Early prediction of severity in coronavirus disease (COVID-19) using quantitative CT imaging.

PURPOSE: To evaluate whether the extent of COVID-19 pneumonia on CT scans using quantitative CT imaging obtained early in the illness can predict its future severity. METHODS: We conducted a retrospective single-center study on confirmed COVID-19 patients between January 18, 2020 and March 5, 2020. A quantitative AI algorithm was used to evaluate each patient's CT scan to determine the proportion of the lungs with pneumonia (VR) and the rate of change (RAR) in VR from scan to scan. Patients were classified as being in the severe or non-severe group based on their final symptoms. Penalized B-splines regression modeling was used to examine the relationship between mean VR and days from onset of symptoms in the two groups, with 95% and 99% confidence intervals. RESULTS: Median VR max was 18.6% (IQR 9.1-32.7%) in 21 patients in the severe group, significantly higher (P < 0.0001) than in the 53 patients in non-severe group (1.8% (IQR 0.4-5.7%)). RAR was increasing with a median RAR of 2.1% (IQR 0.4-5.5%) in severe and 0.4% (IQR 0.1-0.9%) in non-severe group, which was significantly different (P < 0.0001). Penalized B-spline analyses showed positive relationships between VR and days from onset of symptom. The 95% confidence limits of the predicted means for the two groups diverged 5 days after the onset of initial symptoms with a threshold of 11.9%. CONCLUSION: Five days after the initial onset of symptoms, CT could predict the patients who later developed severe symptoms with 95% confidence.

Cardiac T1 and T2 Mapping Showed Myocardial Involvement in Recovered COVID-19 Patients Initially Considered Devoid of Cardiac Damage.

BACKGROUND: Myocardial injury has been found using magnetic resonance imaging in recovered coronavirus disease 2019 (COVID-19) patients unselected or with ongoing cardiac symptoms. PURPOSE: To evaluate for the presence of myocardial involvement in recovered COVID-19 patients without cardiovascular symptoms and abnormal serologic markers during hospitalization. STUDY TYPE: Prospective. POPULATION: Twenty-one recovered COVID-19 patients and 20 healthy controls (HC). FIELD STRENGTH/SEQUENCE: 3.0 T, cine, T2-weighted imaging, T1 mapping, and T2 mapping. ASSESSMENT: Cardiac ventricular function includes end-diastolic volume, end-systolic volume, stroke volume, cardiac output, left ventricle (LV) mass, and ejection fraction (EF) of LV and right ventricle (RV), and segmental myocardial T1 and T2 values were measured. STATISTICAL TESTS: Student's t-test, univariate general linear model test, and chi-square test were used for analyses between two groups. Ordinary one-way analyses of variance or Kruskal-Wallis H test were used for analyses between three groups, followed by post-hoc analyses. RESULTS: Fifteen (71.43%) COVID-19 patients had abnormal magnetic resonance findings, including raised myocardial native T1 (5, 23.81%) and T2 values (10, 47.62%), decreased LVEF (1, 4.76%), and RVEF (2, 9.52%). The segmental myocardial T2 value of COVID-19 patients (49.20 [46.1, 54.6] msec) was significantly higher than HC (48.3 [45.2, 51.7] msec) (P < 0.001), while the myocardial native T1 value showed no significant difference between COVID-19 patients and HC. The myocardial T2 value of serious COVID-19 patients (52.5 [48.1, 57.1] msec) was significantly higher than unserious COVID-19 patients (48.8 [45.9, 53.8] msec) and HC (48.3 [45.2, 51.7]) (P < 0.001). COVID-19 patients with abnormally elevated D-dimer, C-reactive protein, or lymphopenia showed higher myocardial T2 values than without (all P < 0.05). DATA CONCLUSION: Cardiac involvement was observed in recovered COVID-19 patients with no preexisting cardiovascular disease, no cardiovascular symptoms, and elevated serologic markers of myocardial injury during the whole course of COVID-19. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 5.

CT image visual quantitative evaluation and clinical classification of coronavirus disease (COVID-19).

