Deep Learning-Based Automatic CT Quantification of Coronavirus Disease 2019 Pneumonia: An International Collaborative Study.

OBJECTIVE: We aimed to develop and validate the automatic quantification of coronavirus disease 2019 (COVID-19) pneumonia on computed tomography (CT) images. METHODS: This retrospective study included 176 chest CT scans of 131 COVID-19 patients from 14 Korean and Chinese institutions from January 23 to March 15, 2020. Two experienced radiologists semiautomatically drew pneumonia masks on CT images to develop the 2D U-Net for segmenting pneumonia. External validation was performed using Japanese (n = 101), Italian (n = 99), Radiopaedia (n = 9), and Chinese data sets (n = 10). The primary measures for the system's performance were correlation coefficients for extent (%) and weight (g) of pneumonia in comparison with visual CT scores or human-derived segmentation. Multivariable logistic regression analyses were performed to evaluate the association of the extent and weight with symptoms in the Japanese data set and composite outcome (respiratory failure and death) in the Spanish data set (n = 115). RESULTS: In the internal test data set, the intraclass correlation coefficients between U-Net outputs and references for the extent and weight were 0.990 and 0.993. In the Japanese data set, the Pearson correlation coefficients between U-Net outputs and visual CT scores were 0.908 and 0.899. In the other external data sets, intraclass correlation coefficients were between 0.949-0.965 (extent) and between 0.978-0.993 (weight). Extent and weight in the top quartile were independently associated with symptoms (odds ratio, 5.523 and 10.561; P = 0.041 and 0.016) and the composite outcome (odds ratio, 9.365 and 7.085; P = 0.021 and P = 0.035). CONCLUSIONS: Automatically quantified CT extent and weight of COVID-19 pneumonia were well correlated with human-derived references and independently associated with symptoms and prognosis in multinational external data sets.

Prevalence and types of coronary artery fistulas detected with coronary CT angiography.

OBJECTIVE: The prevalence of coronary artery fistula (CAF) based on coronary angiographic findings has been reported. However, the number of incidentally found CAFs is increasing as coronary CT angiography (CTA) has become popular. The purpose of this study was to determine the prevalence and types of CAFs detected with coronary CTA. MATERIALS AND METHODS: Between March 2009 and November 2011, 6341 patients underwent coronary CTA at one institution. The prevalence of CAF was retrospectively evaluated, and the morphologic features were analyzed, including vessel of origin, drainage site, size, and presence of an aneurysmal sac. We also analyzed cardiac and pulmonary findings. RESULTS: Among 6341 patients, 56 (0.9%) patients had CAF. The types of CAF detected, in decreasing frequency, were coronary to pulmonary artery fistula (43 cases [76.8%]), coronary to bronchial artery fistula (five cases [8.9%]), coronary artery to cardiac chamber fistula (five cases [8.9%]), combined coronary to pulmonary and coronary to bronchial artery fistula (two cases [3.6%]), and coronary artery to superior vena cava fistula (one case [1.8%]). Lung parenchymal or vascular anomaly was more frequently noted in coronary to bronchial artery fistulas, combined coronary to pulmonary and coronary to bronchial artery fistulas, and coronary artery to superior vena cava fistulas than in coronary to pulmonary artery and coronary artery to cardiac chamber fistulas. CONCLUSION: The prevalence of CAF at coronary CTA was 0.9%, which is higher than the known prevalence based on conventional angiographic findings (0.05-0.25%). Furthermore, the most common type of CAF in this study was coronary to pulmonary artery, whereas coronary artery to ventricle fistula was previously considered the most common type in studies conducted with conventional angiography. Coronary CTA is a useful, noninvasive imaging modality for the detection of CAF.

2024 Consensus Statement on Coronary Stenosis and Plaque Evaluation in CT Angiography From the Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT).

The Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT) is an instructional initiative of the ASCI School designed to enhance educational standards. In 2021, the ASCI-PT was convened with the goal of formulating a consensus statement on the assessment of coronary stenosis and coronary plaque using coronary CT angiography (CCTA). Nineteen experts from four countries conducted thorough reviews of current guidelines and deliberated on eight key issues to refine the process and improve the clarity of reporting CCTA findings. The experts engaged in both online and on-site sessions to establish a unified agreement. This document presents a summary of the ASCI-PT 2021 deliberations and offers a comprehensive consensus statement on the evaluation of coronary stenosis and coronary plaque in CCTA.

