Comparison of magnetic resonance imaging and computed tomography for bone assessment of neurogenic heterotopic ossification of the hip: a preliminary study.

BACKGROUND: Neurogenic heterotopic ossification (NHO) is a frequent complication, often involving the hip. The functional impact may require surgical management and pre-surgical imaging assessment is necessary, usually by computed tomography (CT). We aimed to compare the performances of magnetic resonance imaging (MRI) and CT for bone assessment on pre-surgical imaging of the heterotopic ossifications and their features in NHO of the hip. METHODS: This single-center prospective preliminary study included all patients who underwent surgery for NHO with joint limitation from July 2019 to March 2020. All patients had a CT after biphasic iodinated solution injection and an MRI including T1-weighted, STIR and ZTE sequences. Standardized reports were completed for both exams for each patient, evaluating location, implantation and fragmentation of NHO, relation to the joint capsule and bone mineralization, then were compared. RESULTS: Seven patients from 32 to 70 years old (mean = 50.2 ± 17.2 years) were evaluated. NHO were bilateral in 2 patients, for a total of nine hips: six right hips and three left hips. Observed concordance rates between MRI and CT were, respectively, 94.4% for location, 100% for circumferential extension, 87.3% for implantation 88.9% for fragmentation, 77.8% for relation to the joint capsule and 66.7% for bone mineralization. It was 100% for femoral neck fracture and osteonecrosis of the femoral head. CONCLUSION: This preliminary study suggests that pre-surgical MRI imaging should be considered as effective as CT for bone assessment of NHO and their features. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03832556. Registered February 6, 2019, https://clinicaltrials.gov/ct2/show/NCT03832556 .

Parotitis-Like Symptoms Associated with COVID-19, France, March-April 2020.

We report the clinical features of 3 patients in France who had parotitis (inflammation of the parotid salivary glands) as a clinical manifestation of confirmed coronavirus disease. Results from magnetic resonance imaging support the occurrence of intraparotid lymphadenitis, leading to a parotitis-like clinical picture.

Visual assessment of diffusion weighted imaging infarct volume lacks accuracy and reliability.

PURPOSE: The DAWN trial (Diffusion weighted imaging or CT perfusion Assessment with clinical mismatch in the triage of Wake-up and late presenting strokes undergoing Neurointervention with Trevo) has demonstrated the benefits of thrombectomy in patients with unknown or late onset strokes, using automated software (RAPID) for measurement of infarct volume. Because RAPID is not available in all centers, we aimed to assess the accuracy and repeatability of visual infarct volume estimation by clinicians and the consequences for thrombectomy decisions based on the DAWN criteria. MATERIALS AND METHODS: 18 physicians, who routinely depend on MRI for acute stroke imaging, assessed 32 MR scans selected from a prospective databaseover two independent sessions. Raters were asked to visually estimate the diffusion weighted imaging (DWI) infarct volume for each case. Sensitivity, specificity, and accuracy of the estimated volumes were compared with the available RAPID measurements for various volume cut-off points. Thrombectomy decisions based on DAWN criteria with RAPID measurements and raters' visual estimates were compared. Inter-rater and intra-rater agreement was measured using kappa statistics. RESULTS: The mean accuracy of raters was <90% for all volume cut-points. Inter-rater agreement was below substantial for each DWI infarct volume cut-off points. Intra-rater agreement was substantial for 55-83% of raters, depending on the selected cut-off points. Applying DAWN criteria with visual estimates instead of RAPID measurements led to 19% erroneous thrombectomy decisions, and showed a lack of reproducibility. CONCLUSION: The visual assessment of DWI infarct volume lacks accuracy and repeatability, and could lead to a significant number of erroneous decisions when applying the DAWN criteria.

Automatic Measurement of the Total Visceral Adipose Tissue From Computed Tomography Images by Using a Multi-Atlas Segmentation Method.

BACKGROUND: The visceral adipose tissue (VAT) volume is a predictive and/or prognostic factor for many cancers. The objective of our study was to develop an automatic measurement of the whole VAT volume using a multi-atlas segmentation (MAS) method from a computed tomography. METHODS: A total of 31 sets of whole-body computed tomography volume data were used. The reference VAT volume was defined on the basis of manual segmentation (VATMANUAL). We developed an algorithm, which measured automatically the VAT volumes using a MAS based on a nonrigid volume registration algorithm coupled with a selective and iterative method for performance level estimation (SIMPLE), called VATMAS_SIMPLE. The results were evaluated using intraclass correlation coefficient and dice similarity coefficients. RESULTS: The intraclass correlation coefficient of VATMAS_SIMPLE was excellent, at 0.976 (confidence interval, 0.943-0.989) (P < 0.001). The dice similarity coefficient of VATMAS_SIMPLE was also good, at 0.905 (SD, 0.076). CONCLUSIONS: This newly developed algorithm based on a MAS can measure accurately the whole abdominopelvic VAT.