Clinical and Payer-Based Analysis of Value of Dual-Energy Computed Tomography for Workup of Incidental Abdominal Findings.

OBJECTIVE: To perform a clinical and payer-based analysis of the value of dual-energy computed tomography (DECT) for workup of incidental abdominal findings. METHODS: This was a single-center, retrospectively designed, Health Insurance Portability and Accountability Act-compliant study approved by our institutional review board. Sixty-nine examinations in 69 patients (45 men, 24 women; mean age, 57.7 years) who underwent single-phase postcontrast abdominal DECT studies between January 1, 2011, and December 31, 2017, were included. Two radiologists, blinded to study objective and design, reviewed all cases and identified incidental abdominal findings needing further imaging. All incidental findings were reviewed by 2 other investigators, who determined whether an imaging-based diagnosis could be made using DECT virtual noncontrast images and iodine maps. Additional studies and associated payer-reimbursement amounts avoided by use of DECT were estimated. All imaging costs were estimated based on the US Centers for Medicare & Medicaid Services reimbursement amounts. RESULTS: Thirty-four incidental findings (renal mass, n = 20; adrenal nodule, n = 8; pancreatic cystic lesions, n = 3; others, n = 3) were identified in 19 (27.5%) of 69 patients. Dual-energy computed tomography characterized 27 incidental findings in 15 patients and accounted for cost savings of 15 additional imaging examinations (abdominal magnetic resonance imaging, n = 11; abdominal computed tomography, n = 4). Based on Centers for Medicare & Medicaid Services reimbursement amounts, we estimated that, by abolishing the need for additional imaging use, DECT saved US $84.95 per patient. CONCLUSIONS: Dual-energy computed tomography can provide an imaging-based diagnosis of incidental abdominal findings, otherwise incompletely characterized on routine abdominal computed tomography, in approximately 21% of patients. In select patients, the monetary savings from abolishing additional imaging may reduce payer costs associated with use of DECT.

Effectiveness of automated quantification of pulmonary perfused blood volume using dual-energy CTPA for the severity assessment of acute pulmonary embolism.

PURPOSE: The purpose of this study was to determine whether automated quantification of pulmonary perfused blood volume (PBV) in dual-energy computed tomography pulmonary angiography is of diagnostic value in assessing the severity of acute pulmonary embolism (PE). MATERIALS AND METHODS: Ethical approval and informed consent were waived by the responsible institutional review board for this retrospective study. Of 224 consecutive patients with dual-energy computed tomography pulmonary angiographic findings positive for acute PE, we excluded 153 patients because of thoracic comorbidities (n = 130), missing data (n = 11), severe artifacts (n = 11), or inadequate enhancement (n = 1). Automated quantification of PBV was performed in the remaining 71 patients (mean [SD] age, 62 [16] years) with acute PE and no cardiopulmonary comorbidities. Perfused blood volume values adjusted for age and sex were correlated with the Qanadli obstruction score, morphological computed tomographic signs of right heart dysfunction, serum levels of troponin, and the necessity for intensive care unit (ICU) admission. RESULTS: Dual-energy computed tomography pulmonary angiography-derived PBV values inversely correlated with the Qanadli score (r = -0.46; P < 0.001), the right and left ventricle (RV/LV) ratio (r = -0.52; P < 0.001), and troponin I (r = -0.45; P = 0.001). The patients with global PBV values lower than 60% were significantly more likely to require admission to an ICU than did the patients with global pulmonary PBV of 60% or higher (47% vs 11%; P = 0.003; positive predictive value, 47%; negative predictive value, 89%). On the univariate analysis, a significant negative correlation was found between the global PBV values and the Qanadli obstruction score (r = -0.46; P < 0.001), the RV/LV diameter ratio (r = -0.52; P < 0.001), and the necessity for ICU admission (r = -0.39; P = 0.001). On the retrospective multivariate regression analysis, the areas under the receiver operating characteristic curve for the prediction of ICU admission were 0.75 for the pulmonary PBV, 0.83 for the Qanadli obstruction score, 0.68 for the computed tomographic signs of right heart dysfunction (interventricular septal bowing and/or contrast reflux), and 0.76 for the RV/LV diameter ratio. CONCLUSIONS: Dual-energy computed tomography pulmonary angiography can be used for an immediate, reader-independent estimation of global pulmonary PBV in acute PE, which inversely correlates with thrombus load, laboratory parameters of PE severity, and the necessity for ICU admission.

Cost-effectiveness of substituting dual-energy CT for SPECT in the assessment of myocardial perfusion for the workup of coronary artery disease.

PURPOSE: We compared cost-effectiveness and potential lifetime benefits of using dual-energy computed tomography (DECT) for myocardial perfusion assessment instead of single photon emission computed tomography (SPECT) for the workup of coronary artery disease (CAD). MATERIALS AND METHODS: A decision and simulation model was developed to estimate cost and health effects of using DECT myocardial perfusion imaging instead of SPECT for identifying patients in need of invasive imaging and possible revascularization. The model was based on the performance indices of stress/rest DECT compared with stress/rest SPECT for detecting myocardial perfusion deficits in 50 patients (mean age 61±10 years) with CAD. Stress/rest perfusion and delayed enhancement cardiac MRI served as reference standard. For DECT a reimbursement of US$1700 was assumed but costs of cardiac MRI were not included in the model. All other actual healthcare costs in these patients were derived from MUSC's hospital billing system. RESULTS: Compared with cardiac MRI, DECT (versus SPECT) had 90% (85%) sensitivity and 71% (58%) specificity for identifying patients with obstructive CAD. Compared with the no imaging and no treatment strategy, routine SPECT gained 13.49 quality-adjusted life-years (QALYs) with an incremental cost-effectiveness ratio (ICER) of US$3557 (in 2010) per QALY. In comparison, DECT ICER was lower (US$3.191 per QALY, p=0.0002) and an additional 0.64 QALYs was obtained (total of 14.13 QALYs) if compared with the SPECT strategy as well as the no imaging and no treatment strategy. CONCLUSION: Using DECT as the first-line imaging test for myocardial perfusion for the workup of patients with CAD has the potential to provide gains in QALYs, while lowering costs if compared to routine myocardial perfusion SPECT.