Effectiveness and Cardiac Safety of Bedaquiline-Based Therapy for Drug-Resistant Tuberculosis: A Prospective Cohort Study.

BACKGROUND: Bedaquiline improves treatment outcomes in patients with rifampin-resistant (RR) tuberculosis but prolongs the QT interval and carries a black-box warning from the US Food and Drug Administration. The World Health Organization recommends that all patients with RR tuberculosis receive a regimen containing bedaquiline, yet a phase 3 clinical trial demonstrating its cardiac safety has not been published. METHODS: We conducted an observational cohort study of patients with RR tuberculosis from 3 provinces in South Africa who received regimens containing bedaquiline. We performed rigorous cardiac monitoring, which included obtaining electrocardiograms in triplicate at 4 time points during bedaquiline therapy. Participants were followed up until the end of therapy or 24 months. Outcomes included final tuberculosis treatment outcome and QT interval prolongation (QT prolongation), defined as any QT interval corrected by the Fridericia method (QTcF) >500 ms or an absolute change from baseline (ΔQTcF) >60 ms. RESULTS: We enrolled 195 eligible participants, of whom 40% had extensively drug-resistant tuberculosis. Most participants (97%) received concurrent clofazimine. Of the participants, 74% were cured or successfully completed treatment, and outcomes did not differ by human immunodeficiency virus status. QTcF continued to increase throughout bedaquiline therapy, with a mean increase (standard deviation) of 23.7 (22.7) ms from baseline to month 6. Four participants experienced a QTcF >500 ms and 19 experienced a ΔQTcF >60 ms. Older age was independently associated with QT prolongation. QT prolongation was neither more common nor more severe in participants receiving concurrent lopinavir-ritonavir. CONCLUSIONS: Severe QT prolongation was uncommon and did not require permanent discontinuation of either bedaquiline or clofazimine. Close monitoring of the QT interval may be advisable in older patients.

A Retrospective Multi-Site Academic Center Analysis of Pneumothorax and Associated Risk Factors after CT-Guided Percutaneous Lung Biopsy.

PURPOSE: To assess the risk factors, incidence and significance of pneumothorax in patients undergoing CT-guided lung biopsy. METHODS: Patients who underwent a CT-guided lung biopsy between August 10, 2010 and September 19, 2016 were retrospectively identified. Imaging was assessed for immediate and delayed pneumothorax. Records were reviewed for presence of risk factors and the frequency of complications requiring chest tube placement. 604 patients were identified. Patients who underwent chest wall biopsy (39) or had incomplete data (9) were excluded. RESULTS: Of 556 patients (average age 66 years, 50.2% women) 26.3% (146/556) had an immediate pneumothorax and 2.7% (15/556) required chest tube placement. 297/410 patients without pneumothorax had a delayed chest X-ray. Pneumothorax developed in 1% (3/297); one patient required chest tube placement. Pneumothorax risk was associated with smaller lesion sizes (OR 0.998; 95% CI (0.997, 0.999); [p = 0.002]) and longer intrapulmonary needle traversal (OR 1.055; 95% CI (1.033, 1.077); [p < 0.001]). Previous ipsilateral lung surgery (OR 0.12; 95% CI (0.031, 0.468); [p = 0.002]) and longer needle traversal through subcutaneous tissue (OR 0.976; 95% CI (0.96, 0.992); [p = 0.0034]) were protective of pneumothorax. History of lung cancer, biopsy technique, and smoking history were not significantly associated with pneumothorax risk. CONCLUSION: Delayed pneumothorax after CT-guided lung biopsy is rare, developing in 1% of our cohort. Pneumothorax is associated with smaller lesion size and longer intrapulmonary needle traversal. Previous ipsilateral lung surgery and longer needle traversal through subcutaneous tissues are protective of pneumothorax. Stratifying patients based on pneumothorax risk may safely obviate standard post-biopsy delayed chest radiographs.

CT Scans Obtained for Nonpulmonary Indications: Associated Respiratory Findings of COVID-19.

