Non-Enhancing Tissue on Diabetic Foot Magnetic Resonance Imaging in Relation to Osteomyelitis Investigation: Magnetic Resonance Imaging Performance, Pitfalls and Clinical Considerations.

Background: Geographic non-enhancing zones in diabetic foot magnetic resonance imaging (MRI) were first described in 2002. No previous report has described the impact and clinical significance of geographic non-enhancing tissue seen in the evaluation of diabetic foot MRI. Purpose: To evaluate the prevalence of devascularization areas on contrast-enhanced MRI in diabetic patients suspected of having foot osteomyelitis, the impact on the performance of the MRI assessment, and the possible pitfalls. Methods: A retrospective study was conducted between January 2016 and December 2017 during which 72 CE-MRIs of 1.5 and 3T were reviewed by 2 musculoskeletal radiologists for the presence of non-enhancing tissue areas and for osteomyelitis. A blinded third party collected clinical data including pathology reports, revascularization procedures, and surgical interventions. The prevalence of devascularization was calculated. Results: Among the 72 CE-MRIs (54 men, 18 women; mean age 64), 28 demonstrated non-enhancing areas (39%). All but 6 patients were found to have been correctly diagnosed on imaging (3 false positives, 2 false negatives, and 1 non-diagnostic). A greater discordance was also observed between the radiological and pathological diagnoses in the MRIs which showed non-enhancing tissue. Conclusion: Non-enhancing tissue is found in a non-negligible portion of diabetic foot MRIs and affects its diagnostic performance when looking for osteomyelitis. The recognition of these areas of devascularization may be helpful for the physician in planning the best treatment option for the patient.

Performance of clear cell likelihood scores in characterizing solid renal masses at multiparametric MRI: an external validation study.

PURPOSE: The purpose of this study is to evaluate the accuracy and interobserver agreement of ccLS in diagnosing clear cell renal cell carcinoma (ccRCC). METHODS: This retrospective single-center study evaluated consecutive patients with solid renal masses who underwent mpMRI followed by percutaneous biopsy and/or surgical excision between January 2010 and December 2020. Predominantly (> 75%) cystic masses, masses with macroscopic fat and infiltrative masses were excluded. Two abdominal radiologists independently scored each renal mass according to the proposed ccLS algorithm. The diagnostic performance of ccLS categories for ccRCC was calculated using logistic regression modeling. Diagnostic accuracy for predicting ccRCC was calculated using 2 × 2 contingency tables. Interobserver agreement for ccLS was evaluated with Cohen's k statistic. RESULTS: A total of 79 patients (mean age, 63 years ± 12 [SD], 50 men) with 81 renal masses were evaluated. The mean size was 36 mm ± 28 (range 10-160). Of the renal masses included, 44% (36/81) were ccRCC. The area under the receiver operating characteristic curve was 0.87 (95% CI 0.79-0.95). Using ccLS ≥ 4 to diagnose ccRCC, the sensitivity, specificity, and positive predictive value were 93% (95% CI 79, 99), 63% (95% CI 48, 77), and 67% (95% CI 58, 75), respectively. The negative predictive value of ccLS ≤ 2 was 93% (95% CI 64, 99). The proportion of ccRCC by ccLS category 1 to 5 were 10%, 0%, 10%, 57%, and 84%, respectively. Interobserver agreement was moderate (k = 0.47). CONCLUSION: In this study, clear cell likelihood score had moderate interobserver agreement and resulted in 96% negative predictive value in excluding ccRCC.

Thyroid Nodules Detected on CT: A Retrospective Audit Study and Analysis of Differences in Reporting Practices Across Radiology Subspecialties.

