Correlation of MRI T2 mapping sequence with knee pain location in young patients with normal standard MRI

'Objective: 'To assess the correlation of T2 mapping abnormalities to knee pain location, in young adults with normal standard knee MRI at 3.0 Tesla. 'Subjects and methods: 'Twenty-three consecutive patients were included prospectively from September 2011 to April 2012. Inclusion criteria were age under 50 years old, knee pain without surgical history, and normal knee MRI at 3.0 Tesla (sagittal T1-weighted images, and sagittal, axial and coronal proton-density-weighted images with saturation of fat signal). Ten asymptomatic volunteers were also included as a control group. Patients and controls had a cartilage T2 mapping MRI sequence in addition to the standard MRI protocol. Two musculoskeletal radiologists, blinded to the patient/control condition and pain location, independently reviewed the T2 mapping images. T2 values below 40 ms were considered normal. They rated the number of hyaline cartilage lesions and their grade according to an ICRS-like score (inspired by the International Cartilage Research Society score) in each anatomical compartment (medial and lateral femoro-tibial and anterior patello-femoral joints). In addition, the T2 value of the largest lesion was measured. Patient’s pain location was classified in the following categories: anterior, lateral, medial and global. T2 mapping findings were compared to pain location, and retrospectively to the initial standard sequences. Sensitivity and specificity were calculated for MRI with T2 mapping according to pain location for each reader. Kappa coefficient was calculated for inter-reader agreement. We used variance analysis in a linear regression to compare T2 values and ICRS-like classification in each compartment. 'Results: 'Sensitivity of MRI with T2 mapping, according to the symptomatic compartment, was respectively: 78% and 87% for Reader 1 and Reader 2 and specificity was 70% for both readers. Kappa coefficient for T2 mapping abnormalities location and pain location was good, with a calculated value of 0.64. There was no significant correlation between ICRS-like classification and T2 values of lesions (p = 0.18). 'Conclusion: 'Our results suggest that T2 mapping is an interesting MRI sequence for the exploration of young patients knee pain in case of normal MRI with a standard protocol, with a good correlation between pain location and focal prolongations of the cartilage T2 relaxation time

Assessment of normal values of fractional anisotropy and mean diffusivity of mobile lumbar spine roots by diffuson tensor MRI: comparison between 1.5 and 3T.

Purpose: To assess the normal values of fractional anisotropy (FA) and mean diffusivity (MD) of L4, L5 and S1 nerve roots using diffusion tensor imaging (DTI) in healthy volunteers. Materials and methods: 37 subjects without previous history of lumbalgia or radiculalgia were prospectively examined: 27 at 1.5T and 10 at 3T MRI. The protocol included standard anatomical sequences and a DTI acquisition. Nerve root fibers were semi automatically extracted from DTI tractography. FA and MD values were measured at 4 key portions along each L4, L5 and S1 nerve roots. Results: At 1.5T MRI, FA and MD were 0.221 ± 0.011 and 460.9 ± 35.5 mm2.s-1 respectively; at 3T MRI, FA and MD were 0.216 ± 0.01 and 480.1 ± 36.1 mm2.s-1 respectively, which may be considered as normal values for mobile lumbar spine nerve roots, independently of intersomatic space level (p = 0.06) and nerve root portion (p = 0.08) or magnetic field (p = 0.06). Conclusion: Normal FA and MD values can be measured along lumbar mobile spine nerve roots in healthy subjects. These values were not dependent on intersomatic space level, side or anatomical portion of the nerve root or magnetic field

Clinical relevance of diffusion tensor imaging parameters in lumbar disco-radicular conflict

Purpose: To measure the fractional anisotropy (FA) and the mean diffusivity (MD) values of L4, L5 and S1 nerve roots using diffusion tensor imaging (DTI) and to correlate them with four different clinical patterns. Patients and methods: Fifty-six human participants were prospectively included and divided between four groups: healthy subjects, patients with clinical symptomatic nerve root pain with and without anatomical discoradicular conflict and patients with incidental anatomical discoradicular conflict seen on magnetic resonance imaging (MRI). MRI protocol included anatomical sequences (sagittal T1- and T2-weighted, axial T2-weighted) and a 25 directions DTI sequence. FA and MD values were measured in consensus by two readers and compared between the four groups. Results: Mean FA and MD values were significantly different for patients with clinically symptomatic nerve root pain (n = 27) both with (n = 16) (FA = 0.187 ± 0.015; MD = 510 ± 40) and without (n = 11) (FA = 0.193 ± 0.011; MD = 490 ± 30.5) anatomical discoradicular conflict compared to healthy subjects (n = 29) (FA = 0.221 ± 0.011; MD = 460.9 ± 35.5) including 2 subjects withincidental anatomical discoradicular conflict (FA = 0.211 ± 0.013; MD = 450.8 ± 41.2) on MRI(P = 0.003).Conclusion: Measurement of FA and MD values of L4, L5 and S1 nerve roots using DTI could beuseful in lumbar nerve root pain assessment. Further studies with different image processingmethods are needed. © 2013 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved

Is intracerebral hemorrhage a time-dependent phenomenon after successful combined intravenous and intra-arterial therapy?

BACKGROUND AND PURPOSE: Onset-to-reperfusion time (ORT) has recently emerged as an essential prognostic factor in acute ischemic stroke therapy. Although favorable outcome is associated with reduced ORT, it remains unclear whether intracranial bleeding depends on ORT. We therefore sought to determine whether ORT influenced the risk and volume of intracerebral hemorrhage (ICH) after combined intravenous and intra-arterial therapy. METHODS: Based on our prospective registry, we included 157 consecutive acute ischemic stroke patients successfully recanalized with combined intravenous and intra-arterial therapy between April 2007 and October 2011. Primary outcome was any ICH within 24 hours posttreatment. Secondary outcomes included occurrence of symptomatic ICH (sICH) and ICH volume measured with the ABC/2. RESULTS: Any ICH occurred in 26% of the study sample (n=33). sICH occurred in 5.5% (n=7). Median ICH volume was 0.8 mL. ORT was increased in patients with ICH (median=260 minutes; interquartile range=230-306) compared with patients without ICH (median=226 minutes; interquartile range=200-281; P=0.008). In the setting of sICH, ORT reached a median of 300 minutes (interquartile range=276-401; P=0.004). The difference remained significant after adjustment for potential confounding factors (adjusted P=0.045 for ICH; adjusted P=0.002 for sICH). There was no correlation between ICH volume and ORT (r=0.16; P=0.33). CONCLUSIONS: ORT influences the rate but not the volume of ICH and appears to be a critical predictor of symptomatic hemorrhage after successful combined intravenous and intra-arterial therapy. To minimize the risk of bleeding, revascularization should be achieved within 4.5 hours of stroke onset

Blood-brain barrier disruption is associated with increased mortality after endovascular therapy

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