FLAIR Vascular Hyperintensities as a Surrogate of Collaterals in Acute Stroke: DWI Matters

BACKGROUND AND PURPOSE

FLAIR vascular hyperintensities are thought to represent leptomeningeal collaterals in acute ischemic stroke. However, whether all-FLAIR vascular hyperintensities or FLAIR vascular hyperintensities-DWI mismatch, ie, FLAIR vascular hyperintensities beyond the DWI lesion, best reflects collaterals remains debated. We aimed to compare the value of FLAIR vascular hyperintensities-DWI mismatch versus all-FLAIR vascular hyperintensities for collateral assessment using PWI-derived collateral flow maps as a reference.

MATERIALS AND METHODS

We retrospectively reviewed the registries of 6 large stroke centers and included all patients with acute stroke with anterior circulation large-vessel occlusion who underwent MR imaging with PWI before thrombectomy. Collateral status was graded from 1 to 4 on PWI-derived collateral flow maps and dichotomized into good (grades 3-4) and poor (grades 1-2). The extent of all-FLAIR vascular hyperintensities and FLAIR vascular hyperintensities-DWI mismatch was assessed on the 7 cortical ASPECTS regions, ranging from 0 (absence) to 7 (extensive), and associations with good collaterals were compared using receiver operating characteristic curves.

RESULTS

Of the 209 included patients, 133 (64%) and 76 (36%) had good and poor collaterals, respectively. All-FLAIR vascular hyperintensity extent was similar between collateral groups (P = .76). Conversely, FLAIR vascular hyperintensities-DWI mismatch extent was significantly higher in patients with good compared with poor collaterals (P < .001). The area under the curve was 0.80 (95% CI, 0.74-0.87) for FLAIR vascular hyperintensities-DWI mismatch and 0.52 (95% CI, 0.44-0.60) for all-FLAIR vascular hyperintensities (P < .001 for the comparison), to predict good collaterals. Variables independently associated with good collaterals were smaller DWI lesion volume (P < .001) and larger FLAIR vascular hyperintensities-DWI mismatch (P = .02).

CONCLUSIONS

In acute ischemic stroke with large-vessel occlusion, the extent of FLAIR vascular hyperintensities does not reliably reflect collateral status unless one accounts for DWI.

Spinal epidural capillary hemangioma: a systematic literature review and an illustrative case

BACKGROUND

Spinal hemangiomas are rare vascular malformations resulting from proliferation of vascular endothelial cells. The cavernous form is the most common and represents 5-12% of spinal vascular malformations, while the capillary form is rare.

CASE DESCRIPTION

A 56-year-old patient with no past medical history presented with progressive spinal cord compression symptoms localizing to the T10 level with MRC grade 4 proximal paraparesis. Preoperative MRI demonstrated a well-delineated, dumbbell-shaped, epidural lesion, without bony involvement, resulting in spinal cord compression at the T7 and T8 levels. The patient underwent gross total surgical resection of the lesion. At the one month follow up, the patient's strength improved to MRC grade 5, and sensation had fully returned. The histopathological diagnosis was a capillary hemangioma. Exclusively epidural capillary hemangiomas are extremely rare with only 26 cases reported in the literature. They are mainly located at the thoracic level (T4-T6). The MRI features include a well-circumscribed mass, hyperintense on T2-weighted sequence in 92% of cases, isointense on T1-weighted sequence in 88% of cases, and homogeneous contrast enhancement in 100% of cases. No tumor recurrence has been observed after gross total surgical removal.

CONCLUSIONS

When evaluating progressive spinal cord compression by a purely epidural spinal lesion, the differential diagnosis should include capillary hemangioma, in addition to schwannoma, meningioma, and lymphoma. Early and complete surgical removal is the first line treatment.

Clot Burden Score and Collateral Status and Their Impact on Functional Outcome in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Collateral status and thrombus length have been independently associated with functional outcome in patients with acute ischemic stroke. It has been suggested that thrombus length would influence functional outcome via interaction with the collateral circulation. We investigated the individual and combined effects of thrombus length assessed by the clot burden score and collateral status assessed by a FLAIR vascular hyperintensity-ASPECTS rating system on functional outcome (mRS).

