Transbronchial Lung Cryobiopsy and Surgical Lung Biopsy: A Prospective Multi-Centre Agreement Clinical Trial (CAN-ICE).

Rationale: Transbronchial cryobiopsy (TBCB) for the diagnosis of interstitial lung disease (ILD) has shown promising results, but prospective studies with matched surgical lung biopsy (SLB) have yielded conflicting results. Objectives: We aimed to assess within- and between-center diagnostic agreement between TBCB and SLB at both the histopathologic and multidisciplinary discussion (MDD) levels in patients with diffuse ILD. Methods: In a multicenter prospective study, we performed matched TBCB and SLB in patients referred for SLB. After a blinded review by three pulmonary pathologists, all cases were reviewed by three independent ILD teams in an MDD. MDD was performed first with TBCB, then with SLB in a second session. Within-center and between-center diagnostic agreement was evaluated using percentages and correlation coefficients. Measurements and Main Results: Twenty patients were recruited and underwent contemporaneous TBCB and SLB. Within-center diagnostic agreement between TBCB-MDD and SLB-MDD was reached in 37 of the 60 (61.7%) paired observations, resulting in a Cohen's κ value of 0.46 (95% confidence interval [CI], 0.29-0.63). Diagnostic agreement increased among high-confidence or definitive diagnoses on TBCB-MDD (21 of 29 [72.4%]), but not significantly, and was more likely among cases with SLB-MDD diagnoses of idiopathic pulmonary fibrosis than fibrotic hypersensitivity pneumonitis (13 of 16 [81.2%] vs. 16 of 31 [51.6%]; P = 0.047). Between-center agreement for cases was markedly higher for SLB-MDD (κ = 0.71 [95% CI, 0.52-0.89]) than TBCB-MDD (κ = 0.29 [95% CI, 0.09-0.49]). Conclusions: This study demonstrated moderate TBCB-MDD and SLB-MDD diagnostic agreement for ILD, while between-center agreement was fair for TBCB-MDD and substantial for SLB-MDD. Clinical trial registered with www.clinicaltrials.gov (NCT02235779).

Assessment of Radiology Artificial Intelligence Software: A Validation and Evaluation Framework.

Artificial intelligence (AI) software in radiology is becoming increasingly prevalent and performance is improving rapidly with new applications for given use cases being developed continuously, oftentimes with development and validation occurring in parallel. Several guidelines have provided reporting standards for publications of AI-based research in medicine and radiology. Yet, there is an unmet need for recommendations on the assessment of AI software before adoption and after commercialization. As the radiology AI ecosystem continues to grow and mature, a formalization of system assessment and evaluation is paramount to ensure patient safety, relevance and support to clinical workflows, and optimal allocation of limited AI development and validation resources before broader implementation into clinical practice. To fulfil these needs, we provide a glossary for AI software types, use cases and roles within the clinical workflow; list healthcare needs, key performance indicators and required information about software prior to assessment; and lay out examples of software performance metrics per software category. This conceptual framework is intended to streamline communication with the AI software industry and provide healthcare decision makers and radiologists with tools to assess the potential use of these software. The proposed software evaluation framework lays the foundation for a radiologist-led prospective validation network of radiology AI software. Learning Points: The rapid expansion of AI applications in radiology requires standardization of AI software specification, classification, and evaluation. The Canadian Association of Radiologists' AI Tech & Apps Working Group Proposes an AI Specification document format and supports the implementation of a clinical expert evaluation process for Radiology AI software.

Comparison of the effect of low- and iso-osmolar contrast agents on heart rate during chest CT angiography: results of a prospective randomized multicenter study.

