White Matter Changes in Comatose Survivors of Anoxic Ischemic Encephalopathy and Traumatic Brain Injury: Comparative Diffusion-Tensor Imaging Study
; ; et al
in Radiology (2014), 270
Purpose:To analyze white matter pathologic abnormalities by using diffusion-tensor (DT) imaging in a multicenter prospective cohort of comatose patients following cardiac arrest or traumatic brain injury ... [more ▼]
Purpose:To analyze white matter pathologic abnormalities by using diffusion-tensor (DT) imaging in a multicenter prospective cohort of comatose patients following cardiac arrest or traumatic brain injury (TBI). Materials and Methods: Institutional review board approval and informed consent from proxies and control subjects were obtained. DT imaging was performed 5–57 days after insult in 49 cardiac arrest and 40 TBI patients. To control for DT imaging–processing variability, patients’ values were normalized to those of 111 control subjects. Automated segmentation software calculated normalized axial diffusivity (λ1) and radial diffusivity (λ) in 19 predefined white matter regions of interest (ROIs). DT imaging variables were compared by using general linear modeling, and side-to-side Pearson correlation coefficients were calculated. P values were corrected for multiple testing (Bonferroni). Results:In central white matter, λ1 differed from that in control subjects in six of seven TBI ROIs and five of seven cardiac arrest ROIs (all P < .01). The λ differed from that in control subjects in all ROIs in both patient groups (P < .01). In hemispheres, λ1 was decreased compared with that in control subjects in three of 12 TBI ROIs (P < .05) and nine of 12 cardiac arrest ROIs (P < .01). The λ was increased in all TBI ROIs (P < .01) and in seven of 12 cardiac arrest ROIs (P < .05). Cerebral hemisphere λ1 was lower in cardiac arrest than in TBI in six of 12 ROIs (P < .01), while λ was higher in TBI than in cardiac arrest in eight of 12 ROIs (P < .01). Diffusivity values were symmetrically distributed in cardiac arrest (P < .001 for side-to-side correlation) but not in TBI patients. Conclusion:DT imaging findings are consistent with the known predominance of cerebral hemisphere axonal injury in cardiac arrest and chiefly central myelin injury in TBI. This consistency supports the validity of DT imaging for differentiating axon and myelin damage in vivo in humans. [less ▲]Detailed reference viewed: 35 (2 ULg)
MR Imaging of Iron Phagocytosis in Intraluminal Thrombi of Abdominal Aortic Aneurysms in Humans.
NCHIMI LONGANG, Alain ; ; Brisbois, Denis et al
in Radiology (2010), 254(3), 973-81Detailed reference viewed: 62 (39 ULg)
Virtual dissection CT colonography: evaluation of learning curves and reading times with and without computer-aided detection.
; ; et al
in Radiology (2008), 248(3), 860-8
PURPOSE: To prospectively evaluate the learning curves and reading times of inexperienced readers who used the virtual dissection reading method for retrospective computed tomographic (CT) colonography ... [more ▼]
PURPOSE: To prospectively evaluate the learning curves and reading times of inexperienced readers who used the virtual dissection reading method for retrospective computed tomographic (CT) colonography data sets, with and without concurrent computer-aided detection (CAD). MATERIALS AND METHODS: An Institutional Review Board approved this study; informed consent was waived. Four radiologists without experience in CT colonography evaluated 100 optical colonoscopy-proved data sets of 100 patients (49 men, 51 women; mean age, 59 years +/- 13 [standard deviation]; range, 21-85 years) by using the virtual dissection reading method. Two readers used concurrent CAD. Data sets were read during five consecutive 1-day sessions (20 