Giovanni Di Leo

In Vivo Evaluation of the Chemical Composition of Urinary Stones Using Dual-Energy CT

OBJECTIVE The purpose of this article is to evaluate in vivo the chemical composition of urinary stones using dual-source and dual-energy CT, with crystallography as the reference standard. MATERIALS AND METHODS Forty patients (mean [± SD] age, 49 ± 17 years) with known or suspected nephrolithiasis underwent unenhanced abdominal CT for urinary tract evaluation using a dual-energy technique (tube voltages, 140 and 80 kVp). For each stone 5 mm or larger in diameter, we evaluated the site, diameter, CT density, surface (smooth vs rough), and stone composition. Patients were treated with extracorporeal shock wave lithotripsy (n = 34), percutaneous nephrolithotomy (n = 4), or therapeutic ureterorenoscopy (n = 2). Collected stones underwent crystallography, and the agreement with the results of dual-energy CT was calculated with the Cohen kappa coefficient. The correlation among stone composition, diameter, and CT density was estimated using the Kruskal-Wallis test. RESULTS Thirty-one patients had a single stone and nine had multiple stones, for a total of 49 stones. Forty-five stones were in the kidneys, and four were in the ureters; 23 had a smooth surface and 26 had a rough surface. The mean stone diameter was 12 ± 6 mm; mean CT density was 783 ± 274 HU. According to crystallography, stone composition was as follows: 33 were calcium oxalate, seven were cystine, four were uric acid, and five were of mixed composition. Dual-energy CT failed to identify four stones with mixed composition, resulting in substantial agreement between dual-energy CT and crystallography (Cohen κ = 0.684). Stone composition was not correlated with either stone diameter (p = 0.920) or stone CT density (p = 0.185). CONCLUSION CT showed excellent accuracy in classifying urinary stone chemical composition, except for uric acid-hydroxyapatite mixed stones.

In Vivo Proton MR Spectroscopy of the Breast Using the Total Choline Peak Integral as a Marker of Malignancy

OBJECTIVE The purpose of our study was to use the total choline-containing compound (tCho) peak integral as a marker of malignancy in breast MR spectroscopy (MRS). SUBJECTS AND METHODS Forty-eight single-voxel water- and fat-suppressed 1.5-T MRS measurements were performed in 42 patients, obtaining both absolute tCho peak integral and tCho peak integral normalized for the volume of interest (VOI). Our reference standard was histology for lesions with BI-RADS category 4 and 5 and histology or at least a 2-year follow-up for findings with BI-RADS 2 and 3 and normal glands. Receiver operating characteristic (ROC) analysis, Mann-Whitney U test, and Spearmans rank correlation were used. RESULTS Three of 48 measurements (6%) failed. Of the remaining 45 spectra, 18 nonmalignant tissues showed no tCho peak, eight nonmalignant tissues showed a tCho peak integral from 0.99 to 9.03 arbitrary units (AU), and 19 malignant lesions showed a tCho peak integral from 1.26 to 19.80 AU. The diameter of nonmalignant tissues was 16.9 +/- 7.4 mm; that of malignant lesions was 15.3 +/- 6.9 mm (p = 0.308). At ROC analysis, the optimal threshold was 1.90 AU for absolute tCho peak, with 0.895 (17/19) sensitivity, 0.923 (24/26) specificity, and an AUC (area under the curve) of 0.917 (95% CI, 0.822-1.000); the optimal threshold was 0.85 AU/mL for the normalized tCho peak integral with 0.842 (16/19) sensitivity, 0.885 (23/26) specificity, and an AUC of 0.941 (0.879-1.000) (p = 0.470). A negative correlation (p = 0.011) was found between the VOI and the normalized tCho peak integral of malignant tissues. CONCLUSION Breast MRS using tCho peak integral reaches a high level of diagnostic performance.

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.

Evidence-based radiology: why and how?

PurposeTo provide an overview of evidence-based medicine (EBM) in relation to radiology and to define a policy for adoption of this principle in the European radiological community.ResultsStarting from Sackett’s definition of EBM we illustrate the top-down and bottom-up approaches to EBM as well as EBM’s limitations. Delayed diffusion and peculiar features of evidence-based radiology (EBR) are defined with emphasis on the need to shift from the demonstration of the increasing ability to see more and better, to the demonstration of a significant change in treatment planning or, at best, of a significant gain in patient outcome. The “as low as reasonably achievable” (ALARA) principle is thought as a dimension of EBR while EBR is proposed as part of the core curriculum of radiology residency. Moreover, we describe the process of health technology assessment in radiology with reference to the six-level scale of hierarchy of studies on diagnostic tests, the main sources of bias in studies on diagnostic performance, and levels of evidence and degrees of recommendations according to the Centre for Evidence-Based Medicine (Oxford, UK) as well as the approach proposed by the GRADE working group. Problems and opportunities offered by evidence-based guidelines in radiology are considered. Finally, we suggest nine points to be actioned by the ESR in order to promote EBR.ConclusionRadiology will benefit greatly from the improvement in practice that will result from adopting this more rigorous approach to all aspects of our work.

