Biomedical subjects

Viviane De Maertelaer

Publications and source records attributed to Viviane De Maertelaer.

17 recordsLinked to original sources

PubMed2006

Treatment for painful calcified chronic pancreatitis: extracorporeal shock wave lithotripsy versus endoscopic treatment: a randomised controlled trial.

BACKGROUND: In chronic pancreatitis, obstruction of the main pancreatic duct (MPD) may contribute to the pathogenesis of pain. Pilot studies suggest that extracorporeal shock wave lithotripsy (ESWL) alone relieves pain in calcified chronic pancreatitis. AIM: To compare ESWL alone with ESWL and endoscopic drainage of the MPD for treatment of pain in chronic pancreatitis. SUBJECTS: Patients with uncomplicated painful chronic pancreatitis and calcifications obstructing the MPD. METHODS: 55 patients were randomised to ESWL alone (n = 26) or ESWL combined with endoscopy (n = 29). RESULTS: 2 years after trial intervention, 10 (38%) and 13 (45%) patients of the ESWL alone and ESWL combined with endoscopy group, respectively, had presented pain relapse (primary outcome) (OR 0.77; 95% CI 0.23 to 2.57). In both groups, a similar decrease was seen after treatment in the MPD diameter (mean decrease 1.7 mm; 95% CI 0.9 to 2.6; p<0.001), and in the number of pain episodes/year (mean decrease, 3.7; 95% CI 2.6 to 4.9; p<0.001). Treatment costs per patient were three times higher in the ESWL combined with endoscopy group compared with the ESWL alone group (p = 0.001). The median delay between the onset of chronic pancreatitis and persistent pain relief for both groups was 1.1 year (95% CI 0.7 to 1.6), as compared with 4 years (95% CI 3 to 4) for the natural history of chronic pancreatitis in a reference cohort (p<0.001). CONCLUSIONS: ESWL is a safe and effective preferred treatment for selected patients with painful calcified chronic pancreatitis. Combining systematic endoscopy with ESWL adds to the cost of patient care, without improving the outcome of pancreatic pain.

Abdominal Pain↗

PubMed2006

Quantitative diffusion imaging in breast cancer: a clinical prospective study.

PURPOSE: To study the correlation between apparent diffusion coefficient (ADC) and pathology in patients with undefined breast lesion, to validate how accurately ADC is related to histology, and to define a threshold value of ADC to distinguish malignant from benign lesions. MATERIALS AND METHODS: Seventy-eight patients (110 lesions) were referred for positive or dubious findings. Three-dimensional fast low-angle shot (3D-FLASH) with contrast injection was applied. EPI diffusion-weighted imaging (DWI) with fat saturation was performed, and ROIs were selected on subtraction 3D-FLASH images before and after contrast injection, and copied on an ADC map. Inter- and intraobserver analyses were performed. RESULTS: At pathology 22 lesions were benign, 65 were malignant, and 23 were excluded. The ADCs of malignant and benign lesions were statistically different. In malignant tumors the ADC was (mean +/- SEM) 0.95 +/- 0.027 x 10(-3)mm(2)/second, and in benign tumors it was 1.51 +/- 0.068 x 10(-3)mm(2)/second. According to receiver operating characteristic (ROC) curves, we found a threshold between malignant and benign lesions for highest sensitivity and specificity (both 86%) around 1.13 +/- 0.10 x 10(-3)mm(2)/second. For a threshold of 0.95 +/- 0.10 x 10(-3)mm(2)/second, specificity was 100% but sensitivity was very low. Inter- and intraobserver studies showed good reproducibility. CONCLUSION: The ADC may help to differentiate benign and malignant lesions with good specificity, and may increase the overall specificity of breast MRI.

Adult↗

PubMed2006

Elastase-induced pulmonary emphysema in rats: comparison of computed density and microscopic morphometry.

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.

Animals↗

PubMed2006

Accuracy of MDCT in predicting site of gastrointestinal tract perforation.

OBJECTIVE: The purpose of this study was to prospectively evaluate the accuracy of MDCT for preoperative determination of the site of surgically proven gastrointestinal tract perforations and to determine the most predictive findings in this diagnosis. SUBJECTS AND METHODS: We prospectively studied 85 consecutive patients with extraluminal air on MDCT who had surgically proven gastrointestinal tract perforations. All patients underwent surgery within 12 hours after MDCT was performed. Two experienced radiologists, blinded to the surgical diagnosis, reached a consensus prediction of the site of the perforation using the following eight MDCT findings: concentration of extraluminal air bubbles adjacent to the bowel wall, free air in supramesocolic or inframesocolic compartments, extraluminal air in both abdomen and pelvis, focal defect in the bowel wall, segmental bowel-wall thickening, perivisceral fat stranding, abscess, and extraluminal fluid. MDCT imaging results were compared with surgical and pathologic findings. Logistic regression analyses were performed to assess the significance of the different radiologic criteria. RESULTS: Analysis of MDCT images was predictive of the site of gastrointestinal tract perforation in 73 (86%) of 85 patients. Logistic regression showed that concentration of extraluminal air bubbles (p < 0.001), segmental bowel wall thickening (p < 0.001), and focal defect of the bowel wall (p = 0.007) were strong predictors of the site of bowel perforation. CONCLUSION: MDCT is highly accurate for predicting the site of gastrointestinal tract perforations. Three of eight CT findings significantly correlate with surgical diagnosis.

Abdomen, Acute↗

PubMed2005

Suspected acute colon diverticulitis: imaging with low-dose unenhanced multi-detector row CT.

