Myocardial Delayed Enhancement CT for the Evaluation of Heart Failure: Comparison to MRI.

Purpose To assess the diagnostic performance of dual-energy CT with myocardial delayed enhancement (MDE) in the detection and classification of myocardial scar in patients with heart failure, with late gadolinium enhancement (LGE) MRI as the standard of reference. Materials and Methods MDE CT and LGE MRI were performed in 44 patients with heart failure (30 men; mean patient age, 66 years ± 14) between 2013 and 2016, and images were retrospectively analyzed. The presence and patterns of MDE on iodine-density and virtual monochromatic (VM) images were assessed by two independent readers. Contrast-to-noise ratio (CNR) and percentage signal intensity increase relative to normal myocardium were measured. Diagnostic performance and area under the receiver operating characteristic curve for MDE CT and kappa values for reader agreement were determined. Results Thirty-five of the 44 patients (80%) demonstrated a focal area of LGE, with a nonischemic pattern in 22 of the 44 patients (50%) and an ischemic pattern in 13 (30%). Iodine-density images demonstrated the highest CNR and percentage signal intensity increase on CT images (P < .05), resulting in the highest diagnostic performance in the detection of any MDE CT abnormality (92% sensitivity [195 of 213 segments] and 98% specificity [481 of 491 segments]). The areas under the receiver operating characteristic curve for iodine-density images and 40-keV VM images in the detection of MDE were 0.97 and 0.95, respectively (P < .001). Kappa values for reader agreement were 0.82 for iodine-density images and 0.72 for 40-keV VM images. Conclusion Myocardial delayed enhancement CT enables accurate detection and localization of scar in patients with heart failure when compared with late gadolinium enhancement MRI, the reference standard.

Measurement of Myocardial Extracellular Volume Fraction From Iodine Density Images Using Single-Source, Dual-Energy Computed Tomography: A Feasibility Study.

OBJECTIVE: The aims of this study were to develop and validate an iodine density method for the quantification of myocardial extracellular volume (ECV) fraction using single-source, dual-energy computed tomography. METHODS: Extracellular volume measurements were carried out in 40 subjects (20 patients with heart failure, 20 control subjects) using single-source, dual-energy computed tomography. Subtraction-derived ECVs (subECVs) were computed by subtracting precontrast from delayed images. Iodine density-derived ECVs (iECVs) were calculated from iodine density images obtained from delayed images. Iodine density-derived ECVs were compared with reference subECVs. RESULTS: A strong correlation (r = 0.896, P < 0.0001) and a small bias (-0.06%) were determined between subECV and iECV with high interobserver concordances (0.915 and 0.906, respectively). Extracellular volume measurements in patients with heart failure were higher in both subECV and iECV compared with control subjects (34.6% [SD, 5.0%] vs 29.5% [SD, 3.6%], P = 0.001, for subECV; 34.9% [SD, 4.5%] vs 29.2% [SD, 2.6%], P < 0.0001, for iECV). CONCLUSIONS: Extracellular volume analysis using iodine density is a useful tool for the noninvasive quantification of ECV in myocardial diseases.

[A case of organizing pneumonia with a reversed halo sign following postoperative irradiation for breast cancer].

A 69-year-old woman received radiation therapy of 50 Gy following surgery for left breast cancer. Eleven months later, chest computed tomography revealed infiltrative shadows with air bronchograms in both lower lung fields and a reversed halo sign in the right lower lobe. Transbronchial lung biopsy revealed polypoid granulation tissue in the terminal air spaces, which was consistent with organizing pneumonia (OP). Prednisolone therapy resolved the radiographic abnormalities. The reversed halo sign was believed to be specific to cryptogenic organizing pneumonia. We reported a case of OP with a reversed halo sign following postoperative irradiation for breast cancer.

Small cell lung cancer complicated by pulmonary sarcoidosis.

In July 2009, a 69-year-old man was admitted to our hospital because an abnormal chest shadow had been noted on medical examination. Chest radiography and computed tomography showed mediastinal and bilateral hilar lymphadenopathy. Bronchoalveolar lavage fluid (BALF) from the right B(5) revealed an increased CD4/CD8 ratio. Histological examination of the biopsy specimens obtained from the tumor in the left upper bronchus revealed small cell lung cancer, whereas examination of the specimens obtained from the left B(3) revealed noncaseating epithelioid cell granulomas containing giant cells, confirming the diagnosis of sarcoidosis. The patient underwent chemotherapy with carboplatin and etoposide without any steroids. After 4 courses of chemotherapy, bronchoscopic examination revealed that the tumor had shrunk, and the BALF CD4/CD8 ratio had decreased; further, no histological evidence of sarcoidosis was seen in specimens obtained from the left B(3). Concomitant small cell lung cancer and sarcoidosis is rare. Interestingly, cancer chemotherapy might improve pulmonary sarcoidosis.