MATERIALS AND METHODS

Patients with anterior circulation acute ischemic stroke due to large-vessel occlusion from the ASTER and THRACE trials treated with endovascular thrombectomy were pooled. The clot burden score and FLAIR vascular hyperintensity score were determined on MR imaging obtained before endovascular thrombectomy. Favorable outcome was defined as an mRS score of 0-2 at 90 days. Association of the clot burden score and the FLAIR vascular hyperintensity score with favorable outcome (individual effect and interaction) was examined using logistic regression models.

RESULTS

Of the 326 patients treated by endovascular thrombectomy with both the clot burden score and FLAIR vascular hyperintensity assessment, favorable outcome was observed in 165 (51%). The rate of favorable outcome increased with clot burden score (smaller clots) and FLAIR vascular hyperintensity (better collaterals) values. The association between clot burden score and functional outcome was significantly modified by the FLAIR vascular hyperintensity score, and this association was stronger in patients with good collaterals, with an adjusted OR = 6.15 (95% CI, 1.03-36.81).

CONCLUSIONS

The association between the clot burden score and functional outcome varied for different collateral scores. The FLAIR vascular hyperintensity score might be a valuable prognostic factor, especially when contrast-based vascular imaging is not available.

Benefit of first-pass complete reperfusion in thrombectomy is mediated by limited infarct growth

BACKGROUND AND PURPOSE

The number of clot retrieval attempts required to achieve complete reperfusion by mechanical thrombectomy impacts functional outcome in acute ischaemic stroke (AIS). Complete reperfusion [expanded Treatment In Cerebral Infarction (eTICI) score = 3] at first pass (FP), is associated with the highest rates of favorable outcome compared to complete reperfusion by multiple passes. The aim of the present study was to investigate the relationship between FP complete reperfusion and infarct growth (IG).

METHODS

Anterior AIS patients with baseline and 24-h diffusion-weighted magnetic resonance imaging were included from two prospective registries. IG was measured by voxel-based segmentation of initial and 24-h diffusion-weighted imaging lesions. IG and favorable 3-month modified Rankin Scale (mRS) score (≤ 2) were compared between patients in whom complete reperfusion (eTICI 3) was achieved with a single pass (FP group) and those for whom multiple passes were required (MP group), after matching for confounding factors. Mediation analysis was performed to examine the association between FP and 3-month mRS score, with IG as mediating variable.

RESULTS

A total of 200 patients were included, of whom 118 (28.9%) had FP complete reperfusion. In case-control analysis, the FP group had lower IG than the MP group [8.7 (5.4-12.9) ml vs. 15.2 (11-22.6) ml, respectively; P = 0.03). Favorable outcome was higher in the FP population compared to a matched MP population (70.9% vs. 53.2%, respectively; P = 0.04). FP compete reperfusion (eTICI 3) was independently associated with favorable outcome in multivariable regression analysis [odds ratio 1.86, 95% confidence interval (CI) 1.01-4.39; P = 0.04]. The effect of complete reperfusion at FP on functional outcome was explained by limited IG in mediation analysis [indirect effect: -0.32 (95% CI -0.47 to -0.09)].

CONCLUSION

Complete reperfusion at FP is independently associated with significant decrease in IG compared to complete reperfusion by multiple attempts, explaining better functional outcomes.

Symptomatic progestin-associated atypical grade II meningioma. A first case report

BACKGROUND

Long-term use of high-dose progestin is known to promote the development of meningioma. Atypical meningioma in a patient under progestin has not previously been reported.

CASE REPORT

A 53-year-old right-handed woman presented with focal onset seizures, without impaired consciousness. Medical history featured endometriosis, treated successively by cyproterone acetate 25mg/day for 2 months then 50mg/day for 101 months, and chlormadinone acetate 5mg/day for 68 months then 10mg/day for 83 months. Brain MRI revealed multiple extra-axial lesions suggestive of left central meningioma associated with anterior skull base meningiomatosis. Surgical resection of the left central meningioma was achieved and progestin was withdrawn. Neuropathology diagnosed grade II atypical meningioma. Close clinical and imaging monitoring was implemented without adjuvant oncological treatment. At 25 months, imaging follow-up showed no recurrence of the left central meningioma and a significant regression of all other lesions, except for the right frontal lesion.

