Francesco Secchi

Relation of Echocardiographic Epicardial Fat Thickness and Myocardial Fat

Epicardial and myocardial fats increase with degree of visceral adiposity and possibly contribute to obesity-associated cardiac changes. Echocardiographic epicardial fat thickness is a new and independent marker of visceral adiposity. The aim of this study was to test whether echocardiographic epicardial fat is related to myocardial fat. Twenty consecutive Caucasian men (body mass index 30.5 +/- 2 kg/m(2), 42 +/- 7 years of age) underwent transthoracic echocardiography for epicardial fat thickness, morphologic and diastolic parameter measurements, hydrogen-1 magnetic resonance spectroscopy for myocardial fat quantification, and magnetic resonance imaging for epicardial fat volume estimation. Hydrogen-1 magnetic resonance spectroscopic myocardial fat content, magnetic resonance imaging of epicardial fat volume, and echocardiographic epicardial fat thickness range varied from 0.5% to 31%, 4.5 to 43 ml, and 3 to 15 mm, respectively. Myocardial fat content showed a statistically significant correlation with echocardiographic epicardial fat thickness (r = 0.79, p <0.01), waist circumference (r = 0.64, p <0.01), low-density lipoprotein cholesterol (r = 0.54, p <0.01), plasma adiponectin levels (r = -0.49, p <0.01), and isovolumic relaxation time (r = 0.59, p <0.01). However, multivariate linear regression analysis showed epicardial fat thickness as the most significant independent correlate of myocardial fat (p <0.001). Although this study is purely correlative and no causative conclusions can be drawn, it can be postulated that increased echocardiographic epicardial fat accumulation could reflect myocardial fat in subjects with a wide range of adiposity.

Monoenergetic extrapolation of cardiac dual energy CT for artifact reduction

Background Monoenergetic extrapolation of cardiac dual-energy computed tomography (DECT) could be useful in artifact reduction in clinical practice. Purpose To evaluate the potential of monoenergetic extrapolation of cardiac DECT data for reducing artifacts from metal and high iodine contrast concentration. Material and Methods With IRB approval and in HIPAA compliance, 35 patients (22 men, 61 ± 12 years) underwent cardiac DECT with dual-source CT (100 kVp and 140 kVp). Contrast material injection protocols were adapted to the patient’s weight using non-ionic low-osmolar 370 mgI/mL iopromide. Datasets were transferred to a stand-alone workstation and dedicated monoenergetic analysis software was used for postprocessing. Reconstructions with the following five photon energies were generated: 40 keV, 60 keV, 80 keV, 100 keV, and 120 keV. Artifact severity was graded on a 5-point Likert scale (0, massive artifact; 5, absence of artifact). The size of artifact and image noise (expressed as HU) in anatomic structures adjacent to the artifact were measured. Quantitative and subjective image quality was compared using Friedman and Wilcoxon tests. Results We observed artifacts arising from densely concentrated contrast material in the superior vena cava (SVC) in 18 patients, from sternal wires in 14, from bypass clips in eight, and from coronary artery stents in seven. Artifact size in monoenergetic reconstructions from 40 to 120 keV decreased from 21.3 to 19 mm for the SVC (P < 0.001), from 8.4 to 2.6 mm for sternal wires (P < 0.001), from 6.4 to 2.2 mm for bypass clips (P < 0.001), and from 5.9 to 2.7 mm for stents (P < 0.001), respectively. The quality score changed from 0.2 to 3.8 for the SVC (P < 0.001), from 0.1 to 4 for sternal wires (P < 0.001), from 0 to 3.9 for bypass clips (P < 0.001), and from 0 to 3.9 for stents (P < 0.001). Lowest noise in adjacent structures was found at 80 keV for the SVC (39.1 HU), for sternal wires (33.3), for bypass clips (26.9), and for stents (33.9). Conclusion A significant reduction of high-attenuation artifacts can be achieved by use of higher monoenergetic energy levels with cardiac DECT. However, image noise in anatomic structures affected by artifacts is lowest at 80 keV, which suggests an evaluation approach that makes use of multiple energy levels for a complete diagnosis.

