Serum from interferon-ß-1b-treated patients with early multiple sclerosis stabilizes the blood-brain barrier in vitro.

Interferon-ß (IFN-ß) stabilizes the blood-brain barrier (BBB) in vitro. Here we investigated the effect of serum from 15 IFN-ß-1b-treated multiple sclerosis (MS) patients on the permeability read-outs of small solutes in an in vitro BBB model consisting of human brain microvascular endothelial cells in co-culture with rat astrocytes. The addition of sera from IFN-ß-treated patients resulted in a significantly (p < 0.05) reduced permeability as compared with untreated patients. Our findings show that sera from IFN-ß-1b-treated MS patients have a stabilizing effect on the in vitro BBB. We suggest an unknown potentially pro-inflammatory factor in the serum of MS patients that may lead to a BBB dysfunction and can be modulated by IFN-ß.

Arterial elongation ("redundancy") is not a feature of spontaneous cervical artery dissection.

The prevalence of elongation of the internal carotid arteries (ICA) is suggested to be significantly higher in patients with spontaneous cervical artery dissection (sCAD) than in other stroke patients. We reassessed this hypothesis in a case-control study by means of an improved semiautomated MR imaging technique. We compared the length of the cervical arteries in patients with and without sCAD. In 40 consecutive patients with MRI proven sCAD, we measured the arterial lengths of both ICA from the cervical bifurcation to the carotid-T, as well as both vertebral arteries (VA) from their origin to the vertebro-basilar junction. The measurements were performed on the basis of high-resolution, three-dimensional (3D) MR-angiographies with the use of specialized software calculating the length of the coaxial line of these arteries. These results were compared to the findings of 40 age-matched controls with an ischemic stroke due to other etiologies. The mean arterial lengths in patients with sCAD (left ICA 169.62 mm, right ICA 170.05 mm, left VA 233.56 mm, right VA 224.57 mm) compared to patients without sCAD (left ICA 171.07 mm, right ICA 171.88 mm, left VA 232.54 mm, right VA 222.08 mm) did not differ significantly. In our case-control study, cervical arteries are not elongated in patients with sCAD when compared to age-matched stroke patients due to other etiologies. The finding of an arterial elongation is not a distinct clinical marker in patients with suspected sCAD. The macroscopic appearance of the cervical arteries on MR-angiograms does not suggest an underlying elongative or dilatative arteriopathy.

High-resolution magnetic resonance imaging of triangular fibrocartilage complex lesions in acute wrist trauma: image quality at different field strengths.

PURPOSE: The purposes of this study were to assess the diagnostic capacity of a new high-resolution imaging protocol for the wrist and triangular fibrocartilage complex (TFCC) lesions at 3.0 T and to compare it with our established 1.5-T protocol. MATERIALS AND METHODS: Twenty-one patients with an acute wrist trauma were examined at a 3.0-T imaging system and agreed to undergo an additional examination at 1.5 T. Magnetic resonance imaging was performed with 1.5-T (standard wrist coil) and 3.0-T (purpose-build phased-array coil) imaging system, using coronal T1-weighted turbo-spin-echo, proton density-weighted fat-saturated, and coronal and axial contrast-enhanced T1-weighted gradient-echo fat-saturated sequences, with reduced voxel size from 0.50 x 0.50 x 3.0 mm (1.5 T) to 0.20 x 0.20 x 1.5 mm (3.0 T). For qualitative analysis, 2 observers assessed in consensus delineation, image quality, and artifacts in anatomical landmarks (cartilage, TFCC, and TFCC lesion) and ranked them on a 5-point scale from 1 (nondiagnostic) to 5 (optimal). For quantitative analysis, measurements of the contrast-to-noise ratio were obtained between disk and surrounding tissue. RESULTS: All parts of the TFCC and TFCC lesions (n = 14) were seen significantly better at 3.0 T (mean [SD], 4.6 [0.5] vs 2.6 [1.2], P < 0.0001), with higher ranked overall image quality. In 3 cases, TFCC lesions were seen only at 3.0 T. Proton density-weighted fat-saturated sequence had significantly more artifacts at 3.0 T (2.5 [0.6] vs 1.9 [0.5], P < 0.001) in contrast to T1 sequences. Quantitative evaluation showed significantly higher contrast-to-noise ratio for 3.0 T (5.0 [1.1] vs 3.9 [0.9], P < 0.0001). CONCLUSION: Depiction of anatomy and pathology of the TFCC benefits significantly from 3.0-T imaging when higher signal-to-noise ratio is invested into improved spatial resolution. Especially small lesions of the disk were detected only or better at 3.0 T.

