Contributions
Abstract: P535
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - Imaging
Background: We previously characterized microstructural features and iron content of MS lesions using multi-parametric ultra-high field (7 Tesla) MRI in a cross-sectional study (Chawla, et al. AJNR 2016).
Objective: To compare distribution, number, size, iron content and lesion-vessel relationship of MS lesions at baseline and on follow-up ultra-high field MRI.
Methods: Nine patients with definite MS underwent MRI on a 7T whole body human MR system (Magnetom; Siemens) equipped with a 24-channel phased array coil (Nova Medical). The imaging protocol included high-resolution (230x230µm3) axial 2D-gradient-echo (GRE)- T2*-weighted imaging, high-resolution (230x230µm3) axial 3D-susceptibility weighted imaging (SWI) and FLAIR and T1-weighted imaging. Only supratentorial brain regions were covered while acquiring 2D-GRE-T2* and 3D-SWI to avoid susceptibility artifacts from air-tissue interfaces. An in-house-developed algorithm was used to reconstruct quantitative susceptibility mapping (QSM) from SWI. Lesions on baseline and follow-up MRI were examined by two experienced observers and compared with respect to total count, location, size, lesion-vessel relationship and iron content. Lesions were classified as "iron-laden" if they demonstrated hypointensity on T2*-weighted images and/or SWI and hyperintensity on QSM and "non-iron-laden" if they were hyperintense on T2* and isointense or hyperintense on QSM.
Results: Longitudinal data on 5 MS patients were analyzed so far. Mean duration of follow up was 36 ±10 months. Total number of lesions at baseline was 74 (average 14.8/scan) and at follow-up - 86 (17.2/scan). Increase in lesion size was evident in 2 lesions (3%) and decrease - in 3 lesions (4%). At baseline, 65% lesions had a visible central venule on GRE-T2*images; at follow up - 66% lesion had a central venule. In only 2 lesions (3%), previously seen venule was no longer detectable at follow-up, and in 2 lesions (3%), a venule was visible on follow up, but not at baseline. Percentage of iron-containing lesions increased from 37% at baseline to 43% at follow-up. In one lesion, iron content was apparently lost over time and in another lesion iron content appeared to be redistributed from nodular to rim-like configuration.
Conclusion: Multi-parametric ultra-high field MRI is a promising technique for monitoring morphological changes in lesional iron content and other microstructural characteristics in vivo. Data on full patient cohort will be presented.
Disclosure: This work was supported by a grant from the Guthy-Jackson Charitable Foundation and the National MS Society
Ilya Kister: nothing to disclose
Sanjeev Chawla:nothing to disclose
Jens Thomas Wuerfel:nothing to disclose
Tim Sinnecker:Friedemann Paul:nothing to disclose
Yulin Ge:nothing to disclose
Abstract: P535
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - Imaging
Background: We previously characterized microstructural features and iron content of MS lesions using multi-parametric ultra-high field (7 Tesla) MRI in a cross-sectional study (Chawla, et al. AJNR 2016).
Objective: To compare distribution, number, size, iron content and lesion-vessel relationship of MS lesions at baseline and on follow-up ultra-high field MRI.
Methods: Nine patients with definite MS underwent MRI on a 7T whole body human MR system (Magnetom; Siemens) equipped with a 24-channel phased array coil (Nova Medical). The imaging protocol included high-resolution (230x230µm3) axial 2D-gradient-echo (GRE)- T2*-weighted imaging, high-resolution (230x230µm3) axial 3D-susceptibility weighted imaging (SWI) and FLAIR and T1-weighted imaging. Only supratentorial brain regions were covered while acquiring 2D-GRE-T2* and 3D-SWI to avoid susceptibility artifacts from air-tissue interfaces. An in-house-developed algorithm was used to reconstruct quantitative susceptibility mapping (QSM) from SWI. Lesions on baseline and follow-up MRI were examined by two experienced observers and compared with respect to total count, location, size, lesion-vessel relationship and iron content. Lesions were classified as "iron-laden" if they demonstrated hypointensity on T2*-weighted images and/or SWI and hyperintensity on QSM and "non-iron-laden" if they were hyperintense on T2* and isointense or hyperintense on QSM.
Results: Longitudinal data on 5 MS patients were analyzed so far. Mean duration of follow up was 36 ±10 months. Total number of lesions at baseline was 74 (average 14.8/scan) and at follow-up - 86 (17.2/scan). Increase in lesion size was evident in 2 lesions (3%) and decrease - in 3 lesions (4%). At baseline, 65% lesions had a visible central venule on GRE-T2*images; at follow up - 66% lesion had a central venule. In only 2 lesions (3%), previously seen venule was no longer detectable at follow-up, and in 2 lesions (3%), a venule was visible on follow up, but not at baseline. Percentage of iron-containing lesions increased from 37% at baseline to 43% at follow-up. In one lesion, iron content was apparently lost over time and in another lesion iron content appeared to be redistributed from nodular to rim-like configuration.
Conclusion: Multi-parametric ultra-high field MRI is a promising technique for monitoring morphological changes in lesional iron content and other microstructural characteristics in vivo. Data on full patient cohort will be presented.
Disclosure: This work was supported by a grant from the Guthy-Jackson Charitable Foundation and the National MS Society
Ilya Kister: nothing to disclose
Sanjeev Chawla:nothing to disclose
Jens Thomas Wuerfel:nothing to disclose
Tim Sinnecker:Friedemann Paul:nothing to disclose
Yulin Ge:nothing to disclose