PURPOSE: To prospectively compare the effect of intravenous injection of low-osmolar iopamidol with that of intravenous injection of iso-osmolar iodixanol on heart rate (HR) during nongated chest computed tomographic (CT) angiography. MATERIALS AND METHODS: This multicenter study was approved by local institutional review boards, and patients provided written informed consent. Patient enrollment and examination at centers in the United States complied with HIPAA regulations. One hundred and thirty patients (54 male; mean age, 52 years) clinically suspected of having pulmonary embolism were referred for pulmonary CT angiography and were randomly assigned to receive 80 mL of either iopamidol (370 mg of iodine per milliliter, n = 63) or iodixanol (320 mg of iodine per milliliter, n = 67) at a rate of 4 mL/sec. HR (measured in beats per minute) was monitored from 5 minutes before the start of injection to the end of imaging, and precontrast HR and maximum postcontrast HR were recorded. Student t and χ(2) tests were used for continuous and categorical variables, respectively. RESULTS: Precontrast HR in patients who received iopamidol (mean, 81 beats per minute ± 18 [standard deviation]) was similar to that in patients who received iodixanol (mean, 77 beats per minute ± 17) (P = .16). Mean postcontrast HR was 87 beats per minute ± 17 and 82 beats per minute ± 18 (P = .16) in the iopamidol and iodixanol groups, respectively. Mean increase from precontrast HR to postcontrast HR was 5 beats per minute ± 9 and 5 beats per minute ± 7 (P = .72) in the iopamidol and iodixanol groups, respectively. Thirty-five (56%) of the 63 patients who received iopamidol and 33 (49%) of the 67 patients who received iodixanol had an HR increase of fewer than 5 beats per minute, 15 (24%) and 18 (27%) patients, respectively, had an increase of 5-9 beats per minute, and four (6%) and three (4%) patients, respectively, had an increase of more than 20 beats per minute. These proportions were not significantly different between the groups (P = .51, χ(2) test). CONCLUSION: High-rate intravenous administration of 80 mL of iopamidol and iodixanol during pulmonary CT angiography slightly increased HR; there was no difference in HR between the contrast agent groups.

Gadolinium-enhanced pulmonary magnetic resonance angiography in the diagnosis of acute pulmonary embolism: a prospective study on 48 patients.

OBJECTIVE: Gadolinium-enhanced pulmonary magnetic resonance angiography (MRA) can be an option in patients with a history of previous adverse reaction to iodinated contrast material and renal insufficiency. Radiation is also avoided. The aim of this study is to prospectively compare the diagnostic value of MRA with that of a diagnostic strategy, taking into account catheter angiography, computed tomography angiography (CTA), and lung scintigraphy [ventilation-perfusion (VQ)]. MATERIAL AND METHODS: Magnetic resonance angiography was done in 48 patients with clinically suspected pulmonary embolism (PE) using fast gradient echo coronal acquisition with gadolinium. Interpretation was done with native coronal images and multiplanar maximum intensity projection reconstructions. Results were compared to catheter angiography (n=15), CTA (n=34), VQ (n=45), as well as 6-12 months clinical follow-ups, according to a sequenced reference tree. RESULTS: The final diagnosis of PE was retained in 11 patients (23%). There were two false negatives and no false positive results with MRA. Computed tomography angiography resulted in no false negatives or false positives. Magnetic resonance angiography had a sensitivity of 82% and a specificity of 100%. CONCLUSION: In our study, pulmonary MRA had a sensitivity of 82% and a specificity of 100% for the diagnosis of PE, with slightly less sensitivity than CTA. In the diagnostic algorithm of PE, pulmonary MRA should be considered as an alternative to CTA when iodine contrast injection or radiation is a significant matter.

Percutaneous CT-guided lung interventions-local pleural anesthesia.

Local pleural anesthesia during percutaneous lung interventions is an important part of the procedure that has not been standardized in the literature. Significant pain can be experienced during lung biopsies, which may affect the outcome of intervention. We describe a step-by-step method of anesthesia targeting the most sensitive anatomical structure involved: the parietal pleura.

Postoperative imaging after lung transplantation.

Lung transplantation (LT) is an established procedure for chronic end-stage lung diseases. Complications are frequent and diverse and are the consequence of the complex surgical technique, the severity of the initial pathology, and the deep state of posttransplantation immunosuppression. Complications following LT include primary graft dysfunction, rejection (hyperacute, acute, and chronic), infections, posttransplantation lymphoproliferative disease, pleural and airway complications, native lung complications, and recurrence of primary disease. An understanding of these complications, their temporal evolution, and the role of radiology and other diagnostic methods in their diagnosis and management will help reduce the morbidity and mortality associated with LT.

