Pulmonary transplant complications: a radiologic review.

Lung transplantation has become the definitive treatment for end stage respiratory disease. Numbers and survival rates have increased over the past decade, with transplant recipients living longer and with greater comorbidities, resulting in greater complexity of care. Common and uncommon complications that occur in the immediate, early, intermediate, and late periods can have significant impact on the course of the transplant. Fortunately, advancements in surgery, medical care, and imaging as well as other diagnostics work to prevent, identify, and manage complications that would otherwise have a negative impact on survivability. This review will focus on contextualizing complications both categorically and chronologically, with highlights of specific imaging and clinical features in order to inform both radiologists and clinicians involved in post-transplant care.

Validation of the Minnesota Pectoralis Risk Score to predict mortality in the HeartMate 3 population.

BACKGROUND: The Minnesota Pectoralis Risk Score (MPRS) utilizes computed tomography-quantified thoracic muscle and clinical variables to predict survival after left ventricular assist device (LVAD) implantation. The model has not been prospectively tested in HeartMate 3 recipients. METHODS: A single-center HeartMate 3 cohort from July 2016 to July 2021 (n = 108) was utilized for this analysis. Cohort subjects with complete covariates for MPRS calculation (pectoralis muscle measures, Black race, creatinine, total bilirubin, body mass index, bridge to transplant status, and presence/absence of contrast) implanted after MPRS development were included. MPRS were calculated on each subject. Receiver operating characteristic curves were generated to test model discrimination at 30-day, 90-day, and 1-year mortality post-LVAD. Next, the performance of the 1-year post-LVAD outcome was compared to the HeartMate 3 survival risk score (HM3RS). RESULTS: The mean age was 58 (15 years), 80% (86/108) were male, and 26% (28/108) were destination therapy. The area under the curve (AUC) for the MPRS model to predict post-LVAD mortality was 0.73 at 30 days, 0.78 at 90 days, and 0.81 at 1 year. The AUC for the HM3RS for the 1-year outcome was 0.693. Each 1-unit point of the MPRS was associated with a significant increase in the hazard rate of death after LVAD (hazard ratio 2.1, 95% confidence interval 1.5-3.0, p < 0.0001). CONCLUSIONS: The MPRS had high performance in this prospective validation, particularly with respect to 90-day and 1-year post-LVAD mortality. Such a tool can provide additional information regarding risk stratification to aid informed decision-making.

A novel, evidence-based, comprehensive clinical decision support system improves outcomes for patients with traumatic rib fractures.

BACKGROUND: Traumatic rib fractures are associated with high morbidity and mortality. Clinical decision support systems (CDSS) have been shown to improve adherence to evidence-based (EB) practice and improve clinical outcomes. The objective of this study was to investigate if a rib fracture CDSS reduced hospital length of stay (LOS), 90-day and 1-year mortality, unplanned ICU transfer, and the need for mechanical ventilation. The independent association of two process measures, an admission EB order set and a pain-inspiratory-cough score early warning system, with LOS were investigated. METHODS: The CDSS was scaled across nine US trauma centers. Following multiple imputation, multivariable regression models were fit to evaluate the association of the CDSS on primary and secondary outcomes. As a sensitivity analysis, propensity score matching was also performed to confirm regression findings. RESULTS: Overall, 3,279 patients met inclusion criteria. Rates of EB practices increased following implementation. On risk-adjusted analysis, in-hospital LOS preintervention versus postintervention was unchanged (incidence rate ratio [IRR], 1.06; 95% confidence interval [CI], 0.97-1.15, p = 0.2) but unplanned transfer to the ICU was reduced (odds ratio, 0.28; 95% CI, 0.09-0.84, p = 0.024), as was 1-year mortality (hazard ratio, 0.6; 95% CI, 0.4-0.89, p = 0.01). Provider utilization of the admission order bundle was 45.3%. Utilization was associated with significantly reduced LOS (IRR, 0.87; 95% CI, 0.77-0.98; p = 0.019). The early warning system triggered on 34.4% of patients; however, was not associated with a significant reduction in hospital LOS (IRR, 0.76; 95% CI, 0.55-1.06; p = 0.1). CONCLUSION: A novel, user-centered, comprehensive CDSS improves adherence to EB practice and is associated with a significant reduction in unplanned ICU admissions and possibly mortality, but not hospital LOS. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level III.

