Utilizing computed tomography volumetry for size matching prior to lung transplantation: a case series.

Background: Appropriate size matching between donor and recipient is critical for successful pulmonary transplantation. Although surrogate measurements such as height and gender are often utilized to approximate predicted lung volume, these methods provide only a gross estimation with wide variability and poor predictive value. Case Description: A single center exploratory study was conducted in which four patients underwent lung transplantation (LT) with pre-operative computed tomography (CT) volumetry obtained in both the donor and recipient to facilitate decision making regarding organ size and suitability. In four cases in which CT volumetry was used, the lung volumes calculated using surrogate measurements significantly overestimated both donor and recipient lung volumes quantified by CT volumetric analysis. All recipients underwent successful LT without necessary graft downsizing. Conclusions: This is an initial report of prospectively utilizing CT volumetry as an adjunct to decision-making regarding suitability of donor lungs. In these cases, CT volumetry facilitated the confident acceptance of donor lungs that were initially predicted to be oversized based on other clinical measures.

Implementation of a peer-learning program in an academic abdominal radiology practice and comparison with a traditional peer-review system.

OBJECTIVE: The purpose of this study was to transition from a traditional score-based peer-review system to an education-oriented peer-learning program in our academic abdominal radiology practice. MATERIAL AND METHODS: This retrospective study compared our experience with a score-based peer-review model used prior to September 2020 and a peer-learning model implemented and used exclusively beginning in October of 2020. In peer review, a web-based peer-review tool randomly generated a list of cases, which were blindly reviewed in consensus. Comparison of the consensus interpretation with the original report was used to categorize each reviewed case and to calculate the rates of significant and minor discrepancies. Only cases with a discrepancy were considered to represent a learning opportunity. In peer learning, faculty prospectively identified and submitted cases for review in several categories, including case interpretations with a discrepancy from subsequent opinion or result, interpretations considered to represent a great call, and interesting or challenging cases meriting further discussion. The peer-learning coordinator showed each case to the group in a manner which blinded the group to both submitting and interpreting radiologist and invited discussion during various stages of the case. RESULTS: During peer review, a total of 172 cases were reviewed over 16 sessions occurring between April 2016 and September 2020. Only 3 cases (1.8%) yielded significant discrepancies whereas 13 (7.6%) yielded minor discrepancies, representing a total of 16 learning opportunities (3.6 per year). In peer learning, 64 cases were submitted and 52 reviewed over 7 sessions occurring between October 2020 and October 2021. 29 (56%) were submitted as an interesting or challenging case meriting further discussion, 18 (35%) were submitted for a discrepancy, and 5 (10%) were submitted for a great call. All 52 presented cases represented learning opportunities (48 per year). CONCLUSION: An education-focused peer-learning program provided a platform for continuous quality improvement and yielded substantially more learning opportunities compared to score-based peer review.

Impact of Pretransplantation CT on Liver Donation in Potential Deceased Organ Donors.

BACKGROUND: Computed tomography (CT) is routinely used to determine the suitability of potential living donor liver transplants, providing important information about liver size, vascular anatomy, and the presence of other diseases that would preclude it from safe donation. CT is not routinely used, however, when evaluating eligible deceased organ donors after brain death, a group which comprises most orthotopic liver transplants. After the installation of a CT scanner at a local procurement facility, CTs have been performed on potential deceased organ donors and used, in conjunction with other evaluative protocols, to help direct donation decisions and assist in procurement procedures. STUDY DESIGN: A retrospective analysis of data from 373 cases spanning 5 years was systematically collected and analyzed, including information pertaining to patient's medical histories, biopsy results, operative findings, and CT results. RESULTS: CT findings directly impacted the directive decision-making process in 29% of cases in this patient cohort, likely an underestimate, and reliably evaluated important factors including variant vascular anatomy and the presence and severity of hepatic steatosis and cirrhosis. CONCLUSION: Overall, this study suggests that CT has the potential to play a significant role in procurement procedures and the directive decision-making process, thereby improving the efficiency and accuracy by which potential deceased organ donors are evaluated.