Preparative fasting for contrast-enhanced CT: reconsideration.

PURPOSE: To evaluate the evidence on the value of preparative fluid fasting for patients undergoing elective computed tomography (CT) with intravenous administration of contrast material and to survey leading institutions in a number of countries on their current policies in this regard. MATERIALS AND METHODS: This study qualified for exempt status by the institutional review board. First, 20 keyword combinations were entered into Medline to ascertain the correlation between fluid ingestion preceding contrast material-enhanced CT and development of aspiration pneumonia. The numbers of patients were summed up to estimate incidence of aspiration pneumonia attributable to ingestion of clear inert fluid before contrast-enhanced CT examination. Second, a multinational survey was conducted about the length of preparative fasting protocols, if any, for fluids and solids that they recommend to patients before elective non-gastrointestinal contrast-enhanced CT. RESULTS: Aspiration was not noted in any of 2001 patients (13 studies in the literature) who underwent contrast-enhanced CT after fluid ingestion. Data were available from 69 (86.3%) of 80 institutions queried (17 Korean, 14 U.S., 11 French, 10 Australian, 10 German, and seven Egyptian hospitals). Two-thirds (14 of 21 [66.7%]) of the French and German hospitals had a no-restriction policy for both fluids and solids, while Australian hospitals had a policy liberal about fluids (no restrictions in eight of 10 [80%]) only. Policies on fluids were variable in Korea, the United States, and Egypt (restrictions of 0-8 hours, 0-4 hours, and 0-6 hours, respectively), as were policies on solids in Korea, the United States, Australia, and Egypt (restrictions of 0-8 hours, 0-6 hours, 0 to 4-6 hours, and 0 hours to overnight, respectively). The length of fasting was longer for solids than for fluids in 20 hospitals. CONCLUSION: There is little evidence that ingestion of clear inert fluid prior to contrast-enhanced CT is a cause of aspiration pneumonia; the length of fasting is variable in any country, being much longer in some hospitals than in others.

Semi-Quantitative Scoring of Late Gadolinium Enhancement of the Left Ventricle in Patients with Ischemic Cardiomyopathy: Improving Interobserver Reliability and Agreement Using Consensus Guidance from the Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT) 2020.

OBJECTIVE: This study aimed to evaluate the effect of implementing the consensus statement from the Asian Society of Cardiovascular Imaging-Practical Tutorial 2020 (ASCI-PT 2020) on the reliability of cardiac MR with late gadolinium enhancement (CMR-LGE) myocardial viability scoring between observers in the context of ischemic cardiomyopathy. MATERIALS AND METHODS: A total of 17 cardiovascular imaging experts from five different countries evaluated CMR obtained in 26 patients (male:female, 23:3; median age [interquartile range], 55.5 years [50-61.8]) with ischemic cardiomyopathy. For LGE scoring, based on the 17 segments, the extent of LGE in each segment was graded using a five-point scoring system ranging from 0 to 4 before and after exposure according to the consensus statement. All scoring was performed via web-based review. Scores for slices, vascular territories, and total scores were obtained as the sum of the relevant segmental scores. Interobserver reliability for segment scores was assessed using Fleiss' kappa, while the intraclass correlation coefficient (ICC) was used for slice score, vascular territory score, and total score. Inter-observer agreement was assessed using the limits of agreement from the mean (LoA). RESULTS: Interobserver reliability (Fleiss' kappa) in each segment ranged 0.242-0.662 before the consensus and increased to 0.301-0.774 after the consensus. The interobserver reliability (ICC) for each slice, each vascular territory, and total score increased after the consensus (slice, 0.728-0.805 and 0.849-0.884; vascular territory, 0.756-0.902 and 0.852-0.941; total score, 0.847 and 0.913, before and after implementing the consensus statement, respectively. Interobserver agreement in scoring also improved with the implementation of the consensus for all slices, vascular territories, and total score. The LoA for the total score narrowed from ± 10.36 points to ± 7.12 points. CONCLUSION: The interobserver reliability and agreement for CMR-LGE scoring for ischemic cardiomyopathy improved when following guidance from the ASCI-PT 2020 consensus statement.