Rotator Cuff Calcific Tendinitis: Does Warm Saline Solution Improve the Short-term Outcome of Double-Needle US-guided Treatment?

PURPOSE To determine whether saline temperature influences procedure performance and outcome in patients undergoing ultrasonography (US)-guided lavage for the treatment of rotator cuff calcific tendinitis (RCCT). MATERIALS AND METHODS This study was approved by the institutional review board, and informed consent was obtained from all patients. From December 2009 to May 2011, 462 patients (191 men and 271 women; mean age, 39.7 years) with painful RCCT diagnosed at US were prospectively enrolled and randomized into two groups. Operators subjectively classified calcifications as hard, soft, or fluid according to their appearance at US. US-guided percutaneous treatment of RCCT (local anesthesia, double-needle lavage, intrabursal steroid injection) was performed with warm saline (42°C, 107°F) in 229 patients and with room-temperature saline in 233. Operators and patients were not blinded to saline temperature. The ease of calcium dissolution was subjectively scored (easy=1, intermediate=2, difficult=3). Procedure duration was recorded. Patient discomfort was assessed by using a visual analog scale (VAS). The occurrence of postprocedure bursitis was recorded. Statistical analyses were performed with Mann-Whitney U, χ2, and analysis of variance tests. RESULTS Procedure duration was significantly shorter (P<.001) in patients treated with warm saline (mean, 576 seconds±121) than in those treated with room-temperature saline (mean, 777 seconds±151). Calcium dissolution was significantly easier in patients treated with warm saline (median score, 1) than in those treated with room-temperature saline (median score, 2). Subgroup analysis according to calcification appearance at US showed a significant difference between groups for both soft (P=.003) and hard (P<.001) calcifications. No overall significant differences were found for VAS score (warm saline group: baseline=8.9±0.6, 1 month=4.7±0.6, 2 months=4.0±0.7, 3 months=3.4±0.4, 1 year=3.0±0.7; room-temperature saline group: baseline=9.2±0.4, 1 month=4.5±0.7, 2 months=4.1±0.9, 3 months=3.1±0.7, 1 year=3.2±0.8; P=.491). Postprocedural bursitis was observed in eight patients in the warm saline group and 20 in the room-temperature saline group (P<.022). CONCLUSION In the treatment of RCCT, warm saline appears to reduce procedure duration and improve calcification dissolution while reducing the frequency of postprocedural bursitis.

Gadobenate Dimeglumine as a Contrast Agent for Dynamic Breast Magnetic Resonance Imaging: Effect of Higher Initial Enhancement Thresholds on Diagnostic Performance

Rationale and Objective:Gadobenate dimeglumine (Gd-BOPTA), a high-relaxivity contrast agent, has been recently proposed for dynamic MR imaging of the breast. The objective of this study was to optimize the diagnostic performance of Gd-BOPTA-enhanced dynamic breast MR imaging by using adjusted initial enhancement thresholds. Methods:Thirty-four patients with 36 breast lesions (malignant/benign = 28/8) underwent dynamic breast MRI with 0.1 mmol/kg Gd-BOPTA and 120-second time resolution. A score system based on shape (round/oval/lobular = 0; linear/dendritic/stellate = 1), margins (defined = 0; undefined = 1), pattern (homogeneous = 0; inhomogeneous = 1; rim = 2), kinetics (continuous = 0; plateau = 1; washout = 2), and initial enhancement was used. Initial enhancement was determined with standard (<50% = 0; 50%–100% = 1; >100% = 2) and adjusted (<100% = 0; 100%–240% = 1; >240% = 2) thresholds. Scores of 0 to 3 indicated benign lesions and scores of 4 to 8 malignant lesions. Diagnostic performance was assessed in terms of sensitivity, specificity, positive and negative predictive values, and overall accuracy. Results:The initial enhancement was >100% for 26 malignant and 7 benign lesions and >240% for 16 and 1 lesions, respectively. The overall score was 5.89 ± 1.34 with standard thresholds and 5.50 ± 1.53 with adjusted thresholds (P = 0.003) for cancers, 4.00 ± 1.93 and 3.25 ± 1.75 (P = 0.028) for benign lesions, respectively. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy was 96%, 13%, 79%, 50%, and 78%, respectively, with standard thresholds and 96%, 75%, 93%, 86%, and 92%, respectively, with adjusted thresholds. A ductal carcinoma in situ was false negative whereas a fat necrosis and a papilloma were false positive with both thresholds. Three fibroadenomas, 1 adenosis, and 1 fibrosis were false positive with standard thresholds but true negatives with adjusted thresholds. Conclusions:Lesion characterization with Gd-BOPTA requires higher thresholds for initial enhancement than those used with conventional Gd-chelates, leading to improved specificity, predictive values, and accuracy.