Late retrograde perfusion of donor lungs does not decrease the severity of primary graft dysfunction.

BACKGROUND: The ideal preservation strategy has yet to be established in lung transplantation. This clinical study compares primary graft dysfunction using antegrade and retrograde perfusion of donor lungs. METHODS: Over a 6-year period, 153 consecutive patients underwent lung transplantation in our institution. Group I consists of 65 patients who received lungs preserved with an antegrade flush of modified Euro-Collins solution. Group II includes 65 patients who received lungs preserved with an antegrade flush of low-potassium dextran (LPD) solution. Group III consists of 23 patients who received lungs preserved with an antegrade and a preimplantation retrograde flush of LPD solution. Endpoints evaluated were the following: acute lung injury (ALI) score, time to achieve a fraction of inspired oxygen (Fio2) of 40% and a positive end-expiratory pressure (PEEP) of 5, length of ventilation, length of intensive care unit (ICU) stay, 90-day operative mortality, and patient survival rates. RESULTS: The patient demographic data, underlying diagnosis, number of single and double lung transplants, use of cardiopulmonary bypass, and mean ischemic times were similar in all 3 groups. The mean ALI score (6.2, 5.8, and 6.0) and the median length of ventilation (23.5, 24.0, and 27.0 hours) in groups I, II, and III, respectively, were not significantly different. The length of ICU stay, the 90-day operative mortality, and the survival rates were not significantly different in the 3 groups. CONCLUSIONS: Our results suggest that late retrograde perfusion of donor lungs does not decrease the severity of primary graft dysfunction when compared with standard antegrade techniques.

Accuracy and rate of coronary artery segment visualization with CT angiography for the non-invasive detection of coronary artery stenoses.

OBJECTIVES: To evaluate CT coronary angiography (CTA) when compared with catheter coronary angiography (CCA), for the detection of coronary artery stenoses and rate of optimal coronary artery segment visualization. METHOD: Retrospective, two-center study enrolling 26 patients who underwent CCA and ECG-gated 16-detector CTA (slice thickness 0.6 mm; rotation 500 ms). RESULTS AND CONCLUSION: 283 segments were available for postprocessing. Sensitivity, specificity, and positive predictive value were, respectively, 80, 100, and 100%, for detecting more than 50% luminal stenoses, when optimally visualized segments were considered, in comparison to CCA. Negative predictive value was excellent (98%). Rate of non-optimally visualized coronary segments was 26%. Most clinical benefits of coronary CT angiography should probably be obtained when it is performed to exclude significant stenoses on selected populations of patients with a low pre-test probability of severe coronary artery disease, and under optimal conditions of controlled heart rate and minimal presence of calcium.

Coronary computed tomography angiography: overview of technical aspects, current concepts, and perspectives.

Multidetector-row electrocardiogram (ECG)-gated cardiac computed tomography (CT) will probably be a major noninvasive imaging option in the near future. Recent developments indicate that this new technology is improving rapidly. This article presents an overview of the current concepts, perspectives, and technical capabilities in coronary CT angiography (CTA). We have reviewed the recent literature on the different applications of this technology; of particular note are the many studies that have demonstrated the high negative predictive value (NPV) of coronary CTA, when performed under optimal conditions, for significant stenoses in native coronary arteries. This new technology's level of performance allows it to be used to evaluate the presence of calcified plaques, coronary bypass graft patency, and the origin and course of congenital coronary anomalies. Despite a high NPV, the robustness of the technology is limited by arrhythmias, the requirement of low heart rates, and calcium-related artifacts. Some improvements are needed in the imaging of coronary stents, especially the smaller stents, and in the detection and characterization of noncalcified plaques. Further studies are needed to more precisely determine the role of CTA in various symptomatic and asymptomatic patient groups. Clinical testing of 64-slice scanners has recently begun. As the technology improves, so does the spatial and temporal resolution. To date, this is being achieved through the development of systems with an increased number of detectors and shorter gantry rotation time, as well as the development of systems equipped with 2 X-ray tubes and the eventual development of flat-panel technology. Thus further improvement of image quality is expected.