Transplantation of Donor Lung With Partial Anomalous Pulmonary Venous Return Using a Carrel Patch.

Partial anomalous pulmonary venous return is a rare congenital aberrancy that involves oxygen-rich pulmonary venous drainage into the right atrium instead of into the systemic circulation. This report describes a case of isolated partial anomalous pulmonary venous return of the right upper lobe in a donor lung. Successful transplantation was performed with a Carrel patch technique for left atrial cuff reconstruction using a segment of donor vena cava. This report of partial anomalous pulmonary venous return in a right donor lung describes this reconstructive approach to restore physiologic venous drainage.

Chest CT and Coronavirus Disease (COVID-19): A Critical Review of the Literature to Date.

OBJECTIVE. Coronavirus disease (COVID-19) is a global pandemic. Studies in the radiology literature have suggested that CT might be sufficiently sensitive and specific in diagnosing COVID-19 when used in lieu of a reverse transcription-polymerase chain reaction test; however, this suggestion runs counter to current society guidelines. The purpose of this article is to critically review some of the most frequently cited studies on the use of CT for detecting COVID-19. CONCLUSION. To date, the radiology literature on COVID-19 has consisted of limited retrospective studies that do not substantiate the use of CT as a diagnostic test for COVID-19.

Apical Sparing Pattern of Longitudinal Strain and Positive Bone Scintigraphy in Metastatic Myocardial Calcification.

An apical sparing pattern of longitudinal strain and positive radionuclide bone scintigraphy are believed to be specific for the diagnosis of transthyretin cardiac amyloidosis. We report on a young woman with apical sparing of longitudinal strain and positive bone scintigraphy who was found to have metastatic myocardial calcification at autopsy. (Level of Difficulty: Intermediate.).

Image-guided Preoperative Localization of Pulmonary Nodules for Video-assisted and Robotically Assisted Surgery.

Video-assisted thoracic surgery (VATS) and robotically assisted surgery are used increasingly for minimally invasive diagnostic and therapeutic resection of pulmonary nodules. Unsuccessful localization of small, impalpable, or deep pulmonary nodules can necessitate conversion from VATS to open thoracotomy. Preoperative localization techniques performed by radiologists have improved the success rates of VATS resection for small and subsolid nodules. Any center at which VATS diagnostic resection of indeterminate pulmonary nodules is performed should be supported by radiologists who offer preoperative nodule localization. Many techniques have been described, including image-guided injection of radioisotopes and radiopaque liquids and placement of metallic wires, coils, and fiducial markers. These markers enable the surgeon to visualize the position of an impalpable nodule intraoperatively. This article provides details on how to perform each percutaneous localization technique, and a group of national experts with established nodule localization programs describe their preferred approaches. Special reference is made to equipment required, optimization of marker placement, prevention of technique-specific complications, and postprocedural treatment. This comprehensive unbiased review provides valuable information for those who are considering implementation or optimization of a nodule localization program according to workflow patterns, surgeon preference, and institutional resources in a particular center. ©RSNA, 2019.

No vascular calcification on cardiac computed tomography spanning asfotase alfa treatment for an elderly woman with hypophosphatasia.