CONCLUSIONS

Neurosurgeons should be aware of the possible aggressiveness of meningioma in patients under progestin, and particularly those treated by different types of progestin over a long period of time without interruption. This may require systematic close monitoring, to adapt neurosurgical management.

Anatomical and functional MR imaging to define tumoral boundaries and characterize lesions in neuro-oncology

Neuroimaging and especially MRI has emerged as a necessary imaging modality to detect, measure, characterize and monitor brain tumours. Advanced MRI sequences such as perfusion MRI, diffusion MRI and spectroscopy as well as new post-processing techniques such as automatic segmentation of tumours and radiomics play a crucial role in characterization and follow up of brain tumours. The purpose of this review is to provide an overview on anatomical and functional MRI use for brain tumours boundaries determination and tumour characterization in the specific context of radiotherapy. The usefulness of anatomical and functional MRI on particular challenges posed by radiotherapy such as pseudo progression and pseudo esponse and new treatment strategies such as dose painting is also described.

Two-Layered Susceptibility Vessel Sign and High Overestimation Ratio on MRI Are Predictive of Cardioembolic Stroke

In a prospective study among patients in the THRombectomie des Artères Cerebrales trial, we analyzed the diagnostic accuracy of 2 imaging biomarkers, the 2-layered susceptibility vessel sign and a high overestimation ratio, obtained on pretreatment brain T2* sequences, to identify cardioembolic stroke etiology (107/260 patients). In combination, these 2 biomarkers, on 1.5T or 3T systems (159 and 101 patients, respectively), demonstrated high specificity (0.77 at 1.5T and 1 at 3T) and their simultaneous presence is highly associated with cardioembolism.

Do Fluid-Attenuated Inversion Recovery Vascular Hyperintensities Represent Good Collaterals before Reperfusion Therapy?

BACKGROUND AND PURPOSE

In acute ischemic stroke, whether FLAIR vascular hyperintensities represent good or poor collaterals remains controversial. We hypothesized that extensive FLAIR vascular hyperintensities correspond to good collaterals, as indirectly assessed by the hypoperfusion intensity ratio.

MATERIALS AND METHODS

We included 244 consecutive patients eligible for reperfusion therapy with MCA stroke and pretreatment MR imaging with both FLAIR and PWI. The FLAIR vascular hyperintensity score was based on ASPECTS, ranging from 0 (no FLAIR vascular hyperintensity) to 7 (FLAIR vascular hyperintensities abutting all ASPECTS cortical areas). The hypoperfusion intensity ratio was defined as the ratio of the time-to-maximum >10-second over time-to-maximum >6-second lesion volumes. The median hypoperfusion intensity ratio was used to dichotomize good (low hypoperfusion intensity ratio) versus poor (high hypoperfusion intensity ratio) collaterals. We then studied the association between FLAIR vascular hyperintensity extent and hypoperfusion intensity ratio.

RESULTS

Hypoperfusion was present in all patients, with a median hypoperfusion intensity ratio of 0.35 (interquartile range, 0.19-0.48). The median FLAIR vascular hyperintensity score was 4 (interquartile range, 3-5). The FLAIR vascular hyperintensities were more extensive in patients with good collaterals (hypoperfusion intensity ratio ≤0.35) than with poor collaterals (hypoperfusion intensity ratio >0.35; P for Trend = .016). The FLAIR vascular hyperintensity score was independently associated with good collaterals (P for Trend = .002).

CONCLUSIONS

In patients eligible for reperfusion therapy, FLAIR vascular hyperintensity extent was associated with good collaterals, as assessed by the pretreatment hypoperfusion intensity ratio. The ASPECTS assessment of FLAIR vascular hyperintensities could be used to rapidly identify patients more likely to benefit from reperfusion therapy.

MRI for in vivo diagnosis of cerebral amyloid angiopathy: Tailoring artifacts to image hemorrhagic biomarkers

Cerebral amyloid angiopathy (CAA) is a frequent age-related small vessel disease (SVD) with cardinal magnetic resonance imaging (MRI) signatures that are hemorrhagic in nature, and include the presence of strictly lobar (superficial) cerebral microbleeds and intracerebral hemorrhages as well as cortical superficial siderosis. When investigating a patient with suspected CAA in the context of intracranial hemorrhage (parenchymal or subarachnoid) or cognitive dysfunction, various MRI parameters influence the optimal detection and characterization (and prognostication) of this frequent SVD. The present report describes the influence of imaging techniques on the detection of the key hemorrhagic CAA imaging signatures in clinical practice, in research studies, and the imaging parameters that must be understood when encountering a CAA patient, as well as reviewing CAA literature.

