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Publications (15)5.4 Total impact

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    ABSTRACT: PURPOSE The purpose of this study was to evaluate the effect of a new reconstruction algorithm called ASIR on radiation dose, image quality and the diagnosis accuracy to study urinary tract stone disease. METHOD AND MATERIALS 80 patients (mean age : 43.5 years, 23 – 73 years ; body mass index : 18 – 26) underwent MDCT examination from diaphragm to pubic bone to study urinary stone with two acquisitions : unenhanced and excretory phase after hyperhydratation using auto-adjusted mA and the following parameters : 0.625mm collimation, 120kv, 0.5s acquisition, reconstruction slice thickness: 1.25 mm. Patients were divided between two groups : Group I (40pts) with standard dose setting as fixed index noise of 22 with filtered back projection (FBP) as reconstruction algorithm and no ASIR, Group II (40pts) with fixed index noise of 50, FBP added with 80% ASIR reconstruction. The radiation dose was calculated. The image noise level was recorded by the SD in an identically sized 300mm2 ROI placed in air outside anterior abdominal wall, on kidney parenchyma and retroperitoneal fat. The image quality on axial, coronal and sagittal multiplanar reformations was evaluated by two independent radiologists using a 3 point score system (excellent : 1, good : 2, bad : 3). RESULTS The average radiation dose was 9.25 + 1.95 mSv for Group I versus 3.45 mSv + 0.95 for Group II. The average DLP and CTDI were 580+ 125 mGy.cm and 14.35 + 2.95 mGy for Group I versus 210mGy.cm + 55 and 3.80 mGy + 1.85 for Group II. The average difference in image noise level in the three area recorded was significantly lower for the Group II with ASIR than for Group I (air : 12%, fat : 38%, unenhanced kidney : 25%, enhanced kidney : 9%). The consensus score for image quality and diagnosis confidency was assessed good to excellent in Group II 80% ASIR (2.5) against 2.9 for Group I, with identification of all stones (3 mm as lower axial diameter). If present, the reduction of motion artefact was constantly observed. No intense oversmoothing on margins of solid organs or calculi that could affect the diagnostic value was noted at that level of ASIR processing applied. CONCLUSION MSCT with ASIR algorithm reconstruction provides an excellent image quality with a confident diagnosis for a reduction dose of more than 60% to study urinary tract stone disease. CLINICAL RELEVANCE/APPLICATION ASIR provides excellent images and confident diagnosis with very low radiation dose
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting; 12/2010
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    ABSTRACT: Evaluate diffusion MRI in the multiparametric assessment of prostate cancer before needle biopsy. One hundred eleven patients with suspected prostate cancer (mean age: 63 years old, median PSA: 7 ng/mL) were examined before undergoing needle biopsy (59 patients with a history of a negative biopsy and 52 without a history of biopsy). A diffusion sequence type SS SE-EPI (TR/TE: 5357/58, fEPI: 73, b 0 and 1000 s/mm², axial) with a qualitative analysis of the ADC map was performed in addition to T2 and T1 gadolinium enhanced sequences on 3 T MRI with an endorectal coil. The histological correlations were obtained by ultrasound guided needle biopsy (85 patients) or radical prostatectomy (26 patients). The correlation of the results of the diffusion sequence in the series of the 111 patients and the biopsies of the entire prostate or the hemiprostate had a sensitivity of: 92%, 77%; a specificity of: 55%, 70%; a positive predictive value of: 77%, 62%; a negative predictive value of: 84%, 80% and an efficacy of 78%, 75% respectively. The agreement of the three sequences had a specificity of 84.3%. The sensitivity of diffusion MRI is high for the detection of cancer of the prostate. Specificity of sequences is good. The results of simple visual assessment of the ADC map are good.
    Journal de Radiologie 11/2010; 91(11 Pt 1):1121-8. · 0.35 Impact Factor
  • C Roy, A Matau, G Bierry, G Bazille
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    ABSTRACT: After being first used for liver imaging, diffusion-weighted imaging of the kidney is in development. The kidney is the only anisotropic organ in the abdomen. It is a complex organ, with different types of flow, that is the subject of multiple research projects. Diffusion-weighted imaging is very sensitive for the detection of tumors, especially small ones. It also facilitates lesion characterization with the help of ADC values. Diffusion restriction indicates hypercellularity, which suggests malignancy. Diffusion-weighted imaging is currently available on clinical scanners. Characterization of different types of collections is possible. The characterization of nephropathies remains investigational.