Background Atypical manifestations of coronavirus disease 2019 (COVID-19) are being encountered as the pandemic unfolds, leading to non-chest CT scans that may uncover unsuspected pulmonary disease. Purpose To investigate patients with primary nonrespiratory symptoms who underwent CT of the abdomen or pelvis or CT of the cervical spine or neck with unsuspected findings highly suspicious for pulmonary COVID-19. Materials and Methods This retrospective study from March 10, 2020, to April 6, 2020, involved three institutions, two in a region considered a hot spot (area of high prevalence) for COVID-19. Patients without known COVID-19 were included who presented to the emergency department (ED) with primary nonrespiratory (gastrointestinal or neurologic) symptoms, had lung parenchymal findings suspicious for COVID-19 at non-chest CT but not concurrent chest CT, and underwent COVID-19 testing in the ED. Group 1 patients had reverse transcription polymerase chain reaction (RT-PCR) results obtained before CT scan reading (COVID-19 suspected on presentation); group 2 had RT-PCR results obtained after CT scans were read (COVID-19 not suspected). Presentation and imaging findings were compared, and outcomes were evaluated. Descriptive statistics and Fisher exact tests were used for analysis. Results Group 1 comprised 62 patients (31 men, 31 women; mean age, 67 years ±17 [standard deviation]), and group 2 comprised 57 patients (28 men, 29 women; mean age, 63 years ± 16). Cough and fever were more common in group 1 (37 of 62 [60%] and 29 of 62 [47%], respectively) than in group 2 (nine of 57 [16%] and 12 of 57 [21%], respectively), with no significant difference in the remaining symptoms. There were 101 CT scans of the abdomen or pelvis and 18 CT scans of the cervical spine or neck. In group 1, non-chest CT findings provided the initial evidence of COVID-19-related pneumonia in 32 of 62 (52%) patients. In group 2, the evidence was found in 44 of 57 (77%) patients. Overall, the most common CT findings were ground-glass opacity (114 of 119, 96%) and consolidation (47 of 119, 40%). Major interventions (vasopressor medication or intubation) were required for 29 of 119 (24%) patients, and 27 of 119 (23%) died. Patients who underwent CT of the cervical spine or neck had worse outcomes than those who underwent abdominal or pelvic CT (P = .01). Conclusion In a substantial percentage of patients with primary nonrespiratory symptoms who underwent non-chest CT, CT provided evidence of coronavirus disease 2019-related pneumonia. © RSNA, 2020.

Ventricular Myocardial Fat: An Unexpected Biomarker for Long-term Survival?

PURPOSE: To examine the association between myocardial fat, a poorly understood finding frequently observed on non-contrast CT, and all-cause mortality in patients with and without a history of prior MI. MATERIALS AND METHODS: A retrospective cohort from a diverse urban academic center was derived from chronic myocardial infarction (MI) patients (n = 265) and three age-matched patients without MI (n = 690) who underwent non-contrast chest CT between 1 January 2005-31 December 2008. CT images were reviewed for left and right ventricular fat. Electronic records identified clinical variables. Kaplan-Meier and Cox proportional hazard analyses assessed the association between myocardial fat and all-cause mortality. The net reclassification improvement assessed the utility of adding myocardial fat to traditional risk prediction models. RESULTS: Mortality was 40.1% for the no MI and 71.7% for the MI groups (median follow-up, 6.8 years; mean age, 73.7 ± 10.6 years). In the no MI group, 25.7% had LV and 49.9% RV fat. In the MI group, 32.8% had LV and 42.3% RV fat. LV and RV fat was highly associated (OR 5.3, p < 0.001). Ventricular fat was not associated with cardiovascular risk factors. Myocardial fat was associated with a reduction in the adjusted hazard of death for both the no MI (25%, p = 0.04) and the MI group (31%, p = 0.018). Myocardial fat resulted in the correct reclassification of 22% for the no MI group versus the Charlson score or calcium score (p = 0.004) and 47% for the MI group versus the Charlson score (p = 0.0006). CONCLUSIONS: Patients with myocardial fat have better survival, regardless of MI status, suggesting that myocardial fat is a beneficial biomarker and may improve risk stratification. KEY POINTS: • Myocardial fat is commonly found on chest CT, yet is poorly understood • Myocardial fat is associated with better survival in patients with and without prior MI and is not associated with traditional cardiovascular risk factors • This finding may provide clinically meaningful prognostic value in the risk stratification of patients.

Can Discrepancies Between Coronary Computed Tomography Angiography and Cardiac Catheterization in High-Risk Patients be Overcome With Consensus Reading?

