Radiologic Manifestations of Pulmonary Vein Ablation Complications: A Pictorial Review.

In patients with atrial fibrillation refractory to drug therapy and cardioversion, pulmonary vein ablation is an alternative treatment that eradicates arrhythmogenic activity originating in the muscles of the pulmonary veins. While this procedure has a low incidence of significant complications, iatrogenic injuries are possible. Through multimodality pictorial examples utilizing computed tomography, nuclear medicine, fluoroscopy, and chest radiographs, the complications associated with pulmonary vein ablation will be reviewed. Examples of pulmonary vein stenosis, right phrenic nerve injury with associated diaphragmatic paralysis, atrioesophageal fistula, and pericardioesophageal fistula will be illustrated.

Diagnosis of Coronavirus Disease 2019 Pneumonia by Using Chest Radiography: Value of Artificial Intelligence.

Background Radiologists are proficient in differentiating between chest radiographs with and without symptoms of pneumonia but have found it more challenging to differentiate coronavirus disease 2019 (COVID-19) pneumonia from non-COVID-19 pneumonia on chest radiographs. Purpose To develop an artificial intelligence algorithm to differentiate COVID-19 pneumonia from other causes of abnormalities at chest radiography. Materials and Methods In this retrospective study, a deep neural network, CV19-Net, was trained, validated, and tested on chest radiographs in patients with and without COVID-19 pneumonia. For the chest radiographs positive for COVID-19, patients with reverse transcription polymerase chain reaction results positive for severe acute respiratory syndrome coronavirus 2 with findings positive for pneumonia between February 1, 2020, and May 30, 2020, were included. For the non-COVID-19 chest radiographs, patients with pneumonia who underwent chest radiography between October 1, 2019, and December 31, 2019, were included. Area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were calculated to characterize diagnostic performance. To benchmark the performance of CV19-Net, a randomly sampled test data set composed of 500 chest radiographs in 500 patients was evaluated by the CV19-Net and three experienced thoracic radiologists. Results A total of 2060 patients (5806 chest radiographs; mean age, 62 years ± 16 [standard deviation]; 1059 men) with COVID-19 pneumonia and 3148 patients (5300 chest radiographs; mean age, 64 years ± 18; 1578 men) with non-COVID-19 pneumonia were included and split into training and validation and test data sets. For the test set, CV19-Net achieved an AUC of 0.92 (95% CI: 0.91, 0.93). This corresponded to a sensitivity of 88% (95% CI: 87, 89) and a specificity of 79% (95% CI: 77, 80) by using a high-sensitivity operating threshold, or a sensitivity of 78% (95% CI: 77, 79) and a specificity of 89% (95% CI: 88, 90) by using a high-specificity operating threshold. For the 500 sampled chest radiographs, CV19-Net achieved an AUC of 0.94 (95% CI: 0.93, 0.96) compared with an AUC of 0.85 (95% CI: 0.81, 0.88) achieved by radiologists. Conclusion CV19-Net was able to differentiate coronavirus disease 2019-related pneumonia from other types of pneumonia, with performance exceeding that of experienced thoracic radiologists. © RSNA, 2021 Online supplemental material is available for this article.

Interobserver and Intraobserver Variability in the CT Assessment of COVID-19 Based on RSNA Consensus Classification Categories.

PURPOSE: To assess the interobserver and intraobserver agreement of fellowship trained chest radiologists, nonchest fellowship-trained radiologists, and fifth-year radiology residents for COVID-19-related imaging findings based on the consensus statement released by the Radiological Society of North America (RSNA). METHODS: A survey of 70 chest CTs of polymerase chain reaction (PCR)-confirmed COVID-19 positive and COVID-19 negative patients was distributed to three groups of participating radiologists: five fellowship-trained chest radiologists, five nonchest fellowship-trained radiologists, and five fifth-year radiology residents. The survey asked participants to broadly classify the findings of each chest CT into one of the four RSNA COVID-19 imaging categories, then select which imaging features led to their categorization. A 1-week washout period followed by a second survey comprised of randomly selected exams from the initial survey was given to the participating radiologists. RESULTS: There was moderate overall interobserver agreement in each group (κ coefficient range 0.45-0.52 ± 0.02). There was substantial overall intraobserver agreement across the chest and nonchest groups (κ coefficient range 0.61-0.67 ± 0.06) and moderate overall intraobserver agreement within the resident group (κ coefficient 0.58 ± 0.06). For the image features that led to categorization, there were varied levels of agreement in the interobserver and intraobserver components that ranged from fair to perfect kappa values. When assessing agreement with PCR-confirmed COVID status as the key, we observed moderate overall agreement within each group. CONCLUSION: Our results support the reliability of the RSNA consensus classification system for COVID-19-related image findings.

Chest Radiographic Appearance of Minimally Invasive Cardiac Implants and Support Devices: What the Radiologist Needs to Know.

Minimally invasive implantable cardiac devices used in valve repair and replacement, cardiovascular support, and partial chamber and appendageal occlusion represent a burgeoning area of both bioengineering and clinical innovation. In addition to familiarizing the reader with the radiographic appearance of the most commonly utilized and encountered newer devices, this review will also address the relevant clinical and pathophysiological indications for usage and deployment as well as potentially encountered complications.

Sonography of traumatic quadriceps tendon tears with surgical correlation.

OBJECTIVES: Using surgical correlation as the reference standard, the purpose of this study was to assess the ability of sonography to detect quadriceps tendon tears that require surgical treatment (high-grade partial tears and complete ruptures). METHODS: Two hundred thirty-nine consecutive sonographic reports of the knee (May 2001 to October 2008) with subsequent surgical correlation were retrospectively reviewed for surgical intervention on the quadriceps tendon. All sonograms were blindly and retrospectively reviewed. Surgical findings were compared with results from the consensus review. Results from the original sonographic reports (nonretrospective interpretation) were also compared with the surgical findings. RESULTS: On the retrospective consensus review, the sensitivity (23 of 23), specificity (16 of 16), and accuracy (39 of 39) were 100% for identifying high-grade partial tears or complete ruptures versus a normal quadriceps tendon. For the original, nonretrospective sonographic reports, 22 of 23 high-grade partial tears or complete ruptures (96%) were correctly diagnosed. CONCLUSIONS: Sonography is an effective tool for identifying quadriceps tendon tears that require surgical treatment (high-grade partial tears and complete ruptures).