Subarachnoid hemorrhage in ten questions

Traumatic subarachnoid hemorrhage (SAH) has an annual incidence of 9 per 100 000 people. It is a rare but serious event, with an estimated mortality rate of 40% within the first 48hours. In 85% of cases, it is due to rupture of an intracranial aneurysm. In the early phase, during the first 24hours, cerebral CT, combined with intracranial CT angiography is recommended to make a positive diagnosis of SAH, to identify the cause and to investigate for an intracranial aneurysm. Cerebral MRI may be proposed if the patient's clinical condition allows it. FLAIR imaging is more sensitive than CT to demonstrate a subarachnoid hemorrhage and offers greater degrees of sensitivity for the diagnosis of restricted subarachnoid hemorrhage in cortical sulcus. A lumbar puncture should be performed if these investigations are normal while clinical suspicion is high.

Susceptibility vessel sign on T2* magnetic resonance imaging and recanalization results of mechanical thrombectomy with stent retrievers: a multicentre cohort study

BACKGROUND AND PURPOSE

The susceptibility vessel sign (SVS) on T2*-weighted magnetic resonance imaging has been reported in several studies as a negative predictor of early recanalization after intravenous thrombolysis. The meaning of SVS regarding the results of mechanical thrombectomy with stent retrievers was investigated.

METHODS

Susceptibility vessel sign presence and length were studied in 153 acute ischaemic stroke patients (82 men; mean ± SD age 59 ± 17 years, baseline National Institutes of Health Stroke Scale score 17.2 ± 6.5) from three stroke centres, treated with either mechanical thrombectomy alone (n = 84) or bridging therapy (n = 69). Variables were compared between recanalizers, defined as thrombolysis in cerebral infarction (TICI) scores ≥2b, and non-recanalizers (TICI<2b).

RESULTS

The SVS was present in 113 (73.8%) patients. There was no association between the presence of SVS and recanalization, obtained in 86 (56.2%) patients, in the whole population [odds ratio (OR) 1.24, 95% confidence interval (CI) 0.53-2.92, P = 0.84) and in treatment subgroups (bridging: OR = 0.91, 95% CI 0.29-2.87, P = 1.0; thrombectomy alone: OR = 1.85, 95% CI 0.48-7.16, P = 0.54). However, in SVS+ patients, recanalization decreased with SVS length (OR 0.94 for each additional mm, 95% CI 0.89-0.99; P = 0.02).

CONCLUSIONS

The success of recanalization in acute stroke patients treated with stent retrievers was related to thrombus length but not to the presence of SVS.

Fast contrast-enhanced 4D MRA and 4D flow MRI using constrained reconstruction (HYPRFlow): potential applications for brain arteriovenous malformations

BACKGROUND AND PURPOSE

HYPRFlow is a novel imaging strategy that provides fast, high-resolution contrast-enhanced time-resolved images and measurement of the velocity of the entire cerebrovascular system. Our hypothesis was that the images obtained with this strategy are of adequate diagnostic image quality to delineate the major components of AVMs.

MATERIALS AND METHODS

HYPRFlow and 3D TOF scans were obtained in 21 patients with AVMs with correlative DSA examinations in 14 patients. The examinations were scored for image quality and graded by using the Spetzler-Martin criteria. Mean arterial transit time and overlap integrals were calculated from the dynamic image data. Volume flow rates in normal arteries and AVM feeding arteries were measured from the phase contrast data.

RESULTS

HYPRFlow was equivalent to 3D-TOF in delineating normal arterial anatomy, arterial feeders, and nidus size and was concordant with DSA for AVM grading and venous drainage in 13 of the 14 examinations. Mean arterial transit time on the AVM side was 0.49 seconds, and on the normal contralateral side, 2.53 seconds with P < .001. Across all 21 subjects, the mean arterial volume flow rate in the M1 segment ipsilateral to the AVM was 4.07 ± 3.04 mL/s; on the contralateral M1 segment, it was 2.09 ± 0.64 mL/s. The mean volume flow rate in the largest feeding artery to the AVM was 3.86 ± 2.74 mL/s.