Hypophosphatasia (HPP) is the inborn-error-of-metabolism characterized enzymatically by insufficient activity of the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP) and caused by either mono- or bi-allelic loss-of-function mutation(s) of the gene ALPL that encodes this cell surface phosphomonoester phosphohydrolase. In HPP, the natural substrates of TNSALP accumulate extracellularly and include inorganic pyrophosphate (PPi), a potent inhibitor of biomineralization. This PPi excess leads to rickets or osteomalacia in all but the most mild "odonto" form of the disease. Adults with HPP understandably often also manifest calcium PPi dihydrate deposition, whereas enthesopathy and calcific periarthritis from hydroxyapatite (HA) crystal deposition can seem paradoxical in face of the defective skeletal mineralization. In 2015, asfotase alfa (AA), a HA-targeted TNSALP, was approved multinationally as an enzyme replacement therapy for HPP. AA hydrolyzes extracellular PPi (ePPi) and in HPP enables HA crystals to grow and mineralize skeletal matrix. In direct contrast to HPP, deficiency of ePPi characterizes the inborn-errors-of-metabolism generalized arterial calcification of infancy (GACI) and pseudoxanthoma elasticum (PXE). In GACI and PXE, deficiency of ePPi leads to ectopic mineralization including vascular calcification (VC). Therefore, in HPP, ectopic mineralization including VC could hypothetically result from, or be exacerbated by, the persistently high circulating TNSALP activity that occurs during AA treatment. Herein, using a routine computed tomography (CT) method to quantitate coronary artery calcium, we found no ectopic mineralization in the heart of an elderly woman with HPP before or after 8 months of AA treatment. Subsequently, investigational high-resolution peripheral quantitative CT and dual-energy X-ray absorptiometry showed absence of peripheral artery and aortic calcium after further AA treatment. Investigation of additional adults with HPP could reveal if the superabundance of ePPi protects against VC, and whether long-term AA therapy causes or exacerbates any ectopic mineralization.

Chest computed tomography imaging improves potential lung donor assessment.

OBJECTIVE: Chest computed tomography (CT) imaging is being increasingly used for potential lung donor assessment. However, the efficacy of CT imaging in this setting remains unknown. We hypothesize that chest CT imaging independently affects the decision-making process in donor lung utilization. METHODS: We conducted a retrospective cohort study of all adult donation after brain death donors managed through our local organ procurement organization from June 2011 to November 2016. An experienced thoracic radiologist independently reviewed donor chest CT and chest x-ray images in a blinded, standardized manner to determine the presence of structural lung disease (eg, emphysema, interstitial lung disease [ILD]) and acute abnormalities (eg, traumatic lung injury [TLI]). Distinct models of lung utilization were fit to groups with initial partial pressure of oxygen (iPaO2) ≤300 mm Hg (suboptimal) and iPaO2 >300 mm Hg (optimal). RESULTS: The organ procurement organization managed 753 donors during the study period, with a lung utilization rate ([lung donors/all organ donors] × 100) of 36.5% (275 of 753). Four hundred forty-five (59.1%) donors received chest CT imaging, revealing emphysema (13.7%), ILD (2.5%), and TLI (7.2%). In univariate analysis, findings of TLI (odds ratio [OR], 2.23; 95% confidence interval [CI], 1.08-4.61) were positively associated with lung utilization, whereas findings of emphysema (OR, 0.18; CI, 0.08-0.40) were negatively associated with utilization. In multivariate analysis, CT findings of emphysema (OR, 0.21; CI 0.08-0.54) remained negatively associated with utilization. No potential donors with CT findings of ILD became lung donors. After controlling for chest x-ray findings, chest CT imaging findings of structural lung disease remained negatively associated with utilization (P = .0001). Lung utilization rate in the suboptimal and optimal iPaO2 populations was 35.1% and 41.4%, respectively, and CT findings of emphysema had a significant association with nonutilization in both groups. CONCLUSIONS: In the evaluation of potential lung donors, chest CT imaging findings of structural lung disease, such as emphysema and ILD, have a significant negative association with lung utilization. Our findings suggest that chest CT imaging might be an important adjunct to conventional lung donor assessment criteria.

Technical Considerations for Lung Transplantation in Kartagener's Syndrome.

