Yvonne Y. Bender

Diagnostic accuracy of susceptibility-weighted magnetic resonance imaging for the evaluation of pineal gland calcification

Objectives To determine the diagnostic performance of susceptibility-weighted magnetic resonance imaging (SWMR) for the detection of pineal gland calcifications (PGC) compared to conventional magnetic resonance imaging (MRI) sequences, using computed tomography (CT) as a reference standard. Methods 384 patients who received a 1.5 Tesla MRI scan including SWMR sequences and a CT scan of the brain between January 2014 and October 2016 were retrospectively evaluated. 346 patients were included in the analysis, of which 214 showed PGC on CT scans. To assess correlation between imaging modalities, the maximum calcification diameter was used. Sensitivity and specificity and intra- and interobserver reliability were calculated for SWMR and conventional MRI sequences. Results SWMR reached a sensitivity of 95% (95% CI: 91%-97%) and a specificity of 96% (95% CI: 91%-99%) for the detection of PGC, whereas conventional MRI achieved a sensitivity of 43% (95% CI: 36%-50%) and a specificity of 96% (95% CI: 91%-99%). Detection rates for calcifications in SWMR and conventional MRI differed significantly (95% versus 43%, p<0.001). Diameter measurements between SWMR and CT showed a close correlation (R2 = 0.85, p<0.001) with a slight but not significant overestimation of size (SWMR: 6.5 mm ± 2.5; CT: 5.9 mm ± 2.4, p = 0.02). Interobserver-agreement for diameter measurements was excellent on SWMR (ICC = 0.984, p < 0.0001). Conclusions Combining SWMR magnitude and phase information enables the accurate detection of PGC and offers a better diagnostic performance than conventional MRI with CT as a reference standard.

Assessment of intracranial meningioma-associated calcifications using susceptibility-weighted MRI.

To determine the diagnostic accuracy of susceptibility‐weighted MRI (SW‐MRI) for the detection of intracranial meningioma‐associated calcifications compared with standard MR sequences, using computed tomography (CT) as a reference standard.

Evaluation of sclerosis in Modic changes of the spine using susceptibility-weighted magnetic resonance imaging

PURPOSE To evaluate the diagnostic performance of susceptibility-weighted magnetic resonance imaging (SWMR) for the differentiation of sclerotic and non-sclerotic Modic changes (MC) of the spine compared to computed tomography (CT) and radiographs. MATERIALS AND METHODS The Institutional Ethics-Review-Board approved this prospective study in advance. Written consent was obtained from all subjects. SWMR and standard T1/T2 MR of the cervical (n=21) and/or lumbar spine (n=34) were performed in 54 patients. 21 patients served as control. 18 patients were evaluated with CT; in all other patients radiographs were available. 67 Modic changes were identified on T1/T2 MR. On SWMR changes were classified as sclerotic and non-sclerotic based on signal intensity measurements. The sensitivity and specificity of SWMR and T1/T2 MR for differentiating between sclerotic and non-sclerotic Modic changes were determined with CT and radiographs as reference standard. RESULTS On SWMR, signal measurements between sclerotic and non-sclerotic Modic changes differed significantly (p<0.01). On T1- and T2-weighted MR no significant difference (p>0.05) was measured. On SWMR, a reliable differentiation between sclerotic and non-sclerotic Modic changes could be achieved, with a sensitivity of 100% and specificity of 95%. In contrast, the combination of T1-/T2-weighted MR yielded a significantly lower sensitivity to detect sclerosis (20%). CONCLUSION SWMR allows a reliable detection of sclerosis in Modic changes with a higher accuracy compared to standard spine MR sequences, using radiographs and CT as reference standard.

Evaluation of osseous cervical foraminal stenosis in spinal radiculopathy using susceptibility-weighted magnetic resonance imaging

ObjectiveThe aim of this study was to evaluate the diagnostic performance of susceptibility-weighted magnetic resonance imaging (SW-MRI) for the evaluation of osseous foraminal stenosis (FS) of the cervical spine compared to conventional MRI-sequences, using computed tomography (CT) as a reference standard.Materials and methodsTwenty-one patients with suspected radiculopathy of the cervical spine were prospectively included. CT and MRI data sets were available for all patients. As standard of reference, 280 neuroforamina of the cervical spine, including 58 foraminal stenosis, were identified on sagittal CT images. T1-, T2-, and SW-MRI of the cervical spine were performed. The presence of foraminal stenosis was assessed on sagittal views in all sequences. Sensitivity and specificity were calculated and differences in detection rate and severity scoring of foraminal stenosis between the different sequences were tested. CT was used as reference standard for all analysis.ResultsFifty-six of 58 osseous foraminal stenosis could be correctly identified on SW-MR magnitude images. SW-MRI achieved a sensitivity of 96.6% and specificity of 99.5% for the identification of foraminal stenosis. In comparison, conventional T1-weighted MRI sequences achieved a sensitivity and specificity of 43.1% and 100% respectively. T2-weighted MRI sequences achieved a sensitivity and specificity of 65.5% and 99.1%, respectively. The overall detection rate was significantly (p < 0.05) higher on SW-MRI and there was no significant difference (p > 0.05) in severity scoring compared to CT. T1- and T2-weighted MRI underestimated the degree of foraminal stenosis. Intermodality and interobserver agreements were highest for SW-MRI.ConclusionsSW-MRI enables the reliable detection of osseous foraminal stenosis of the cervical spine in patients with spinal radiculopathy with a higher sensitivity compared to conventional T1- and T2-MRI sequences, with CT as a reference standard.Key Points• Susceptibility-weighted magnetic resonance imaging enables the reliable detection of osseous foraminal stenosis of the cervical spine with CT as a reference standard.• This could be relevant for younger patients in order to prevent unnecessary radiation exposure.• This may also facilitate a one-stop-shop approach and speed up diagnostic work-up.