data sets per session). Polyp detection and false-positive rates, receiver operating characteristics (ROCs), and reading times were calculated for individual, CAD group, and non-CAD group readings. Diagnostic values were compared by calculating the 95% confidence intervals (CIs) around the relative risk. Areas under ROC curves (AUCs) (Hanley and McNeil for paired analysis and z statistics for unpaired analysis) and reading times (Wilcoxon signed rank test) were compared across the sessions, within each session and for the whole study. RESULTS: The range of detection rates was 79 of 111 (.71 [95% CI: .61, .79]) to 91 of 111 (.82 [95% CI: .73, .88]). The range of false-positive rates was 17 of 111 (.15 [95% CI: .09, .23]) to 22 of 111 (.20 [95% CI: .12, .28]). All readers' AUCs rose from session 1 to session 4; this rise was significant (P < .05) for the non-CAD group. Only during session 1 was the CAD group AUC (.83) higher than the non-CAD group AUC (.54) (P < .05). Comparison of CAD and non-CAD reading times showed no significant difference for the whole study or during each session (P > .05). CONCLUSION: The virtual dissection reading technique allows short learning curves, which may be improved by the concurrent use of CAD, without significant effect on average reading time. [less ▲]Detailed reference viewed: 10 (0 ULg)
Severe pulmonary embolism: Pulmonary artery clot load scores and cardiovascular parameters as predictors of mortality
Ghaye, Benoît ; Ghuysen, Alexandre ; et al
in Radiology (2006), 239(3), 884-891
Purpose: To retrospectively evaluate pulmonary artery (PA) clot load scores and computed tomographic (CT) cardiovascular parameters as predictors of mortality in patients with severe pulmonary embolism ... [more ▼]
Purpose: To retrospectively evaluate pulmonary artery (PA) clot load scores and computed tomographic (CT) cardiovascular parameters as predictors of mortality in patients with severe pulmonary embolism (PE). Materials and Methods: Institutional review board approval was obtained with waiver of informed consent. A total of 82 consecutive patients (42 women, 40 men; mean age +/- standard deviation, 61 years +/- 15) were admitted to the intensive care unit for PE-related conditions and were evaluated by using CT pulmonary angiography. Two independent readers who were blinded to clinical outcome quantified PA clot load by using four scoring systems. Cardiovascular measurements included right ventricular (RV) and left ventricular (LV) short-axis measurements; RV short axis to LV short axis (RV/LV) ratios; main PA, ascending aorta, azygos vein, and superior vena cava diameters; and main PA diameter to aorta diameter ratios. Reflux of contrast medium into the inferior vena cava, leftward bowing of the interventricular septum, pleural or pericardial effusion, pulmonary consolidation, infarct, platelike atelectasis, and mosaic ground-glass opacity were also recorded. Results were correlated with patient outcome during hospital stay by using the Wilcoxon rank sum and x(2) tests. Results: Twelve patients died within 1-14 days. RV and LV short axis; RV/LV ratio; azygos vein, superior vena cava, and aorta diameters; and contrast medium reflux into the inferior vena cava were significantly different between survivors and nonsurvivors (P <.05). No significant relationship was found between PA clot load and mortality rate. RV/LV ratio and azygos vein diameter allowed correct prediction of survival in 89% of patients (P <.001). Conclusion: RV/LV ratio and azygos vein diameter are predictors of mortality in patients with severe PE. (c) RSNA, 2006 [less ▲]Detailed reference viewed: 81 (5 ULg)
Elastase-induced pulmonary emphysema in rats: comparison of computed density and microscopic morphometry.