Ultrasound guidance to perform intra-articular injection of gadolinium-based contrast material for magnetic resonance arthrography as an alternative to fluoroscopy: the time is now

Abstract Magnetic resonance (MR) imaging has been definitively established as the reference standard in the evaluation of joints in the body. Similarly, magnetic resonance arthrography has emerged as a technique that has been proven to increase significantly the diagnostic performance if compared with conventional MR imaging, especially when dealing with fibrocartilage and articular cartilage abnormalities. Diluted gadolinium can be injected in the joint space using different approaches: under palpation using anatomic landmarks or using an imaging guidance, such as fluoroscopy, computed tomography, or ultrasound. Fluoroscopy has been traditionally used, but the involvement of ionizing radiation should represent a remarkable limitation of this modality. Conversely, ultrasound has emerged as a feasible, cheap, quick, and radiation-free modality that can be used to inject joints, with comparable accuracy of fluoroscopy. In the present paper, we discuss the advantages and disadvantages of using fluoroscopy or ultrasound in injecting gadolinium-based contrast agents in joints to perform magnetic resonance arthrography, also in view of the new EuroSAFE Imaging initiative promoted by the European Society of Radiology and the recent updates to the European Atomic Energy Community 2013/59 directive on the medical use of ionizing radiation.Key Points• Intra-articular contrast agent injection can be performed using different imaging modalities• Fluoroscopy is widely used, but uses ionizing radiation• Ultrasound is an accurate, quick, and radiation-free modality for joint injection• X-rays should be avoided when other radiation-free modalities can be used

The value of true-FISP sequence added to conventional gadolinium-enhanced MRA of abdominal aorta and its major branches

To test true-fast imaging with steady-state precession (true-FISP) added to gadolinium-based MR angiography (Gd-MRA) for imaging abdominal aorta and major abdominal vessels, 35 consecutive patients (age 67+/-11 years) with known or suspected abdominal and/or peripheral vascular disease were studied with sagittal and axial 2D true-FISP during free breathing and coronal 3D fast low-angle shot (FLASH) Gd-MRA (breath-holding, 0.2 mmol/kg of Gd-DOTA at 2 ml/s). We evaluated: suprarenal aorta, celiac trunk, superior mesenteric artery, right renal artery, left renal artery, infrarenal aorta, inferior mesenteric artery, aortic bifurcation/common iliac arteries, lumbar arteries and aortic atheromasia. The possible presence of accessory renal arteries, collateral vasculature and vascular prosthesis/stent was evaluated. A quality four-point score was assigned to each item on both sequences, from 0 (not visible) to 3 (good-to-excellent image quality) and Wilcoxon test was used. Main diagnoses resulted: normal or atheromasic aorta (n=25); aortic aneurysm (n=2); patent aorto-iliac surgical prosthesis (n=2); patent vascular iliac stent (n=2); aneurysm of iliac artery (n=1); patent aortic endovascular prosthesis (n=1); patent aorto-femural bypass (n=1) and aorto-iliac surgical prosthesis endoleak (n=1). We also found three patients with accessory renal arteries, two with collateral circulation, and three with surgical aorto-iliac prosthesis. The score of true-FISP (25.9+/-4.1, median 27) was significantly higher (p=0.003) than that of Gd-MRA (23.9+/-3.6, median 24). True-FISP was superior for visualizing inferior mesenteric artery (score 2.5+/-1.1 vs. 1.0+/-1.4; p<0.001) and atheromasic plaques (2.5+/-1.1 vs. 1.2+/-1.1; p<0.001). One collateral vasculature was demonstrated only with Gd-MRA. Summarizing, true-FISP is a power and fast non-breath-hold sequence to be added to Gd-MRA, obtaining an information increase.

