Luca Saba

Diagnostic accuracy of colour Doppler ultrasonography, CT angiography and blood-pool-enhanced MR angiography in assessing carotid stenosis: a comparative study with DSA in 170 patients

PurposeThis study was undertaken to prospectively evaluate the diagnostic performance of colour Doppler ultrasonography (CDUS), first-pass (FP) and steady-state (SS) contrast-enhanced magnetic resonance angiography (MRA) and computed tomography angiography (CTA) of the carotid arteries using digital subtraction angiography (DSA) as the reference standard.Materials and methodsA total of 170 patients with previous cerebrovascular events and suspected carotid artery stenoses underwent CDUS, blood-pool MRA, CTA and DSA. Accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for CDUS, FP MRA, SS MRA and CTA. The McNemar and Wilcoxon tests and receiver operating characteristic (ROC) curve analysis were used to determine significant differences (p<0.05) between the diagnostic performances of the four modalities, and the degree of stenosis was compared using linear regression.ResultsA total of 336 carotid bifurcations were studied. The area under the curve (AUC) for degree of stenosis was: CDUS 0.85±0.02, FP MRA 0.982±0.005, SS MRA 0.994±0.002 and CTA 0.997±0.001. AUC analysis showed no statistically significant difference between CTA and MRA (p=0.0174) and a statistically significant difference between CDUS and the other techniques (p<0.001). Plaque morphology analysis showed no significant difference between CTA and SS MRA; a significant difference was seen between CTA and SS MRA versus FP MRA (p=0.04) and CDUS (p=0.038). Plaque ulceration analysis showed a statistically significant difference between MRA and CTA (0.04< p<0.046) versus CDUS (p=0.019).ConclusionsCTA is the most accurate technique for evaluating carotid stenoses, with a slightly better performance than MRA (97% vs. 95% for SS MRA and 92% for FP MRA) and a greater accuracy than CDUS (97% vs. 76%). Blood-pool contrast-enhanced SS sequences offer improved evaluation of degree of stenosis and plaque morphology with accuracy substantially identical to CTA.RiassuntoObiettivoL’obiettivo di questo studio è stato di valutare prospetticamente l’accuratezza dell’eco-color Doppler (ECD), dell’angiografia con risonanza magnetica (angio-RM), ottenuta con sequenze di primo passaggio (PP) ed allo stato stazionario (SS) e dell’angiografia con tomografia computerizzata (angio-TC) nella diagnostica della stenosi carotidea utilizzando l’angiografia con sottrazione digitale (DSA) come metodica di riferimento.Materiali e metodiCentosettanta pazienti sintomatici e con sospetta stenosi carotidea sono stati sottoposti ad ECD, angio-RM, angio-TC e DSA. Accuratezza, sensibilità, specificità, valore predittivo positivo (VPP) e valore predittivo negativo (VPN) sono stati calcolati per ECD, angio-RM ed angio-TC. Le differenze di performance tra le metodiche sono state valutate utilizzando il test di McNemar, il test di Wilcoxon e l’analisi delle curve receiver operating characteristic (ROC) (p<0,05). Inoltre il valore di stenosi attribuito dalla valutazione dell’ECD, dell’angio-RM e dell’angio-TC è stato confrontato con il valore della DSA tramite regressioni lineari.RisultatiSono state valutate 336 biforcazioni carotidee. Per la valutazione del grado di stenosi è stata calcolata l’area sotto la curva (AUC) delle quattro metodiche che è risultata: ECD 0,85±0,02, angio-RM PP=0,982±0,005, angio-RM SS=0,994±0,002 ed angio-TC=0,997±0,001 con sostanziale equivalenza tra angio-TC ed angio-RM (p=0,0174) ed una differenza statisticamente significativatra l’ECD e le altre metodiche (p<0,001). Per la valutazione della morfologia di placca l’analisi delle AUC delle quattro metodiche ha evidenziato una sostanziale equivalenza tra angio-TC ed angio-RM con SS, ma ha evidenziato una lieve differenza di entrambe le metodiche nei confronti dell’angio-RM con PP (p=0,04) e dell’ECD (p=0,038). La valutazione delle ulcere ha evidenziato una differenza statisticamente significativa tra l’angio-RM e l’angio-TC (p=0,04–0,046) e l’ECD (p=0,019).ConclusioniL’angio-TC è la metodica più affidabile con una leggera superiorità diagnostica rispetto all’angio-RM (97% vs. 95% per