DBS-implanted Parkinson\u27s Disease Patients Show Better Olfaction Than Those Treated Medically

Dysosmia in PD (Parkinson’s Disease) may result from changes in the olfactory apparatus or in structures involved in olfactory perception. Previous work1,2 has suggested that deep brain stimulation (DBS) pa-tients have improved odor discrimination in stimulation-on/medication-off state in comparison to their own scores in a stimulation-off/medication-off state. What remains unclear is whether it is the ON state itself or an effect of stimulation that leads to improved olfaction. In this study we evaluate dysosmia in two PD cohorts in the ON state, those treated with medication alone and those treated with medication and DBS. A prospective study geared at improving predictive value of olfactory testing with a battery of psychological tests enrolled 45 PD patients and 44 controls. Of the PD patients, 9 had bilateral STN (subthalamic nucleus) DBS and 36 were medically treated. Subset analysis of PD patients with and without DBS placement revealed no difference in apathy or depression. DBS patients had better olfaction on UPSIT (Univ of Pennsylvania Smell Identification Test) (p This study provides further data that DBS patients have improved ol-faction. It also provides preliminary evidence that DBS with medica-tion improves dysosmia to a greater extent than medication alone. This may result from indirect stimulation of olfactory processing cen-ters or changes in olfactory circuitry metabolism

Nontraumatic brain parenchymal hemorrhage: The usual suspects and more

Brain parenchymal hemorrhage is a common neuroimaging finding in an emergency room. It is considered primary in the absence of an underlying lesion or coagulopathy. Secondary hemorrhages are caused by various structural causes and pathologies. The goals of imaging are to identify the hematoma, assess factors that have prognostic significance, assess associated complications, identify an underlying etiology whenever possible, and guide therapeutic decisions. The review provides an illustrative review of various etiologies of non-traumatic brain parenchymal hemorrhage and their imaging evaluation

Vertebral artery ostial stenosis: prevalence by digital subtraction angiography, MR angiography, and CT angiography

BACKGROUND AND PURPOSE: (1) To determine the prevalence of vertebral arterial ostial stenosis (VOS) as determined by the gold standard of digital subtraction angiography (DSA). (2) To learn the correlation between vertebral ostial stenosis and study indication. (3) To determine the ability of contrast-enhanced magnetic resonance angiography (CE MRA) and computed tomographic angiography (CTA) to reflect the true prevalence of vertebral ostial stenosis as determined by DSA. METHODS: Three hundred and twenty-nine patients who underwent DSA had recorded evaluation of 443 vertebral artery origins. Cases were categorized by patient age and study indication. Similar numbers of CTA and MRA studies were assessed. RESULTS: The prevalence of VOS in the study population was 5.4%. VOS was not observed in patients under 40 years of age, and was seen in 12.5% of patients over 70 years. CE MRA demonstrated decreased signal at the vertebral origins consistent with stenosis in 20% of patients. CTA estimated VOS at .8%, and yielded 7.3% of studies, which were nondiagnostic for VOS. CONCLUSION: The prevalence of VOS as determined by DSA is low and increases with patient age and correlates with factors such as anterior infarct (18.4%), posterior infarct (33.3%), carotid atherosclerosis (30.8%), and vertebrobasilar insufficiency (33%). Patients being evaluated for reasons less closely correlated with atherosclerotic disease, such as arteriovenous malformation (AVM) or hemorrhage showed a lower prevalence of VA stenosis (brain aneurysm or AVM 5/121, 4.1%, brain hemorrhage 5/153, 3.3%). Routine clinical MRA significantly overestimates VOS prevalence, and findings suggest that CTA underestimates the degree and prevalence of VOS

MR imaging of acute cervical spinal ligamentous and soft tissue trauma

The increasing availability of magnetic resonance imaging (MRI) and the high sensitivity of MRI for soft tissue injury are resulting in the increased use of MRI for the evaluation of acute trauma. As cervical spine injury can have a devastating consequence, MRI is being more commonly used to evaluate cervical spine injury in the acute setting, necessitating emergent interpretation by the on-call radiologist. Unless one is formally trained in a trauma center, the MRI findings of soft tissue and ligamentous cervical spine injury may not be fully appreciated. The goal of this pictorial review is to familiarize the reader with some of the more common soft tissue, vascular, and ligamentous injuries seen on MRI of the cervical spine in the emergent setting

