Ernesto Forte

Coronary artery aneurysms detected by computed tomography coronary angiography

Aims Coronary artery aneurysms (CAAs) are incidentally revealed by coronary angiography and consist in a localized dilation of a coronary artery. Although invasive coronary angiography (ICA) is the gold standard imaging technique, it can lead to the underestimation of CAAs diameter in presence of parietal thrombi. Computed tomography coronary angiography (CTCA) is a very sensitive tool in CAAs detection and provides a clear visualization of coronary lumen highlighting intraluminal thrombi. Methods and results We retrospectively reviewed 390 CTCA performed at our institution, 9 patients (6 men, 3 women) resulted affected by CAAs and represented the aneurysmal group (A group). Matched controls were identified among the non-aneurysmal patients with healthy coronaries to CTCA (NAH group). Clinical variables and imaging findings were compared and correlated. CAAs prevalence in our population was 2.31%. 15 CAAs were detected, mainly on the right coronary artery (RCA) (9 aneurysms) followed by the left anterior descending coronary artery (LAD) (three aneurysms) and the left circumflex coronary artery (CX) (three aneurysms). In six patients (66.7%) CTCA displayed an aneurysmal thrombosis and in 5 patients (55.5%) CAAs were associated to coronary artery stenoses. A statistically significant difference was found between the diameters of coronary vessels measured in healthy segments in A and NAH group. Conclusions CTCA has led to a non-invasive estimation of CAAs prevalence and characterization of aneurysmal features and coronary anatomy. Overcoming ICA limitations, CTCA has provided a fine analysis of the aneurysms, also in presence of intraluminal thrombi.

Anomalous left main coronary artery detected by CT angiography.

The growing improvements of computed tomography have made this technique more and more available for cardiac evaluation. Coronary artery anomalies (CAAs) are often incidental findings in subjects with suspected coronary artery disease (CAD) undergoing coronary angiography or computed tomography coronary angiography (CTCA). In some cases, CAAs can be clinically relevant so their identification could change radically patient management and treatment. We report the case of a 68-year-old male patient with known CAD and associated anomalous origination of the left coronary artery from the opposite sinus.

In Vivo and In Vitro Analysis in Coronary Artery Disease Related to Type 2 Diabetes

Aim The leading cause of morbidity and mortality in patients with type 2 diabetes mellitus (DM) is coronary artery disease (CAD), a condition often asymptomatic but severe in these patients. Although glucose metabolism impairment and oxidative stress are known actors in the endothelial dysfunction/remodeling that occurs in diabetic patients, the relationship between cardiovascular disorders and DM is not fully understood. We have performed both an in vivo imaging and in vitro molecular analysis to investigate diabetic-specific CAD alterations. Methods Computed tomography coronary angiography (CTCA) was performed in a group of 20 diabetic patients with CAD (DM+CAD+), 20 non-diabetic with CAD (DM−CAD+), 10 diabetic non-CAD patients (DM+CAD−), and 20 non-diabetic healthy subjects (HS). Imaging quantitative parameters such as calcium score (Cascore), calcified plaque volume (CPV), non-calcified plaque volume (NCPV), total plaque volume (TPV), remodeling index (RI), and plaque burden were extracted for each CAD subject. Moreover, the expression levels of superoxide dismutase 2 (SOD2) and liver X receptor alpha (LXRα) genes were analyzed in the peripheral blood mononuclear cells, whereas hyaluronan (HA) concentrations were evaluated in the plasma of each subject. Results Imaging parameters, such as Cascore, CPV, RI, and plaque burden, were significantly higher in DM+CAD+ group, compared to DM−CAD+ (P = 0.019; P = 0.014; P < 0.001, P < 0.001, respectively). SOD2 mRNA was downregulated, while LXRα gene expression was upregulated in DM+CAD−, DM+CAD+, and DM−CAD+ groups compared to HS (P = 0.001, P = 0.03, and P = 0.001 for SOD2 and P = 0.006, P = 0.008, and P < 0.001 for LXRα, respectively). Plasmatic levels of HA were higher in DM−CAD+, DM+CAD−, and DM+CAD+ groups, compared to HS (P = 0.001 for the three groups). When compared to DM−CAD+, HA concentration was higher in DM+CAD− (P = 0.008) and DM+CAD+ (P < 0.001) with a significant difference between the two diabetic groups (P = 0.003). Moreover, HA showed a significant association with diabetes (P = 0.01) in the study population, and the correlation between HA levels and glycemia was statistically significant (ρ = 0.73, P < 0.001). Conclusion In our population, imaging parameters highlight a greater severity of CAD in diabetic patients. Among molecular parameters, HA is modulated by diabetic CAD-related alterations while SOD2 and LXRα are found to be more associated with CAD but do not discriminate between diabetic and non-diabetic subgroups.

Triaxial fiber optic magnetic field sensor for MRI applications

In this paper, we report a fiber-optic triaxial magnetic field sensor, based on Fiber Bragg Gratings (FBGs) integrated with giant magnetostrictive material, the Terfenol-D. The realized sensor has been designed and engineered for Magnetic Resonance Imaging (MRI) applications. A full magneto-optical characterization of the triaxial sensing probe has been carried out, providing the complex relationship among the FBGs wavelength shift and the applied magnetostatic field vector. Finally, the developed fiber optic sensors have been arranged in a sensor network composed of 20 triaxial sensors for mapping the magnetic field distribution in a MRI-room at a diagnostic center in Naples (SDN), equipped with Positron emission tomography/magnetic resonance (PET/MR) instrumentation. Experimental results reveal that the proposed sensor network can be efficiently used in MRI centers for performing quality assurance tests, paving the way for novel integrated tools to measure the magnetic dose accumulated day by day by MRI operators.