OBJECTIVES: To explore the relationship between the imaging manifestations and clinical classification of COVID-19. METHODS: We conducted a retrospective single-center study on patients with COVID-19 from Jan. 18, 2020 to Feb. 7, 2020 in Zhuhai, China. Patients were divided into 3 types based on Chinese guideline: mild (patients with minimal symptoms and negative CT findings), common, and severe-critical (patients with positive CT findings and different extent of clinical manifestations). CT visual quantitative evaluation was based on summing up the acute lung inflammatory lesions involving each lobe, which was scored as 0 (0%), 1 (1-25%), 2 (26-50%), 3 (51-75%), or 4 (76-100%), respectively. The total severity score (TSS) was reached by summing the five lobe scores. The consistency of two observers was evaluated. The TSS was compared with the clinical classification. ROC was used to test the diagnosis ability of TSS for severe-critical type. RESULTS: This study included 78 patients, 38 males and 40 females. There were 24 mild (30.8%), 46 common (59.0%), and 8 severe-critical (10.2%) cases, respectively. The median TSS of severe-critical-type group was significantly higher than common type (p < 0.001). The ICC value of the two observers was 0.976 (95% CI 0.962-0.985). ROC analysis showed the area under the curve (AUC) of TSS for diagnosing severe-critical type was 0.918. The TSS cutoff of 7.5 had 82.6% sensitivity and 100% specificity. CONCLUSIONS: The proportion of clinical mild-type patients with COVID-19 was relatively high; CT was not suitable for independent screening tool. The CT visual quantitative analysis has high consistency and can reflect the clinical classification of COVID-19. KEY POINTS: • CT visual quantitative evaluation has high consistency (ICC value of 0.976) among the observers. The median TSS of severe-critical type group was significantly higher than common type (p < 0.001). • ROC analysis showed the area under the curve (AUC) of TSS for diagnosing severe-critical type was 0.918 (95% CI 0.843-0.994). The TSS cutoff of 7.5 had 82.6% sensitivity and 100% specificity. • The proportion of confirmed COVID-19 patients with normal chest CT was relatively high (30.8%); CT was not a suitable screening modality.

Effect of a Novel Intracycle Motion Correction Algorithm on Dual-Energy Spectral Coronary CT Angiography: A Study with Pulsating Coronary Artery Phantom at High Heart Rates.

OBJECTIVE: Using a pulsating coronary artery phantom at high heart rate settings, we investigated the efficacy of a motion correction algorithm (MCA) to improve the image quality in dual-energy spectral coronary CT angiography (CCTA). MATERIALS AND METHODS: Coronary flow phantoms were scanned at heart rates of 60-100 beats/min at 10-beats/min increments, using dual-energy spectral CT mode. Virtual monochromatic images were reconstructed from 50 to 90 keV at 10-keV increments. Two blinded observers assessed image quality using a 4-point Likert Scale (1 = non-diagnostic, 4 = excellent) and the fraction of interpretable segments using MCA versus conventional algorithm (CA). Comparison of variables was performed with the Wilcoxon rank sum test and McNemar test. RESULTS: At heart rates of 70, 80, 90, and 100 beats/min, images with MCA were rated as higher image scores compared to those with CA on monochromatic levels of 50, 60, and 70 keV (each p < 0.05). Meanwhile, at a heart rate of 90 beats/min, image interpretability was improved by MCA at a monochromatic level of 60 keV (p < 0.05) and 70 keV (p < 0.05). At a heart rate of 100 beats/min, image interpretability was improved by MCA at monochromatic levels of 50 keV (from 69.4% to 86.1%, p < 0.05), 60 keV (from 55.6% to 83.3%, p < 0.05) and 70 keV (from 33.3% to 69.3%, p < 0.05). CONCLUSION: Low-keV monochromatic images combined with MCA improves image quality and image interpretability in CCTAs at high heart rates.

Improving Patient to Patient CT Value Uniformity with an Individualized Contrast Medium Protocol Tailored to Body Weight and Contrast Medium Concentration in Coronary CT Angiography.

