Contributions
Abstract: P1081
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - Imaging
Background: Sagittal T2-weighted Magnetic Resonance Imaging (MRI) is an integral component of the routine radiological assessment of patients with multiple sclerosis. The reconstruction slice thickness for this T2 sagittal sequence in our institution has recently been reduced from 4mm to 3mm. For patients suspected to have optic neuropathy (ON), MRI orbits with coronal Short Tau Inversion recovery (STIR) is used and this sequence is considered the gold standard. This study compared the influence of slice thickness on the accuracy of the T2 sagittal sequence of the brain for identification of ON.
Materials and methods: Forty-one consecutive patients who underwent MRI brain and orbits, incorporating both T2 sagittal (with 4mm reconstruction) brain and coronal STIR orbit sequences, have been included. Each STIR sequence was reviewed by a neuroradiologist and radiology resident, in consensus, in a blinded fashion and assigned as positive or negative for optic neuropathy based on the presence of increased T2 signal within a segment of optic nerve. On a separate occasion, the sagittal T2 sequences of the brain were reviewed in a similar blinded fashion. The location of abnormality was noted (intraorbital, intracanalicular or intracranial). Since the reduction in T2 sagittal slice thickness at our institution, consecutive patients undergoing both sequences have been recorded and recruitment is ongoing, aiming to included another forty-one cases.
Results: The forty-one consecutive cases with 4mm T2 sagittal reconstruction have been analysed. Twelve patients had ON evident on STIR imaging, eight intraorbital and four intracanalicular. The T2 sagittal sequence achieved a sensitivity of 42% (95% CI 13.9-70.1) and specificity of 86% (95%CI 73.4-98.6) for ON with positive and negative predictive values of 0.56 and 0.78 respectively. Six out of the seven cases of ON missed by sagittal T2 sequence were intra orbital. Analysis of the patients with 3mm T2 sagittal reconstruction will be performed once all patients have been recruited.
Conclusion: Routine T2 sagittal brain imaging with 4mm slice thickness has poor sensitivity but high specificity for optic neuropathy. The T2 sagittal slice thinkness has now been reduced and recruitment of patients is ongoing.
Disclosure: No disclosures
Abstract: P1081
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - Imaging
Background: Sagittal T2-weighted Magnetic Resonance Imaging (MRI) is an integral component of the routine radiological assessment of patients with multiple sclerosis. The reconstruction slice thickness for this T2 sagittal sequence in our institution has recently been reduced from 4mm to 3mm. For patients suspected to have optic neuropathy (ON), MRI orbits with coronal Short Tau Inversion recovery (STIR) is used and this sequence is considered the gold standard. This study compared the influence of slice thickness on the accuracy of the T2 sagittal sequence of the brain for identification of ON.
Materials and methods: Forty-one consecutive patients who underwent MRI brain and orbits, incorporating both T2 sagittal (with 4mm reconstruction) brain and coronal STIR orbit sequences, have been included. Each STIR sequence was reviewed by a neuroradiologist and radiology resident, in consensus, in a blinded fashion and assigned as positive or negative for optic neuropathy based on the presence of increased T2 signal within a segment of optic nerve. On a separate occasion, the sagittal T2 sequences of the brain were reviewed in a similar blinded fashion. The location of abnormality was noted (intraorbital, intracanalicular or intracranial). Since the reduction in T2 sagittal slice thickness at our institution, consecutive patients undergoing both sequences have been recorded and recruitment is ongoing, aiming to included another forty-one cases.
Results: The forty-one consecutive cases with 4mm T2 sagittal reconstruction have been analysed. Twelve patients had ON evident on STIR imaging, eight intraorbital and four intracanalicular. The T2 sagittal sequence achieved a sensitivity of 42% (95% CI 13.9-70.1) and specificity of 86% (95%CI 73.4-98.6) for ON with positive and negative predictive values of 0.56 and 0.78 respectively. Six out of the seven cases of ON missed by sagittal T2 sequence were intra orbital. Analysis of the patients with 3mm T2 sagittal reconstruction will be performed once all patients have been recruited.
Conclusion: Routine T2 sagittal brain imaging with 4mm slice thickness has poor sensitivity but high specificity for optic neuropathy. The T2 sagittal slice thinkness has now been reduced and recruitment of patients is ongoing.
Disclosure: No disclosures