Rare malignant anomalous right coronary artery incidentally detected by dual source computed tomography angiography in an adult referred for transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) is a safe treatment option for elderly patients with aortic stenosis (AS) with high or intermediate surgical risk. The anomalous origin of coronaries from a single Valsalva sinus has a higher risk of coronary obstruction during the TAVI procedure, so prior knowledge of these anatomical variants is of paramount importance as it can change the surgical strategy. In this report, we present the case of an adult patient suffering from severe aortic stenosis and incidentally diagnosed with an anomalous malignant variant of right coronary artery (RCA) by pre-procedural Computed Tomography (CT) Angiography. In TAVI planning, the use of electrocardiography (ECG) gated Dual Source CT (DSCT) enables accurate coronary and aorto-iliac vascular study, useful for detecting congenital coronary anomalies.

Cardiac Imaging in Athlete's Heart: The Role of the Radiologist.

Athlete's heart (AH) is the result of morphological and functional cardiac modifications due to long-lasting athletic training. Athletes can develop very marked structural myocardial changes, which may simulate or cover unknown cardiomyopathies. The differential diagnosis between AH and cardiomyopathy is necessary to prevent the risk of catastrophic events, such as sudden cardiac death, but it can be a challenging task. The improvement of the imaging modalities and the introduction of the new technologies in cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) can allow overcoming this challenge. Therefore, the radiologist, specialized in cardiac imaging, could have a pivotal role in the differential diagnosis between structural adaptative changes observed in the AH and pathological anomalies of cardiomyopathies. In this review, we summarize the main CMR and CCT techniques to evaluate the cardiac morphology, function, and tissue characterization, and we analyze the imaging features of the AH and the key differences with the main cardiomyopathies.

The sub-millisievert era in CTCA: the technical basis of the new radiation dose approach.

Computed tomography coronary angiography (CTCA) has become a cornerstone in the diagnostic process of the heart disease. Although the cardiac imaging with interventional procedures is responsible for approximately 40% of the cumulative effective dose in medical imaging, a relevant radiation dose reduction over the last decade was obtained, with the beginning of the sub-mSv era in CTCA. The main technical basis to obtain a radiation dose reduction in CTCA is the use of a low tube voltage, the adoption of a prospective electrocardiogram-triggering spiral protocol and the application of the tube current modulation with the iterative reconstruction technique. Nevertheless, CTCA examinations are characterized by a wide range of radiation doses between different radiology departments. Moreover, the dose exposure in CTCA is extremely important because the benefit-risk calculus in comparison with other modalities also depends on it. Finally, because anatomical evaluation not adequately predicts the hemodynamic relevance of coronary stenosis, a low radiation dose in routine CTCA would allow the greatest use of the myocardial CT perfusion, fractional flow reserve-CT, dual-energy CT and artificial intelligence, to shift focus from morphological assessment to a comprehensive morphological and functional evaluation of the stenosis. Therefore, the aim of this work is to summarize the correct use of the technical basis in order that CTCA becomes an established examination for assessment of the coronary artery disease with low radiation dose.

Third generation dual source CT with ultra-high pitch protocol for TAVI planning and coronary tree assessment: feasibility, image quality and diagnostic performance.