Ventricular septal aneurysms in adults: findings of cardiac CT images and correlation with clinical features.

BACKGROUND: With the increasing use of multidetector computed tomography (MDCT), the number of incidentally detected ventricular septal aneurysms (VSAs) in adults has increased. However, to date, there are not sufficient well-organized data regarding VSAs in adults on MDCT. PURPOSE: To evaluate the CT findings of ventricular septal aneurysms (VSAs) in adults and correlate the findings with clinical features. MATERIAL AND METHODS: We performed a retrospective review of the cardiac CT reports in our electronic database of 3402 patients who underwent ECG-gated cardiac CT scans using a 64-slice multidetector CT or dual-source CT from October 2006 to December 2009 at our institute. Among them, eight patients were diagnosed with a VSA. We evaluated the location, size, and morphology of VSAs on cardiac CT angiographies (CCTAs) and correlated the findings with the clinical features of the patients. RESULTS: On CCTAs, all eight patients were found to have VSAs in the membranous portion of the interventricular septum and toward the right ventricle. The VSAs were 10-22 mm at their longest diameter and had wide necks. The VSAs were lobulated along the outer margin and were incidental findings in all patients. Four of the eight patients had a conduction abnormality such as first-degree atrio-ventricular block or incomplete right bundle branch block seen on ECG, whereas the other four patients had normal ECGs. CONCLUSION: VSA in adults is usually detected incidentally. It is seen in the membranous portion of the interventricular septum with a lobulated shape on CCTA. It is occasionally associated with a conduction anomaly.

Usefulness of multi-detector CT in Boyd-Griffin type 2 intertrochanteric fractures with clinical correlation.

OBJECTIVE: To investigate the usefulness of multi-detector computed tomography (MDCT) in three-part intertrochanteric fractures of proximal femur. MATERIALS AND METHODS: Twenty-six patients with Boyd-Griffin type 2 intertrochanteric fractures with MDCT (group 1) and 36 patients of the same type fracture without MDCT (group 2) were compared. Lesser trochanter (LT)/greater trochanter (GT) volume ratio above 0.5 or the volumetric proportion of GT in total volume of proximal femur below 25% was considered an unstable fracture. The fractures were fixed with dynamic compression hip screws (DCS). Additional greater trochanter stabilizing (GTS) plate or bone cement augmentation of the femoral head was performed in unstable fractures. Clinical outcome between the two groups by fixation failure and radiological results was compared. RESULTS: The volume ratio of the LT/GT was 0.33 (range, 0.13-0.73). The volume of the LT was inversely correlated with that of the GT (p < 0.001). The volume of the GT was significantly correlated with the LT/GT ratio or the head and neck (HN)/GT ratio (p < 0.001). Seven cases were regarded as unstable fractures in group 1. Fixation failures happened in one case in group 1 and five cases in group 2. There was significantly lower failure rate in group 1 than group 2 (p = 0.03). Neck-shaft angle at last follow-up was 134.8 degrees +/- 5.3 in group 1 and 131.3 degrees +/- 5.1 in group 2 (p = 0.01). The sliding length of lag screws were 5.6 degrees +/- 2.9 mm in group 1 and 8.3 degrees +/- 3.2 in group 2 (p = 0.03). CONCLUSION: Preoperative use of MDCT provides useful information about the fracture pattern and the geometry of the proximal femur in unstable intertrochanteric fractures and helps surgical planning. The ratio of the LT to the GT is inversely correlated with fracture stability.

[Noninvasive Imaging of Pericardium]. / 심막의 영상 소견.