Performance of a Chest Radiograph AI Diagnostic Tool for COVID-19: A Prospective Observational Study.

Purpose: To conduct a prospective observational study across 12 U.S. hospitals to evaluate real-time performance of an interpretable artificial intelligence (AI) model to detect COVID-19 on chest radiographs. Materials and Methods: A total of 95 363 chest radiographs were included in model training, external validation, and real-time validation. The model was deployed as a clinical decision support system, and performance was prospectively evaluated. There were 5335 total real-time predictions and a COVID-19 prevalence of 4.8% (258 of 5335). Model performance was assessed with use of receiver operating characteristic analysis, precision-recall curves, and F1 score. Logistic regression was used to evaluate the association of race and sex with AI model diagnostic accuracy. To compare model accuracy with the performance of board-certified radiologists, a third dataset of 1638 images was read independently by two radiologists. Results: Participants positive for COVID-19 had higher COVID-19 diagnostic scores than participants negative for COVID-19 (median, 0.1 [IQR, 0.0-0.8] vs 0.0 [IQR, 0.0-0.1], respectively; P < .001). Real-time model performance was unchanged over 19 weeks of implementation (area under the receiver operating characteristic curve, 0.70; 95% CI: 0.66, 0.73). Model sensitivity was higher in men than women (P = .01), whereas model specificity was higher in women (P = .001). Sensitivity was higher for Asian (P = .002) and Black (P = .046) participants compared with White participants. The COVID-19 AI diagnostic system had worse accuracy (63.5% correct) compared with radiologist predictions (radiologist 1 = 67.8% correct, radiologist 2 = 68.6% correct; McNemar P < .001 for both). Conclusion: AI-based tools have not yet reached full diagnostic potential for COVID-19 and underperform compared with radiologist prediction.Keywords: Diagnosis, Classification, Application Domain, Infection, Lung Supplemental material is available for this article.. © RSNA, 2022.

Granulomatous-Lymphocytic Interstitial Lung Disease Mimicking Sarcoidosis.

Common variable immunodeficiency (CVID) is one of the most common primary immunodeficiency disorders characterized by hypogammaglobulinemia and inadequate antibody response to immunizations. The impaired antibody response occurs due to the failure of B cells to differentiate into plasma cells resulting in low immunoglobulins levels and increased frequency of infections. Granulomatous and Lymphocytic Interstitial Lung Disease (GLILD) is a non-infectious complication of CVID that is seen in 10-30% of cases. GLILD is a multisystem inflammatory disease involving the lungs, lymph node, liver, spleen and gastrointestinal tract that mimics sarcoidosis. This report describes a series of cases who presented with dyspnea, recurrent respiratory infections or autoimmunity and on further evaluation revealed features suggestive of GLILD. There is very limited understanding of GLILD in terms of clinical presentation, the histo-pathological logical findings, and the diagnostic criteria by itself are limited. A diagnosis of GLILD is established in cases of CVID when there is evidence of lymphoproliferation, cytopenia, autoimmune processes and a lung biopsy demonstrating lymphocytic interstitial pneumonia, follicular bronchiolitis, lymphoid hyperplasia, and/or non-necrotizing granulomas. We review the treatment strategies, including replacement of immunoglobulin and agents targeting B and T lymphocytes. Systematic characterization of GLILD cases and long term follow up studies are sorely needed to understand the natural history of GLILD.

A Prospective Observational Study to Investigate Performance of a Chest X-ray Artificial Intelligence Diagnostic Support Tool Across 12 U.S. Hospitals.