    Journal de Radiologie 03/2010; 91(3 Pt 2):408-18; quiz 419-20. · 0.35 Impact Factor
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    ABSTRACT: To investigate the usefulness of diffusion-weighted imaging (DWI) to discriminate between metastatic and non-metastatic small lymph nodes in pelvic carcinoma. A total of 259 patients (180 normal, 79 metastatic) prospectively underwent DWI at 3 T. We measured the short-axis diameter and the mean apparent diffusion coefficient (ADC) value. Lymph nodes with a short-axis diameter larger than 8 mm were recorded as being suspected metastatic lymph nodes. Imaging data were correlated station by station with histopathological results. A total of 140 metastatic nodes were accurately matched with histology. On T2w, the short-axis diameter for non-metastatic and metastatic lymph nodes was 6.4 mm +/- 2.5 mm and 8.3 mm +/- 4.5 mm, respectively. Almost all metastatic or non-metastatic nodes had similar high signal intensity on DWI (except in 5 cases) with a homogeneous pattern. The mean ADC values (10(-3) mm(3)/s +/- standard deviation) of involved lymph nodes, control iliac nodes and control inguinal nodes were 924 +/- 217, 968 +/- 182 and 1,036 +/- 181, respectively. There were no statistically significant differences in the ADC of metastatic and non-metastatic nodes. Isolated measurement of mean ADC values in a suspected station does not contribute to the diagnosis of metastatic nodes, in patients with small ambiguous nodes.
    European Radiology 02/2010; 20(8):1803-11. · 4.34 Impact Factor
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    ABSTRACT: After being first used for liver imaging, diffusion-weighted imaging of the kidney is in development. The kidney is the only anisotropic organ in the abdomen. It is a complex organ, with different types of flow, that is the subject of multiple research projects. Diffusion-weighted imaging is very sensitive for the detection of tumors, especially small ones. It also facilitates lesion characterization with the help of ADC values. Diffusion restriction indicates hypercellularity, which suggests malignancy. Diffusion-weighted imaging is currently available on clinical scanners. Characterization of different types of collections is possible. The characterization of nephropathies remains investigational.
    Journal De Radiologie - J RADIOL. 01/2010; 91(3):408-420.
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    ABSTRACT: AimEvaluate diffusion MRI in the multiparametric assessment of prostate cancer before needle biopsy.
    Journal De Radiologie - J RADIOL. 01/2010; 91(11):1121-1128.
  • Journal de Radiologie 10/2009; 90(10):1618-1618. · 0.35 Impact Factor
  • Journal De Radiologie - J RADIOL. 01/2009; 90(10):1458-1459.
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    ABSTRACT: Objectifs Evaluation prospective des performances d’une séquence 3DTSEpT2 (VISTA) pour l’exploration du pelvis féminin à 3T. Matériels et méthodes Cent dix-huit patientes (84 cas d’endométriose, 14 néoplasmes ovariens, 4 néoplasmes utérins, 16 bilans léiomyomes) explorées en IRM 3T (Achieva, Philips) avec comparaison 3 plans 2D pT2 TSE et séquence 3D TSE (VISTA) (TR/TE/TA 2113/ 200/120, 0,9 × 0,9 × 1,1 mm3, 4 : 48 min). Evaluation subjective de la qualité d’image, des orientations multiplanaires et calculs des rapports S/B graisse, urine, utérus, lésion et rapport C/B de la lésion -tissu normal environnant. Résultats Le rapport S/B graisse, urine, lésion et C/B lésion - tissu normal défini par ROI était supérieur avec la séquence 3D (1237, 1527, 258, 985 ± 11) qu’avec la séquence 2DT2 (1197, 1443, 589, 589 ± 15) respectivement. L’intensité et l’homogénéité de l’image étaient supérieures en 3D dans les plans axial et obliques, mais inférieures en sagittal et frontal. Quelques artefacts et un faible blurring n’affectaient pas le diagnostic. La visualisation des extensions tumorales et des adénopathies était excellente. L’utilisation d’un logiciel 3D interactif multiplanaire est essentielle. Conclusion La séquence 3D TSEpT2 permet une couverture de toute la cavité pelvienne, un excellent contraste et une bonne analyse multiplanaire de la lésion avec ses extensions. Elle pourrait remplacer les 3 acquisitions 2DpT2.
    Journal De Radiologie - J RADIOL. 01/2009; 90(10):1197-1197.
  • C. Roy, A. Matau, R. Pasquali
    Journal De Radiologie - J RADIOL. 01/2009; 90(10):1399-1399.
  • Journal De Radiologie - J RADIOL. 01/2009; 90(10):1261-1261.
  • Journal De Radiologie - J RADIOL. 01/2009; 90(10):1532-1532.
  • Journal De Radiologie - J RADIOL. 01/2009; 90(10):1509-1509.
  • C. Roy, A. Matau, R. Mialin, H. Lang
    Journal De Radiologie - J RADIOL. 01/2009; 90(10):1440-1440.
  • Journal De Radiologie - J RADIOL. 01/2008; 89(10):1642-1642.