Utility of 3D T1-weighted turbo spin echo black blood sequence for the diagnosis of cerebral venous thrombosis

PURPOSE

Accurate assessment of dural sinus, deep and cortical venous thrombosis on MR imaging is challenging. The aim of this study is to evaluate the accuracy of 3D-T1 turbo spin echo (T1S), sequences in detecting venous thrombosis and comparing it with susceptibility-weighted imaging (SWI), magnetic resonance venography (MRV) and post contrast T1 magnetization-prepared rapid acquisition gradient echo (T1C).

METHODS

A blinded retrospective observational analysis of 71 consecutive patients evaluated for cerebral venous thrombosis (CVT) and 30 control patients was performed. Multimodality reference standard adopted included T1C, SWI with MRV. Sub-analyses in superficial, deep and cortical venous segments were performed in addition to correlation of signal intensity of thrombus with the clinical stage.

RESULTS

A total of 2222 segments in 101 complete MRI examinations were evaluated. Sensitivity/specificity/positive predictive value/negative predictive value/accuracy and precision of T1S for detection of cortical vein thrombosis was 0.994/1/1/0.967/0.995/1, 1/0.874/0.949/1/0.963/0.950 for detection of superficial venous sinus thrombosis and 1/1/1/1/1/1 for deep venous thrombosis. The AUC yield for T1S was 0.997 for cortical, 1 for deep and 0.988 for superficial venous segments.

CONCLUSION

T1S paralleled the accuracy of conventional sequences in the overall detection of CVT but showed superior accuracy in the detection of cortical venous thrombosis. It makes a fitting addition to the CVT MRI protocol in scenarios demanding negation of gadolinium administration.

Multi-echo in steady-state acquisition improves MRI image quality and lumbosacral radiculopathy diagnosis efficacy compared with T2 fast spin-echo sequence

PURPOSE

This study compares the performance of a 4-min multi-echo in steady-state acquisition (MENSA) with a 6-min fast spin echo with variable flip angle (CUBE) protocol for the assessment of lumbosacral plexus nerve root lesions.

METHODS

Seventy-two subjects underwent MENSA and CUBE sequences on a 3.0-T MRI scanner. Two musculoskeletal radiologists independently assessed the images for quality and diagnostic capability. A qualitative assessment scoring system for image quality and quantitative nerve signal-to-noise ratio (SNR) and iliac vein and muscle contrast-to-noise ratios (CNR) was applied. Using surgical reports as the reference, sensitivity, specificity, accuracy, and area under the receiver operating characteristic curves (AUC) were evaluated. Intraclass correlation coefficients (ICC) and weighted kappa were used to calculate reliability.

RESULTS

MENSA image quality rating (3.679 ± 0.47) was higher than for CUBE images (3.038 ± 0.68), and MENSA showed higher mean nerve root SNR (36.935 ± 8.33 vs. 27.777 ± 7.41), iliac vein CNR (24.678 ± 6.63 vs. 5.210 ± 3.93), and muscle CNR (19.414 ± 6.07 vs. 13.531 ± 0.65) than CUBE (P < 0.05). Weighted kappa and ICC values indicated good reliability. Sensitivity, specificity, and accuracy of diagnosis based on MENSA images were 96.23%, 89.47%, and 94.44%, respectively, and AUC was 0.929, compared with 92.45%, 84.21%, 90.28%, and 0.883 for CUBE images. The two correlated ROC curves were not significantly different. Weighted kappa values for intraobserver (0.758) and interobserver (0.768-0.818) reliability were substantial to perfect.

CONCLUSION

A time-efficient 4-min MENSA protocol exhibits superior image quality and high vascular contrast with the potential to produce high-resolution lumbosacral nerve root images.

Combined high-resolution 3D CUBE T1-weighted imaging and non-contrast-enhanced magnetic resonance venography for evaluation of vein stenosis in May-Thurner syndrome

PURPOSE

To explore the feasibility of high-resolution MRI 3-dimensional (3D) CUBE T1-weighted magnetic resonance imaging (MRI) in combination with non-contrast-enhanced (NCE) magnetic resonance venography (MRV) for the assessment of lumen stenosis in May-Thurner syndrome.

METHODS

Twenty-nine patients underwent computed tomography venography (CTV) and high-resolution MRI-CUBE T1, and NCE MRV acquisitions. ANOVA and LSD tests were used to compare the stenosis rate and narrowest and distal diameters of the vessel lumen.

RESULTS

There were no significant differences in the estimated stenosis rate between CTV, CUBE T1, and NCE MRV (p = 0.768). However, there were significant differences in the measured stenosis diameters of the left common iliac vein (LCIV), with CTV giving the largest mean diameter and CUBE had the smallest mean diameter (p < 0.05). The measured normal LCIV diameters did not significantly differ between MRV and CUBE (p = 0.075) but were significantly larger on CTV than on MRV and CUBE (p < 0.05).

