Diagnostic reliability and interobserver agreement in T1-weighted phase sensitive inversion recovery sequence for detection of cervical cord demyelinating plaques

Abstract

Purpose: To evaluate the diagnostic reliability of PSIR sequence as compared to STIR in detection & counting of MS plaques in cervical cord and assess inter and intra-observer agreement. Patient and methods: A retrospective analysis of cervical MRI of 39 patients with Multiple sclerosis; Phase sensitive inversion recovery (PSIR) & short time inversion recovery (STIR) sequences were analyzed by 2 readers twice with 2 weeks interval for plaque detection, number and lesion conspicuity. Results: Mean conspicuity of lesions in PSIR and STIR was (3.4, 3.1 and 3.1, 2.8) for R1 and R2 without significant statistical difference (p = 0.18, 0.11). There was substantial inter-observer agreement between R1 and R2 regarding number of lesions in STIR and PSIR (K = 0.7, 0.72), almost perfect intra-reader observer agreement for STIR and PSIR (K = 0.85, 0.87 for R1, 0.8, 0.85 for R2). No statistical difference between number of lesions detected in STIR and PSIR by 2 readers (P = 0.5, 0.4). PSIR had higher sensitivity, specificity and accuracy compared to STIR (88.4/81.2, 98/96.1, 95/91.4) yet no statistical difference in accuracy (p value = 0.13). Conclusion: PSIR sequence is accurate and reproducible in detection of MS lesions; it has higher sensitivity, specificity and accuracy than STIR sequence. Keywords: MS plaques, PSIR, STIR, Cervical cord