A new modified MR dual precision positioning of thin-slice oblique sagittal fat suppression proton density weighted imaging: its diagnostic accuracy in anterior cruciate ligament injury.

To evaluate the diagnostic accuracy of a new modified MR dual precision positioning of thin-slice oblique sagittal fat suppression proton density-weighted imaging (DPP-TSO-Sag-FS-PDWI) sequence in detecting ACL injuries and its grades compared to standard sequences using arthroscopy as the standard reference. 42 patients enrolled in this retrospective study received the 1.5-T MRI with standard sequences and the new modified DPP-TSO-Sag-FS-PDWI sequence, and their arthroscopy results was recorded. The Mc Nemer-Bowker and weighted Kappa was performed to compare the consistency of MRI diagnosis with arthroscopic results. Finally, the diagnostic accuracy was calculated based on the true positive, true negative, false negative and false positive values. The diagnostic consistency of the DPP-TSO-Sag-FS-PDWI were higher than standard sequences for both reader 1 (K = 0.876 vs. 0.620) and reader 2 (K = 0.833 vs. 0.683) with good diagnostic repeatability (K = 0.794 vs. 0.598). Furthermore, the DPP-TSO-Sag-FS-PDWI can classify and diagnose three grades of ACL injury [the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value were more than 84%], especially for grade II injury as the PPV was superior for reader 1 (92.3% vs. 53.9%) and reader 2 (84.6% vs. 69.2%). The new modified DPP-TSO-Sag-FS-PDWI sequence can display the ACL injury on one or continuous levels by maximizing the acquisition of complete ligament shape and true anatomical images, and excluding the influence of anatomical differences between individuals. It can improve the diagnostic accuracy with good repeatability and classify three grades of the ACL injury.

Qualitative and quantitative diagnosis of intramuscular hemangioma subtypes: Diagnostic performance comparison of ESWAN and conventional MRI.

BACKGROUND: Preoperative identification of intramuscular hemangioma (IMH) subtypes (capillary hemangioma, cavernous hemangioma, and mixed hemangioma) is urgently necessary. Enhanced T2*-weighted angiography (ESWAN) is sensitive to vessels and metabolites and can be used to diagnose IMH subtypes. PURPOSE: To compare the diagnostic performances of ESWAN and conventional magnetic resonance imaging (MRI) for qualitative and quantitative diagnosis of IMH subtypes. MATERIAL AND METHODS: In total, 23 patients with IMHs were examined using conventional MRI and ESWAN. The signal intensity ratios (SIRs) of conventional MRI and ESWAN were measured. RESULTS: There was no significant difference for volume among the three subtypes (P = 0.124, P = 0.145). Various shapes and MRI signals were shown in the three subtypes of IMH. There was no significant difference for SIRs of conventional MRI (P = 0.558, P = 0.259, P = 0.385, P = 0.347). However, there was a significant difference for SIRs of ESWAN parameters (P = 0.050, P < 0.001, P = 0.005, P = 0.002). Capillary hemangiomas can be diagnosed when R2* SIR is <0.912 and intratumoral susceptibility signal (ITSS) percentage is <29.085%. Cavernous hemangiomas should be considered when R2* SIR is >0.912, ITSS percentage >35.226%, and phase SIR >2.536. In addition, mixed hemangiomas should be considered when T2* SIR is >0.662 and R2* SIR <1.618. CONCLUSION: Conventional MRI can only display the volume, shape, and signal of IMHs. 3D-MinIP imaging of ESWAN can show the veins and minor hemorrhage. SIRs of ESWAN parameters including T2* value, R2* value, phase value, and percentage of ITSS can be used to quantitatively diagnose capillary hemangiomas, cavernous hemangiomas, and mixed hemangiomas.

The Diagnostic Accuracy of Different MRI Sequences for Different Meniscus Lesions: A Meta-analysis.

BACKGROUND: It is still uncertain to determine the exact diagnostic accuracy of MRI for medial meniscus (MM) tear, lateral meniscus (LM) tear and MM posterior root tear (MMPRT) at different magnetic field intensities (MFIs), different sequences and different publication dates. This study aimed to identify the diagnostic performance of MRI for different meniscus lesions at different MFIs, different sequences and different publication dates, and also to compare it with physical examination. METHODS: PubMed, Embase, Ovid database, Biosis Previews, Cochrane library, Web of Sciences and manual searching were performed from 1 January 2000 to 31 December 2021. Prospective studies of meniscus injuries examined by physical examination, MRI and arthroscopy were included. RESULTS: Thirteen studies with 1583 meniscal tears were included. The pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), diagnostic odds ratio (DOR) and area under curve (AUC) were 87% (95% confidence interval (CI), 86-89%), 82% (80-83%), 7.44 (5.11- 10.75), 0.18 (0.14-0.23), 45.95 (26,68-79.15) and 0.93, respectively. The pooled specificity between MM and LM (p = 0.015), the pooled sensitivity and LR- between MM and MMPR (p = 0.031), different MRI sequences (p = 0.035, p = 0.027), and the accuracy of less than 1.5T and 3.0T (p = 0.04), 1.5T and 3.0T (p = 0.035) were statistically different. There was no publication bias (p = 0.54). CONCLUSION: MRI performed well in the diagnosis of MM tear, LM tear and MMPRT, and the diagnostic performance of physical examination is similar to MRI. The diagnostic accuracy of 3.0T is the highest, and the -weighted imaging (SWI) sequence may be beneficial for diagnosing meniscus tear. However, there are not enough evidence to prove that recent studies are significantly better than previous ones.