High resolution 3.0 Tesla MR imaging findings in patients with bilateral Madelung's deformity.

PURPOSE: Madelung deformity (MD) is a rare, normally painful abnormality of the wrist and forearm which characteristically begins in adolescence. Usually the deformity appears between the age of 8 and 14 years, often progressing from initially mild functional pain to fatigue and loss of strength and finally, reduced mobility. We present the MR-findings in three patients with bilateral MD, using a high-resolution imaging protocol adapted for 3.0 Tesla (3.0 T) examinations. MATERIALS AND METHODS: Wrist images of three patients were acquired at a 3.0 T Scanner (Gyroscan Intera, Philips Medical Systems, Best, The Netherlands), using a dedicated phased array coil. The imaging protocol consisted of coronal T1-weighted Turbo-spin-echo (T1w-TSE) and coronal and sagittal T2-weighted TSE sequences (T2w-TSE). RESULTS: MR-images of these three girls demonstrated severe volar bayonet configuration of the forearms with a dorsal prominence of the ulnar head, also a curved distal radial articular surface with increased ulnar angulation, due to a deceleration of growth in the ulnar portion of the distal epiphysis. The proximal carpal row showed pyramidal configuration. Also visible was a prominent short radiolunate ligament, the so called Vickers ligament, which originates from the ulnar border of the radius, inserts into the volar pole of the lunate and likely contributes to carpal pyramidalization. Furthermore, the images demonstrated an anomalous hypertrophied and elongated volar radiotriquetral ligament which, to our knowledge, has been described elsewhere only in another case. CONCLUSION: High resolution imaging at 3.0 T permitted a detailed analysis of the complex pathomorphology in patients with MD. Investing the better signal-to-noise ratio at higher field strengths into spatial resolution an excellent image quality could be obtained, depicting the Vickers ligament and the anomalous volar radiotriquetral ligament in this rare disease.

Neurosonographical follow-up in patients with spontaneous cervical artery dissection.

OBJECTIVE: Neurovascular ultrasound (nUS) is widely used as a screening and monitoring tool in patients with spontaneous cervical artery dissection (sCAD). The aim of the study was to describe the sonographical course of the affected arteries in patients with a MRI-proven sCAD by repetitive nUS. METHODS: Thirty-seven consecutive patients aged<60 years with 1.5 T MRI-proven sCAD were prospectively investigated by nUS, and within 48 hours after admission before MRI. The patients were re-investigated after 6 months and again after a period>12 months. RESULTS: Forty-nine sCAD were detected in 37 patients; 24 lesions (49%) were located in the internal carotid arteries (ICA), and 25 (51%) in the vertebral arteries (VA). An arterial occlusion was found in 13 arteries (27%). The recanalization rate of occluded arteries was 62%. Regression of stenosis/occlusion within the first 6 months was found in 34 (69%) of the affected arteries, while between 6 and >12 months, the improvement rate was lower (19%). A complete recanalization without residual stenosis after 6 months was found in 39%. In only one artery, initial high grade ICA stenosis progressed to complete persistent occlusion (2%). DISCUSSION: The course of arterial stenosis or occlusion caused by sCAD is highly dynamic during the first 6 month after the event. The vast majority of arteries show regression of stenosis or recanalization of initial occlusion. Only a minority of patients experience a persistent deterioration of the vessel status.

Detection of asymptomatic cerebral microbleeds: a comparative study at 1.5 and 3.0 T.