le sequenze SS e 92% per le sequenze PP) ed una superiorità molto marcata rispetto all’ECD (97% vs. 76%). L’angio-RM con l’utilizzo delle sequenze allo stato stazionario ottenute con mezzo di contrasto intravascolare ad alta relassività tende sostanzialmente ad eguagliare l’accuratezza dell’angio-TC.Purpose. This study was undertaken to prospectively evaluate the diagnostic performance of colour Doppler ultrasonography (CDUS), first-pass (FP) and steady-state (SS) contrast-enhanced magnetic resonance angiography (MRA) and computed tomography angiography (CTA) of the carotid arteries using digital subtraction angiography (DSA) as the reference standard. Materials and methods. A total of 170 patients with previous cerebrovascular events and suspected carotid artery stenoses underwent CDUS, blood-pool MRA, CTA and DSA. Accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for CDUS, FP MRA, SS MRA and CTA. The McNemar and Wilcoxon tests and receiver operating characteristic (ROC) curve analysis were used to determine significant differences (p<0.05) between the diagnostic performances of the four modalities, and the degree of stenosis was compared using linear regression. Results. A total of 336 carotid bifurcations were studied. The area under the curve (AUC) for degree of stenosis was: CDUS 0.85±0.02, FP MRA 0.982±0.005, SS MRA 0.994±0.002 and CTA 0.997±0.001. AUC analysis showed no statistically significant difference between CTA and MRA (p=0.0174) and a statistically significant difference between CDUS and the other techniques (p<0.001). Plaque morphology analysis showed no significant difference between CTA and SS MRA; a significant difference was Riassunto Obiettivo. L’obiettivo di questo studio e stato di valutare prospetticamente l’accuratezza dell’eco-color Doppler (ECD), dell’angiografia con risonanza magnetica (angio-RM), ottenuta con sequenze di primo passaggio (PP) ed allo stato stazionario (SS) e dell’angiografia con tomografia computerizzata (angio-TC) nella diagnostica della stenosi carotidea utilizzando l’angiografia con sottrazione digitale (DSA) come metodica di riferimento. Materiali e metodi. Centosettanta pazienti sintomatici e con sospetta stenosi carotidea sono stati sottoposti ad ECD, angio-RM, angio-TC e DSA. Accuratezza, sensibilita, specificita, valore predittivo positivo (VPP) e valore predittivo negativo (VPN) sono stati calcolati per ECD, angio-RM ed angio-TC. Le differenze di performance tra le metodiche sono state valutate utilizzando il test di McNemar, il test di Wilcoxon e l’analisi delle curve receiver operating characteristic (ROC) (p<0,05). Inoltre il valore di stenosi attribuito dalla valutazione dell’ECD, dell’angio-RM e dell’angio-TC e stato confrontato con il valore della DSA tramite regressioni lineari. Risultati. Sono state valutate 336 biforcazioni carotidee. Per la valutazione del grado di stenosi e stata calcolata l’area sotto la curva (AUC) delle quattro metodiche che e risultata: ECD 0,85±0,02, angio-RM PP=0,982±0,005, angio-RM SS=0,994±0,002 ed angio-TC=0,997±0,001 con sostanziale equivalenza tra angio-TC ed angio-RM (p=0,0174) ed una differenza statisticamente significativa VASCULAR AND INTERVENTIONAL RADIOLOGY RADIOLOGIA VASCOLARE E INTERVENTISTICA Diagnostic accuracy of colour Doppler ultrasonography, CT angiography and blood-pool-enhanced MR angiography in assessing carotid stenosis: a comparative study with DSA in 170 patients Accuratezza diagnostica nella valutazione della stenosi carotidea di eco-color Doppler, angio-TC ed angio-RM con mezzo di contrasto intravascolare: valutazione comparativa dell’accuratezza diagnostica con DSA in 170 pazienti M. Anzidei1 • A. Napoli1 • F. Zaccagna1 • P. Di Paolo1 • L. Saba2 • B. Cavallo Marincola2 • C. Zini1 G. Cartocci1 • L. Di Mare1 • C. Catalano1 • R. Passariello1 1 Department of Radiological Sciences, University of Rome “La Sapienza”, Viale Regina Elena 324, 00161 Rome, Italy 2 Department of Radiology, Azienda Ospedaliera Universitaria (A.O.U.) Cagliari, Polo di Monserrato, Italy Correspondence to: M. Anzidei, Tel.: +39-06-4455602, Fax: +39-06-490243, e-mail: michele.anzidei@gmail.com Received: 27 July 2010 / Accepted: 7 September 2010 / Published online: 19 March 2011