Role of noncontrast head CT in the assessment of vascular abnormalities in the emergency room

Noncontrast CT of the head is a widely used noninvasive investigation for a variety of acute and chronic neurological conditions. Since CT head without contrast is usually the first and often the only investigation in the emergency room for many neurological symptoms, it is imperative to detect subtle vascular changes, which in many patients can be life-saving. The vascular abnormalities may present with increased density and/or size of the vessels, filling defects, and be associated with parenchymal and bony changes. In this article, we present examples of several vascular pathologies which can be identified on the noncontrast CT of the head, and learn imaging and interpretation techniques to help recognize what often are nebulous changes. While some of the findings are diagnostic by themselves and others subtle, any suspicious abnormality should be followed with dedicated vascular imaging such as CT/MR angiogram, venogram, or catheter angiogram for confirmation and better characterization

Improved image quality and detection of small cerebral infarctions with diffusion-tensor trace imaging

OBJECTIVE: The purpose of this study was to test a hypothesis that routinely performed diffusion-tensor trace imaging is of sufficient image quality and sensitivity for infarct detection to safely and routinely replace standard diffusion-weighted imaging (DWI) in the clinical setting. MATERIALS AND METHODS: Both routine DWI and 15-direction diffusion-tensor imaging (DTI) with parallel acquisition technique were obtained on all brain MRI studies from a single 1.5-T MRI scanner at a tertiary care referral center over a 1-year period, permitting direct comparison of the two different diffusion studies on the same patients (2537 studies, 365 infarct-positive studies). A subset of images was assessed for image quality and quantitatively for ability to detect brain infarctions. The total set of positive studies was reviewed qualitatively for ability to detect small cerebral infarctions. RESULTS: Fifteen-direction isotropic DWI (DTI trace images) with parallel acquisition technique resulted in consistently higher image quality with less distortion and higher image detail than routine DWI. Small infarcts were better seen, and in 12 cases, infarcts could only be seen on 15-direction isotropic diffusion-weighted images. The additional scanning time required for 15-direction isotropic DWI did not result in significantly increased motion-related reduction in image quality compared with standard DWI. CONCLUSION: Diffusion-tensor trace images obtained with parallel acquisition technique are of improved image quality and improved sensitivity for detection of small cerebral infarctions relative to standard DWI. If such DTI data are acquired, routine DWI can be omitted

Paramagnetic Rim Lesions in Multiple Sclerosis: Comparison of Visualization at 1.5-T and 3-T MRI

Background: Multiple sclerosis (MS) is characterized by both acute and chronic intrathecal inflammation. A subset of MS lesions show paramagnetic rims on susceptibility-weighted MRI sequences, reflecting iron accumulation in microglia. These paramagnetic rim lesions (PRLs) have been proposed as a marker of compartmentalized smoldering disease. PRLs have been demonstrated at 7 T and, more recently, at 3 T. As susceptibility effects are weaker at lower field strength, it remains unclear if PRLs are visible at 1.5 T. Objective: To compare the visualization of PRLs using susceptibility-weighted imaging at 1.5-T and 3-T MRI in patients with MS. Methods: This retrospective study included 9 patients (5 women, 4 men; mean age, 46.8 years) with MS who underwent both 1.5-T and 3-T MRI using a comparable susceptibility-weighted sequence from the same manufacturer (GE SWAN). Lesions measuring \u3e3 mm were annotated. Two reviewers independently assessed images at each field strength in separate sessions, classifying the annotated lesions based on susceptibility-weighted images as isointense, diffusely paramagnetic, or PRL. Discrepancies were discussed at consensus sessions including a third reviewer. Agreement was assessed using kappa coefficients. Results: Of 140 annotated lesions, based on the 3-T consensus readings, 115 (82%) were isointense, 16 (11%) were diffusely paramagnetic, and 9 (6%) were PRLs; based on the 1.5-T consensus readings, 115 (82%) were isointense, 14 (10%) were diffusely paramagnetic, and 11 (8%) were PRLs. Mean lesion diameter was 11.9 mm for PRLs, versus 6.4 mm for diffusely paramagnetic lesions (p=.006) and 7.8 mm for isointense lesions (p=.003). Interrater agreement for lesion classification as PRL was substantial at 1.5 T (kappa=0.65) and 3 T (kappa=0.70). Agreement for PRL was also substantial between the consensus readings at the two field strengths (kappa=0.79). Conclusion: We show comparable identification of PRLs at 1.5-T and 3-T MRI, with substantial interrater agreement at both field strengths and substantial consensus agreement between the field strengths. Clinical Impact: PRL may be an emerging marker of chronic neuroinflammation in MS. Their visibility at 1.5 T supports the translational potential of PRL identification to more widespread clinical settings, where 1.5-T scanners are prevalent

