Reversibility of the Enlargement of the Pulmonary Artery in COVID-19 Pneumonia as a Marker of Remission of the Disease.

Coronavirus disease 2019 (COVID-19) pneumonia is associated with extensive pulmonary microangiopathy and the enlargement of the pulmonary artery (PA), while its progression after the remission of the disease has not been investigated yet. The aim was to assess the diametral increase in the PA in COVID-19 pneumonia, as revealed on chest computed tomography (CT), and further investigate its progression. This was a retrospective cohort study of patients with COVID-19 pneumonia, without prior history of pulmonary hypertension, who underwent CT pulmonary angiography before, during, and after the infection. Pulmonary embolism was excluded in all cases. The main PA diameter (MPAD) was assessed in consecutive chest imaging. Statistical analysis was performed with the non-parametric Wilcoxon and Kruskal-Wallis tests, while correlations were performed with the non-parametric Spearman test. A mean ± SD MPAD of 3.1 ± 0.3 cm in COVID-19 pneumonia was significantly decreased to 2.8 ± 0.3 cm in the post-infectious state after 2-18 months in 31 patients (p-value: <0.0001). In a subgroup of six patients with more than one post-COVID-19 CT, a significant further decline in the diameter was observed (p-value: 0.0313). On the other hand, in accordance with the literature, a significant increase in the MPAD during COVID-19 pneumonia was noted in a group of 10 patients with a pre-COVID-19 CT (p-value: 0.0371). The enlargement of the PA is a common finding in COVID-19 pneumonia that regresses after the remission of the disease, indicating that this reversible cardiovascular event is a potential marker of disease activity, while its course in long COVID is yet to be determined.

Assessment of myocardial salvage in patients with STEMI undergoing thrombolysis: ticagrelor versus clopidogrel.

BACKGROUND: In the setting of ST-segment elevation myocardial infarction (STEMI), the faster and stronger antiplatelet action of ticagrelor compared to clopidogrel, as well as its pleiotropic effects, could result in a greater degree of cardioprotection and final infarct size (FIS) limitation. The aim of our study was to comparatively evaluate the effect of ticagrelor and clopidogrel on myocardial salvage index (MSI) in STEMI patients undergoing thrombolysis. METHODS: Forty-two STEMI patients treated with thrombolysis were randomized to receive clopidogrel (n = 21) or ticagrelor (n = 21), along with aspirin. Myocardial area at risk (AAR) was calculated according to the BARI and the APPROACH jeopardy scores. FIS was quantified by cardiac magnetic resonance imaging (CMR) performed 5-6 months post-randomization. MSI was calculated as (AAR-FIS)/AAR × 100%. Primary endpoint of our study was MSI. Secondary endpoints were FIS and CMR-derived left ventricular ejection fraction (LVEF) at 5 -6 months post-randomization. RESULTS: By using the BARI score for AAR calculation, mean MSI was 52.25 ± 30.5 for the clopidogrel group and 54.29 ± 31.08 for the ticagrelor group (p = 0.83), while mean MSI using the APPROACH score was calculated at 51.94 ± 30 and 53.09 ± 32.39 (p = 0.9), respectively. Median CMR-derived FIS-as a percentage of LV-was 10.7% ± 8.25 in the clopidogrel group and 12.09% ± 8.72 in the ticagrelor group (p = 0.6). Mean LVEF at 5-6 months post-randomization did not differ significantly between randomization groups. CONCLUSIONS: Our results suggest that the administration of ticagrelor in STEMI patients undergoing thrombolysis offer a similar degree of myocardial salvage, compared to clopidogrel.

Deformation and distensibility distribution along the abdominal aorta in the presence of aneurysmal dilatation.

BACKGROUND: In order to evaluate the elastic behavior of the abdominal aortic aneurysm (AAA), the distribution of aortic deformation during the cardiac cycle is measured. Moreover, the distensibility of the AAA composite structure consisting of the AAA wall and the intraluminal thrombus (ILT), as well as that of the adjacent non-aneurysmal aortic segment (NAA), are calculated. METHODS: Ten patients underwent electrocardiographically-gated computed tomography. 3D-surfaces of aortic wall and lumen were reconstructed during peak-systole and end-diastole and cross-sections perpendicular to the centerline were extracted 1 mm apart. Comparison of cross-sectional areas between peak-systole and end-diastole provided the relative area change (RAC). Mean values were calculated for NAA (RACNAA), aneurysmal wall (RACWall), and aneurysmal lumen (RACLumen). Distensibility of aneurysmal and unaffected aorta was calculated using brachial blood pressure measurements (DAAA and DNAA respectively). Normalized distensibility (DNORM) of the AAA was calculated with respect to normal aortic segment distensibility and related to aneurysm size and thrombus content. RESULTS: A map of aortic deformation during the cardiac cycle was obtained. Differences between RACWall (median=0.7%, range=0.3-2.1%) and both RACNAA (median=2.8%, range=0.9-4.8%) and RACLumen (median=1.8%, range=0.5-3.4%) were statistically significant. DAAA (median=0.30∙10-5 Pa-1, range=0.05-0.64∙10-5 Pa-1) was lower than DNAA (median=0.43∙10-5 Pa-1, range=0.16-0.83∙10-5 Pa-1) but difference was not statistically significant. Median DNORM was 0.73 (range=0.1-3.1) and presented a significant positive correlation with AAA size and thrombus content. CONCLUSIONS: Aneurysmal wall deforms significantly less than non-aneurysmal wall and aneurysmal lumen, due to altered elastic properties and reduced loading. In large AAAs with larger amounts of ILT, the lumen deformation is comparable or even exceeds that of NAA and subsequently so does the distensibility of the Wall-ILT composite, an observation suggesting a thrombus cushioning effect. DNORM may provide insight in the estimation of AAA evolution and assist in rupture risk assessment.