Importance: An artificial intelligence (AI)-based model to predict COVID-19 likelihood from chest x-ray (CXR) findings can serve as an important adjunct to accelerate immediate clinical decision making and improve clinical decision making. Despite significant efforts, many limitations and biases exist in previously developed AI diagnostic models for COVID-19. Utilizing a large set of local and international CXR images, we developed an AI model with high performance on temporal and external validation. Objective: Investigate real-time performance of an AI-enabled COVID-19 diagnostic support system across a 12-hospital system. Design: Prospective observational study. Setting: Labeled frontal CXR images (samples of COVID-19 and non-COVID-19) from the M Health Fairview (Minnesota, USA), Valencian Region Medical ImageBank (Spain), MIMIC-CXR, Open-I 2013 Chest X-ray Collection, GitHub COVID-19 Image Data Collection (International), Indiana University (Indiana, USA), and Emory University (Georgia, USA). Participants: Internal (training, temporal, and real-time validation): 51,592 CXRs; Public: 27,424 CXRs; External (Indiana University): 10,002 CXRs; External (Emory University): 2002 CXRs. Main Outcome and Measure: Model performance assessed via receiver operating characteristic (ROC), Precision-Recall curves, and F1 score. Results: Patients that were COVID-19 positive had significantly higher COVID-19 Diagnostic Scores (median .1 [IQR: 0.0-0.8] vs median 0.0 [IQR: 0.0-0.1], p < 0.001) than patients that were COVID-19 negative. Pre-implementation the AI-model performed well on temporal validation (AUROC 0.8) and external validation (AUROC 0.76 at Indiana U, AUROC 0.72 at Emory U). The model was noted to have unrealistic performance (AUROC > 0.95) using publicly available databases. Real-time model performance was unchanged over 19 weeks of implementation (AUROC 0.70). On subgroup analysis, the model had improved discrimination for patients with "severe" as compared to "mild or moderate" disease, p < 0.001. Model performance was highest in Asians and lowest in whites and similar between males and females. Conclusions and Relevance: AI-based diagnostic tools may serve as an adjunct, but not replacement, for clinical decision support of COVID-19 diagnosis, which largely hinges on exposure history, signs, and symptoms. While AI-based tools have not yet reached full diagnostic potential in COVID-19, they may still offer valuable information to clinicians taken into consideration along with clinical signs and symptoms.

Impact of 2016 SCCT/STR guidelines for coronary artery calcium scoring of noncardiac chest CT scans on lung cancer screening CT reporting.

The 2016 SCCT/STR guideline for coronary artery calcification (CAC) scoring on non-cardiac chest CT (NCCT) scans explicitly calls for the reporting of CAC. Whether the publication of the 2016 SCCT/STR guideline has had any impact on CAC reporting in lung cancer screening (LCS) scans has not been investigated. Consecutive patients with a LCS scan were identified from the University of Minnesota LCS registry and evaluated for CAC reporting in 3 separate cohorts: 6 months before, 6 months after, and 1 year after the publication of the 2016 SCCT/STR guideline. Scans were evaluated for CAC and quantified using the Agatston method. CAC reporting, downstream testing and initiation of preventive therapy were assessed. Among 614 patients (50% male, mean age 64.1 ± 6.0 years), CAC was present in 460 (74.9%) with a median Agatston score of 62 (IQR 0, 230). Of these, 196 (31.9%) had a CAC score of 1-100, 125 (20.4%) had 101-300, and 118 (19.2%) had > 300. Overall, CAC was reported in 325 (70.7%) patients with CAC present. CAC reporting relative to publication of the 2016 SCCT/STR guideline was as follows: 6 months prior-74.1%, 6 months after-64.6%, and 1 year after-77.5%. In the 308 patients with a new diagnosis of sub-clinical CAD based on CAC presence, 6 (1.9%) patients were referred to cardiology, and 15 (4.9%) patients underwent testing for obstructive CAD. Only 6 (1.9%) and 9 (2.9%) patients were newly started on aspirin and statin respectively. CAC detected incidentally on lung cancer screening CT scans is prevalent, and rarely acted upon clinically. CAC reporting is fairly high, and publication of the 2016 SCCT/STR guideline for CAC scoring on NCCT scans did not have any significant impact on CAC reporting.

Clinical characteristics and organ system involvement in sarcoidosis: comparison of the University of Minnesota Cohort with other cohorts.