OBJECTIVE: To assess the incidence and cause of discrepancies between coronary computed tomography angiography (CTA) and catheterization in a high-risk, diverse, predominantly overweight inner-city population. METHODS: Ninety-two patients who underwent coronary CTA and catheterization on March 2007 to December 2012 were retrospectively identified. Clinical coronary CTA interpretation and reinterpretation by a review panel was compared with catheterization results. RESULTS: Severe stenosis was present on catheterization in 65% (60/92). Clinical coronary CTA was concordant with catheterization for severe stenosis in 78% (72/92), whereas panel interpretation was concordant in 77% (70/91). Sensitivity and specificity of clinical and panel coronary CTA interpretations were 92% (55/60) and 53% (17/32) versus 82% (48/59) and 68% (22/32), respectively. CONCLUSIONS: Both coronary CTA interpretations were concordant with catheterization for severe stenosis in three quarters of patients. However, the diagnostic profile of the 2 interpretations differed, with higher sensitivity for the clinical report. This supports the clinical practice, which favored overestimation of difficult to quantify stenoses.

Acute aortic syndromes: a second look at dual-phase CT.

OBJECTIVE: The purpose of this article is to assess the diagnostic performance of the unenhanced and contrast-enhanced phases separately in patients imaged with CT for suspected acute aortic syndromes. MATERIALS AND METHODS: All adults (n = 2868) presenting to our emergency department from January 1, 2006, through August 1, 2010, who underwent unenhanced and contrast-enhanced CT of the chest and abdomen for suspected acute aortic syndrome were retrospectively identified. Forty-five patients with acute aortic syndrome and 45 healthy control subjects comprised the study population (55 women; mean age, 61 ± 16 years). Unenhanced followed by contrast-enhanced CT angiography (CTA) images were reviewed. Contrast-enhanced CTA examinations of case patients and control subjects with isolated intramural hematoma were reviewed. Radiation exposure was estimated by CT dose-length product. RESULTS: Forty-five patients had one or more CT findings of acute aortic syndrome: aortic dissection (n = 32), intramural hematoma (n = 27), aortic rupture (n = 10), impending rupture (n = 4), and penetrating atherosclerotic ulcer (n = 2). Unenhanced CT was 89% (40/45) sensitive and 100% (45/45) specific for acute aortic syndrome. Unenhanced CT was 94% (17/18) and 71% (10/14) sensitive for type A and type B dissection, respectively (p = 0.142). Contrast-enhanced CTA was 100% (8/8) sensitive for isolated intramural hematoma. Mean radiation effective dose was 43 ± 20 mSv. CONCLUSION: Unenhanced CT performed well in detection of acute aortic syndrome treated surgically, although its performance does not support its use in place of contrast-enhanced CTA. Unenhanced CT may be a reasonable first examination for rapid triage when IV contrast is contraindicated. Contrast-enhanced CTA was highly sensitive for intramural hematoma, suggesting that unenhanced imaging may not always be needed. Acute aortic syndrome imaging protocols should be optimized to reduce radiation dose.

Cracking the Opium Den: Cardiothoracic Manifestations of Drug Abuse.

Recreational drug use is increasing worldwide, with emergency room visits and total deaths from drug overdose rising in recent years. Complications from prescription and recreational drug use may result from the biochemical effects of the drugs themselves, impurities mixed with substances, or from causes related to the method of drug administration. The presentation of drug overdose may be complex due to multisubstance abuse, including cigarette smoking and alcoholism, and can impact any organ system. Patients may present without history, and radiologists may be the first clinicians to suggest the diagnosis. We aim to explore the cardiothoracic manifestations of drug abuse and their multimodality imaging manifestations.

High prevalence of pulmonary findings in computed tomographies of HTLV-1-infected patients with and without adult-T cell leukemia/lymphoma - implications for staging.

Lung involvement has been reported in HTLV-1 carriers and in patients with ATLL. Whether there are differences in the pattern of lung involvement between ATLL and HTLV carriers in North American patients is unknown. We aimed to compare CT pulmonary findings among patients with HTLV-1 infection with and without ATLL. Among 140 patients with HTLV-1 diagnosis, 97 had CT chest available. Of these, 72 (74.2%) had ATLL and 25 (25.8%) did not have ATLL. CT chest abnormalities were present in 90 (92.8%) participants (94.4% in ATLL; 88% in non-ATLL). Higher rates of lymphadenopathy (69.4% versus 24%, p < .01) and lower rates of bronchiectasis (25% versus 48%, p = .04) were seen in ATLL compared to non-ATLL. Our study supports that staging of lung involvement in ATLL should consider HTLV-associated pulmonary findings as not all CT chest abnormalities necessarily represent malignant infiltration.