MRI Findings of Injury to the Longus Colli Muscle in Patients With Neck Trauma

OBJECTIVE: The longus colli muscle (LCM) forms the bulk of the deep flexor muscles of the neck. To our knowledge, very little information on the effects of trauma on this muscle group has been published. We describe MRI findings related to injury of the LCM in patients with a history of neck trauma. MATERIAL AND METHODS: A radiology department database was searched to identify patient medical records from 2008 to 2013 that included the keywords longus colli and deep flexors. Patients with fractures and ligament injuries were excluded. Patients with other obvious large soft-tissue injuries and nontraumatic conditions were also omitted. A total of 12 patients met the inclusion criterion of having an isolated or predominant injury to the LCM. Five patients had been involved in a motor vehicle accident, and seven patients had fallen. Eleven patients had undergone a CT examination before MRI was performed. RESULTS: No fractures were noted on CT. MRI examinations of the cervical spine were obtained for the following reasons: for increased prevertebral soft-tissue swelling noted on a CT scan plus neck pain (n = 6), for neck pain only (n = 4), or as part of a routine protocol for assessment of obtunded patients (n = 2). Eight of the 12 patients had isolated injury to the LCM. The remaining four patients also had minor injuries to the other neck muscles. The MR image showed swelling and T2 hyperintensity in the LCM and revealed free fluid in the prevertebral space. CONCLUSION: Isolated injury to the LCM may occur in neck injuries. The MRI findings indicating such injury include increased T2 signal, swelling of the muscle, and the presence of prevertebral fluid

Sinus pericranii with a hair collar sign

Sinus pericranii is a rare vascular malformation in which the extracranial veins are connected to the intracranial venous circulation. It typically appears as a soft mass with a blue hue on the scalp. We describe a patient with sinus pericranii and associated hair collar sign

Flow artifact in the anterior communicating artery resembling aneurysm on the time of flight MR angiogram

BACKGROUND: Magnetic resonance angiogram (MRA) of the brain is a widely employed non-invasive test to diagnose aneurysms. However, its overall accuracy is less than digital subtraction angiography and is prone to give false-positive or false-negative results. False-negative results can be seen with hemorrhage, lipoma, dermoid, posterior lobe of the pituitary gland, and the flow artifacts. PURPOSE: To describe the findings associated with false aneurysms in the anterior communicating artery on the time of flight MRA and review the physical principles behind this artifact. MATERIAL AND METHODS: This short series comprises of four patients whose MRA showed suspicious aneurysms in the region of the anterior communicating artery (ACOM) on time of flight MRA. RESULTS: Two patients underwent catheter angiogram and the other two patients had computed tomography angiogram. None of these cases proved to have aneurysms and normal anterior communicating arteries were seen in all the patients. The findings on the MR angiograms were considered artifacts. All of the pseudoaneurysm had tapered appearance. CONCLUSION: MR angiogram can result in artifacts at ACOM which may be mistaken for aneurysm. Such pseudoaneurysms have characteristic appearance and should be followed up with non-invasive tests