Thyroid nodules (TNs) are common incidental findings  on imaging and TN reporting practices are variable among radiologists, leading to unnecessary or inadequate investigations. We aimed to document current literature adherence for TN reporting practices on thoracic CTs and assess the variability in TN reporting across radiology subspecialties. This is a 2-parts retrospective study. First part was an audit study including all adult patients with thoracic CTs in January 2020. Patients with prior thyroidectomy and/or lack of TN were excluded. A local committee was created for literature review and elaboration of a local TN management algorithm. The algorithm was shared with the thoracic radiology team. Imaging and medical records were reviewed and adequate adherence was assessed in the pre- and post-intervention cohorts. Second part included all adult patients who underwent neck or cervical spine CT imaging in the same timeframe and with same inclusion/exclusion criteria as the pre-intervention thoracic cohort. In the pre-intervention cohort 802 participants were screened and 137 patients included. TNs were reported in "body" and "conclusion" of the report in 51% and 7% of the time respectively. Thyroid US was recommended in 10% of the patients and inadequately recommended 3% of the time. Overall adequate adherence was 86%. In the post-intervention cohort 962 participants were screened and 167 patients included. Thyroid US was recommended in 7% of the patients and no inadequate US recommendation was made. Overall adequate adherence in the post-intervention cohort was 93%, increased by 7% (P= 0.039). The musculoskeletal and neuroradiology cohorts reported more TNs in "conclusion" (P= 0.013 and P< 0.0001) and recommended more thyroid US (P = 0.033 and P= 0.0018) compared to the preintervention thoracic cohort. No significant difference in overall adequate adherence between subspecialties (P= 0.48 and P= 0.51). Improvement in adequate TN reporting on thoracic CT by 7% while reducing inadequate thyroid US recommendations from 3% to none. Significant reporting trends were also noted across radiology subspecialties.

Diabetic foot infections: how to investigate more efficiently? A retrospective study in a quaternary university center.

BACKGROUND: Diabetic foot infections are frequent and associated with substantial morbidity and substantial cost to the healthcare system. Up to 34% of diabetic patients will develop an ulcer potentially leading to osteomyelitis. Imaging plays a crucial role in the diagnostic process. Imaging modalities to investigate the diabetic foot infection are many and imaging prescription habits remain heterogeneous across physicians. We aimed to improve the appropriateness of imaging examination requested, and performed, for diabetic foot osteomyelitis and we aimed to reduce the overall imaging-related cost. METHODS: Local committee was created to develop an algorithm for suspected diabetic foot osteomyelitis. Best practices were defined by the local algorithm. The algorithm was shared with our physicians. Pre- and post-intervention analysis was conducted retrospectively. All adult diabetic patients with suspected foot osteomyelitis were included. Adherence to best practices was measured. Statistical analysis with Chi-Square and two tailed unpaired t-test was performed. RESULTS: Pre-intervention cohort had 223 patients (mean age: 63; 168 men). Adherence to best practice was 43%. Scintigraphy (48%) preferred over MRI (44%) and performed simultaneously in 15 patients. Post-intervention cohort had 73 patients (mean age: 66; 62 men). Adherence to best practice was 78%, improved by 35% (p < 0.001). MRI (51%) preferred over scintigraphy (23%) and performed simultaneously in three patients. Scintigraphy examinations decreased by 25% (p < 0.001). MRI examinations increased by 7% (p = 0.32). Hospital imaging related fees decreased by 22% per patient (p = 0.002). CONCLUSION: Interval improvement in adequate adherence while reducing unnecessary examinations for patients and decreasing costs for the healthcare system was observed.

Frameless Stereotactic Radiosurgery With Linear Accelerator (LINAC)-Based Technology for Brain Metastases: Outcomes Analysis in 141 Patients.

Objectives Brain metastases (BM) are the most common intracranial tumors in adults. Surgery and frame-based stereotactic radiosurgery (SRS) are well-described treatment options. Frameless SRS is an emerging BM treatment option offering fewer side effects. The aim of this study was to describe the therapeutic outcomes and toxicity of frameless SRS with linear accelerator (LINAC)-based technology for BM treatment in our institution. Materials and methods We performed a retrospective study including all adult patients treated with frameless SRS with LINAC-based technology for BM between October 2010 and July 2016. Patients were followed routinely with MRI scans at three-month intervals. Primary endpoints were progression-free survival, local control, overall survival, and toxicity related to the treatment. All survival times were computed with the Kaplan-Meier method. All cumulative incidences were computed using competing risk analyses. Results A total of 194 metastatic lesions in 141 patients were treated in a 69-month interval. At the time of analysis, 33 patients were still alive, with a median follow-up time of 25.1 months. The overall median survival was 8.7 months. The median progression-free survival was 5.3 months. Local recurrence as a first event was 25% and 38% at one and two years, respectively, while distant brain recurrence as a first event was 18% and 21%. Death before any brain event occurred in 31% of patients. The cumulative incidence of radiation necrosis as a first brain event was 2% at one and two years. Conclusions The treatment of BM with LINAC-based frameless SRS in our institution had an overall and progression-free survival comparable with the literature for frameless SRS and for conventional frame-based SRS while being less invasive and more comfortable for the patient. In our study, frameless SRS with LINAC technology seems to be safe for BM treatment with minimal rates of radiation necrosis.