To determine whether body weight and concentration dependent contrast medium (CM) injection protocols can improve patient to patient CT value uniformity more than the conventional injection protocols with fixed injection parameters in coronary CT angiography (CCTA), one hundred and sixty patients who underwent CCTA were prospectively randomized into two groups. Group A (n = 80) used individualized-protocol with adjusted injection rate based on patient weight and contrast medium concentration to obtain constant iodine load of 280 mgI/kg while group B (n = 80) followed the conventional contrast injection protocol with total injection volume of 80ml and constant injection rate of 5.5ml/s. For both groups, patients were further divided into four subgroups with different CM concentrations: A1, B1 (300 mg I/ml); A2, B2 (320 mg I/ml); A3, B3 (350 mg I/ml) and A4 and B4 (370 mg I/ml). For each patient, the CT values of the ascending aorta, left ventricle and coronary arteries were measured. One-way analysis of variance was used to compare CT values among subgroups. Among the subgroups of A, sufficient attenuation of greater than 300HU was obtained in all target vessels with no difference among them. Among the subgroups of B, the CT values had significant difference in left ventricle, left circumflex branch, proximal and distal segment of the right coronary artery (all p < 0.05), and the attenuation with 300 mg I/ml CM concentration was significantly lower than that with 370 mg I/ml. Compared with group B, group A used less volume (62.83 ml vs. 80.00 ml, P<0.001) and lower rate (5.21 ml/s vs. 5.50 ml/s, P<0.001) of CM. Compared with the conventional contrast medium injection protocol with fixed volume and injection rate, the individualized-protocol based on patient weight and contrast concentration provides overall contrast dose reduction and achieves more homogenous attenuation among different coronary vessels and patients.

Comparison of congenital coronary artery anomalies between Uyghur and Han: a multi-slice computed tomography study in Xinjiang, China.

BACKGROUND: The incidence of congenital coronary artery anomalies (CCAAs) is different between ethnic groups, but there is no report about Uyghur CCAAs because of the limitation of inspection methods. This study determined the prevalence of Uyghur CCAAs and analysis the difference of CCAAs between Uyghur and Han ethnic groups by the method of multi-slice computed tomography coronary angiography (MSCTCA). METHODS: Seven thousand four hundred and sixty-nine MSCTCA were analyzed for the CCAAs retroactively, 1934 were Uyghur patients while 4746 were Han patients. All the coronary artery images dates obtained by MSCTCA were evaluated for the CCAAs by two doctors. RESULTS: Nineteen kinds of CCAAs were found: (1) The overall incidence of CCAAs was 2.72% (203/7469) among all patients, 2.34% (111/4746) among Han patients whereas a significant higher 3.93% (76/1934) among Uyghur patients (χ2 = 12.780,P < 0.05); (2) the incidence of CCAAs among male patients was 2.48% (76/3069) in Han while 4.33% (56/1293) in Uyghur (χ2 = 10.663, P < 0.05); (3) the incidence of CCAAs on the left side was 1.07% (51/4746) among Han patients while 2.17% (42/934) among Uyghur patients (χ2 = 12.047, P < 0.05); (4) among these 19 kinds of CCAAs, there were significant differences of the incidence of the following kinds of CCAAs between Uyghur and Han: Left coronary artery (LCA) high location (χ2 = 8.320, P = 0.004), right coronary artery (RCA) originate from left coronary sinus (χ2 = 5.450, P = 0.020), and RCA originate from left Coronary sinus + LCA high location (P = 0.024). CONCLUSIONS: There exists some difference in CCAAs between Uyghur and Han ethnic groups. The CCAAs incidence of Uyghur is higher than that of Han, especially in male patients and on the left side; among all kinds of CCAAs, the incidence of LCA high location, RCA originate from left coronary sinus, RCA originate from left coronary sinus + LCA high locations of Uyghur is higher than Han.

Multidetector CT and MR imaging cardiac hydatidosis: case report and review of the literature.

Cardiac hydatid cysts are uncommon but potentially fatal. We present a case of isolated unilocular and multivesicular hydatid cysts in the heart, and provide a literature review of this rare condition. A 35-year-old man presented to our cardiology unit with acute chest pain. Computed tomography showed two cystic lesions in the heart. One unilocular cyst was located close to the left atrium and compressed the pulmonary artery. The other multivesicular cyst adhered to the left ventricle and displaced the left coronary arteries. T2-weighted magnetic resonance images revealed lesions in the pericardial cavity with bright signal intensity. Dot immunogold filtration assay was performed, and positive results for anti-EgCF antibody, anti-EgP antibody and anti-EgB antibody for cystic hydatidosis were found. Cardiac hydatidosis was diagnosed because of typical imaging findings and positive serology. The patient underwent surgical excision of the cysts. Postoperatively, symptoms of the patient resolved.