Percutaneous vertebroplasty: Multi-centric results from EVEREST experience in large cohort of patients

PURPOSEnThe purpose of this study was to prospectively evaluate results and complications of percutaneous vertebroplasty (PV) performed in 6 different Italian Centres belonging to the European VErtebroplasty RESearch Team (E.VE.RES.T) in a large series of patients.nnnMATERIALS AND METHODSnFollow-up was obtained in 4547 patients (3211 females and 1336 males; mean age 70.2 years) that underwent PV for a total of 13.437 treated vertebrae. Procedures were performed by using fluoroscopic guidance or combined CT-fluoroscopic guidance. All patients underwent PV in local anaesthesia except for second cervical vertebrae treated with a trans-oral approach that required general anaesthesia.nnnRESULTSn4004 out of 4547 (88.0%) patients reported significant pain relief (difference>or=2 point in pain evaluated with an 11-point visual analogue scale; p<0.0001) within 48 h: an average of 7.7 ± 0.4 dropped to 1.8 ± 0.6 in the osteoporotic patients; 8.3 ± 0.4 to 2.4 ± 0.4 in metastases; 8.3 ± 0.4 to 1.7 ± 1.0 in myeloma; 6.2 ± 3.5 to 0.3 ± 0.2 in angioma and 7.4 ± 0.4 to 1.4 ± 0.9 in trauma. 430 osteoporotic patients (13%) were retreated for a subsequent fracture; in 302/430 patients (70.2%), the new fracture occurred in the contiguous vertebra. No major neurologic complications were reported and the most frequent minor complication was venous leakage (20.5%).nnnCONCLUSIONSnThis large series of patients confirms that percutaneous vertebroplasty is an effective and safe procedure in the treatment of vertebral fractures. Best results are obtained in the treatment of myeloma and trauma.

A comparative approach of four different image registration techniques for quantitative assessment of coronary artery calcium lesions using intravascular ultrasound

In IVUS imaging, constant linear velocity and a constant angular velocity of 1800 rev/min causes displacement of the calcium in subsequent image frames. To overcome this error in intravascular ultrasound video, IVUS image frames must be registered prior to the lesion quantification. This paper presents a comprehensive comparison of four registration methods, namely: Rigid, Affine, B-Splines and Demons on five set of calcium lesion quantification parameters namely: (i) the mean lesion area, (ii) mean lesion arc, (iii) mean lesion span, (iv) mean lesion length, and (v) mean lesion distance from catheter. Using our IRB approved data of 100 patient volumes, our results shows that all four registrations showed a decrease in five calcium lesion parameters as follows: for Rigid registration, the values were: 4.92%, 5.84%, 5.89%, 5.27%, and 4.57%, respectively, for Affine registration the values were: 6.06%, 6.51%, 7.28%, 6.50%, and 5.94%, respectively, for B-Splines registration the values were: 7.35%, 8.03%, 9.54%, 8.18%, and 7.62%, respectively, and for Demons registration the five parameters were 7.32%, 8.02%, 10.11%, 7.94%, and 8.92% respectively. The relative overlap of identified lesions decreased by 5.91% in case of Rigid registration, 6.23% in case of Affine registration, 4.48% for Demons registration, whereas it increased by 3.05% in case of B-Splines registration. Rigid and Affine transformation-based registration took only 0.1936 and 0.2893 s per frame, respectively. Demons and B-Splines framework took only 0.5705 and 0.9405 s per frame, respectively, which were significantly slower than Rigid and Affine transformation based image registration.