The clinical manifestation of pericardial disease is similar to that of coronary artery disease and aortic disease. Therefore, a timely and accurate diagnosis is necessary. The pericardium is a 2-layered membrane that envelops the heart and great vessels, and there are numerous anatomic variations and pathologic conditions. Large or unusually located pericardial recesses can be easily mistaken for abnormal findings. Additionally, primary pericardial diseases resulting from infections, tumors, and injuries are possible; further, diseases can quickly spread along the pericardium. Echocardiography is generally the first imaging tool used to evaluate the pericardium. However, it has limited windows and poor resolution. Besides, the evaluation of postoperative echocardiography is sometimes limited. Currently, CT and MR imaging are useful for evaluating pericardial diseases. Detailed knowledge of the pericardium is important for interpreting the images and clinical results.

Anomalous right coronary artery originated from left coronary sinus with interarterial course: evaluation of the proximal segment on multidetector row computed tomography with clinical correlation.

PURPOSE: Anomalous origin of the right coronary artery (RCA) with an interarterial course is a potentially life-threatening anomaly. Clinical significance could depend on its orifice and interarterial course. We evaluated the anomalous RCA on multidetector row computed tomography (MDCT) with clinical correlation. MATERIALS AND METHODS: Twenty-five electrocardiography-gated MDCT cases of 24 patients (mean [SD] age, 58.2 [12.3] years; 12 men and 12 women) with anomalous origin of RCA from left coronary sinus with an interarterial course were retrospectively reviewed in 3 hospitals. The cases were evaluated for the location of orifice, a takeoff angle from coronary sinus, mean diameters of RCA (orifice, interarterial, and reference), and the ratio of the diameters of RCA (orifice-reference and interarterial-reference) on MDCT with clinical correlation. RESULTS: The orifice and the interarterial course of all anomalous RCAs were well visualized on MDCT. The narrowest portion of RCA was more frequent in the orifice (16/25 cases) than the interarterial course (6 cases). Three cases revealed the same diameter between the orifice and the interarterial course. The location of the orifice was not correlated with the diameters of anomalous RCA. Takeoff angles were correlated with the relative narrowing of the orifice of anomalous RCA (P = 0.001) and the relative narrowing of the interarterial course (P = 0.007). Only 1 patient showed significant luminal narrowing (>50% stenosis), and this patient showed a minimal takeoff angle and a persistent symptom. The symptom of this patient had disappeared after operation, and postoperative MDCT revealed an increased takeoff angle and no significant luminal narrowing. The other patients showed no significant luminal narrowing. Symptoms were not correlated with the takeoff angle and relative luminal narrowing (orifice-reference and interarterial-reference; P = 0.923, P = 0.915, and P = 0.703). CONCLUSIONS: The takeoff angles of anomalous RCA with an interarterial course are correlated with the relative narrowing of luminal diameters at the orifice and the interarterial course. Most cases show a benign nature. Evaluation of the proximal structure of anomalous RCA with an interarterial course could be important in a treatment plan.

Erdheim-Chester disease with lung involvement mimicking pulmonary lymphangitic carcinomatosis.

Erdheim-Chester disease (ECD) is a rare proliferative non-Langerhans cell histiocytosis of multiple organs with unknown etiology. Around 20% of ECD cases are reported to be associated with lung involvement and there are very few cases manifested solely by nonspecific respiratory symptoms. A 50-year-old woman presented with dry cough and dyspnea for 2 weeks. Chest computed tomography (CT) revealed diffuse interlobular septal and fissural thickening with perilymphatic and subpleural nodular opacities, suggesting pulmonary lymphangitic spread of metastatic carcinoma. Bone scintigraphy and positron emission tomography/CT showed multiple skeletal and lymph node involvement. The patient underwent surgical lung biopsy and the pathologic feature was consistent with ECD. We describe this case to emphasize that ECD should be included in the differential diagnosis of cases suspected to have lymphangitic lung carcinomatosis. Moreover, the findings of positron emission tomography/CT scan, which showed hot uptakes in the affected areas, are also described.

Guidelines for Cardiovascular Magnetic Resonance Imaging from the Korean Society of Cardiovascular Imaging-Part 3: Perfusion, Delayed Enhancement, and T1- and T2 Mapping.