BACKGROUND: Sarcoidosis is a systemic granulomatous disease of unknown etiology. Clinical cohort studies of different populations are important to understand the high variability in clinical presentation and disease course of sarcoidosis. The aim of the study is to evaluate clinical characteristics, including organ involvement, pulmonary function tests, and laboratory parameters, in a sarcoidosis cohort at the University of Minnesota. We compare the organ system involvement of this cohort with other available cohorts. METHODS: We conducted a retrospective data collection and analysis of 187 subjects with biopsy-proven sarcoidosis seen at a tertiary center. Organ system involvement was determined using the WASOG sarcoidosis organ assessment instrument. Clinical phenotype groups were classified using the Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis criteria. RESULTS: Mean subject age at diagnosis was 45.8 ± 12.4, with a higher proportion of males (55.1%), and a higher proportion of blacks (17.1%) compared to the racial distribution of Minnesota residents (5.95%). The majority (71.1%) of subjects required anti-inflammatory therapy for at least 1 month. Compared to the A Case Control Etiologic Study of Sarcoidosis cohort, there was a higher frequency of extra-thoracic lymph node (34.2% vs. 15.2%), eye (20.9% vs. 11.8%), liver (17.6% vs. 11.5%), spleen (20.9% vs. 6.7%), musculoskeletal (9.6% vs. 0.5%), and cardiac (10.7% vs. 2.3%) involvement in our cohort. A multisystem disease with at least five different organs involved was identified in 13.4% of subjects. A restrictive physiological pattern was observed in 21.6% of subjects, followed by an obstructive pattern in 17.3% and mixed obstructive and restrictive pattern in 2.2%. Almost half (49.2%) were Scadding stages II/III. Commonly employed disease activity markers, including soluble interleukin-2 receptor and angiotensin-converting enzyme, did not differ between treated and untreated groups. CONCLUSIONS: This cohort features a relatively high frequency of high-risk sarcoidosis phenotypes including cardiac and multiorgan disease. Commonly-utilized serum biomarkers do not identify subpopulations that require or do better with treatment. Findings from this study further highlight the high-variability nature of sarcoidosis and the need for a more reliable biomarker to predict and measure disease severity and outcomes for better clinical management of sarcoidosis patients.

Pulmonary vein occlusion and veno-occlusive disease in a bilateral lung transplant patient: A case report.

A pulmonary vein occlusion and biopsy proven pulmonary veno-occlusive disease (PVOD) and hemangiomatosis is found in a bilateral lung transplant patient. A 61-year-old male presents with dyspnea and chest pain with minimal exertion at routine follow up on post-transplant day of 50. Chest CT demonstrates new occlusion of bilateral superior pulmonary veins and diffuse pulmonary edema. Pulmonary vein occlusion is confirmed by trans-esophageal echocardiogram, and PVOD and hemangiomatosis is corroborated with lung biopsy. Normal pulmonary capillary wedge pressure (PCWP) and reduced DLCO are also consistent with PVOD. Vigilant evaluation of large pulmonary venous thrombus is as important as of arterial thrombus in a postsurgical transplant status. A dedicated protocol of pulmonary venous phase scan would be beneficial to identify subtle pulmonary venous abnormalities. Although PVOD/PCH is normally considered in patients with nonspecific PAH symptoms, lacking of direct manifestation of PAH should not dismiss the diagnosis of PVOD/PCH, particularly in lung transplant individuals with large pulmonary vein occlusion, progressive respiratory symptoms, DLCO abnormalities, and pulmonary congestion since it may represent a wide spectrum of occlusive vascular disease.

A Novel Model Incorporating Pectoralis Muscle Measures to Predict Mortality After Ventricular Assist Device Implantation.

BACKGROUND: We have previously demonstrated that pectoralis muscle mass and tissue attenuation obtained on preoperative CT scans were powerful predictors of mortality after left ventricular assist device implantation. In this analysis, we confirm our findings in a separate left ventricular assist device implantation cohort, and we present a novel, user-friendly mortality-prediction model incorporating these measures. METHODS AND RESULTS: Patients with chest CTs performed ≤ 3 months prior to left ventricular assist device implantation at University of Minnesota (n = 143) and Houston Methodist Hospital (n = 133) were identified. Unilateral pectoralis muscle mass indexed to body surface area (PMI) and attenuation (approximated by mean Hounsfield units) (PHUm) were measured on preoperative chest CT scans. To develop a prediction model incorporating pectoralis muscle measures, we implemented a cross-validated model-selection approach using Cox proportional hazards regression models. The final model included PHUm, PMI, African American race, creatinine, total bilirubin, body mass index, bridge to transplant, and presence or absence of contrast. Receiver-operating characteristic curves for 30-, 90- and 365-day survival were generated. The area under the curve for the model at 30, 90 and 365 days was 0.78, 0.76 and 0.76, respectively. CONCLUSIONS: The Minnesota Pectoralis Risk Score had favorable discrimination in this multicenter dataset. These skeletal-muscle measures appear to add important information to preoperative risk assessment.