Current state of the art in perforator flap imaging with computed tomographic angiography

Computed tomographic angiography (CTA) has become increasingly adopted for preoperative imaging in perforator flap surgery, as it has been shown to improve operative outcomes and decrease operating times prior to deep inferior epigastric artery perforator (DIEP) flap and anterolateral thigh perforator flap surgery. Current technologies are readily available for the preoperative imaging of all perforator flaps, however only sporadic reports of the use of CTA for the imaging of other perforators have been described. We describe our experience with 325 CTAs performed for the preoperative imaging of perforators prior to 370 perforator flaps throughout several body regions. The scanning techniques, software reconstructions and technical issues are explored. In all cases, CTA was scored by the radiologist as at least “sufficient”, and described as “optimal” in the majority of cases. Similarly, the surgeon described the correlation of imaging to operative findings as at least “good”, and described the correlation as “optimal” in the majority of cases. As such, a standardized protocol for the use of CTA prior to perforator flap surgery is provided, which has been shown to be successful prior to a range of perforator flap operations.

Automated stratification of liver disease in ultrasound

PURPOSEnFatty liver disease (FLD) is one of the most common diseases in liver. Early detection can improve the prognosis considerably. Using ultrasound for FLD detection is highly desirable due to its non-radiation nature, low cost and easy use. However, the results can be slow and ambiguous due to manual detection. The lack of computer trained systems leads to low image quality and inefficient disease classification. Thus, the current study proposes novel, accurate and reliable detection system for the FLD using computer-based training system.nnnMATERIALS AND METHODSnOne hundred twenty-four ultrasound sample images were selected retrospectively from a database of 62 patients consisting of normal and cancerous. The proposed training system was generated offline parameters using training liver image database. The classifier applied transformation parameters to an online system in order to facilitate real-time detection during the ultrasound scan. The system utilized six sets of features (a total of 128 features), namely Haralick, basic geometric, Fourier transform, discrete cosine transform, Gupta transform and Gabor transform. These features were extracted for both offline training and online testing. Levenberg-Marquardt back propagation network (BPN) classifier was used to classify the liver disease into normal and abnormal categories.nnnRESULTSnRandom partitioning approach was adapted to evaluate the classifier performance and compute its accuracy. Utilizing all the six sets of 128 features, the computer aided diagnosis (CAD) system achieved classification accuracy of 97.58%. Furthermore, the four performance metrics consisting of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) realized 98.08%, 97.22%, 96.23%, and 98.59%, respectively.nnnCONCLUSIONnThe proposed system was successfully able to detect and classify the FLD. Furthermore, the proposed system was benchmarked against previous methods. The comparison established an advanced set of features in the Levenberg-Marquardt back propagation network reports a significant improvement compared to the existing techniques.

IOTA simple rules for discriminating between benign and malignant adnexal masses: prospective external validation

To determine the diagnostic performance of International Ovarian Tumor Analysis (IOTA) ‘simple’ rules for discriminating between benign and malignant adnexal masses.

Fully Automated Dual-Snake Formulation for Carotid Intima-Media Thickness Measurement A New Approach

Automated computer‐aided detection systems for measurement of the carotid intima‐media thickness (IMT) are becoming popular. These systems yield lumen‐intima (LI) and media‐adventitia (MA) borders. In this work, we developed and validated a novel and patented completely automated IMT measurement system called carotid measurement using dual snakes (CMUDS): a class of AtheroEdge system (Global Biomedical Technologies, Inc, Roseville, CA). CMUDS is modeled as a dual parametric system corresponding to LI and MA borders with initialization from the far adventitia layer. The novelty of CMUDS is the first‐order absolute moment–based external energy, which provides stable deformation. The dual snakes evolve simultaneously and are forced to maintain a regularized distance to prevent collapsing or bleeding. Two independent readers manually traced the LI/MA boundaries of a multi‐institutional, multi‐ethnic, and multi‐scanner database of 665 longitudinal images for performance evaluation. CMUDS was also benchmarked against a previously developed automated technique. CMUDS correctly processed 660 images (99.2% success). The differences between the CMUDS and two manual IMT measurements (mean ± SD) were 0.013 ± 0.216 and −0.021 ± 0.197 mm, respectively. The corresponding figures of merit for CMUDS compared to reader tracings were 98.4% and 97.5%. Compared to the previous technique (IMT differences, 0.022 ± 0.276 and −0.012 ± 0.266 mm), CMUDS improved accuracy (Wilcoxon P < 0.009) and variability (Fisher P < 10−8). Among different resolution images from original equipment manufacturer ultrasound scanners, CMUDS performed best with high‐resolution images corresponding to 0.0789 mm/pixel. Accuracy in IMT measurement with the proposed automated CMUDS technique makes this system adaptable to large multi‐center studies, in which such an IMT measurement system would be very useful tool.