CONCLUSIONS

HYPRFlow provides an alternative approach to the MRA evaluation of AVMs, with the advantages of increased coverage, 0.75-second temporal resolution, 0.68-mm isotropic spatial resolution, and quantitative measurement of flow in 6 minutes.

Do FLAIR vascular hyperintensities beyond the DWI lesion represent the ischemic penumbra?

BACKGROUND AND PURPOSE

In acute stroke with proximal artery occlusion, FLAIR vascular hyperintensities observed beyond the boundaries of the cortical lesion on DWI (newly defined "FLAIR vascular hyperintensity-DWI mismatch") may be a marker of tissue at risk of infarction. Our aim was to compare the occurrence of FLAIR vascular hyperintensity-DWI mismatch relative to that of perfusion-weighted imaging-DWI mismatch in patients with proximal MCA occlusion before IV thrombolysis.

MATERIALS AND METHODS

In 141 consecutive patients with proximal MCA occlusion, 2 independent observers analyzed FLAIR images for the presence of FLAIR vascular hyperintensity-DWI mismatch before IV thrombolysis. PWI-DWI mismatch was defined as Volumehypoperfusion > 1.8 × VolumeDWI, with Volumehypoperfusion > 6 seconds on time to maximum value of the residue function maps in the 94 patients with available PWI. The presence of FLAIR vascular hyperintensity-DWI mismatch, PWI-DWI mismatch, and infarct growth on 24-hour follow-up DWI was compared.

RESULTS

A FLAIR vascular hyperintensity-DWI mismatch was present in 102/141 (72%) patients, with an excellent interobserver reliability (κ = 0.91), and a PWI-DWI mismatch, in 61 of the 94 (65%) patients with available PWI. FLAIR vascular hyperintensity-DWI mismatch predicted PWI-DWI mismatch with a sensitivity of 92% (95% CI, 85%-99%) and a specificity of 64% (95% CI, 47%-80%). Patients with FLAIR vascular hyperintensity-DWI mismatch had smaller initial DWI lesion and larger infarct growth (P < .001) than patients without FLAIR vascular hyperintensity-DWI mismatch, even though their final infarcts remained smaller (P < .001).

CONCLUSIONS

Albeit being moderately specific, probably due to inclusion of oligemic tissue, the FLAIR vascular hyperintensity-DWI mismatch identifies large PWI-DWI mismatch with high sensitivity.

Oedema-based model for diffuse low-grade gliomas: application to clinical cases under radiotherapy

OBJECTIVES

Diffuse low-grade gliomas are characterized by slow growth. Despite appropriate treatment, they change inexorably into more aggressive forms, jeopardizing the patient's life. Optimizing treatments, for example with the use of mathematical modelling, could help to prevent tumour regrowth and anaplastic transformation. Here, we present a model of the effect of radiotherapy on such tumours. Our objective is to explain observed delay of tumour regrowth following radiotherapy and to predict its duration.

MATERIALS AND METHODS

We have used a migration-proliferation model complemented by an equation describing appearance and draining of oedema. The model has been applied to clinical data of tumour radius over time, for a population of 28 patients.

RESULTS

We were able to show that draining of oedema accounts for regrowth delay after radiotherapy and have been able to fit the clinical data in a robust way. The model predicts strong correlation between high proliferation coefficient and low progression-free gain of lifetime, due to radiotherapy among the patients, in agreement with clinical studies. We argue that, with reasonable assumptions, it is possible to predict (precision ~20%) regrowth delay after radiotherapy and the gain of lifetime due to radiotherapy.

CONCLUSIONS

Our oedema-based model provides an early estimation of individual duration of tumour response to radiotherapy and thus, opens the door to the possibility of personalized medicine.