A case of coronary arterio-venous fistula: the role of cardiac computed tomography

Coronary artery fistulas (CAFs) are often incidental findings in patients undergoing conventional coronary angiography (CAG). CAFs represent a congenital or acquired abnormal vascular communication of coronary arteries with cardiac chambers or any segment of the systemic or pulmonary circulation bypassing capillaries within myocardium (1).

Influence of image reconstruction parameters on cardiovascular risk reclassification by Computed Tomography Coronary Artery Calcium Score

OBJECTIVE To investigate the influence of different CT reconstruction parameters on coronary artery calcium scoring (CACS) values and reclassification of predicted cardiovascular (CV) risk. METHODS CACS was evaluated in 113 patients undergoing ECG-gated 64-slice CT. Reference CACS protocol included standard kernel filter (B35f) with slice thickness/increment of 3/1.5 mm, and field-of-view (FOV) of 150-180 mm. Influence of different image reconstruction algorithms (reconstructed slice thickness/increment 2.0/1.0-1.5/0.8-3.0/2.0-3.0/3.0 mm; slice kernel B30f-B45f; FOV 200-250 mm) on Agatston score was assessed by Bland-Altman plots and concordance correlation coefficient (CCC) analysis. Classification of CV risk was based on the Mayo Clinic classification. RESULTS Different CACS reconstruction parameters showed overall good accuracy and precision when compared with reference protocol. Protocols with larger FOV, thinner slices and sharper kernels were associated with significant CV risk reclassification. Use of kernel B45f showed a moderate positive correlation with reference CACS protocol (Agatston CCC = 0.67), and yielded significantly higher CACS values (p < .05). Reconstruction parameters using B30f or B45f kernels, 250 mm FOV, or slice thickness/increment of 2.0/1.0 mm or 1.5/0.8 mm, were associated with significant reclassification of CV risk (p < .05). CONCLUSIONS Kernel, FOV, slice thickness and increment are major determinants of accuracy and precision of CACS measurement. Despite high agreement and overall good correlation of different reconstruction protocols, thinner slices thickness and increment, and sharper kernels were associated with significant upward reclassification of CV risk. Larger FOV determined both upward and downward reclassification of CV risk.

Image Quality and Dose Reduction by Dual Source Computed Tomography Coronary Angiography: Protocol Comparison:

Purpose: To compare image quality and radiation dose among different protocols in patients who underwent a 128-slice dual source computed tomography coronary angiography (DSCT-CTCA). Methods: Ninety patients were retrospectively grouped according to heart rate (HR): 26 patients (group A) with stable HR ≤60 bpm were acquired using high pitch spiral mode (FLASH); 48 patients (group B) with irregular HR ≤60 bpm or stable HR between 60 and 70 bpm using step and shoot mode; and 16 patients (group C) with irregular HR >60 bpm or stable HR ≥70 bpm by retrospective electrocardiogram pulsing acquisition. Signal to noise ratio (SNR) and contrast to noise ratio (CNR) were measured for the main vascular structures. Moreover, the dose-length product and the effective dose were assessed. Results: Both SNR and CNR were higher in group A compared to group C (18.27 ± 0.32 vs 11.22 ± 0.50 and 16.75 ± 0.32 vs 10.17 ± 0.50; P = .001). The effective dose was lower in groups A and B (2.09 ± 1.27 mSv and 4.60 ± 2.78 mSv, respectively) compared to group C (9.61 ± 5.95 mSv) P < .0001. Conclusion: The correct selection of a low-dose, HR-matched CTCA scan protocol with a DSCT scanner provides substantial reduction of radiation exposure and better SNR and CNR.

Triaxial Fiber Optic Magnetic Field Sensor for Magnetic Resonance Imaging

We present a fiber optic magnetic field sensor conceived for magnetic resonance imaging (MRI) applications. The sensor is based on the integration of fiber optic strain sensors (fiber Bragg gratings—FBGs) with a sensing material (Terfenol-D). The response of an FBG integrated with a block of Terfenol-D was preliminarily investigated by taking into account the dependence of the Terfenol-D magnetostrictive response on both the longitudinal and transversal magnetic fields, with different preloads. Based on the performed characterizations, a triaxial magnetic field sensor was designed, characterized, and fabricated. An algorithm enabling the demodulation of the magnetic field from the readout of the three FBGs was also implemented, by taking into account the interdependence among the different sensor responses. Experimental results demonstrate the ability of the triaxial sensor to measure the magnetic field. Performance assessment and critical analysis are reported as well, elucidating both the abilities and limitations of the implemented sensing configuration. Finally, as proof of principle, a sensing system constituted of 20 triaxial sensors has been fabricated and used to map the magnetic field strength distribution in an MRI diagnostic centre.

A Case Report of a Mediastinal Fistula with Liver Abscesses as a Complication of Aortic Valve Replacement Surgery

We report a case of mediastinal fistula with liver abscesses detected by thoracic and abdominal computed tomography as a complication of aortic valve replacement surgery.