Ultrasound-guided interventional procedures around the shoulder

Ultrasound is an established modality for shoulder evaluation, being accurate, low cost and radiation free. Different pathological conditions can be diagnosed using ultrasound and can be treated using ultrasound guidance, such as degenerative, traumatic or inflammatory diseases. Subacromial-subdeltoid bursitis is the most common finding on ultrasound evaluation for painful shoulder. Therapeutic injections of corticosteroids are helpful to reduce inflammation and pain. Calcific tendinopathy of rotator cuff affects up to 20% of painful shoulders. Ultrasound-guided treatment may be performed with both single- and double-needle approach. Calcific enthesopathy, a peculiar form of degenerative tendinopathy, is a common and mostly asymptomatic ultrasound finding; dry needling has been proposed in symptomatic patients. An alternative is represented by autologous platelet-rich plasma injections. Intra-articular injections of the shoulder can be performed in the treatment of a variety of inflammatory and degenerative diseases with corticosteroids or hyaluronic acid respectively. Steroid injections around the long head of the biceps brachii tendon are indicated in patients with biceps tendinopathy, reducing pain and humeral tenderness. The most common indication for acromion-clavicular joint injection is degenerative osteoarthritis, with ultrasound representing a useful tool in localizing the joint space and properly injecting various types of drugs (steroids, lidocaine or hyaluronic acid). Suprascapular nerve block is an approved treatment for chronic shoulder pain non-responsive to conventional treatments as well as candidate patients for shoulder arthroscopy. This review provides an overview of these different ultrasonography-guided procedures that can be performed around the shoulder.

Technical prerequisites and imaging protocols for dynamic and dual energy myocardial perfusion imaging.

Coronary CT angiography (CCTA) is an established imaging technique used for the non-invasive morphological assessment of coronary artery disease. As in invasive coronary angiography, CCTA anatomical assessment of coronary stenosis does not adequately predict hemodynamic relevance. However, recent technical improvements provide the possibility of CT myocardial perfusion imaging (CTMPI). Two distinct CT techniques are currently available for myocardial perfusion assessment: static CT myocardial perfusion imaging (sCTMPI), with single- or dual-energy modality, and dynamic CT myocardial perfusion imaging (dCTMPI). The combination of CCTA morphological assessment and CTMPI functional evaluation holds promise for achieving a comprehensive assessment of coronary artery anatomy and myocardial perfusion using a single image modality.

Optimizing dose and administration regimen of a high-relaxivity contrast agent for myocardial MRI late gadolinium enhancement

OBJECTIVES To investigate the time-course of late gadolinium enhancement of infarcted myocardium using gadobenate dimeglumine at different dosages and administration regimens. MATERIALS AND METHODS After institutional review board approval and informed consent, we studied 13 patients (aged 63±11 years) with chronic myocardial infarction. They underwent two gadobenate dimeglumine-enhanced MR examinations (interval 24-48 h) using short-axis inversion-recovery gradient-echo sequences, with the following two different protocols, in randomized order: 0.05 mmol/kg and imaging at the 2.5th, 5th, 7.5th and 10th minute plus 0.05 mmol/kg and imaging at the 12.5th, 15th, 17.5th and 20th minute; the same as before but using 0.1 mmol/kg for both contrast injections. Contrast-to-noise ratios (CNRs) between infarcted myocardium, non-infarcted myocardium and left ventricle cavity were calculated for each time-point (2.5-min steps). Friedman ANOVA was used for comparing the CNR time-course; Wilcoxon test for comparing CNR at the 10th and the 20th minute. RESULTS The CNR between infarcted and non-infarcted myocardium obtained at the 20th minute with 0.05 plus 0.05 mmol/kg resulted significantly higher than that obtained at the 10th minute with 0.05 mmol/kg (P=0.033) while not significantly different from that obtained at the 10th (0.1mm/kg) or at the 20th minute with 0.1 plus 0.1 mmol/kg. The CNR between infarcted myocardium and the left ventricle cavity obtained at the 20th minute with 0.05 plus 0.05 mmol/kg resulted significantly higher than all other measured values (P≤0.017). CONCLUSION Using gadobenate dimeglumine, 0.05 plus 0.05 mmol/kg allows for a higher CNR between infarcted myocardium and the left ventricle cavity allowing for reliable assessment of the sub-endocardial infarctions.