; ; Gustin, Pascal et al
in Radiology (2006), 241(3), 763-70
PURPOSE: To prospectively compare computed tomographic (CT) quantification of pulmonary emphysema in elastase-treated rats with morphometry and to evaluate the information yielded by CT quantification and ... [more ▼]
PURPOSE: To prospectively compare computed tomographic (CT) quantification of pulmonary emphysema in elastase-treated rats with morphometry and to evaluate the information yielded by CT quantification and pulmonary function tests. MATERIALS AND METHODS: This study was approved by the local committee on care and use of animals in research. Thirty-six animals were used. Emphysema was produced by means of one or two tracheal injections of 300 IU of elastase, 8 weeks apart, in seven and 12 rats, respectively. As a control group, 10 rats received an injection of normal saline. The dynamic resistance, dynamic compliance, and static compliance were measured. CT was performed with 1-mm section thickness and 3-mm intervals. Relative areas of lung with attenuation coefficients lower than nine chosen thresholds (from -900 to -980 HU) and eight percentiles (from 1st to 18th percentiles) of the distribution of attenuation coefficients were compared with measurements of alveoli size--that is, mean interwall distance (MIWD) and mean perimeter per field (MP). Correlations between data obtained with thresholds and percentiles and MIWD and MP were investigated by means of Spearman coefficients (r(s)). Values of pulmonary function tests, most appropriate relative area threshold, and percentile were investigated by means of stepwise multiple regressions. RESULTS: For thresholds, relative surface area with attenuation coefficients less than -940 HU (RA(940)) showed the strongest correlations with findings at microscopy (r(s) = 0.676, P < .001 for MIWD; r(s) = -0.720, P < .001 for MP). For percentiles, the 3rd percentile showed the strongest correlations (r(s) = -0.647, P < .001 for MIWD; r(s) = 0.701, P < .001 for MP). Dynamic compliance and RA(940) or 3rd percentile were complementary for predicting microscopic measurements. CONCLUSION: In rats, RA(940) and the 3rd percentile reflect the extent of elastase-induced pulmonary emphysema and are complementary to dynamic compliance to predict microscopic extent. [less ▲]Detailed reference viewed: 24 (2 ULg)
Does multi-detector row CT pulmonary angiography reduce the incremental value of indirect CT venography compared with single-detector row CT pulmonary angiography?
Ghaye, Benoit ; NCHIMI LONGANG, Alain ; et al
in Radiology (2006), 240(1), 256-62
PURPOSE: To compare retrospectively the incremental value of indirect computed tomographic (CT) venography performed after multi-detector row CT pulmonary angiography and single-detector row CT pulmonary ... [more ▼]
PURPOSE: To compare retrospectively the incremental value of indirect computed tomographic (CT) venography performed after multi-detector row CT pulmonary angiography and single-detector row CT pulmonary angiography for the diagnosis of venous thromboembolism (VTE). MATERIALS AND METHODS: The institutional ethics committee approved this study; informed consent was not required. The authors retrospectively reviewed results of 1100 combined single-detector row CT pulmonary angiographic and indirect CT venographic examinations (542 men, 558 women; mean age, 61 years +/- 17 [standard deviation]) (group 1) and 308 combined multi-detector row CT pulmonary angiographic and indirect CT venographic examinations (150 men, 158 women; mean age, 62 years +/- 18) (group 2), performed in 1408 patients suspected of having pulmonary embolism (PE). Frequency of deep venous thrombosis (DVT), PE, and VTE, and the incremental value of indirect CT venography were recorded in both groups. Data were compared by means of the Student t test for continuous data and z statistics for independent proportions. RESULTS: VTE, PE, and DVT were found in 23.3% (n = 256), 19.9% (n = 219), and 18.3% (n = 201) of the 1100 patients in group 1, respectively, and in 23.7% (n = 73), 17.2% (n = 53), and 18.8% (n = 58) of the 308 patients in group 2, respectively (P values ranging from .273 to .876). The incremental value of indirect CT venography was 14.4% (37 of 256 patients) in group 1 and 27.4% (20 of 73 patients) in group 2. CONCLUSION: Despite potential improved accuracy of multi-detector row CT pulmonary angiography for the diagnosis of PE, the addition of indirect CT venography increased the diagnosis of VTE in 27.4% of patients. [less ▲]Detailed reference viewed: 9 (0 ULg)