CONCLUSIONS

Compared with CTV, a combination of CUBE and MRV could provide an improved assessment of the degree of lumen stenosis in May-Thurner syndrome and demonstrate acute thrombosis. MRI underestimates the diameter of the vessel in comparison with CTV. MRI can be a substitute tool for Duplex ultrasound and CTV.

Quantitative evaluation of knee cartilage and meniscus destruction in patients with rheumatoid arthritis using T1ρ and T2 mapping

OBJECTIVE

To calculate T1ρ and T2 values of articular cartilage and menisci in knee joints of patients with RA, and compare the values between RA patients and healthy volunteers, to gain insight into the pathogenesis of cartilage and meniscus degradation in patients with RA.

MATERIALS AND METHODS

Nine patients with RA and knee joints symptoms were enrolled in the study, twenty healthy volunteers without knee joint diseases were included as controls. Sagittal fat-saturated T1ρ and T2 mapping images were obtained on a 3T MR scanner (GE750, GE Healthcare, Waukesha, WI), using a dedicated 8-channel knee coil. In the T1rho mapping sequence, the amplitude of the spin-lock pulse was 500Hz, spin lock durations=10/20/30/50ms. In the T2 mapping sequence,TR/TE were 1794/6.5, 13.4, 27, 40.7ms. Both sequences were performed with the following parameters: flip angle (FA)=90°, matrix: 320×256, FOV: 16×16cm², slice thickness: 3mm, bandwidth: 62.5kHZ, and a total scan time of 5:11min. T1ρ- and T2-mapping images were used for the segmentation of the articular cartilage of the patella, femoral trochlea, medial and lateral femoral condyle, medial and lateral tibial plateau. These images were also used for the segmentation of the anterior and posterior horns of the medial and lateral menisci with livewire semi-automatic segmentation algorithm of MATLAB. A Mann-Whitney U test was performed to compare the T1ρ and T2 values of the above mentioned regions between the two groups.

RESULTS

T1ρ (Z=-3.913 to -2.121, P=0.000-0.034) and T2 (Z=-3.866 to -2.216, P=0.000-0.026) values of knee cartilage in patients with RA were higher than that in healthy volunteers, except the cartilage of the patella (T1ρ: Z=-1.273, P=0.203,T2: Z=-0.236, P=0.814) and lateral tibial plateau (T1ρ:Z=-1.037, P=0.317). The T1ρ (Z=-1.462 to 0.572, P=0.095-0.908) and T2 (Z=-1.461 to 0.278, P=0.153-0.764) values of medial and lateral menisci showed no difference between the two groups.

CONCLUSION

Patients with RA exhibit diffuse knee cartilage destruction in the medial and lateral tibiofemoral joints and in the femoral trochlea. However, we found no increase in T1ρ and T2 values in menisci, this finding warrants further investigation.

Fast comprehensive single-sequence four-dimensional pediatric knee MRI with T2 shuffling

PURPOSE

To develop and clinically evaluate a pediatric knee magnetic resonance imaging (MRI) technique based on volumetric fast spin-echo (3DFSE) and compare its diagnostic performance, image quality, and imaging time to that of a conventional 2D protocol.

MATERIALS AND METHODS

A 3DFSE sequence was modified and combined with a compressed sensing-based reconstruction resolving multiple image contrasts, a technique termed T₂ Shuffling (T₂ Sh). With Institutional Review Board (IRB) approval, 28 consecutive children referred for 3T knee MRI prospectively underwent a standard clinical knee protocol followed by T₂ Sh. T₂ Sh performance was assessed by two readers blinded to diagnostic reports. Interpretive discrepancies were resolved by medical record chart review and consensus between the readers and an orthopedic surgeon. Image quality was evaluated by rating anatomic delineation, with 95% confidence interval. A Wilcoxon rank-sum test assessed the null hypothesis that T₂ Sh structure delineation compared to conventional 2D is unchanged. Intraclass correlation coefficients were calculated for interobserver agreement. Imaging time of the conventional protocol and T₂ Sh was compared.

RESULTS

There was 81% and 87% concordance between T₂ Sh reports and diagnostic reports, respectively, for each reader. Upon consensus review, T₂ Sh had 93% sensitivity and 100% specificity compared to clinical reports for detection of clinically relevant findings. The 95% confidence interval of diagnostic or better rating was 95-100%, with 34-80% interobserver agreement. There was no significant difference in structure delineation between T₂ Sh and 2D, except for the retinaculum (P < 0.05), where 2D was preferred. Typical imaging time for T₂ Sh and the conventional exam was 7 and 13 minutes, respectively.

CONCLUSION

A single-sequence pediatric knee exam is feasible with T₂ Sh, providing multiplanar, reformattable 4D images.

LEVEL OF EVIDENCE

2 J. MAGN. RESON. IMAGING 2017;45:1700-1711.