Quantitative evaluation of activity of thyroid-associated Ophthalmopathy using short-tau inversion recovery (STIR) sequence

Objective Quantitatively staging TAO using MRI remains limited. Our study aims to identify the cut-off signal intensity value for staging TAO using STIR sequence scan. Methods Between June 2018 and July 2020, a number of 51 patients with TAO (102 eyes) and 19 volunteer controls (38 eyes) were recruited. The clinical and biochemical parameters were measured in each patient. Disease activity was diagnosed based on the Clinical Activity Score (CAS). The signal intensities of extraocular muscles were scanned using short-tau inversion recovery (STIR) sequences from MRI. Results Compared to the inactive TAO patients and the controls, the signal intensity ratios (SIRs) of the superior rectus, inferior rectus, medial rectus, lateral rectus on STIR images were significantly increased in the active TAO patients. After adjustment for age and smokers, the SIRs of four extraocular muscles showed strong associations with CAS. By receiver operator characteristic (ROC) curve analysis, all four muscle SIRs demonstrated good efficiency for predicting disease activity [area under curve (AUC) 0.75–0.83, all P < 0.01]. The identified cut-off SIR values were further validated in a new group of TAO patients (30 eyes) enrolled between September 2020 and January 2021. The cut-off SIR value of > 2.9 in the inferior rectus showed optimal diagnostic value for staging the active TAO. Conclusions the signal intensity of extraocular muscles on STIR sequence was a good predictor for TAO activity. A cut-off SIR value of > 2.9 in the inferior rectus could be applied to evaluate the active stage of TAO.

A Comprehensive Assessment of Hip Damage in Ankylosing Spondylitis, Especially Early Features

Ankylosing spondylitis (AS) is most common in adolescents and the ultimate result is disability, which places a huge burden on patients and society. Therefore, the key to improve the prognosis of AS is the early diagnosis of hip injury. To examine if AS patients whose hip pain is either absent or minimal might already have observable MRI and X-ray hip changes. Clinical and imaging hip data were systematically analyzed in 200 healthy controls (HC) and 300 AS with varying degrees of hip pain. Forty-four patients with early hip osteoarthritis (OA) served as positive imaging controls. In MRI images, BME lesions in the STIR sequence were much more frequent in AS (62%) compared to HC (2%) (p &lt; 0.0001). Most importantly, 42% of AS with no or minimal hip pain had one or more MRI lesions. This was much more frequent compared to the 2% in HC (p &lt; 0.05). These lesions in AS were observed singly or in combination in the trochanters (8%), femoral heads (12%), and acetabula (13%). Parallel finding that X-ray changes were present in patients with minimal or no hip pain was also observed with X-ray. Based on the normal hip width of HC, joint space narrowing was observed in 94.3% of the entire AS cohort, and importantly 56.7% of AS patients with no or mild hip pain. In these latter patients, functional activities of the hips such as walking were normal. At least 40% of AS patients with minimal or no hip pain might already show MRI and X-ray changes.

3-T MRI in Patients Received Anterior Cervical Discectomy and Fusion Surgery with MAVRIC SL IR Sequence: A Feasibility Study

Objective: We aimed to investigate the feasibility of multi-acquisition with variable resonance image combination slab selectivity inversion recovery (MAVRIC SL IR) sequence on 3.0 T MRI in patients with anterior cervical discectomy and fusion (ACDF) surgery compared to bandwidth-optimized short tau inversion recovery (STIR) sequence. Methods: Paired sagittal MR images of MAVRIC SL IR and bandwidth-optimized STIR sequences were acquired and analyzed for 21 patients after ACDF surgery with PEEK cage-plate construct. Quantitative comparisons were made on the metal artifact areas of paired mid-sagittal images. In qualitative analysis, the consistency of fat suppression and visibility of anatomic structures (bone-metal interface, surrounding soft tissues, and spinal cord) were independently assessed, based on a five-point scale by two musculoskeletal radiologists, who were blind to the images and patient details. Results: The application of the MAVRIC SL IR sequence resulted in a significant reduction of 48% in the mean area of metal artifacts (t =-7.141, P < 0.001). Based on the comments received from both the reviewers, MAVRIC SL IR sequence showed greater visibility of the bone-metal interface (P < 0.001), considerable visibility of the surrounding soft tissues (P > 0.05) but worse visibility obtained of the spinal cord (P < 0.001), including the consistency of fat suppression (P < 0.001) relative to the bandwidth-optimized STIR sequence. Conclusion: With significantly reduced metal artifacts, the MAVRIC SL IR sequence can be implemented in patients undergoing ACDF surgery with PEEK cage-plate construct for 3.0 T MRI, despite the poor visibility of the spinal cord.

Coronal STIR sequence, a simple adjustment to routine MRI protocol for extra-spinal sciatica and sciatica-like symptoms

Background The value of adding coronal STIR images to MR imaging of sciatica aiming to detect extra-spinal abnormalities. Results Additional coronal STIR images detected extra-spinal abnormalities in 20% of the patients, thereby downgraded the normal studies from 21 to 13%. The extra-spinal abnormalities included bone abnormalities (36.4%), soft tissue abnormalities (4.5%), neurological abnormalities (2.3%), gynecological abnormalities (50%), and miscellaneous (6.8%). In 6.9% of patients, the extra-spinal abnormalities explained the patients’ pain and influenced their management. Extra-spinal causes of pain significantly correlated to positive trauma and neoplasm history, normal routine protocol images, and absent nerve root impingement. Extra-spinal abnormalities were more prevalent in age groups (20–39 years). Conclusion Coronal STIR images (field of view: mid abdomen to the lesser trochanters) identify extra-spinal abnormalities that maybe overlooked on routine MRI protocol. It is of additional value in young adults, trauma, neoplasm, and negative routine images.

Comparing the accuracy and reliability of detecting intensity of spinal inflammation on STIR sequence with ADC values in axial spondyloarthritis

Objective To compare the accuracy and reliability of detecting the intensity of spinal inflammation on short tau inversion recovery (STIR) with the apparent diffusion coefficient (ADC) values of the active MRI lesions in axial spondyloarthritis (axSpA). Materials and methods Fifty active lesions in STIR sequence of spinal MRI were identified. With reference to sites of active lesions in STIR, the corresponding region of interest (ROI) on ADC map was drawn to determine the maximum ADC (ADCmax), mean ADC (ADCmean), normalized maxium (nADCmax) and mean (nADCmean). Four independent readers scored the identified active lesions as “intense” or “non-intense” according to the SPARCC MRI index. They were compared to various ADC parameters for assessment of accuracy and reliability. Regression analyses were used to adjust potential factors that could affect ADC. Results Significant differences were found in ADCmax between “intense” and “non-intense” lesions scored by 3 of the 4 readers (1405.7±271.4 vs 1165.8±223.8, p=0.01; 1420.7±272.1 vs 1209.0±248.5, p=0.01; 1438.0±307.2 vs 1213.6±231.0, p=0.01). Only 1 reader could differentiate a difference in “intense” and “non-intense” lesions with respect to ADCmean (899.2±248.3 vs 711.0±222.6, p=0.01) and nADCmean (4.4±2.1 vs 3.4±1.4, p=0.05). Inter-reader agreements were slight to moderate (Kappa=0.07-0.45). Reliability substantially improved when only the lowest and highest 25th percentiles of ADC values were included (Kappa=0.17-0.75). Regression analyses showed the “intense” lesions were associated with higher ADC values after adjustment for confounders. Conclusion Reading of STIR MRI is limited by the lack of ability in differentiating subtle differences of spinal inflammation. ADC could be an alternative method.