venous thrombosis (DVT), ultrasonography provides useful information. But it depends on the operator's technique, each image is limited to a small field of view and interpretation may be subjective. On the other hand, magnetic resonance (MR) imaging is now available with several postprocessing techniques using workstations to demonstrate the gross and objective morphology of these lesions less invasively than the conventional ascending venography. As non-contrast MR venography, fat suppressed three-dimensional (3D) coronal balanced turbo field echo (bTFE) is mainly applied in the semisupine position. The varicose veins on the muscle fascia are easily recognized on volume rendering and the perforating veins can be identified on maximum intensity projection (MIP) and axial multiplanar reconstructions. Gadolinium-enhanced fluid attenuated inversion recovery-bTFE is added when coexisting joint effusion or edema masks the veins. For DVT, direct thrombus imaging (DTI) using fat suppressed 3D coronal inversion recovery-prepared blood suppressed gradient echo sequence is applied. However, the signal intensity of DVT depends on the clot's age on DTI and is sometimes confusing on bTFE. After gadolinium administration, blood shows higher signal intensity than clots regardless of the age and DVT can be easily depicted as filling defects on the axial reformations and summarized on the soap bubble-MIP.

Purpose: There are a few reports on leptomeningeal high signal intensity (LMHI: ivy sign) on fluid-attenuated inversion-recovery (FLAIR) images in moyamoya disease, but the feature of this finding has not been completely understood. The purpose of this study was to characterize LMHI on FLAIR images in moyamoya disease and to assess usefulness of this finding in the diagnosis of moyamoya disease in conventional MR imaging., Material and Methods: MR imaging of 28 patients with moyamoya disease was retrospectively reviewed. The grade of LMHI on FLAIR images was classified as "absent," "minimal," "moderate" and "marked." Fifty-four hemispheres of 28 patients (2 patients had unilateral disease) were assessed for the frequency of visualization and distribution of LMHI. The correlations between LMHI on FLAIR images, moyamoya vessels on T1- and T2-weighted images and MR angiography findings were also analyzed., Results: Moderate and marked LMHI was seen in 31 out of 54 hemispheres (57%). LMHI was seen more prominently in the frontal and parietal lobes than in the temporal and occipital lobes. Although there was a tendency for LMHI on FLAIR images to be prominent in groups with moderate and marked moyamoya vessels on T1- and T2-weighted images, there was no significant correlation. More prominent LMHI was observed in the hemispheres in which cortical branches of the middle cerebral arteries were poorly visualized on MR angiography., Conclusion: Leptomeningeal high signal intensity (ivy sign) on FLAIR images is predominantly seen in the frontal and parietal lobes. Because this sign can be seen in patients with unremarkable moyamoya vessels, LMHI is a useful sign in conventional MR imaging for the diagnosis of moyamoya disease.

In hearing preservation surgery for the treatment of vestibular schwannoma (VS), one of the important factors is the determination of the origin of VS. In this study, we investigated the diagnostic significance of using an MRI obtained by the three-dimensional Fourier transform fast spin-echo technique (3D-reconstructed MRI) in order to determine the origin of VS. The subjects consisted of 20 patients with mainly intra-canalicular sized VS who underwent tumor removal at our hospital. The origin of VS was determined from the 3D-reconstructed MRI findings and the results of the caloric test. These findings were then compared with the surgical findings. In 15 out of 20 patients, the MRI findings closely corresponded to the surgical ones, while the origin of VS hardly could be detected when a tumor filled up to the fundus acoustics on the MRI findings of the axial sections. On the other hand, 6 out of 15 patients (40%) whose tumor originated from the inferior vestibular nerve showed canal paresis. In conclusion, 3D-reconstructed MRI is considered to be helpful in obtaining more precise information regarding the origin of VS compared to the caloric test.