Patent foramen ovale in patients with pulmonary embolism: A prognostic factor on CT pulmonary angiography?

BACKGROUND: Patent foramen ovale (PFO) in patients with acute pulmonary embolism (PE) represents a risk factor for mortality, but this has not been evaluated for CT pulmonary angiography (CTPA). The purpose of the present study was to assess the relationship between PFO and mortality in patients with acute PE diagnosed on CTPA. MATERIALS AND METHODS: This retrospective study included 268 adults [173 women, mean age 61 (range 22-98) years] diagnosed with acute PE on non-ECG-gated 64-slice CTPA in 2012 at our medical center. The images were reviewed for PFO by a panel of cardiothoracic radiologists with an average of 11 years of experience (range 1-25 years). CT signs of right heart strain and PE level were noted. Transthoracic echocardiograms (TTE), when available (n = 207), were reviewed for PFO by a cardiologist with subspecialty training in advanced imaging and with 3 years of experience. The main outcome was 30-day mortality. Fischer's exact test was utilized to compare mortality. RESULTS: PFO prevalence on CTPA was 22% (58/268) and 4% (9/207) on TTE. Overall 30-day mortality was 6% (16/268), 9% (5/58) for patients with PFO and 5% (11/210) for those without (p = 0.35). CT signs of right heart strain trended with higher mortality, but statistically significant only for hepatic vein contrast reflux [14% (6/44) vs 4% (10/224), p = 0.03]; right ventricular (RV) to left ventricular (LV) diameter ratio >1 [8% (13/156) vs RV:LV ≤ 1 3% (3/112), p = 0.07], septal bowing [10% (4/42) vs without 5% (12/226), p = 0.30]. CONCLUSION: PFO was demonstrated on CTPA in a proportion similar to the known population prevalence, while routine TTE was less sensitive. Mortality was non-significantly higher in patients with acute PE and PFO in this moderate-sized study. A larger study to answer this clinically important question is worthwhile.

Ventricular myocardial fat: CT findings and clinical correlates.

OBJECTIVES: Replacement of the myocardium by fat is a feature of arrythmogenic right ventricular dysplasia (ARVD). Pathology literature describes ventricular myocardial fat to be present not only in ARVD, but much more frequently related to aging, prior myocardial infarction (MI), and chronic ischemia. We noted focal ventricular myocardial fat in a group of patients who underwent chest computed tomography (CT) for varied indications. The aim of this study is to describe the noncontrast CT findings and clinical correlates of ventricular myocardial fat in this population. MATERIALS AND METHODS: We prospectively identified 26 patients whose noncontrast chest CT (5/03 to 6/04) demonstrated ventricular myocardial fat and whose clinical charts were available. There were 14 men and 12 women with a mean age of 70 years. Twenty-three percent (6/26) had prior CTs. Each CT was reviewed by 3 radiologists in consensus. The site of the ventricular fat was noted. Each patient was categorized based on the location of the fat as follows: group 1-right ventricle (RV) only, group 2-left ventricle (LV) only, group 3-biventricular. Results of cardiac history, laboratory tests, and cardiac imaging were noted. RESULTS: The distribution of ventricular myocardial fat was: group 1 RV-27% (7/26), group 2 LV-46% (12/26), and group 3 biventricular-27% (7/26). Echocardiographic, nuclear cardiology, or electrocardiographic data localizing a prior MI to a specific site were available in 35% (9/26) of patients: 14% (1/7) of group 1, 50% (6/12) of group 2, and 29% (2/7) of group 3. Myocardial fat corresponded to the site of MI in 89% (8/9). The presence and distribution of ventricular fat on CT was unchanged from prior CT in 100% (6/6). When comparing group 1 and group 2, group 1 was older (77 vs. 64 y, P=0.005), more often female (57% vs. 17%, P=0.13) and had fewer prior MI (14% vs. 50%, P=0.17) than group 2. Only 1 patient in this series had ARVD. He was in group 3. CONCLUSIONS: The significance of ventricular myocardial fat varies by location. Fat in the RV is most often related to aging. Prior RV MI and ARVD are less common etiologies. Fat in the LV is frequently related to prior MI. Recognition of myocardial fat on a noncontrast chest CT may be the first opportunity to diagnose a silent MI.