RATIONALE AND OBJECTIVES: The magnitude of iron-induced susceptibility changes in gradient echo T2*-weighted magnet resonance imaging (T2* MRI) increases with the field strength and should increase the sensitivity for detection of cerebral microbleeds (CMBs) at 3.0 T. To test these hypotheses, we prospectively examined individuals with documented CMBs at 1.5 and 3.0 T. MATERIALS AND METHODS: Five hundred fifty elderly individuals, who participated in an interdisciplinary study of healthy aging, were examined at 3.0 T using T2* MRI sequences (repetition time [TR]/echo time [TE]/flip angle [FA] = 573 ms/16 ms/18 degrees ). Individuals positive for CMBs were asked to undergo an additional examination at 1.5 T (TR/TE/FA = 663 ms/23 ms/18 degrees ). Images were analyzed independently by two observers. CMBs were counted throughout the brain and were qualitatively analyzed comparing the degree of visible hypointensity on a 5-point scale from 1 (complete signal loss) to 5 (no detection) for both field strengths. Contrast-to-noise ratio of CMBs to surrounding brain tissue was calculated. RESULTS: At 3.0 T, CMBs were detected in 45 of 550 individuals; 25 agreed to an additional examination at 1.5 T. In this group (n = 25), a total of 53 CMBs were detected at 3.0 T, compared to 41 CMBs at 1.5 T. The mean contrast-to-noise ratio of CMBs was significantly increased at 3.0 T compared to 1.5 T (27.4 +/- 8.2 vs. 17.4 +/- 8.0; p < .001). On qualitative analysis, visibility of CMBs was ranked significantly higher at 3.0 T (1.3 +/- 0.4 vs. 2.9 +/- 1.1; p < .001). CONCLUSION: Evidence of past microbleeds may even be found in neurologically normal elderly individuals by MRI. Detection rate and visibility of CMBs benefit from the higher field strength, resulting in a significantly improved depiction of iron-containing brain structures (CMBs) at 3.0 T with potential clinical relevance.

High-resolution magnetic resonance imaging of the temporomandibular joint: image quality at 1.5 and 3.0 Tesla in volunteers.

PURPOSE: To assess the image quality of a high-resolution imaging protocol for the temporomandibular joint (TMJ) at 3.0 T and to compare it with our standard 1.5 T protocol. MATERIALS AND METHODS: Fifteen volunteers without history of TMJ dysfunction underwent bilateral magnetic resonance imaging (MRI) of the TMJ with the jaw in closed and open position. MRI was performed with using a 1.5 T (standard TMJ coil) and 3.0 T (purpose build phased array coil) MR system (Gyroscan Intera 1.5 T and 3.0 T; Philips Medical Systems, Best, the Netherlands). Imaging protocols consisted of a parasagittal PDw-TSE sequence and a coronal PDw-TSE sequence in closed mouth position and a sagittal PDw-TSE sequence in open mouth position. Acquisition parameters were adjusted for 3.0 T and voxel size was reduced from 0.29 x 0.29 x 3.0 mm (1.5 T) to 0.15 x 0.15 x 1.5 mm (3.0 T). Total examination time (15 minutes) was similar for both systems. Two observers assessed in consensus delineation, image quality, and artifacts of anatomic landmarks (disk, bilaminar zone, capsular attachment, cortical bone) and ranked them qualitatively on a 5-point scale from 1 (optimal) to 5 (nondiagnostic). Disk position and motility was noted. For CNR analysis, signal intensity from disk and retrodiscal tissue was measured. RESULTS: Disk position and mobility was identical at both field strengths. All anatomic landmarks were visualized significantly better at 3.0 T. In particular, the capsular attachment was depicted in more detail. Overall image quality was ranked significantly higher at 3.0 T, whereas artifact score was similar. Quantitative evaluation showed significantly higher CNR for 3.0 T (10.23 vs. 8.08, P < 0.0001). CONCLUSION: Depiction of the normal anatomy of the TMJ benefits significantly when investing the higher SNR at 3.0 T into better spatial resolution. We anticipate that this advantage of 3.0 T MRI will also permit a more detailed analysis of capsular and disk pathology.

High-resolution magnetic resonance imaging (MRI) at 3.0 Tesla in the short-term follow-up of patients with proven cervical artery dissection.