Kartagener's syndrome is a rare genetic disorder of ciliated epithelial cells associated with recurrent respiratory tract infections, bronchiectasis, and situs inversus. In some patients, the accumulation of airway secretions and recurrent infections lead to end-stage lung disease, for which lung transplantation is the only effective treatment. Anatomical variations, such as dextrocardia and pulmonary situs inversus, make the procedure challenging, yet feasible with certain technical modifications and careful preparation of donor lungs. We report a case of bilateral lung transplantation without the use of cardiopulmonary bypass in a patient with Kartagener's syndrome while describing important technical details of the operation.

Transplantation of Lungs Procured From a Donor With an Atrioesophageal Fistula.

Lung transplantation continues to be limited by a shortage of donor organs. We report the case of procurement and transplantation of lungs from a young donor who died from an atrioesophageal fistula, complicating catheter ablation for atrial fibrillation. Our case illustrates that structural damage to the left atrium is not an absolute contraindication to lung donation. As atrioesophageal fistulas are being increasingly recognized as a rare but often lethal complication of catheter ablation, such donors can contribute to the expansion of the donor pool.

Transcatheter Aortic Valve Replacement: Alternative Access beyond the Femoral Arterial Approach.

Aortic stenosis is the most prevalent valvular cardiovascular disease affecting the population over the age of 65 years. Transcatheter aortic valve replacement (TAVR) was developed as a minimally invasive surgical intervention to treat aortic stenosis in patients at high risk for surgical complications. Although the most commonly used approach for placement of a transcatheter aortic valve is in retrograde fashion via a transfemoral approach, narrowed luminal diameters, extensive atherosclerotic disease, or significant tortuosity may limit use of this route. In these patients, alternative methods including subclavian, transaortic, and transapical approaches should be considered. An understanding of these access routes and their respective indications and contraindications allows the radiologist to provide additional preprocedure measurements and images to help guide placement of the valve. ©RSNA, 2018.

Anomalous Origin of Left Pulmonary Artery From the Aorta: A Rare Entity in Congenital Heart Disease.

Anomalous origin of the left pulmonary artery (ALPA) from the aorta is a rare form of congenital heart disease, leading to long-term morbidity if not treated early. There is a reported association of this anomaly with 22q11 microdeletion syndrome. Surgical repair is commonly performed by direct reimplantation to the main pulmonary artery with or without patch or flap techniques. This report presents two unique cases of ALPA, describing embryologic considerations for morphogenesis of ALPA with 22q11 microdeletion syndrome and a novel surgical technique involving unroofing of the unique anatomy of the common wall between the left and main pulmonary arteries.

Overnight Resident versus 24-hour Attending Radiologist Coverage in Academic Medical Centers.

Academic medical centers have long relied on radiology residents to provide after-hours coverage, which means that they essentially function with autonomy. In this approach, attending radiologist review of resident interpretations occurs the following morning, often by subspecialist faculty. In recent years, however, this traditional coverage model in academic radiology departments has been challenged by an alternative model, the 24-hour attending radiologist coverage. Proponents of this new model seek to improve patient care after hours by increasing report accuracy and the speed with which the report is finalized. In this article, we review the traditional and the 24-hour attending radiologist coverage models. We summarize previous studies that indicate that resident overnight error rates are sufficiently low so that changing to an overnight attending model may not necessarily provide a meaningful increase in report accuracy. Whereas some centers completely replaced overnight residents, we note that most centers use a hybrid model, and overnight residents work alongside supervising attending radiologists, much as they do during the day. Even in this hybrid model, universal double reading and subspecialist final review, typical features of the traditional autonomous resident coverage model, are generally sacrificed. Because of this, changing from resident coverage to coverage by an attending radiologist that is 24 hours/day, 7 days/week may actually have detrimental effects to patient safety and quality of care provided. Changing to an overnight attending radiologist model may also have negative effects on the quality of radiology resident training, and it significantly increases cost.

Aortic arch compliance and idiopathic unilateral vocal fold paralysis.