Malignant Incidental Extracardiac Findings on Cardiac CT: Systematic Review and Meta-Analysis

OBJECTIVE The objective of our study was to systematically review the evidence on incidental extracardiac findings on cardiac CT with a focus on previously unknown malignancies. MATERIALS AND METHODS A systematic search was performed (PubMed, EMBASE, Cochrane databases) for studies reporting incidental extracardiac findings on cardiac CT. Among 1099 articles initially found, 15 studies met the inclusion criteria. The references of those articles were hand-searched and 14 additional studies were identified. After review of the full text, 10 articles were excluded. Nineteen studies including 15,877 patients (64% male) were analyzed. A three-level analysis was performed to determine the prevalence of patients with incidental extracardiac findings, the prevalence of patients with major incidental extracardiac findings, and the prevalence of patients with a proven cancer. Heterogeneity was explored for multiple variables. Pooled prevalence and 95% CI were calculated. RESULTS The prevalence of both incidental extracardiac findings and major incidental extracardiac findings showed a high heterogeneity (I2>95%): The pooled prevalence was 44% (95% CI, 35-54%) and 16% (95% CI, 14-20%), respectively. No significant explanatory variables were found for using or not using contrast material, the size of the FOV, and study design (I2>85%). The pooled cancer prevalence for 10 studies including 5082 patients was 0.7% (95% CI, 0.5-1.0%), with an almost perfect homogeneity (I2<0.1%). Of 29 reported malignancies, 21 (72%) were lung cancers; three, thyroid cancers; two, breast cancers; two, liver cancers; and one, mediastinal lymphoma. CONCLUSION Although the prevalence of reported incidental extracardiac finding at cardiac CT was highly variable, a homogeneous prevalence of previously unknown malignancies was reported across the studies, for a pooled estimate of 0.7%; more than 70% of these previously unknown malignancies were lung cancers. Extracardiac findings on cardiac CT require careful evaluation and reporting.

In vivo detection of choline in ovarian tumors using 3D magnetic resonance spectroscopy.

Objectives:To assess the clinical feasibility of 3-dimensional (3D) proton magnetic resonance spectroscopy (MRS) of ovarian masses at 1.5 T. Materials and Methods:We prospectively evaluated 16 patients with 23 ovarian masses using contrast-enhanced magnetic resonance imaging and 3D chemical shift imaging MRS (time of reception/time of echo = 700/135 ms, number of excitations = 6, interpolated voxel = 5 × 5 × 5 mm3, water and fat suppression). Spectral editing consisted of water reference, filtering, zero-filling, Fourier transformation, frequency shift, automatic baseline and phase correction, and curve fitting. The volume of interest was placed to encompass both solid and cystic tumor components as well as apparently healthy pelvic tissues. The presence of a choline peak at 3.14 to 3.34 ppm was considered as a marker of malignancy. All patients underwent surgery and histopathological evaluation. Results:Of 23 masses, 19 were malignant and the remaining 4 benign lesions were a fibrothecoma, an endometriosis, a cyst, and a cystadenofibroma. A choline peak was detected in 17/19 malignant tumors (sensitivity 89%), absent in 2 G1 tumors. It was visible in 16 solid components of 19 malignant tumors (in one of them, a choline peak was detected only in the cystic component, in 6 in both solid and cystic components). The choline peak was absent in 20/21 apparently healthy pelvic tissues, with a very low choline peak being detected in one intraperitoneal fluid collection with malignant cells at cytologic analysis; 3/4 benign tumors showed a choline peak (overall specificity 21/25 = 84%). A significant difference between the mean choline peak integral detected within the solid component and that within the cystic component was observed (P = 0.002). No correlation between the choline peak integral and the tumor size was found (r = 0.120, P = 0.615). Conclusions:3D MRS of ovarian masses is clinically feasible at 1.5 T. This opens new research strategies for early diagnosis of ovarian cancer.

Segmentation of cardiac cine MR images of left and right ventricles: Interactive semiautomated methods and manual contouring by two readers with different education and experience

To test interactive semiautomated methods (ISAM) vs. manual contouring (MC) in segmenting cardiac cine MR images.

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.