This document is the third part of the guidelines for the protocol, the interpretation and post-processing of cardiac magnetic resonance (CMR) studies. These consensus recommendations have been developed by the Consensus Committee of the Korean Society of Cardiovascular Imaging to standardize the requirements for image interpretation and post-processing of CMR. This third part of the recommendations describes tissue characterization modules, including perfusion, late gadolinium enhancement, and T1- and T2 mapping. Additionally, this document provides guidance for visual and quantitative assessment consisting of "What-to-See," "How-To," and common pitfalls for the analysis of each module. The Consensus Committee hopes that this document will contribute to the standardization of image interpretation and post-processing of CMR studies.

Guidelines for Cardiovascular Magnetic Resonance Imaging from the Korean Society of Cardiovascular Imaging-Part 2: Interpretation of Cine, Flow, and Angiography Data.

Cardiovascular magnetic resonance imaging (CMR) is expected to be increasingly used in Korea due to technological advances and the expanded national insurance coverage of CMR assessments. For improved patient care, proper acquisition of CMR images as well as their accurate interpretation by well-trained personnel are equally important. In response to the increased demand for CMR, the Korean Society of Cardiovascular Imaging (KOSCI) has issued interpretation guidelines in conjunction with the Korean Society of Radiology. KOSCI has also created a formal Committee on CMR guidelines to create updated practices. The members of this committee review previously published interpretation guidelines and discuss the patterns of CMR use in Korea.

Guideline for Cardiovascular Magnetic Resonance Imaging from the Korean Society of Cardiovascular Imaging-Part 1: Standardized Protocol.

Cardiac magnetic resonance (CMR) imaging is widely used in many areas of cardiovascular disease assessment. This is a practical, standard CMR protocol for beginners that is designed to be easy to follow and implement. This protocol guideline is based on previously reported CMR guidelines and includes sequence terminology used by vendors, essential MR physics, imaging planes, field strength considerations, MRI-conditional devices, drugs for stress tests, various CMR modules, and disease/symptom-based protocols based on a survey of cardiologists and various appropriate-use criteria. It will be of considerable help in planning and implementing tests. In addressing CMR usage and creating this protocol guideline, we particularly tried to include useful tips to overcome various practical issues and improve CMR imaging. We hope that this document will continue to standardize and simplify a patient-based approach to clinical CMR and contribute to the promotion of public health.

Subepicardial aneurysm of left ventricle adjacent to the aortic root: demonstration on multidetector CT.

We report a case of subepicardial aneurysm, which developed in the anterobasal portion of the left ventricle wall and extended into the space between the aortic root and the right ventricular outflow tract (RVOT). Multidetector computed tomography (MDCT) demonstrates this rare aneurysm well.

Pseudomyxoma peritonei: extraperitoneal spread to the pleural cavity and lung.

Abdominal and pelvic recurrence of pseudomyxoma peritonei after the surgery is occasionally seen but extraperitoneal spread and hematogeneous metastases are rare. This case of pseudomyxoma peritonei provides interesting radiologic findings of extraperitoneal spread, which occurred after an extremely long interval from initial diagnosis.

Intrapulmonary recurrence after computed tomography-guided percutaneous needle biopsy of stage I lung cancer.

Tumor seeding, along the needle tract after percutaneous needle biopsy, is a rare condition and most of the reported cases are implantation metastasis, which occurred in the chest wall or the pleura. We present a case of implantation metastasis that occurred in the pulmonary parenchyma, after a computed tomography-guided percutaneous needle biopsy (CT-PNB) of stage I lung cancer.

Use of Reversed Iliac Leg Stent-Graft for the Treatment of Isolated Aneurysm of Internal Iliac Artery.

This is to report the technique of reversed iliac leg stent-graft in endovascular treatment for isolated internal iliac artery (IIA) aneurysm, which had significant size discrepancy between the common iliac artery (CIA) and external iliac artery (EIA) in 3 patients from different hospitals. Three patients were a 85- and two 82-year-old men. Treated were right IIA aneurysms, sized 6.5×6.2 cm, 5.0×4.0 cm, and 4.1 cm in longest diameter, respectively. The diameters of the right CIA and right EIA measured 21 mm/11 mm, 15 mm/11 mm, and 20 mm/10 mm, respectively. In all cases, reversed iliac leg stent-grafts were prepared on-site; unsheathed and mounted upside-down manually, and deployed in each right CIA. Post-stent-graft angiograms showed complete exclusion of the aneurysms, except for minimal type 1 endoleak in one case. This technique is a useful treatment option in patients with isolated IIA aneurysm.