PURPOSE: To evaluate the feasibility, image quality (IQ) and diagnostic performance of third generation 192 × 2 dual source computer tomography (DSCT) with ultra-high pitch acquisition for trans-catheter aortic valve implantation (TAVI) planning and coronary tree assessment. METHOD: In this prospective study, 223 patients underwent to DSCT for TAVI. Coronary calcium scoring (CCS) was calculated. Attenuation values were measured at aortic levels, femoral and coronary arteries. IQ was evaluate with a 4-point scale. The CT performance, in the assessment of coronary stenosis ≥50 % and ≥70 %, was compared with invasive coronary angiography (ICA), served as reference standard. Aortic annulus (AoA) CT derived area and implanted prosthesis size were correlate with Spearman's test. RESULTS: Attenuation values >400HU were obtain in all segments. IQ median value was ≥ 3. In the assessment of stenosis ≥50 %, on a segment-based analysis, CT sensitivity, specificity, positive and negative predictive values and diagnostic accuracy were 97.6 %, 87.6 %, 64.2 %, 99.0 % and 89.6 %, on patient-based analysis were 97.8 %, 88.8 %, 68.8 %, 99.4 % and 90.6 %, respectively. In the assessment of stenosis ≥70 %, on segment-based analysis, were 88.5 %, 83.8 %, 54.7 %, 96.8 % and 84.8 %, and on patient-based analysis were 92.5 %, 85.8 %, 58.7 %, 98.1 % and 87.0 %, respectively. The CT performed better in the group with lower CCS. A direct correlation was found between AoA CT derived area and prosthesis size. CONCLUSION: DSCT, using a single prospective ECG-triggered ultra-high pitch acquisition, is feasible for TAVI planning and in the assessment of coronary stenosis. CT performed worse in patients with severe coronary calcifications.

In vivo radiation dosimetry and image quality of turbo-flash and retrospective dual-source CT coronary angiography.

PURPOSE: To compare measured radiation dose (MD), estimated radiation dose (ED) and image quality in coronary computed tomography between turbo-flash (TFP) and retrospective protocol (RP) and correlate MD with size-specific dose estimates (SSDE). MATERIALS AND METHODS: In this prospective study, we selected 68 patients (mean age, 59.2 ± 9.7 years) undergoing 192 × 2 dual-source CT (SOMATOM Force, Siemens) to rule out coronary artery disease. Thirty-one underwent TFP and 37 RP. To evaluate in vivo MD, thermoluminescent dosimeters were placed, superficially, at thyroid and heart level, left breast areola and left hemi-thorax. MD in each site, and ED parameters, such as volume CT dose index (CTDIvol), SSDE, dose length product (DLP), effective dose (E), were compared between two protocols with a t test. Image quality was compared between two protocols. Inter-observer agreement was evaluated with a kappa coefficient (k). In each protocol, MD was correlated with SSDE using a Pearson coefficient (r). RESULTS: Comparing TFP and RP, MD at thyroid (1.43 vs. 2.58 mGy; p = 0.0408), heart (3.58 vs. 28.72 mGy; p < 0.0001), left breast areola (3.00 vs. 24.21 mGy; p < 0.0001) and left hemi-thorax (2.68 vs. 24.03 mGy; p < 0.0001), CTDIvol, SSDE, DLP and E were significantly lower. Differences in image quality were not statistically significant. Inter-observer agreement was good (k = 0.796) in TFP and very good (k = 0.817) in RP. MD and SSDE excellently correlated with TFP (r = 0.9298, p < 0.0001) and RP (r = 0.9753, p < 0.0001). CONCLUSIONS: With TFP, MD, CTDIvol, SSDE, DLP and E were significantly lower, than with RP. Image quality was similar between two protocols. MD correlated excellently with SSDE in each protocol.

Third-generation dual-source dual-energy CT in pediatric congenital heart disease patients: state-of-the-art.

Cardiovascular computer tomography (CT) in pediatric congenital heart disease (CHD) patients is often challenging. This might be due to limited patient cooperation, the high heart rate, the complexity and variety of diseases and the need for radiation dose minimization. The recent developments in CT technology with the introduction of the third-generation dual-source (DS) dual-energy (DE) CT scanners well suited to respond to these challenges. DSCT is characterized by high-pitch, long anatomic coverage and a more flexible electrocardiogram-synchronized scan. DE provides additional clinical information about vascular structures, myocardial and lung perfusion and allows artifacts reduction. These advances have increased clinical indications and modified CT protocol for pediatric CHD patients. In our hospital, DSCT with DE technology has rapidly become an important imaging technique for both pre- and postoperative management of pediatric patients with CHDs. The aim of this article is to describe the state-of-the-art in DSCT protocol with DE technology in pediatric CHD patients, providing some case examples of our experience over an 18-month period.

