DeBoNet: A deep bone suppression model ensemble to improve disease detection in chest radiographs.

Automatic detection of some pulmonary abnormalities using chest X-rays may be impacted adversely due to obscuring by bony structures like the ribs and the clavicles. Automated bone suppression methods would increase soft tissue visibility and enhance automated disease detection. We evaluate this hypothesis using a custom ensemble of convolutional neural network models, which we call DeBoNet, that suppresses bones in frontal CXRs. First, we train and evaluate variants of U-Nets, Feature Pyramid Networks, and other proposed custom models using a private collection of CXR images and their bone-suppressed counterparts. The DeBoNet, constructed using the top-3 performing models, outperformed the individual models in terms of peak signal-to-noise ratio (PSNR) (36.7977±1.6207), multi-scale structural similarity index measure (MS-SSIM) (0.9848±0.0073), and other metrics. Next, the best-performing bone-suppression model is applied to CXR images that are pooled from several sources, showing no abnormality and other findings consistent with COVID-19. The impact of bone suppression is demonstrated by evaluating the gain in performance in detecting pulmonary abnormality consistent with COVID-19 disease. We observe that the model trained on bone-suppressed CXRs (MCC: 0.9645, 95% confidence interval (0.9510, 0.9780)) significantly outperformed (p < 0.05) the model trained on non-bone-suppressed images (MCC: 0.7961, 95% confidence interval (0.7667, 0.8255)) in detecting findings consistent with COVID-19 indicating benefits derived from automatic bone suppression on disease classification. The code is available at https://github.com/sivaramakrishnan-rajaraman/Bone-Suppresion-Ensemble.

Fragility fracture of the fourth rib in a patient with a cardiac pacemaker: an uncommon case.

PURPOSE: In patients with a cardiac pacemaker, pocket-related complications such as nerve impairment or bone fractures are infrequent. We present a man with a fracture of the 4th rib several months after pacemaker implantation. CASE PRESENTATION: A 74-year-old man, with a left prepectoral pacemaker implanted 13 months ago, presented complaining of chest pain. The pain started after a sudden trunk rotation and right arm flexion movement with a crack. There was tenderness to palpation and crepitation over the left upper ribs. Computed tomography identified a non-displaced fracture line in the anterior aspect of the left 4th rib. After kinesiotaping and activity restriction, pain alleviated. CONCLUSION: Pacemaker implantation might have caused shoulder dysfunction and pectoral tightness resulting in reduced flexibility of the trunk. Consequently, a reaching motion of the arm with a trunk rotation might have directed rotational force vectors towards the osteopenic left 4th rib causing a fragility fracture. In elderly with a pacemaker, osteopenia and concomitant sarcopenia may create a predisposition to this atypical complication.