Acute exacerbation of interstitial lung disease after procedures.

Interstitial lung disease (ILD) is a category of diffuse parenchymal lung diseases characterized by inflammation and/or fibrosis. The best characterized ILD is idiopathic pulmonary fibrosis (IPF). Acute exacerbation of IPF is a dreaded occurrence with grim prognosis and suboptimal treatment options. There have been recent reports that acute exacerbation can occur in other ILDs (AE-ILD). Of note, some of these acute exacerbations follow lung procedures. This review summarizes the available information on AE-ILD and discusses the procedures reported to cause AE-ILD. We also discuss proposed mechanisms, risk factors, treatment and prognosis. This review should help to inform decision-making about risks versus benefits of procedures that are commonly recommended to diagnose ILD.

Crohn's disease-associated interstitial lung disease mimicking sarcoidosis: a case report and review of the literature.

Respiratory involvement in Crohn's disease (CD) is a rare manifestation known to involve the large and small airways, lung parenchyma, and pleura. The clinical presentation is nonspecific, and diagnostic tests can mimic other pulmonary diseases, posing a diagnostic challenge and delay in treatment. We report a case of a 60-year-old female with a history of CD and psoriatic arthritis who presented with dyspnea, fever, and cough with abnormal radiological findings. Diagnostic testing revealed an elevated CD4:CD8 ratio in the bronchoalveolar lavage fluid, and cryoprobe lung biopsy results showed non-necrotizing granulomatous inflammation. We describe here the second reported case of pulmonary involvement mimicking sarcoidosis in Crohn's disease and a review of the literature on the approaches to making a diagnosis of CD-associated interstitial lung disease.

Lung Cancer Screening With Low-Dose CT: Implementation Amid Changing Public Policy at One Health Care System.

Screening for lung cancer with low-dose CT has evolved rapidly in recent years since the National Lung Screening Trial (NLST) results. Subsequent professional and governmental organization guidelines have shaped policy and reimbursement for the service. Increasingly available guidance describes eligible patients and components necessary for a high-quality lung cancer screening program; however, practical instruction and implementation experience is not widely reported. We launched a lung cancer screening program in the face of reimbursement and guideline uncertainties at a large academic health center. We report our experience with implementation, including challenges and proposed solutions. Initially, we saw less referrals than expected for screening, and many patients referred for screening did not clearly meet eligibility guidelines. We educated primary care providers and implemented system tools to encourage referral of eligible patients. Moreover, in response to the Centers for Medicare & Medicaid Services (CMS) final coverage determination, we report our programmatic adaptation to meet these requirements. In addition to the components common to all quality programs, individual health delivery systems will face unique barriers related to patient population, available resources, and referral patterns.

IgG4-related lung disease: a case series of 6 patients and review of the literature.

IgG4 related disease has been recently proposed as a unifying term for a group of inflammatory conditions previously referred to by a plethora of other names. The common denominator for these entities is the histopathologic finding of lymphocytic infiltrates rich in IgG4 producing plasma cells, often accompanied by storiform fibrosis and obliterative phlebitis. Many medical conditions have been attributed to IgG4-related disease,but few reports of IgG4-related lung disease have been published, and it remains a rare condition about which little is known. In this report, we describe the clinical and pathologic features of six patients with IgG4-related disease of the lung. Patients were followed 1-5 years following their diagnosis. We describe unique features of IgG4-related lung disease, including one patient who presented with alveolar hemorrhage and a positive anti-neutrophil cytoplasmic antibody and two patients whose disease improved after treatment with mycophenylate mofetil. Two patients presented with pulmonary pseudotumor. We conclude that the clinical presentation of IgG4-related lung disease varies widely, and histopathology remains the key to diagnosis.