Unilateral vocal fold paralysis (UVP) occurs related to recurrent laryngeal nerve (RLN) impairment associated with impaired swallowing, voice production, and breathing functions. The majority of UVP cases occur subsequent to surgical intervention with approximately 12-42% having no known cause for the disease (i.e., idiopathic). Approximately two-thirds of those with UVP exhibit left-sided injury with the average onset at ≥50 yr of age in those diagnosed as idiopathic. Given the association between the RLN and the subclavian and aortic arch vessels, we hypothesized that changes in vascular tissues would result in increased aortic compliance in patients with idiopathic left-sided UVP compared with those without UVP. Gated MRI data enabled aortic arch diameter measures normalized to blood pressure across the cardiac cycles to derive aortic arch compliance. Compliance was compared between individuals with left-sided idiopathic UVP and age- and sex-matched normal controls. Three-way factorial ANOVA test showed that aortic arch compliance (P = 0.02) and aortic arch diameter change in one cardiac cycle (P = 0.04) are significantly higher in patients with idiopathic left-sided UVP compared with the controls. As previously demonstrated by other literature, our finding confirmed that compliance decreases with age (P < 0.0001) in both healthy individuals and patients with idiopathic UVP. Future studies will investigate parameters of aortic compliance change as a potential contributor to the onset of left-sided UVP.NEW & NOTEWORTHY Unilateral vocal fold paralysis results from impaired function of the recurrent laryngeal nerve (RLN) impacting breathing, swallowing, and voice production. A large proportion of adults suffering from this disorder have an idiopathic etiology (i.e., unknown cause). The current study determined that individuals diagnosed with left-sided idiopathic vocal fold paralysis exhibited significantly greater compliance than age- and sex-matched controls. These seminal findings suggest a link between aortic arch compliance levels and RLN function.

ANGPTL3 Deficiency and Protection Against Coronary Artery Disease.

BACKGROUND: Familial combined hypolipidemia, a Mendelian condition characterized by substantial reductions in all 3 major lipid fractions, is caused by mutations that inactivate the gene angiopoietin-like 3 (ANGPTL3). Whether ANGPTL3 deficiency reduces risk of coronary artery disease (CAD) is unknown. OBJECTIVES: The study goal was to leverage 3 distinct lines of evidence-a family that included individuals with complete (compound heterozygote) ANGPTL3 deficiency, a population based-study of humans with partial (heterozygote) ANGPTL3 deficiency, and biomarker levels in patients with myocardial infarction (MI)-to test whether ANGPTL3 deficiency is associated with lower risk for CAD. METHODS: We assessed coronary atherosclerotic burden in 3 individuals with complete ANGPTL3 deficiency and 3 wild-type first-degree relatives using computed tomography angiography. In the population, ANGPTL3 loss-of-function (LOF) mutations were ascertained in up to 21,980 people with CAD and 158,200 control subjects. LOF mutations were defined as nonsense, frameshift, and splice-site variants, along with missense variants resulting in <25% of wild-type ANGPTL3 activity in a mouse model. In a biomarker study, circulating ANGPTL3 concentration was measured in 1,493 people who presented with MI and 3,232 control subjects. RESULTS: The 3 individuals with complete ANGPTL3 deficiency showed no evidence of coronary atherosclerotic plaque. ANGPTL3 gene sequencing demonstrated that approximately 1 in 309 people was a heterozygous carrier for an LOF mutation. Compared with those without mutation, heterozygous carriers of ANGPTL3 LOF mutations demonstrated a 17% reduction in circulating triglycerides and a 12% reduction in low-density lipoprotein cholesterol. Carrier status was associated with a 34% reduction in odds of CAD (odds ratio: 0.66; 95% confidence interval: 0.44 to 0.98; p = 0.04). Individuals in the lowest tertile of circulating ANGPTL3 concentrations, compared with the highest, had reduced odds of MI (adjusted odds ratio: 0.65; 95% confidence interval: 0.55 to 0.77; p < 0.001). CONCLUSIONS: ANGPTL3 deficiency is associated with protection from CAD.