Pulmonary infarction: spectrum of findings on multidetector helical CT.

OBJECTIVE: Despite the dual blood supply to the lung, acute pulmonary embolism (PE) can lead to a spectrum of ischemic injury to the lung resulting in infarction and hemorrhage. In this series we systematically describe the spectrum of CT findings and clinical correlates of pulmonary infarction in patients with PE. METHODS: We retrospectively identified 24 consecutive adults with pulmonary infarction on multidetector CT between July 2002 and March 2004. There were 13 women and 11 men, with a mean age of 59 years. The cases were identified by review of 74 consecutive CTs demonstrating PE. Each CT was evaluated by 2 of 3 reviewers in consensus for presence and characteristics of peripheral parenchymal opacities and extent of PE. Peripheral opacities were evaluated for degree of enhancement, internal air lucencies, and contour. The presence of adjacent vessels and linear strands were noted. At the end of interpreting each case, the reviewers determined whether or not an infarct was present based on the constellation of previously described imaging features. The extent of pulmonary vascular obstruction was graded using the CT clot burden scoring system. Each chart was reviewed for predisposing factors for PE and infarction, presenting clinical symptoms/signs, and co-existing pulmonary or cardiac conditions. RESULTS: Thirty-two percent (24/74) of patients with PE had pulmonary infarction. Thirty-three percent (8/24) of patients had more than 1 infarct. Seventy-three percent (27/37) of infarcts were in the lower lobes. The CT findings of pulmonary infarction included: focal decrease in parenchymal enhancement in 95% (35/37), broad pleural base in 65% (24/37), truncated apex in 57% (21/37), convex border in 46% (17/37), internal air lucencies in 32% (12/37), linear stranding from the apex toward the hilum in 24% (9/37), and a thickened vessel leading to the apex of the infarct in 14% (5/37). There was a trend toward a higher mean clot burden (12.3 vs. 10.5) between the patients with PE with and without infarction. Ninety-six percent (23/24) of patients with pulmonary infarction had predisposing factors for infarction, including PE involving more than 1 lobe (n = 21), malignancy (n = 5), and heart failure (n = 3). Pleuritic chest pain was significantly more frequent in patients with infarction (P = 0.0064). CONCLUSION: Pulmonary infarction occurred in nearly 1/3 of patients with PE in this series. The infarcts were peripheral parenchymal opacities characterized by a distinctive complex of findings on CT reflecting ischemic injury in the setting of a dual blood supply to the lung. Pleuritic chest pain was significantly associated with infarction.

CT pulmonary angiography in pregnant and postpartum women: low yield, high dose.

PURPOSE: To compare the diagnostic utility of computed tomography pulmonary angiography (CTPA) in pregnant/postpartum women with age-matched controls. MATERIALS: We performed a retrospective case-control series of pregnant/postpartum women and control women who underwent CTPA from 2008 to 2011. RESULTS: The study included 34 pregnant women, 16 postpartum women, and 50 controls. CTPAs were positive in 2% of pregnant/postpartum women and 16% of controls (P=.003). The main pulmonary artery mean opacification was 271 Hounsfield units (HU) for pregnant/postpartum women vs. 303 HU (P=.12). Radiation exposure was high in both groups but lower in pregnant/postpartum women, 10 vs. 14 mSv (P=.003). CONCLUSION: CTPA in pregnant and postpartum women had low yield and remained high dose.

Can left ventricular function be assessed on non-ECG-gated CT?

To evaluate whether non-gated computed tomography (CT) can assess left ventricular (LV) function, 101 patients with both CT and echocardiography were selected, with ejection fraction <50% on echocardiography used as a reference standard. CTs were blindly reevaluated, and qualitative assessment of LV dysfunction on CT correlated with echocardiographic dysfunction, odds ratio of 21.0 (95% confidence interval=6.55-71.0), specificity of 86% (56/65). Systolic and diastolic images were identified on CT, and the ratio of systolic to diastolic LV internal diameters and ratio of LV to RV internal diameter were determined, both showing correlation with LV dysfunction on echocardiography (P<.0001). Non-gated CT can be used to predict LV dysfunction.