Some evidence suggests that the primary locus of the lesion in Leber's hereditary optic neuropathy (LHON) may be intraocular rather than retrobulbar. To clarify this issue, the condition of the retrobulbar portion of the optic nerve was evaluated in patients with the acute stage of LHON. High resolution MRI with fast spin echo sequences of the optic nerve complex in the orbit was carried out. Five patients with acute stage LHON were compared with seven patients with acute stage optic neuritis. On T2 weighted fast spin echo MRI, signal changes did not appear in the retrobulbar optic nerve complex in acute stage LHON. By comparison, patients with optic neuritis showed pronounced high signals in the optic nerve. Subsequent orbital MRI in the atrophic stages of the same patients with LHON showed an increase in signal intensity in the optic nerve toward the orbital apex in both eyes. The present results support the hypothesis that a primary lesion in LHON may be intraocular.

Objective: To evaluate the orbital portion of the optic nerve and the subarachnoid space using fast spin-echo magnetic resonance imaging in normal subjects and in patients with papilledema or optic atrophy., Design: Measurements of the optic nerve complex on coronal images were made using high-resolution magnetic resonance imaging with fast spin-echo sequences., Patients: Twenty-one patients, including 5 patients with papilledema due to congenital hydrocephalus, intracranial tumors, or meningitis, as well as 16 patients with optic atrophy, were studied. Sixteen healthy volunteers served as controls., Main Outcome Measures: The longitudinal diameter of the optic nerve, the longitudinal outer diameter of the subarachnoid space, the diameter ratio, and the area of the subarachnoid space were determined., Results: In normal subjects, the ring-shaped area of high signal intensity that represented the subarachnoid space was widest behind the globe, then narrowed toward the orbital apex. In patients with papilledema, the area of the subarachnoid space was markedly dilated, the optic nerve was compressed, and the nerve sheath was widened, resulting in a small diameter ratio compared with that of controls. Patients with pallor of the temporal aspect of the optic disc appeared to exhibit dilation of the subarachnoid space; the size of the optic nerve was decreased more than that of the nerve sheath, resulting in a small diameter ratio compared with controls. Patients with complete pallor of the disc, however, exhibited hyperintense optic nerve complexes without a ring-shaped appearance toward the orbital apex., Conclusion: Fast spin-echo magnetic resonance imaging appears useful for objectively evaluating the optic nerve and surrounding subarachnoid space in patients with papilledema and optic atrophy.

Eighteen cases with bladder tumors were examined by means of superconducting MRI. Sequences used were spin echo (TR/TE (msec) = 500/20 as T1WI (weighted image) and 1500/80 as T2WI) and serial "fast spin echo (fast SE)" pre/post Gd-DTPA administration. "Fast SE" was a new technique offering a distinct T1WI (TR/TE = 100/14, utilizing a 14 second breath hold). Slice thickness of "fast SE" was 10 mm and slice plane was selected perpendicular to the tumor base to detect the extent of invasion. Serial scan of "fast SE" was performed before and immediately after 0.1 mmol/kg Gd administration. Scanning was completed before the bladder was opacified by Gd. Tumor and normal mucosa were both markedly enhanced whereas the surrounding muscle layer remained hypointense. On delayed scan, the elevated character of the tumor was outlined by opacified urine but the distinction between the mucosa and the muscle layer became unclear. Total cystectomy (TC) was performed in 6 of 18 cases and pathological tumor extension was correlated with MR findings. Transurethral resection (TUR) was performed in the remaining 12 patients, and the tumor extension was assessed by follow-up biopsy after TUR. Intact liner hypointensity indicated superficial lesions (= less than pT2), while disruption of the linear hypointensity corresponded pathologically to deep muscle invasion (= greater than pT3a). Accuracy of serial "fast SE" in tumor staging was 94% (17/18). Serial "fast SE" allowed the distinction of superficial from invasive tumors more accurately than conventional studies, and therefore assisted in choosing the correct operative method.

We present the case of an 86‐year‐old female with spontaneous spinal epidural hematoma. Although T1‐ and T2‐weighted images showed the dilated posterior epidural space at the cervical spine, this finding was non‐specific on conventional magnetic resonance imaging obtained 15 h after the onset of symptoms. Diffusion‐weighted imaging with the use of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER), which clearly revealed the high intensity hematoma, was useful for detection and diagnosis of acute spinal epidural hematoma. [ABSTRACT FROM AUTHOR]