Italian registry of cardiac magnetic resonance

OBJECTIVES Forty sites were involved in this multicenter and multivendor registry, which sought to evaluate indications, spectrum of protocols, impact on clinical decision making and safety profile of cardiac magnetic resonance (CMR). MATERIALS AND METHODS Data were prospectively collected on a 6-month period and included 3376 patients (47.2 ± 19 years; range 1-92 years). Recruited centers were asked to complete a preliminary general report followed by a single form/patient. Referral physicians were not required to exhibit any specific certificate of competency in CMR imaging. RESULTS Exams were performed with 1.5T scanners in 96% of cases followed by 3T (3%) and 1T (1%) magnets and contrast was administered in 84% of cases. The majority of cases were performed for the workup of inflammatory heart disease/cardiomyopathies representing overall 55.7% of exams followed by the assessment of myocardial viability and acute infarction (respectively 6.9% and 5.9% of patients). In 49% of cases the final diagnosis provided was considered relevant and with impact on patients clinical/therapeutic management. Safety evaluation revealed 30 (0.88%) clinical events, most of which due to patients preexisting conditions. Radiological reporting was recorded in 73% of exams. CONCLUSIONS CMR is performed in a large number of centers in Italy with relevant impact on clinical decision making and high safety profile.

A geometric reappraisal of proximal landing zones for thoracic endovascular aortic repair according to aortic arch types

Objective: This study assessed whether the additional use of the aortic arch classification in type I, II, and III may complement Ishimarus aortic arch map and provide valuable information on the geometry and suitability of proximal landing zones for thoracic endovascular aortic repair. Methods: Anonymized thoracic computed tomography scans of healthy aortas were reviewed and stratified according to the aortic arch classification, and 20 of each type of arch were selected. Further processing allowed calculation of angulation and tortuosity of each proximal landing zone. Data were described indicating both proximal landing zone and type of arch (eg, 0/I). Results: Angulation was severe (>60°) in 2/III and in 3/III. Comparisons among the types of arch showed an increase in proximal landing zones angulation (P < .001) and tortuosity (P = .009) depending on the type of arch. Comparisons within type of arch showed no change in angulation and tortuosity across proximal landing zones within type I arch (P = .349 and P = .409), and increases in angulation and tortuosity toward more distal proximal landing zones within type II (P = .003 and P = .043) and type III (P < .001 in both). Conclusions: The aortic arch classification is associated with a consistent geometric pattern of the aortic arch map, which identifies specific proximal landing zones with suboptimal angulation for stent graft deployment. Arches II and III also appear to have progressively less favorable anatomy for thoracic endovascular aortic repair compared with arch I.

Myocardial Fatty Foci in Adult Patients with Tuberous Sclerosis Complex: Association with Gene Mutation and Multiorgan Involvement

PURPOSE To estimate the association between myocardial fatty foci (MFF) on chest computed tomographic (CT) images and type of gene mutation or multiorgan involvement in patients with tuberous sclerosis complex (TSC). MATERIALS AND METHODS This retrospective case-control study was approved by the ethics committee, which waived the need for patient consent. Forty-eight patients with definite TSC (41 women; mean age, 35 years ± 11 [standard deviation]) and 96 age- and sex-matched patients without TSC who had undergone chest CT were evaluated. Two blinded readers independently scored MFF as low-attenuation areas within the myocardium. Patient history, gene mutation, and multiorgan involvement were obtained from clinical records. Cohen κ, Mann-Whitney U, χ(2) or Fisher exact, Kruskal-Wallis, and Spearman statistics were calculated. RESULTS One or more MFF was detected in 50% (24 of 48) of patients with TSC; however, no MFF was detected in control patients (P < .001). MFFs were oval (62%, 15 of 24) or linear (38%, nine of 24) and involved the left ventricle in 13 patients and both ventricles in 24 patients (mostly the apical or midleft ventricle); median size was 127 mm(2). After four patients with TSC and unknown mutational status (two with MFF) were excluded, MFF was detected in 53% (10 of 19) of patients with TSC1 mutation, 65% (11 of 17) of patients with TSC2 mutation, and 12% (one of eight) of patients with TSC but without an identified mutation (P = .044). MFF presence was associated with brain (P = .011) and multiorgan (P = .008) involvement. The number of MFF per patient correlated with the degree of multiorgan involvement (P = .014). With MFF considered predictive of TSC, 50% (24of 48) sensitivity, 100% (96 of 96) specificity, 100% (24 of 24) positive predictive value, and 80% (96 of 120) negative predictive value were obtained. CONCLUSION MFF was highly specific for TSC. MFF presence was associated with TSC gene mutations and with brain or multiorgan involvement; their number per patient was correlated with the degree of multiorgan involvement.