Chest radiograph findings and time to culture conversion in patients with multidrug-resistant tuberculosis and HIV in Tugela Ferry, South Africa.

BACKGROUND: The majority of patients with multidrug-resistant tuberculosis (MDR-TB) in South Africa are co-infected with HIV, but the radiographic features of MDR-TB and their relationship with time to sputum culture conversion in the antiretroviral therapy era have not been described. METHODS: We reviewed baseline chest radiographs for 56 patients with MDR-TB from a rural area of South Africa. We analyzed the association of cavities, consolidation, pleural effusion and hilar lymphadenopathy with time to sputum culture conversion, adjusting for HIV status, baseline sputum smear and CD4 count. RESULTS: Of the 56 subjects, 49 (88%) were HIV-positive, with a median CD4 count of 136 cells/mm(3) (IQR 65-249). Thirty-two (57%) patients were sputum smear positive. Twenty-two (39%) patients had a cavity and 37 (66%) patients had consolidations. Cavitary disease and consolidations were each associated with longer time to culture conversion on bivariate analysis but not after adjusting for sputum smear status (aORs 1.79 [0.94-3.42] and 1.09 [0.67-1.78], respectively). Positive baseline sputum smear remained independently associated with longer time to conversion (aOR 3.45 [1.39-8.59]). We found no association between pleural effusion or hilar lymphadenopathy and time to conversion. Seventy-nine percent of patients were cured at the end of treatment. CONCLUSIONS: Despite high rates of HIV co-infection and advanced immunodeficiency, the majority of patients had severe pathology on baseline chest radiograph. Nevertheless, culture conversion rates were high and treatment outcomes were favorable. Cavitation and consolidation do not appear to have an independent association with time to culture conversion beyond that of baseline sputum smear status.

Computed tomography evaluation of right heart dysfunction in patients with acute pulmonary embolism.

PURPOSE: To evaluate the role of qualitative assessment of right heart dysfunction on multidetector computed tomography (CT) in patients with acute pulmonary embolism. METHODS: Seventy-four consecutive adults with pulmonary embolism diagnosed on multidetector nongated CT were identified between July 2002 and March 2004. There were 47 women and 27 men, with a mean age of 62 years. Each CT scan was jointly reviewed by 2 of 3 reviewers in consensus. The CT scans were qualitatively assessed for dilatation of the right ventricle and the position of the interventricular septum. Scans were considered positive for right heart dysfunction if, on visual integration of multiple axial images, the right ventricle was dilated or the interventricular septum was straightened or bowed into the left ventricle. The extent of pulmonary vascular obstruction was graded using the CT clot burden scoring system. Reports of echocardiograms (n = 30) were reviewed when available. The sensitivity and specificity of CT and echocardiography in demonstrating right heart dysfunction were calculated and compared using pulmonary vascular obstruction of > or =30% as the reference standard. RESULTS: Sixty-six percent (49 of 74 patients) with pulmonary embolism had right heart dysfunction on CT, with right ventricular dilatation in 38 patients and septal straightening or bowing in 44 patients. Forty-nine percent (36 of 74 patients) had pulmonary vasculature obstruction of > or =30%. There was a significant difference between the mean clot burden of patients with (12.8) and without (7.5) right heart dysfunction on CT (P = 0.0021). The sensitivity and specificity of CT in demonstrating right heart dysfunction were 81% (29 of 36 patients) and 47% (18 of 38 patients), respectively. Forty-one percent (30 of 74 patients) had technically adequate echocardiograms within 48 hours of CT. Fifty-seven percent (17 of 30) of the echocardiograms were positive for right heart dysfunction. There was no significant difference between the mean clot burden of patients with (12.7) and without (10.3) right heart dysfunction on echocardiography. Echocardiography had a sensitivity of 56% (10 of 17 patients) and a specificity of 42% (5 of 13 patients) in demonstrating right heart dysfunction. CONCLUSION: Qualitative assessment of the cardiac chambers is a quick and practical means of evaluating for right heart dysfunction on CT. Computed tomography findings of right heart dysfunction in patients with acute pulmonary embolism compare favorably with echocardiography and correlate with a higher mean pulmonary arterial clot burden. Because most patients do not undergo echocardiography, chest CT often provides the only opportunity to evaluate for right heart dysfunction in patients with acute pulmonary embolism.