Radiation exposure related to cardiovascular CT examination: comparison between conventional 64-MDCT and third-generation dual-source MDCT.

PURPOSE: To compare radiation exposure associated with daily practice cardiovascular (CV) examinations performed on two different multidetector computed tomography (MDCT) scanners, a conventional 64-MDCT and a third-generation dual-source (DS) MDCT. MATERIALS AND METHODS: In this retrospective study, 1458 patients who underwent CV examinations between January 2017 and August 2018 were enrolled. A single-source 64-MDCT (Lightspeed VCT, GE) scan was performed in 705 patients from January to August 2017 (207 coronary examinations and 498 vascular examinations) and 753 patients underwent third-generation 192 × 2-DSCT (Somatom FORCE, Siemens) scan from January to August 2018 (302 coronary examinations and 451 vascular examinations). Volume CT dose index (CTDIvol), dose length product (DLP), effective dose (ED), tube voltage (TV) and exposure time (ET), pitch factor (PF) were registered for each patient. Student's t test was used to compare mean values between each corresponding group of MDCT and DSCT. RESULTS: In coronary examinations with DSCT, CTDIvol was 24.4% lower (23.1 mGy vs 30.6 mGy, p < 0.0001) and DLP and ED reductions were 35.6% than with MDCT (465.0 mGy * cm vs 732.3 mGy * cm and 6.5 mSv and 10.3 mSv; vs p < 0.0001). Concerning scan parameters, kVp and ET reductions were 12.7% and 69.4%, respectively (p < 0.0001); PF increase was 73.8% (p < 0.0001). In all vascular studies, DSCT, compared with MDCT, permitted to reduce CTDIvol from 43.5 to 70.6%; DLP and ED reductions were from 50.3 to 73.1%; kVp and ET decreases were from 10.7 to 32.5% and from 26.3 to 68.7%. PF increase was from 16.7 to 58.1% (all differences with p < 0.0001). CONCLUSIONS: In daily practice, CV examinations CTDI, DLP, ED, ET and TV were lower and PF was higher with 192 × 2-DSCT compared to 64-MDCT.

Radiation dose and image quality with new protocol in lower extremity computed tomography angiography.

PURPOSE: To compare radiation dose and image quality of lower extremity computed tomography angiography (CTA) between cranio-caudal acquisition with single-source CT (SSCT) and flash caudo-cranial acquisition with dual-source CT (DSCT). MATERIALS AND METHODS: In this prospective study, 60 patients were randomly assigned to Group A (control) or Group B (experimental) to undergo lower extremity CTA for peripheral obliterative arterial disease. Group A received protocol 1 (P1) with SSCT cranio-caudal acquisition. Group B received protocol (P2) with DSCT flash caudo-cranial acquisition. Intravascular attenuation (IVA), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image noise were compared. Two radiologists assessed the image quality. Computed tomography volume dose index (CTDIvol) and dose-length product (DLP) were also compared. RESULTS: IVA with P2 was higher than with P1 (586.8 ± 140.3 vs. 496.1 ± 129.3 HU, p = 0.011), as was SNR (33.0 ± 11.3 vs. 27.4 ± 12.3; p = 0.042), CNR (30.1 ± 13.3 vs. 24.2 ± 10.3; p = 0.029) and image quality score of small arteries below the knee (3.8 ± 0.2 vs. 3.1 ± 0.2; p = 0.001). Radiation dose was significantly lower in P2 than in P1 with CTDIvol reduction of 40.9% (1.3 ± 0.1 vs. 2.2 ± 0.3 mGy; p = 0.006) and DLP reduction of 42.8% (148.7 ± 21.9 vs 260.2 ± 59.1 mGy * cm; p = 0.018). CONCLUSION: Lower extremity CTA with DSCT flash caudo-cranial acquisition allows lower radiation dose with higher IVA, SNR, CNR and better image quality for small arteries below the knee than SSCT cranio-caudal acquisition.

MRI evaluation of peripheral vascular anomalies using time-resolved imaging of contrast kinetics (TRICKS) sequence.