Rheumatoid hand joint synovitis: gray-scale and power Doppler US quantifications following anti-tumor necrosis factor-alpha treatment: pilot study
Ribbens, Clio ; Andre, Béatrice ; et al
in Radiology (2003), 229(2), 562-569
PURPOSE: To evaluate by using B-mode and power Doppler ultrasonography (US) and clinical assessment the response of hand joint synovitis in patients with active rheumatoid arthritis (RA) to treatment with ... [more ▼]
PURPOSE: To evaluate by using B-mode and power Doppler ultrasonography (US) and clinical assessment the response of hand joint synovitis in patients with active rheumatoid arthritis (RA) to treatment with the anti-tumor necrosis factor-alpha agent infliximab. MATERIALS AND METHODS: Wrists, metacarpophalangeal (MCP) joints, and proximal interphalangeal (PIP) joints in 11 patients with active RA were assessed before and 6 weeks after three infliximab infusions. US assessment was performed at a single site in the MCP and PIP joints and at two sites (radiocarpal and intercarpal) in the wrists. Twenty measurements were performed in the wrists; 110 measurements, in the MCP joints; and 103 measurements, in the PIP joints. Two wrists and seven PIP joints were excluded owing to complete joint destruction. US parameters (synovial thickness, number of US-positive joints [ie, with synovial thickness > or = 1 mm], cumulative synovial thickness index, and presence of Doppler signal) and clinical parameters (swollen joint count) were independently assessed and compared with baseline values by using the McNemar chi2 and paired Student t tests. RESULTS: After infliximab treatment, there was a significant decrease in the mean numbers of swollen and US-positive joints and in the cumulative synovial thickness (P <.05). The mean synovial thickness decreased in all joints swollen at baseline and in the MCP and PIP joints not swollen at baseline (P <.01). Change from baseline cumulative synovial thickness correlated significantly with change in disease activity score (r = 0.69, P <.05). The number of positive Doppler US signals decreased significantly (in 13 US-positive joints at baseline, in five after treatment; P <.05). CONCLUSION: US is a feasible imaging modality for measurement of the response of RA small-joint synovitis to therapy. [less ▲]Detailed reference viewed: 17 (3 ULg)
Differentiation between begnin and malignant breast lesions with MR imaging and scintimammography
; ; Seret, Alain et al
in Radiology (1997), 205(1), 283
No abstract for this letter.Detailed reference viewed: 48 (1 ULg)
Pituitary microadenomas: diagnosis with two-and three-dimensional MR imaging at 1.5 T before and after injection of gadolinium.
; Stevenaert, Achille ; Beckers, Albert et al
in Radiology (1990), 176(2), 419-428
The usefulness of different magnetic resonance (MR) imaging sequences (coronal and sagittal spin-echo [SE] and three-dimensional fast low-angle shot [3D FLASH]) in the detection of pituitary microadenomas ... [more ▼]
The usefulness of different magnetic resonance (MR) imaging sequences (coronal and sagittal spin-echo [SE] and three-dimensional fast low-angle shot [3D FLASH]) in the detection of pituitary microadenomas before and after gadolinium injection was prospectively evaluated in 28 patients with surgical confirmation. When evaluated separately, the most useful sequences in the detection of these microadenomas were coronal pregadolinium T1-weighted SE, coronal pregadolinium 3D FLASH, coronal postgadolinium T1-weighted SE, and coronal postgadolinium 3D FLASH. The combination of pre- and postgadolinium T1-weighted sequences with pre-and postgadolinium 3D FLASH sequences produced the highest number of true-positive findings (90%) and the lowest number of false-positive findings (5%). When a 1.5-T imaging unit with a high signal-to-noise ratio allowing useful three-dimensional acquisition is used, the authors advocate a coronal T1-weighted SE sequence, followed (if necessary) by a coronal 3D FLASH sequence, both without injection of gadolinium, in the diagnosis of pituitary microadenomas. When no confident diagnosis is reached, the same sequences should be performed after the injection of gadolinium. The sagittal pre- and postgadolinium T1-weighted SE and long-TR SE sequences are useful only in specific cases. [less ▲]Detailed reference viewed: 32 (1 ULg)
The comparison of two dimensional and three dimensional sequences before and after Gadolinium injection in the diagnosis of microadenomas at 1.5 Tesla.
; Stevenaert, Achille ; Beckers, Albert et al
in Radiology (1990), 176Detailed reference viewed: 2 (0 ULg)