Automatic Lung Segmentation Using Control Feedback System: Morphology and Texture Paradigm

Interstitial Lung Disease (ILD) encompasses a wide array of diseases that share some common radiologic characteristics. When diagnosing such diseases, radiologists can be affected by heavy workload and fatigue thus decreasing diagnostic accuracy. Automatic segmentation is the first step in implementing a Computer Aided Diagnosis (CAD) that will help radiologists to improve diagnostic accuracy thereby reducing manual interpretation. Automatic segmentation proposed uses an initial thresholding and morphology based segmentation coupled with feedback that detects large deviations with a corrective segmentation. This feedback is analogous to a control system which allows detection of abnormal or severe lung disease and provides a feedback to an online segmentation improving the overall performance of the system. This feedback system encompasses a texture paradigm. In this study we studied 48 males and 48 female patients consisting of 15 normal and 81 abnormal patients. A senior radiologist chose the five levels needed for ILD diagnosis. The results of segmentation were displayed by showing the comparison of the automated and ground truth boundaries (courtesy of ImgTracer™ 1.0, AtheroPoint™ LLC, Roseville, CA, USA). The left lung’s performance of segmentation was 96.52xa0% for Jaccard Index and 98.21xa0% for Dice Similarity, 0.61xa0mm for Polyline Distance Metric (PDM), −1.15xa0% for Relative Area Error and 4.09xa0% Area Overlap Error. The right lung’s performance of segmentation was 97.24xa0% for Jaccard Index, 98.58xa0% for Dice Similarity, 0.61xa0mm for PDM, −0.03xa0% for Relative Area Error and 3.53xa0% for Area Overlap Error. The segmentation overall has an overall similarity of 98.4xa0%. The segmentation proposed is an accurate and fully automated system.

Cyst with a mural nodule tumor of the brain

Abstract The purpose of this article is to illustrate the imaging findings of lesions that present as cyst with a mural nodule tumor (CMNT). CMNT is a subtype pattern of intra-axial enhancement in central nervous system tumors, typical of a variety of brain neoplasms, including, as the most common, hemangioblastoma, pilocytic astrocytoma, ganglioglioma and pleomorphic xanthoastrocytoma and as less common tanycytic ependymoma, intraparenchymal schwannoma, desmoplastic infantile ganglioglioma and cystic metastasis. A retrospective design was chosen given the rarity of CMNT. Relevant cases were obtained retrospectively to review the different lesions that can present with the appearance of CMNT.

Reliable and Accurate Calcium Volume Measurement in Coronary Artery Using Intravascular Ultrasound Videos

Quantitative assessment of calcified atherosclerotic volume within the coronary artery wall is vital for cardiac interventional procedures. The goal of this study is to automatically measure the calcium volume, given the borders of coronary vessel wall for all the frames of the intravascular ultrasound (IVUS) video. Three soft computing fuzzy classification techniques were adapted namely Fuzzy c-Means (FCM), K-means, and Hidden Markov Random Field (HMRF) for automated segmentation of calcium regions and volume computation. These methods were benchmarked against previously developed threshold-based method. IVUS image data sets (around 30,600 IVUS frames) from 15 patients were collected using 40xa0MHz IVUS catheter (Atlantis® SR Pro, Boston Scientific®, pullback speed of 0.5xa0mm/s). Calcium mean volume for FCM, K-means, HMRF and threshold-based method were 37.84u2009±u200917.38xa0mm3, 27.79u2009±u200910.94xa0mm3, 46.44u2009±u200919.13xa0mm3 and 35.92u2009±u200916.44xa0mm3 respectively. Cross-correlation, Jaccard Index and Dice Similarity were highest between FCM and threshold-based method: 0.99, 0.92u2009±u20090.02 and 0.95u2009+u20090.02 respectively. Student’s t-test, z-test and Wilcoxon-test are also performed to demonstrate consistency, reliability and accuracy of the results. Given the vessel wall region, the system reliably and automatically measures the calcium volume in IVUS videos. Further, we validated our system against a trained expert using scoring: K-means showed the best performance with an accuracy of 92.80u2009%. Out procedure and protocol is along the line with method previously published clinically.