Pilot study of MRI/ultrasound fusion imaging in postpartum assessment of Cesarean section scar

To evaluate prospectively the uterine scar after Cesarean section (CS) and the corresponding uterine region after vaginal delivery (VD) at 6 weeks postpartum using transabdominal (TAS) and transvaginal (TVS) sonography with magnetic resonance imaging (MRI) fusion to investigate whether fusion imaging allows standardized and reproducible identification of the scar location and measurement of uterine wall thickness compared with high‐resolution MRI alone.

Differentiation of Osteophytes and Disc Herniations in Spinal Radiculopathy Using Susceptibility-Weighted Magnetic Resonance Imaging.

Objective The aim of this study was to evaluate the diagnostic performance of susceptibility-weighted magnetic resonance imaging (SW-MRI) for the differentiation of osteophytes and disc herniations of the spine compared with that of conventional spine MR sequences and radiography. Materials and Methods This study was approved by the local ethics review board; written consent was obtained from all subjects. Eighty-one patients with suspected radiculopathy of the spine were included prospectively. Radiography, T1/T2, and SW-MRI of the cervical/lumbar spine were performed. As reference standard, 93 osteophytes (n = 48 patients) were identified on radiographs in combination with conventional T1/T2 images. One hundred fourteen posterior disc herniations (n = 60 patients) were identified on T1/T2 in combination with radiography excluding osteophytes. For this study, 2 observers independently assessed the presence of osteophytes and disc herniations on T1/T2 and SW-MRI, with radiographs excluded from the analysis. In a subgroup of patients (n = 19), additional computed tomography images were evaluated. Sensitivity, specificity, and interobserver agreement were calculated. Results Most osteophytes (n = 92 of 93) and disc herniations (n = 113 of 114) could be identified and differentiated on SW-MRI magnitude/phase images, if radiographs were excluded from analysis. Susceptibility-weighted magnetic resonance imaging achieved a sensitivity of 98.9% and specificity of 99.1% for the identification of osteophytes. Conventional T1/T2 spine MR sequences achieved a sensitivity and specificity of 68.6% and 86.5%, respectively, if radiographs were excluded from analysis. Regarding the size of osteophytes, SW-MRI showed a strong correlation with computed tomography (R2 = 0.96) and radiography (R2 = 0.95). In addition, SW-MRI achieved a higher interobserver agreement compared with conventional MR. Conclusions Susceptibility-weighted magnetic resonance imaging enables the reliable differentiation of osteophytes and disc herniations in patients with spinal radiculopathy with a higher sensitivity and specificity compared with conventional T1/T2 MR sequences.

MRI for the detection of calcific features of vertebral haemangioma

AIM To evaluate the diagnostic performance of susceptibility-weighted-magnetic-resonance imaging (SW-MRI) for the detection of vertebral haemangiomas (VHs) compared to T1/T2-weighted MRI sequences, radiographs, and computed tomography (CT). MATERIALS AND METHODS The study was approved by the local ethics review board. An SW-MRI sequence was added to the clinical spine imaging protocol. The image-based diagnosis of 56 VHs in 46 patients was established using T1/T2 MRI in combination with radiography/CT as the reference standard. VHs were assessed based on T1/T2-weighted MRI images alone and in combination with SW-MRI, while radiographs/CT images were excluded from the analysis. RESULTS Fifty-one of 56 VHs could be identified on T1/T2 MRI images alone, if radiographs/CT images were excluded from analysis. In five cases (9.1%), additional radiographs/CT images were required for the imaging-based diagnosis. If T1/T2 and SW-MRI images were used in combination, all VHs could be diagnosed, without the need for radiography/CT. Size measurements revealed a close correlation between CT and SW-MRI (R2=0.94; p<0.05). CONCLUSIONS This study demonstrates that SW-MRI enables reliable detection of the typical calcified features of VHs. This is of importance for routine MRI of the spine, as the use of additional CT/radiography can be minimized.

Pilot Study of MRI/US Fusion in the Assessment of the Cesarean Section Scar in the Postpartum Period.

To evaluate prospectively the uterine scar after Cesarean section (CS) and the corresponding uterine region after vaginal delivery (VD) at 6 weeks postpartum using transabdominal (TAS) and transvaginal (TVS) sonography with magnetic resonance imaging (MRI) fusion to investigate whether fusion imaging allows standardized and reproducible identification of the scar location and measurement of uterine wall thickness compared with high‐resolution MRI alone.