Advanced technologies applied to physiopathological analysis of central nervous system aneurysms and vascular malformations

While depiction and definition of morphological and architectural characteristics of CNS vascular disorders remains the first step of an MR analysis, emerging imaging techniques offer new functional information that might help to characterize rupture risk of CNS vascular disorders. Two main orientations are suggested by recent studies: inflammation of the vessel wall and analysis of physical constraints of blood flow using 4D flow imaging (shear parietal). This paper will focus on radiological application of 4D flow imaging and inflammation imaging, in the characterization of potential prognostic markers of CNS vascular disorders. We will review the basic technical considerations of 4D flow MRA, inflammation imaging and discuss their applications in CNS vascular disorders: aneurysms, arteriovenous malformation, dural arteriovenous fistulas. We will illustrate their potential in the development of individual rupture risk criteria in brain vascular disorders.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is a recently proposed cliniconeuroradiologic entity with several well-known causes, such as hypertensive encephalopathy, eclampsia, and the use of cytotoxic and immunosuppressive drugs, as well as some causes more recently described. PRES is characterized by neuroimaging findings of reversible vasogenic subcortical edema without infarction. The pathogenesis is incompletely understood. Two opposing hypotheses are commonly cited, but the issue is controversial: (1) the current more popular theory suggests that severe hypertension exceeds the limits of autoregulation, leading to breakthrough brain edema; (2) the earlier original theory suggests that hypertension leads to cerebral autoregulatory vasoconstriction, ischemia, and subsequent brain edema. The clinical syndrome of PRES typically involves headache, encephalopathy, visual symptoms, and seizures. The clinical presentation is often nonspecific, and therefore the diagnosis of PRES has come to increasingly rely on magnetic resonance imaging (MRI) abnormalities consistent with PRES with documented recovery clinically and on repeated neuroimaging. The diagnosis has important therapeutic and prognostic implications because the reversibility of the clinical and radiologic abnormalities is contingent on the prompt control of blood pressure and/or discontinuing the offending drug.

Tips and traps in brain MRI: applications to vascular disorders

The French Society of Radiology's guide to good use of medical imaging examinations recommends MRI as the first-line examination for exploring cerebrovascular events or disorders. This paper will discuss the main traps in the images when stroke is suspected and provide the technical tips or knowledge necessary for an optimal radiological report.

3D fast spin-echo T1 black-blood imaging for the diagnosis of cervical artery dissection

SUMMARY

We performed non-contrast-enhanced 3D fast spin-echo T1 imaging with variable flip angles (CUBE T1) at 3T in 11 patients with CAD. CUBE T1 allowed easy diagnosis of CAD, owing to its comprehensive neck coverage, high spatial resolution enabling multiplanar reformations, fat saturation, and BB effect, the latter also allowing lumen patency to be studied. This sequence may replace 2D axial T1WI for the diagnosis of CAD.

Optimizing MR imaging detection of type 2 focal cortical dysplasia: best criteria for clinical practice

BACKGROUND AND PURPOSE

Type 2 FCD is one of the main causes of drug-resistant partial epilepsy. Its detection by MR imaging has greatly improved surgical outcomes, but it often remains overlooked. Our objective was to determine the prevalence of typical MR imaging criteria for type 2 FCD, to provide a precise MR imaging pattern, and to optimize its detection.

MATERIALS AND METHODS

We retrospectively reviewed 1.5T MR imaging of 71 consecutive patients with histologically proved type 2 FCD. The protocol included millimetric 3D T1-weighted, 2D coronal and axial T2-weighted, and 2D or 3D FLAIR images. Two experienced neuroradiologists looked for 6 criteria: cortex thickening, cortical and subcortical signal changes, blurring of the GWM interface, the "transmantle" sign, and gyral abnormalities. The frequency of each sign and their combination were assessed. We compared the delay between epilepsy onset and surgery, taking into account the time of type 2 FCD detection by MR imaging.

RESULTS

Only 42 patients (59%) had positive MR imaging findings. In this group, a combination of at least 3 criteria was always found. Subcortical signal changes were constant. Three characteristic signs (cortical thickening, GWM blurring, and transmantle sign) were combined in 64% of patients, indicating that MR imaging can be highly suggestive. However, typical features of type 2 FCD were overlooked on initial imaging in 40% of patients, contributing to a delay in referral for surgical consideration (17 versus 11.5 years when initial MR imaging findings were positive).

CONCLUSIONS

A combination of 3 major MR imaging signs allows type 2 FCD to be recognized in clinical practice, thereby enabling early identification of candidates for surgery.