A case of pneumomediastinum and parapneumonic effusions following pharyngeal perforation caused by shouting.

Spontaneous pneumomediastinum is an uncommon disorder, and usually affects young men and has a benign course. Common triggers are asthma, the smoking of illicit drugs, the Valsalva maneuver, and respiratory infections. Most cases are usually due to alveolar rupture into the pulmonary interstitium caused by excess pressure. The air dissects to the hilum along the peribronchovascular sheaths and spreads into the mediastinum. However, pneumomediastinum following pharyngeal perforation is very rare, and has only been reported in relation to dental procedures, head and neck surgery, or trauma. We report a case of pneumomediastinum that developed in a 43-year-old patient with pharyngeal perforation after shouting. His course was complicated by mediastinitis and parapneumonic effusions.

Risk factors for the development of reexpansion pulmonary edema in patients with spontaneous pneumothorax.

BACKGROUND: Reexpansion pulmonary edema (REPE) is known as a rare and fatal complication after tube thoracostomy. OBJECTIVES: We investigated the risk factors for the development of REPE in patients with spontaneous pneumothorax. METHODS: We selected patients who were diagnosed with spontaneous pneumothorax and were initially treated with tube thoracostomy between August 1, 2003 and December 31, 2011. The patients' electronic medical records, including operative notes and chest x-ray and computed tomography scans, were reviewed. RESULTS: REPE developed in 49 of the 306 patients (16.0%). REPE was more common in patients with diabetes (14.3% vs 3.9%, P=0.004) or tension pneumothorax (46.8% vs 16.2%, P=0.000). The pneumothorax was larger in patients with REPE than without REPE (57.0±16.0% vs 34.2±17.6%, P=0.000), and the incidence of REPE increased with the size of pneumothorax. On multivariate analysis, diabetes mellitus [(odds ratio (OR)=9.93, P=0.003), and the size of pneumothorax (OR=1.07, P=0.000) were independent risk factors of REPE. CONCLUSIONS: The presence of diabetes increases the risk of REPE development in patients with spontaneous pneumothorax. The risk of REPE also increases significantly with the size of pneumothorax.

Tension pneumothorax, is it a really life-threatening condition?

BACKGROUND: Tension pneumothorax is a life-threatening occurrence that is infrequently the consequence of spontaneous pneumothorax. The aim of this study was to identify the risk factors for the development of tension pneumothorax and its effect on clinical outcomes. METHODS: We reviewed patients who were admitted with spontaneous pneumothorax between August 1, 2003 and December 31, 2011. Electronic medical records and the radiological findings were reviewed with chest x-ray and high-resolution computed tomography scans that were retrieved from the Picture Archiving Communication System. RESULTS: Out of the 370 patients included in this study, tension pneumothorax developed in 60 (16.2%). The bullae were larger in patients with tension pneumothorax than in those without (23.8 ± 16.2 mm vs 16.1 ± 19.1 mm; P = 0.007). In addition, the incidence of tension pneumothorax increased with the lung bulla size. Fibrotic adhesion was more prevalent in the tension pneumothorax group than in that without (P = 0.000). The bullae were large in patients with fibrotic adhesion than in those without adhesion (35.0 ± 22.3 mm vs 10.4 ± 11.5 mm; P = 0.000). On multivariate analysis, the size of bullae (odds ratio (OR) = 1.03, P = 0.001) and fibrotic adhesion (OR = 10.76, P = 0.000) were risk factors of tension pneumothorax. Hospital mortality was 3.3% in the tension pneumothorax group and it was not significantly different from those patients without tension pneunothorax (P = 0.252). CONCLUSIONS: Tension pneumothorax is not uncommon, but clinically fatal tension pneumothorax is extremely rare. The size of the lung bullae and fibrotic adhesion contributes to the development of tension pneumothorax.