Publications (36) View all
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Article: Total-liver-volume perfusion CT using 3-D image fusion to improve detection and characterization of liver metastases
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ABSTRACT: The purpose of this study was to evaluate the feasibility of a total-liver-volume perfusion CT (CTP) technique for the detection and characterization of liver metastases. Twenty patients underwent helical CT of the total liver volume before and 11 times after intravenous contrast-material injection. To decrease distortion artifacts, all phases were co-registered using 3-D image fusion before creating blood-flow maps. Lesion-based sensitivity and specificity for liver metastases of first the conventional four phases (unenhanced, arterial, portal venous, and equilibrium) and later all 12 phases including blood-flow maps were determined as compared to intraoperative ultrasound and surgical exploration. Arterial and portal venous perfusion was calculated for normal-appearing and metastatic liver tissue. Total-liver-volume perfusion values were comparable to studies using single-level CTP. Compared to four-phase CT, total -liver-volume CTP increased sensitivity to 89.2 from 78.4% (P = 0.046) and specificity to 82.6 from 78.3% (P = 0.074). Total -liver-volume CTP is a noninvasive, quantitative, and feasible technique. Preliminary results suggest an improved detection of liver metastases for CTP compared to four-phase CT.European Radiology 04/2012; 18(10):2345-2354. · 3.22 Impact Factor -
Article: Combined anatomical and functional diagnostic work-up of patients with suspected coronary artery disease using cardiac computed tomography and magnetic resonance imaging
Journal of Cardiovascular Magnetic Resonance. 01/2011; -
Article: MR enteroclysis in refractory celiac disease: proposal and validation of a severity scoring system.
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ABSTRACT: To determine magnetic resonance (MR) enteroclysis findings in patients with uncomplicated celiac disease (CD), refractory CD (RCD) type I, and RCD type II, to develop and validate a scoring system to identify patients with RCD II and to determine the diagnostic accuracy of MR enteroclysis to detect CD-related malignancies. This study was performed with approval of the institutional review board. One radiologist blinded to clinical details retrospectively evaluated quantitative and qualitative criteria of 28 studies obtained in symptomatic patients with CD (uncomplicated CD, n = 10; RCD I, n = 8; RCD II, n = 10). A scoring system was developed by using parameters identified in multivariate analysis to be associated with RCD II, which two radiologists evaluated in a second group of 40 symptomatic patients with CD. Accuracy to detect malignancy was assessed in the total study group. Cumulative survival was evaluated in the total study group by using the Kaplan-Meier method. MR enteroclysis could not be used to discriminate between uncomplicated CD and RCD I. The presence of less than 10 folds per 5 cm jejunum, mesenteric fat infiltration, and bowel wall thickening were associated with RCD II. A positive MR score was defined as the presence of two or more of these features. In the validation group, the MR score was positive in 13 of 15 patients with RCD II (sensitivity, 0.87) and negative in 24 of 25 patients without RCD II (specificity, 0.96). The 5-year survival rate was 95% in patients with a negative MR score and 56% in patients with a positive MR score (P < .0001). MR enteroclysis helped to identify the presence of seven of eight malignancies and to diagnose absence of malignancy in 58 of 60 studies. MR enteroclysis can be used to investigate the presence of RCD II or malignancy in symptomatic patients with CD.Radiology 02/2011; 259(1):151-61. · 5.73 Impact Factor -
Article: Dynamic contrast-enhanced CT in patients treated with sorafenib and erlotinib for non-small cell lung cancer: a new method of monitoring treatment?
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ABSTRACT: We investigated the feasibility of serial dynamic contrast-enhanced computed tomography (DCE-CT) in patients with advanced/metastatic non-small cell lung cancer (NSCLC) receiving anti-angiogenic (sorafenib) and anti-EGFR (erlotinib) treatment, and correlated tumour blood flow (BF) with treatment outcome. DCE-CTs were performed at baseline and 3 and 6 weeks after starting treatment. Tumour BF, calculated with the maximum slope method, and percentage change were measured in 23 patients (14 male; median age 59 years). Tumour BF was compared at baseline and weeks 3 and 6; the relation with RECIST/Crabb response and progression-free survival (PFS) was assessed. Mean tumour perfusion decreased from 39.2 ml/100 g/min at baseline to 15.1 ml/100 g/min at week 3 (p < 0.001) and 9.4 ml/100 g/min at week 6 (p < 0.001). Tumour perfusion was lower in RECIST and Crabb responders versus non-responders at week 3 (4.2 versus 17.7 ml/100 g/min, p = 0.03) and week 6 (0 versus 13.4 ml/100 g/min, p = 0.04). Patients with a decrease larger than the median at week 6 tended to have a longer PFS (7.1 versus 5.7 months, p = 0.06). Serial DCE-CTs are feasible in patients with NSCLC and demonstrated a significant decrease in tumour BF following sorafenib/erlotinib therapy. Early changes in tumour BF correlated with objective response and showed a trend towards longer PFS.European Radiology 12/2010; 20(12):2890-8. · 3.22 Impact Factor -
Article: Positive predictive value of computed tomography coronary angiography in clinical practice.
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ABSTRACT: Several studies have investigated the diagnostic performance of computed tomography coronary angiography (CTCA) for the detection of significant coronary artery disease (CAD). These studies were performed in patients that were already referred for invasive coronary angiography (ICA) and prevalence of significant CAD was high. Although the negative predictive value of CTCA was consistently high, a wide range of positive predictive values (PPVs) was reported. Thus, the PPV of CTCA in patients that undergo CTCA as part of a clinical diagnostic evaluation remains unclear. This study investigated the PPV of CTCA for the detection of significant CAD in clinical practice. A total of 181 patients with low to intermediate pre-test probability CAD that were referred for non-invasive evaluation of chest pain underwent 64-slice CTCA. CTCA was scored per segment as normal, non-obstructive CAD or obstructive CAD (>50% diameter stenosis). All patients with obstructive CAD according to CTCA, underwent ICA. Significant CAD was defined as >50% diameter stenosis on ICA. According to CTCA, 65 (35.9%) patients had obstructive CAD. In 26 (14.4%) patients, significant CAD was found by ICA. The PPV for detection of significant CAD per patient, per vessel and per segment were 40.0% (26/65, 95% CI: 30.6-50.2%), 31.3% (36/115, 95% CI: 24.7-38.8%) and 25.5% (42/165; 95% CI: 20.3-31.4%), respectively. The PPV of CTCA for detection of significant CAD in patients with low to intermediate probability CAD that are clinically referred for non-invasive evaluation of chest pain is markedly lower than generally reported.International journal of cardiology 12/2010; 156(3):315-9. · 7.08 Impact Factor