Automated versus manual in vivo segmentation of carotid plaque MRI

BACKGROUND AND PURPOSE

Automatically identifying carotid plaque composition using MR imaging remains a challenging task in vivo. The purpose of our study was to compare the detection and quantification of carotid artery atherosclerotic plaque components based on in vivo MR imaging data using manual and automated segmentation.

MATERIALS AND METHODS

Sixty patients from a multicenter study were split into a training group (20 patients) and a study group (40 patients). Each MR imaging study consisted of 4 high-resolution carotid wall sequences (T1, T2, PDw, TOF). Manual segmentation was performed by delineation of the vessel wall and different plaque components. Automated segmentation was performed in the study group by a supervised classifier trained on images from the training group of patients.

RESULTS

For the detection of plaque components, the agreement between the visual and automated analysis was moderate for calcifications (κ = 0.59, CI 95% [0.36-0.82]) and good for hemorrhage (0.65 [0.42-0.88]) and lipids (0.65 [0.03-1.27]). For quantification of plaque volumes, the intraclass correlation was high for hemorrhage (0.80 [0.54-0.92]) and fibrous tissue (0.80 [0.65-0.89]), good for lipids (0.65 [0.43-0.80]), and poor for calcifications.

CONCLUSIONS

In 40 patients with carotid stenosis, our results indicated that it was possible to automatically detect carotid plaque components with substantial or good agreement with visual identification, and that the volumes obtained manually and automatically were reasonably consistent for hemorrhage and lipids but not for calcium.

Correlations of cerebello-thalamo-prefrontal structure and neurological soft signs in patients with first-episode psychosis

OBJECTIVE

This study aimed at determining brain structural imaging correlates of neurological soft signs (NSS) in patients suffering from a first-episode psychosis.

METHOD

Fifty-two patients with a DSMIV diagnosis of first-episode psychosis (schizophrenia or schizophrenia spectrum disorder) were consecutively included. Subjects were assessed using a standardized neurological examination for motor coordination, motor integration and sensory integration. Anatomical magnetic resonance images (MRI) were analysed in the whole brain using optimized voxel-based morphometry.

RESULTS

Neurological soft signs (NSS) total score (P-corrected = 0.013) and motor integration subscore (P-corrected = 0.035) were found to negatively correlate with grey matter structure of the dorsolateral prefrontal cortices. Motor coordination subscore was positively correlated with grey matter structure of the thalami (P-corrected = 0.002) and negatively with white matter structure of the cerebellum (P-corrected = 0.034). The addition of age and gender as covariate yielded similar results. We did not find any correlation between neither sensory integration subscore and grey matter structure nor NSS total score, motor integration subscore and voxel-based morphometry (VBM) white matter structure.

CONCLUSION

Structural alteration in the cerebello-thalamo-prefrontal network is associated with neurological soft signs in schizophrenia, a candidate network for 'cognitive dysmetria'.

Is it possible to recognize cervical artery dissection on stroke brain MR imaging? A matched case-control study

BACKGROUND AND PURPOSE

Extracranial CAD accounts for nearly 20% of cases of stroke in young adults. The mural hematoma frequently extends cranially to the petrous carotid segment in cCAD or is distally located in vCAD. We hypothesized that standard brain MR imaging could allow the early detection of CAD of the upper portion of carotid and vertebral arteries.

MATERIALS AND METHODS

Our prospectively maintained stroke data base was retrospectively queried to identify all patients with the final diagnosis of CAD. In the 103 consecutive patients studied, analysis of cervical fat-suppressed T1-weighted sequences demonstrated that the mural hematoma was located in the FOV of brain MR imaging in 77 patients. Subsequent to enrollment of a patient, a control patient was extracted from the same data base, within a similar categories for sex, age, NIHSS score, and stroke on DWI. Two blinded observers independently reviewed the 5 brain MR sequences of each examination and determined whether a CAD was present.

RESULTS

Fifty-nine of the 77 patients with CAD (76.6%) and 73 of the 77 patients without CAD (94.8%) were correctly classified. Brain MR imaging demonstrated cCAD more frequently than vCAD in 54/58 (93.1%) and 5/19 (26.3%) patients, respectively, (P < .0001).

CONCLUSIONS

Initial brain MR imaging can correctly suggest CAD in more than two-thirds of patients. This may have practical implications in patients with stroke with delayed cervical MRA or in those who are not initially suspected of having CAD.