Vulnerable carotid plaque imaging and histopathology without a dedicated MRI receiver coil.

Stroke is associated with vulnerable carotid artery plaques showing specific histopathologic features, namely a lipid-rich necrotic core, intraplaque hemorrhage, ulceration, and thin fibrous cap. While ultrasound and computed tomography (CT) can identify carotid plaques and determine the extent of stenosis, magnetic resonance imaging (MRI) provides further information regarding plaque composition and morphology. In this feasibility study, three patients with symptomatic, moderately stenosed plaques were imaged with CT angiography (CTA) and MRI (3T and 1.5T) without a dedicated receiver coil. The patients subsequently underwent carotid endarterectomy with en-bloc excision of the plaque. The CT and MR images were analyzed independently by three neuroradiologists to identify vulnerable plaque features. The images were correlated with the histopathology to confirm the findings. All three patients had one or more vulnerable plaque features on histopathology. MRI allowed for better characterization of these features when compared to CTA. The pre- and post-contrast T1-weighted (T1W) images were most helpful for identifying the lipid-rich necrotic core and thin fibrous cap, while the time of flight-magnetic resonance angiography (TOF-MRA) and contrast-enhanced (CE)-MRA were excellent for detecting plaque hemorrhage and ulceration, respectively. The 3T images showed superior spatial and contrast resolution compared to the 1.5T images for all sequences. By providing direct correlation between imaging and histopathology, this study demonstrates that 3T MRI without a dedicated surface coil is an excellent tool for assessing plaque vulnerability. In smaller hospitals or those with limited resources, it is reasonable to consider conventional MRI for patient risk stratification. Further studies are needed to determine how MRI and plaque vulnerability can be incorporated into routine clinical practice.

Magnetic resonance brain imaging in patients with visual vertigo.

INTRODUCTION: Patients with visual vertigo (VV) report dizziness provoked by moving visual surroundings. It has been suggested that these subjects develop a compensation strategy for a vestibulo-proprioceptive deficit and rely excessively on visual input. We have postulated that patients with VV might have brain abnormalities that interfere with appropriate processing of visual stimulation and performed a brain MRI study to verify this hypothesis. MATERIALS AND METHODS: Patients with VV of more than 3 months duration were included. They were asked to complete the Situational Characteristic Questionnaire (SCQ) that scores for the symptoms of VV. Dizzy patients without VV served as controls. A brain MRI was performed with a Siemens 1.5 Tesla scanner in patients and controls. RESULTS: Twenty-four patients with VV were included. Their mean SCQ score was 1.45 ± 0.9 (normal 0.16 ± 0.28). In 50% of patients, abnormalities in MRI imaging were found. Thirty-three percent of 27 controls demonstrated an abnormal brain MRI. The two groups were similar in respect to the prevalence of a localized hemispheric or posterior fossa lesion (P = 0.13), but VV patients had more unspecific white matter brain changes than controls (P = 0.009). Patients and controls did not differ in age and gender distribution (P = 0.9) or the history of a neurotological event preceding their symptoms (P = 0.3). CONCLUSIONS: Our study suggests that multiple white matter lesions might contribute to occurrence of the phenomenon of VV. Future prospective large-scale studies by specific MR techniques are indicated to validate our preliminary findings and elucidate the pathological mechanism of VV.

Hyperbaric oxygen may induce angiogenesis in patients suffering from prolonged post-concussion syndrome due to traumatic brain injury.

PURPOSE: Recent clinical studies present convincing evidence that hyperbaric oxygen therapy (HBOT) may be the coveted neurotherapeutic method for brain repair. One of the most interesting ways in which HBOT can induce neuroplasticity is angiogenesis. The objective in this study was to assess the neurotherapeutic effect of HBOT in post TBI patients using brain perfusion imaging and clinical cognitive functions. METHODS: Retrospective analysis of patients suffering from chronic neuro-cognitive impairment from TBI treated with HBOT. The HBOT protocol included 60 daily HBOT sessions, 5 days per week. All patients had pre and post HBOT objective computerized cognitive tests (NeuroTrax) and brain perfusion MRI. RESULTS: Ten post-TBI patients were treated with HBOT with mean of 10.3±3.2 years after their injury. After HBOT, whole-brain perfusion analysis showed significantly increased cerebral blood flow and cerebral blood volume. Clinically, HBOT induced significant improvement in the global cognitive scores (p = 0.007). The most prominent improvements were seen in information processing speed, visual spatial processing and motor skills indices. CONCLUSION: HBOT may induce cerebral angiogenesis, which improves perfusion to the chronic damage brain tissue even months to years after the injury.

Acceptance of forensic imaging in Israel.