INTRODUCTION: We describe the use of time-resolved imaging of contrast kinetics (TRICKS) sequence in the diagnosis of Peripheral Vascular Anomalies. In case of suspected vascular malformations time-resolved MR angiography might add important information for therapeutic decisions and follow-up. OBJECTIVE: The objective of our study was to assess the usefulness and diagnostic performance of time-resolved imaging of contrast kinetics sequence in the evaluation of peripheral vascular anomalies. SUBJECTS AND METHODS: Sixty-six patients (23 pediatric, 43 adult; mean age 26) affected by upper or lower limb vascular anomalies and studied using time-resolved imaging of contrast kinetics sequence were prospectively evaluated. All studies were performed on a 1.5-T whole-body MR system. Two independent readers tried to categorized the suspected vascular anomalies in pre-contrast and post-contrast MR sequences and assessed the overall TRICKS image quality. In 11 patients, the diagnostic performance comparability between TRICKS sequence and digital subtraction angiography was evaluated. RESULTS: On the basis of time-resolved imaging of contrast kinetics, 31 of the vascular anomalies were classified as high-flow vascular malformations, 29 as low-flow vascular lesions and 6 as hemangiomas. There was no significant difference in image quality evaluation and vascular anomaly classification between the two observers. The vascular anomalies characteristics provided by moderate, good or excellent quality TRICKS images were confirmed by digital subtraction angiography. CONCLUSION: Time-resolved imaging of contrast kinetics sequence let the radiologist to acquire useful temporal information to correctly evaluate vascular anomalies components, adding more data to those provided by conventional MR sequences, especially in case of arteriovenous malformation. Therefore, both in pediatric and adult population, TRICKS could be used as an additional initial diagnostic tool to rightly classify these lesions and evaluate if a treatment is needed and which.

Role of Contrast-Enhanced Sonography in the Evaluation of Axillary Lymph Nodes in Breast Carcinoma: A Monocentric Study.

OBJECTIVES: To evaluate the diagnostic performance of contrast-enhanced sonography for characterization of the lymph node status (metastatic or not) in patients with breast carcinomas by comparison with sentinel lymph node biopsy. METHODS: From January to August 2015, 50 female patients with a histologic diagnosis of invasive breast carcinoma were prospectively examined by ipsilateral axillary contrast-enhanced sonography. The test was performed by a single radiologist using an ultrasound system with a broadband 8-12-MHz, 38-mm high-resolution linear transducer. For the target lymph node, we chose a node with a sonographic pattern that was suspicious for malignancy: ie, a longitudinal-to-transverse diameter ratio of less than 2, absence of a central hyperechogenic hilum, or both. In cases with a lack of sonographic signs of malignancy, we evaluated the node with the maximal transverse diameter. Nodes were considered malignant in cases with total absence of contrast enhancement and in those with enhancement alterations. Within 1 week, all patients underwent sentinel lymph node biopsy, followed by a histologic test. RESULTS: The histologic test showed benignity in 22 of 50 sentinel lymph nodes, whereas 28 were metastatic. Among the 22 patients with negative biopsy results, contrast-enhanced sonography showed 18 concordances and 4 false-positives results; among the 28 with positive biopsy results, contrast-enhanced sonography obtained 100% correct characterizations of the axillary status. The sensitivity, specificity, and accuracy were 100%, 82%, and 92%, respectively. CONCLUSIONS: Contrast-enhanced sonography appears to be a method with high accuracy for characterization of axillary lymph nodes, very close to the reference-standard sentinel lymph node biopsy. This technique seems to have overall high sensitivity.

Multicenter review: role of cardiovascular magnetic resonance in diagnostic evaluation, pre-procedural planning and follow-up for patients with congenital heart disease.