PURPOSE: For the imaging evaluation of patients with suspected cervical artery dissection (CAD) in the last decade, magnetic resonance imaging (MRI) has become the first line imaging modality. However, CAD is a highly dynamic process with rapid changes over time. Aim of this study was to assess the short-term morphologic changes in patients with proven CAD by MRI within 2 weeks after the initial diagnosis using a multicontrast high-resolution noninvasive vessel wall imaging approach at 3.0 T. MATERIALS AND METHODS: Eighty-two patients with clinically suspected CAD were examined using a 3.0 T system (Gyroscan Intera, Philips). Imaging protocol consisted of 3-dimensional inflow MRA (repetition time [TR]/echo time [TE]/flip angle [FA] = 25 milliseconds/3.1 milliseconds/16 degrees, reconstructed voxel size 0.3 x 0.3 x 0.8 mm), black blood T1w 3-dimensional spoiled gradient echo (TR/TE/FA = 31 milliseconds/7.7 milliseconds/15 degrees, 0.3 x 0.3 x 1.0 mm), and fat suppressed T2w turbo spin echo (TSE) (TR/TE/echo train length = 3 heart beats/44 milliseconds/7, 0.3 x 0.3 x 2 mm). Three observers in consensus performed image analysis. Images were assessed with regard to presence and size of intramural hematoma, degree of stenosis, presence of intraluminal thrombus, development of pseudoaneurysm, and incidence of additional dissections. In 29 patients (35%) a dissection had initially been proven by direct visualization of an intramural hematoma. Twenty-one patients (72%; 7 male, 14 female; mean age 41.5 years) were available for follow-up studies leading to a total of 24 diseased cervical arteries being reevaluated 2 weeks later for prospective follow-up. RESULTS: Mean interval between initial study and follow-up was 14.2 days (range 7-30 days). Eighteen patients had presented with an acute CAD in 1 artery, 3 patients with an acute CAD in 2 arteries. At follow-up, degree of stenosis had increased in 2 arteries, remained unchanged in 13, and decreased in 5 arteries. Four initially occluded arteries were recanalized at follow-up. In 3 arteries a pseudoaneurysm had been visible in the initial study and remained unchanged at follow-up; in 1 artery a new pseudoaneurysm was observed. In 3 arteries, new dissections were identified during follow-up. CONCLUSION: High-resolution MRI of acute CAD at 3.0 T permits a refined cross-sectional and longitudinal analysis of the morphologic features of CAD. The increased signal-to-noise ratio at 3.0 T allows for a high spatial resolution permitting detailed analysis of the diseased vessel segment. An unequivocal distinction between intramural hematoma and thrombus was possible. Information could be gained with regard to recanalization, degree of stenosis, formation of pseudoaneurysm, and appearance of new dissections making short-term follow-up in pts with acute CAD recommendable. Further studies are needed to assess the relationship between short-term results and definite outcome.

Spontaneous acute dissection of the internal carotid artery: high-resolution magnetic resonance imaging at 3.0 tesla with a dedicated surface coil.

PURPOSE: Magnetic Resonance Imaging (MRI) has become the method of choice in the evaluation of patients with suspected cervical artery dissection (CAD). However, reliable identification of acute CAD might be impaired by the limited spatial resolution of standard 1.5 T MRI. In this preliminary study, we implemented a multicontrast high-resolution noninvasive vessel wall imaging approach at 3.0 T in patients with spontaneous CAD. METHODS AND MATERIALS: Ten patients with CAD of the internal carotid artery (ICA) were included in the study. 3.0 T MRI (Gyroscan Intera, Philips) was acquired using a dedicated phased-array coil. MRI-protocol consisted of: (1) bright blood 3D inflow MRA (TR/TE/FA = 25 milliseconds/3.1 millisecond/16 degrees , 120 slices, reconstructed voxel size 0.3 x 0.3 x 0.8 mm); (2) black blood cardiac-gated water-selective T1w 3D spoiled GE (TR/TE/FA = 31 milliseconds/7.7 milliseconds/15 degrees , 36 slices, 0.3 x 0.3 x 1.0 mm); and (3) black blood cardiac triggered fat suppressed T2w TSE (TR/TE/ETL = 3 heart beats/44 milliseconds/7, 18 slices, 0.3 x 0.3 x 2 mm). Three observers in consensus performed image analysis. Special attention was paid to the integrity of the luminal and adventitial vessel boundary and the presence of a communicating intimal tear or flap. RESULTS: 3.0 T MRI provided excellent delineation of vessel lumen and vessel wall as a result of the nearly complete suppression of arterial blood signal. An intramural hematoma could be identified in all patients, confined between the luminal and adventitial vessel boundary. In no patient a communicating intimal tear could be identified. Clear distinction between intramural hematoma and thrombus was possible. CONCLUSION: High-resolution vessel wall imaging in patients with acute CAD is feasible. The increased signal-to-noise ratio at 3.0 T can be invested to obtain a higher spatial resolution, permitting depiction of intimal and adventitial vessel wall boundary and the intramural hematoma in the diseased vessel segment. The morphologic information that is gained is helpful in the understanding of the underlying pathomechanismen of CAD.