Significance of granulomatous inflammation in usual interstitial pneumonia.

Sarcoidosis is a systemic granulomatous disease of unclear etiology with characteristic pulmonary lesions. We describe 2 unique cases of sarcoidosis where after approximately 20 years of clinical quiescence, patients developed interstitial opacities on chest CT scan and an increase in shortness of breath. With lack of therapeutic response to a course of prednisone, both patients underwent a surgical lung biopsy that revealed a pattern consistent with Usual Interstitial Pneumonia (UIP) with honeycombing and fibroblastic foci. Postoperatively, the course of the disease was consistent with what would be expected in Idiopathic Pulmonary Fibrosis. Ultimately the disease progressed with one patient needed lung transplantation and the other requiring high-flow oxygen supplementation. In conclusion, we present two patients in whom a diagnosis of sarcoidosis preceded the diagnosis of UIP by 20 years or more. The subsequent course of disease in both patients was consistent with Idiopathic Pulmonary Fibrosis.

Human CT Measurements of Structure/Electrode Position Changes During Respiration with Electrical Impedance Tomography.

For pulmonary applications of Electrical Impedance Tomography (EIT) systems, the electrodes are placed around the chest in a 2D ring, and the images are reconstructed based on the assumptions that the object is rigid and the measured resistivity change in EIT images is only caused by the actual resistivity change of tissue. Structural changes are rarely considered. Previous studies have shown that structural changes which result in tissue/organ and electrode position changes tend to introduce artefacts to EIT images of the thorax. Since EIT reconstruction is an ill-posed inverse problem, any small inaccurate assumptions of object may cause large artefacts in reconstructed images. Accurate information on structure/electrode position changes is a need to understand factors contributing to the measured resistivity changes and to improve EIT reconstruction algorithm. Our previous study using MRI technique showed that chest expansion leads to electrode and tissue/organ movements but not significant as proposed. The accuracy of the measurements by MRI may be limited by its relatively low temporal and spatial resolution. In this study, structure/electrode position changes during respiration cycle in patients who underwent chest CT scans are further investigated. For each patient, sixteen fiduciary markers are equally spaced around the surface, the same as the electrode placement for EIT measurements. A CT scanner with respiration-gated ability is used to acquire images of the thorax. CT thoracic images are retrospectively reconstructed corresponding temporally to specific time periods within respiration cycle (from 0% to 90%, every 10%). The average chest expansions are 2 mm in anterior-posterior and -1.6 mm in lateral directions. Inside tissue/organ move down 9.0±2.5 mm with inspiration of tidal volume (0.54±0.14 liters), ranging from 6 mm to 12 mm. During normal quiet respiration, electrode position changes are smaller than expected. No general patterns of electrode position changes are observed. The results in this study provide guidelines for accommodating the motion that may introduce artefacts to EIT images.

Combined contrast-enhanced computed tomography and 18-fluoro-2-deoxy-D-glucose-positron emission tomography in the diagnosis and staging of non-small cell lung cancer.

We present the current optimal uses and limitations of positron emission tomography/computed tomography (PET/CT) as it relates to the diagnosis and staging of non-small cell lung cancer (NSCLC). PET/CT demonstrates increased accuracy in the workup of solitary pulmonary nodules for malignancy compared with CT alone, and we discuss its benefits and limitations. We review pitfalls in measured standardized uptake values of lung lesions caused by respiratory artifacts, the lower sensitivity for detection of small lung nodules on non-breath-hold CT, and the benefits of obtaining an additional diagnostic CT for the maximum sensitivity of lung nodule detection. There are limitations of quantitatively comparing separate PET/CT examinations from different facilities with standardized uptake values. As for staging, we describe how PET/CT supplements clinical tumor-nodes-metastases (ie, TNM) staging, as well as mediastinoscopy, endobronchial ultrasound, and endoscopic ultrasound, which are the gold standard pathologic staging methods. We touch on the 7th edition TNM staging system based on the work by the International Association for the Study of Lung Cancer, an anatomically based staging method.