The number of patients with congenital heart disease (CHD) is rapidly increasing in the adult population, mainly due to the improved long-term survival. Serial follow-up with cardiac magnetic resonance imaging (CMR) is very appealing due to its non-invasive nature. CMR exam is able to provide specific information about cardiac function, hemodynamics, anatomy and tissue characterization unlikely achievable by other diagnostic techniques. CMR in CHD plays a role both in early diagnosis and in post-operative follow-up. Black Blood T1 weighted sequences are used to acquire morphological information. Cine Steady State Free Precession sequences are mainly used to provide data about cardiac function and kinesis. Hemodynamic assessment is routinely performed using phase contrast sequences, which provide reliable information concerning vessel flow pattern, cardiac output and intracardiac shunts. Magnetic Resonance Angiography (MRA) and 3D coronary MRA of the whole thorax can provide detailed morphological information regarding great vessels and proximal coronary arteries. Presence of late gadolinium enhancement suggesting myocardial macroscopic fibrosis seems to play a prognostic and diagnostic role even in this field.

CT imaging of a rare case of persistent fifth aortic arch in newborn.

Congenital persistence of the fifth aortic arch is an unusual, often misdiagnosed and underestimated pathological finding. It is usually associated with other cardiac or vascular anomalies, which makes every case quite unique in its clinical presentation and treatment. Our subject was a newborn (1-month-old male) who was referred to our hospital from a peripheral centre owing to difficulty in obtaining a clear diagnosis with traditional means (echocardiography). He presented with Type II left-sided malformation (atresia or interruption of the superior arch with patent inferior arch) and also showed an associated atrial septal defect with left-to-right-shunt. The investigation was carried out with a contrast-enhanced CT scan owing to the serious clinical condition (haemodynamic instability) of the subject that made an MRI examination too hazardous. The study succeeded in plainly depicting the malformation, providing a clear diagnosis and also giving the surgeons (especially with the assistance of three-dimensional volume rendering reconstruction) an accurate anatomical model, which played a crucial role in planning the operation. The ability of a multislice CT scan to rapidly perform a full, panoramic and minimally invasive study of the cardiovascular system is clearly demonstrated in this study. The only downside of this procedure is the use of ionizing radiation on a newborn, although it is justified in this case by the emergent need for a quick diagnosis. Furthermore, a CT scan is characterized by a higher spatial resolution compared with an MRI and for vascular anomalies, a CT scan is often preferred. An MRI is mainly used in case of functional imaging. Exactly for this reason, we planned the procedure in order to maintain the equivalent radiation dose as low as possible [equivalent dose (H) ≤ 1 mSV].

Myocardial perfusion defects in scleroderma detected by contrast-enhanced cardiovascular magnetic resonance.

PURPOSE: The authors investigated whether contrast-enhanced cardiovascular magnetic resonance (CMR) imaging may be used to detect early cardiac involvement in patients with systemic sclerosis (SSc). MATERIALS AND METHODS: Twenty-six SSc patients (nine with diffuse cutaneous SSc and 17 with limited cutaneous SSc) and 13 sex- and age-matched healthy controls (HC) were studied. Contrast-enhanced CMR allowed the analysis of first-pass images (areas of hypo-enhancement indicating perfusion defects) and delayed images (persistent hyper-enhancement indicating fibrosis). Clinical variables including disease duration and presence of major visceral complications of SSc were investigated in each patient. RESULTS: Perfusion defects were detected in 53.8 % of SSc patients but in none of the HC. Perfusion abnormalities were detected in 28.6 % of SSc patients with disease duration less than 2 years and in 29.2 % of asymptomatic SSc patients. Delayed contrast enhancement was present in 25 % of SSc patients but not in HC. All patients with delayed contrast enhancement showed first-pass hypoperfusion. Right ventricular wall thickness was significantly increased in all SSc patients when compared to HC (p < 0.001); a similar trend was observed when SSc patients without pulmonary arterial hypertension were analysed (p < 0.04). A trend to lower end-diastolic and end-systolic right ventricular volumes in SSc versus HC was observed (p < 0.05 and p < 0.04, respectively). CONCLUSIONS: Myocardial hypoperfusion is common in SSc and occurs early in the course of the disease. Co-localisation of perfusion defects and delayed contrast enhancement indicative of fibrosis suggests that myocardial hypoxia may play a role in the pathogenesis of myocardial fibrosis.