Estimation of wall properties and wall strength of aortic aneurysms using modern imaging techniques. One more step towards a patient-specific assessment of aneurysm rupture risk.

Abdominal aortic aneurysmal disease is a major health problem with rupture representing its main complication accompanied by great mortality. Elective repair is currently performed with mortality rates <3%, based upon size or expansion rate, with a recommended threshold of 5.5 cm maximum diameter or >1cm/year enlargement. It is well established that even small AAAs without indication for surgical repair can experience rupture with catastrophic outcomes whereas larger aneurysms often remain intact for a long period. It is recognized, therefore, that the currently used, maximum diameter criterion can not accurately predict AAAs evolution. There is increasing interest in the role of patient-specific biomechanical profiling of AAA development and rupture. Biomechanically, rupture of a vessel occurs when intravascular forces exceed vessel wall structural endurance. Peak Wall Stress (PWS) has been previously shown to better identify AAAs prone to rupture than maximum diameter, but currently stress analysis takes into account several assumptions that influence results to a large extent and limit their use. Moreover stress represents only one of two determinants of rupture risk according to the biomechanical perspective. Wall strength and mechanical properties on the other hand cannot be assessed in vivo but only ex vivo through mechanical studies with mean values of these parameters taken into account for rupture risk estimations. New possibilities in the field of aortic imaging offer promising tools for the validation and advancement of stress analysis and the in vivo evaluation of AAAs' wall properties and wall strength. Documentation of aortic wall motion during cardiac cycle is now feasible through ECG-gated multi-detector CT imaging offering new possibilities towards an individualized method for rupture risk and expansion-rate predictions based on data acquired in vivo.

Right ventricular volumes and ejection fraction by MR imaging and stereology: comparison with standard image analysis method.

The purpose of this study was to examine the accuracy of the stereological method for estimating right ventricular parameters on cine MR images. The end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) were estimated in 19 consecutive patients with suspected or known coronary artery disease employing the stereological point counting method. Stereological measurements were performed with different grids of test points. The RV parameters were also derived by the standard method based on the manual adjustment of automatically obtained endocardial contours. The statistical difference and agreement between the two methods was found. Measurement reproducibility of both methods was determined. The counting of about 100 test points on all MR images provided EDV and ESV with a mean coefficient of error of 7.0 ± 1.3% and 7.4 ± 2.1%, respectively. The volume estimation precision was not significantly improved by counting more points (EDV: P = 0.058; ESV:P = 0.333). Stereological estimations were not significantly different from those by the standard method (EDV: P = 0.093; ESV: P = 0.072; SV: P = 0.291; EF: P = 0.300). The 95% limits of agreement between the two methods were clinically acceptable (EDV: -12.1 cm(3) , 18.9 cm(3) ; ESV: -6.4 cm(3) , 10.4 cm(3) ; SV: -10.5 cm(3) , 13.5 cm(3) ; EF: -7.5%, 6.3%). The repeatability of stereological estimations was better than that of the standard method (coefficient of variability: 3.4-5.3% versus 4.0-7.1%). The measurement time with stereolgy was less than 4 min. The stereological method may be considered as an improvement over the standard method due to its accuracy and repeatability.

Myocardial and liver iron status using a fast T*2 quantitative MRI (T*2qMRI) technique.

This work demonstrates the use of a fast and precise methodology for evaluating myocardial and liver iron status in multitransfused thalassemic patients by means of a fast T(2) (*) quantitative MRI (T(2) (*)qMRI) technique. Myocardial and liver T(2) (*) values were calculated in 48 thalassemic patients and 21 normal subjects on a 1.5T MRI system using a breath-hold 2D single-slice multiecho gradient-echo (MEGRE) sequence (16 echoes, TR/TE1/TE16/FA = 160/2.7/37.65 ms/25 degrees ). No ECG gating was used. Myocardial T(2) (*), liver T(2) (*), and myocardial to muscle (CR/MS) and liver to muscle (LV/MS) T(2) (*) ratios were correlated with serum ferritin concentration (SFC) levels for all patients. Significant differences in myocardial and liver mean T(2) (*), CR/MS, and LV/MS T(2) (*) values between patients and normal subjects were found (P < 0.0005). Differences in paraspinous muscle mean T(2) (*) values between patients and normal subjects were not significant. Myocardial T(2) (*) and CR/MS T(2) (*) values were not correlated with SFC levels. Liver T(2) (*) and LV/MS T(2) (*) values were significantly correlated with SFC (r = 0.540, P < 0.0005). Myocardial T(2) (*) and CR/MS T(2) (*) values were not correlated with either liver T(2) (*) or LV/MS T(2) (*) values, respectively. We conclude that myocardial and liver iron deposition can be evaluated using the fast non-ECG-gated T(2) (*)qMRI technique.

Proliferative myositis: value of imaging.

Imaging findings in a 52-year-old woman with proven proliferative myositis are described. US revealed preservation of continuous muscle bundles and patchy areas of hyperechogenicity, containing hypoechoic lines. MRI showed at T2-w sequences an ill-defined, hyperintense, intramuscular lesion, containing isointense lines. Subtotal enhancement, a nonenhancing geometrical web, and fascial enhancement were noted. In patients with painful growing masses, US and MRI correlation may suggest the diagnosis of proliferative myositis leading to biopsy, thus avoiding mutilating surgery.