BACKGROUND: Forensic imaging was officially introduced in Israel in 2011. Religious and cultural opposition to autopsies prevails in most of the population of Israel. OBJECTIVES: To examine the extent to which forensic imaging has been accepted as an adjuvant or partial replacement of forensic autopsy, particularly among those opposed to forensic autopsy. METHODS: The study was conducted in the pediatric population. Data were collected from the National Center of Forensic Medicine and Assaf Harofeh Medical Center during the 18 month period following the introduction of forensic imaging (group A). The data were compared to those of the previous 18 months (group B). The examined parameters were cases submitted, examined, autopsied or imaged depending on family consent. RESULTS: Consent to autopsy was similar in both groups (A = 56% vs. B = 54%). In group A, consent for imaging was 24% of all cases, and of those imaged 77% underwent autopsy. Of those examined externally only, 16% consented to imaging. For 7% of the total cases in group A, estimation of cause of death was based on virtopsy alone. CONCLUSIONS: In a country with a high level of religious and cultural opposition to autopsy, it is a challenge to add forensic imaging to the pediatric forensic investigation. Those consenting to forensic imaging are more likely to be those consenting to autopsy. Consent for forensic imaging only was given in 7% of cases. Greater efforts should be invested to educate and inform the public regarding the benefits of virtual autopsy and the importance of data acquired from forensic images.

Contrast-Enhanced Computed Tomography as a Necessary Scan in Acute Stroke: A Case Series.

BACKGROUND: We present a number of exemplary cases where the diagnostic value of the contrast-enhanced computed tomography (CT) after CT angiography in our acute stroke imaging protocol was of fundamental clinical significance. METHODS: We retrospectively reviewed 7 cases presented to the emergency room, between 2012 and 2014, suspected of acute stroke, with findings diagnosed by the contrast-enhanced CT. RESULTS: Seven exemplary cases: acute midbrain infarct versus posterior-fossa artefact differentiation in contrast-enhanced CT; differentiation between an M1 occlusion and an internal carotid artery dissection in contrast-enhanced CT; diagnosis of veno-occlusive disease rather than arterial occlusion; bleeding arterial aneurysm revealed by contrast-enhanced CT; previously unsuspected sinus vein thrombosis; sinus vein thrombosis suspected in CT angiography, ruled out by contrast-enhanced CT; and space occupying lesion clearly diagnosed by contrast-enhanced CT. CONCLUSIONS: Adding contrast-enhanced CT as a part of the acute stroke imaging protocol presents additional diagnoses and avoids pitfalls. Therefore, we consider the contrast-enhanced CT to be essential to the acute stroke setting imaging protocol.

The relationship between ureteral stone characteristics and secondary signs in renal colic.

PURPOSE: To assess correlations between stone size/location and severity of secondary signs for ureteral obstruction. METHODS: Unenhanced multi-detector computed tomography examinations of 150 patients with acute renal colic were reviewed. Stone size, location in the ureter, kidney size and Hounsfield unit values, perinephric edema, and degree of hydronephrosis were assessed. RESULTS: Pale kidney sign was detected in 36%. Hydronephrosis was mild in 63% and severe in 21%; severe hydronephrosis was associated with larger stones. Mid-ureter and ureteropelvic junction stones were more likely to cause hydronephrosis. Perinephric edema (56%) was not correlated with stone size/location. CONCLUSION: Only severe hydronephrosis was significantly associated with larger stone size.

Coronal reconstruction of unenhanced abdominal CT for correct ureteral stone size classification.

PURPOSE: To determine whether size measurement of a urinary calculus in coronal reconstruction of computed tomography (CT) differs from stone size measured in the axial plane, and whether the difference alters clinical decision making. METHODS: We retrospectively reviewed unenhanced CT examinations of 150 patients admitted to the emergency room (ER) with acute renal colic. Maximal ureteral calculus size was measured on axial slices and coronal reconstructions. Clinical significance was defined as an upgrading or downgrading of stone size according to accepted thresholds of treatment: < or =5 mm, 6-9 mm and > or =10 mm. RESULTS: There were 151 stones in 150 patients (male:female 115:34, mean age 41 years). Transverse stone diameters ranged from 1 to 11 mm (mean 4 mm). On coronal images, 56 (37%) stones were upgraded in severity; 46 (30%) from below 5 mm to 6 mm or more, and ten (7%) from 6-9 mm to 10 mm or more. Transverse measurement on the axial slices enabled correct categorization of 95 stones (63%). CONCLUSION: Transverse calculus measurement on axial slices often underestimates stone size and provides incorrect clinical classification of the true maximal stone diameter. Coronal reconstruction provides additional information in patients with renal colic that may alter treatment strategy.