PURPOSE: To prospectively compare the sensitivity and specificity of unenhanced low-dose multi-detector row computed tomography (CT) with those of contrast material-enhanced standard-dose multi-detector row CT in patients suspected of having acute diverticulitis. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. One hundred ten consecutive patients (40 men, 70 women; age range, 30-82 years; mean, 57 years) suspected of having acute diverticulitis underwent unenhanced multi-detector row CT with 4 x 2.5-mm collimation, 120 kVp, and 30 effective mAs, as well as contrast-enhanced standard-dose multi-detector row CT with the same parameters but with 120 mAs. All scans were independently read by four readers. Intra- and interobserver agreements were calculated with the kappa statistic. Contrast-enhanced standard-dose scans read by three other experts and considered together with results from colonoscopy, surgery, and pathologic evaluation were used as reference. Differences in sensitivity and specificity between readers, radiation doses, and reading sessions were investigated. Pearson exact test and logistic regression models were used. RESULTS: Colon diverticulitis was present in 39 patients (34%) and was graded as mild in 22 patients (56%) and severe in 17 (44%). Agreement within and between readers was good to excellent. No significant difference was observed in sensitivity (P ranging from .081 to >.99) or in specificity (P ranging from .326 to >.99) for any sign or overall diagnosis between radiation doses by all readers, except wall thickening, which for one reader had a higher specificity at low dose than at standard dose (P = .025). No significant difference in misclassification was detected between doses, regardless of the reader (P ranging from .481 to >.99). At both doses, the most predictive sign for acute diverticulitis was retroperitoneal fat stranding (P < .001). CONCLUSION: Low-dose unenhanced multi-detector row CT has a diagnostic performance similar to that of contrast-enhanced standard-dose multi-detector row CT in patients suspected of having acute diverticulitis.

Acute Disease↗

PubMed2005

Multi-detector row CT pulmonary angiography: comparison of standard-dose and simulated low-dose techniques.

PURPOSE: To compare standard-dose and simulated low-dose multi-detector row computed tomography (CT) pulmonary angiography. MATERIALS AND METHODS: The institutional review board approved the study protocol and waived patient informed consent because the study was based on existing data. Raw data from 21 CT scans obtained at 90 mAs (effective) in 11 women and 10 men aged 25-74 years (mean, 52 years) that showed at least one filling defect within a pulmonary artery were used to simulate CT pulmonary angiography with reduced radiation doses, at 60, 40, 20, and 10 mAs. Three independent readers coded each central and segmental pulmonary artery twice as positive, negative, or inconclusive for presence of a filling defect. The second reading of images obtained with 90 mAs was considered the reference standard. The potential dependence of results on reader, radiation dose, and/or pulmonary artery segment was investigated with analysis of variance. Positive and negative consistent values were calculated for standard-dose scans and simulated low-dose scans in the first reading session. The branching order of the artery with the most distal filling defect was recorded. The quality of intravascular contrast at each tube current-time product setting was scored on a five-point scale. Interreader agreement was investigated with kappa statistics. RESULTS: The frequencies of positive and inconclusive results (P = .21 and .08, respectively), positive and negative consistent values (P = .19 and .34, respectively), and branching order of the most distal artery with a filling defect (P = .41) did not depend on the radiation dose. Values for inter- and intrareader agreement were higher for central arterial segments than for branch arteries but were not influenced by dose reduction, regardless of arterial segment. The quality of intravascular contrast was not significantly changed when the tube current-time product was reduced from 90 to 40 mAs (P = .10 to >.99). CONCLUSION: The evaluated parameters remained stable when tube current-time product was reduced from 90 (effective) to 10 (simulated) mAs at multi-detector row CT pulmonary angiography.

Adult↗

PubMed2005

Comparison of US and unenhanced multi-detector row CT in patients suspected of having acute appendicitis.

PURPOSE: To prospectively compare the diagnostic performance of ultrasonography (US) and unenhanced multi-detector row computed tomography (CT) in patients suspected of having acute appendicitis by using surgery or clinical follow-up as the reference standard. MATERIALS AND METHODS: The institutional review board approved the research protocol. Written informed consent was obtained from all patients or, for those who were adolescents, from their parents. Ninety-four patients (59 female and 35 male patients) aged 16-81 years (mean, 38 years) who were suspected of having acute appendicitis underwent both US and unenhanced multi-detector row CT of the entire abdomen. The examinations were performed within 1-2 hours of each other. US and CT images were obtained and prospectively interpreted by a different radiologist from a group of abdominal radiologists or a group of residents and general radiologists. Radiologists proposed an overall diagnosis and an alternative diagnosis. Data from US and CT were compared, and the definite diagnosis was established with surgical findings (n = 40) or results of clinical follow-up (n = 54) as the reference standard. Comparisons were made for each group of radiologists and the patient's age, body mass index (BMI), and sex. Proportion comparisons were made by using the Pearson chi2 test or the Fisher exact test. Continuous variables were compared between groups with the Mann-Whitney U test. RESULTS: Thirty patients had definite appendicitis. The sensitivity, specificity, positive and negative predictive values, and accuracy were not significantly different between US and CT or between groups of radiologists (P values ranged from .389 to >.99), regardless of the patient's BMI (P values ranged from .073 to >.99). Misclassifications were compared with the definite alternative diagnosis and were not significantly different between US and CT or between groups of radiologists (P = .061-.592), regardless of patient age (P = .875) or sex (P = .151 and >.99 for male and female patients, respectively). The frequency of inconclusive examinations, however, was significantly higher with US than with CT, regardless of radiologist experience (P = .020 and <.001, respectively). CONCLUSION: Although the diagnostic performances of US and multi-detector row CT are comparable, more inconclusive images were obtained with US.

Acute Disease↗

PubMed2005

Silicosis: expiratory thin-section CT assessment of airway obstruction.

PURPOSE: To prospectively evaluate if findings on paired inspiratory and expiratory thin-section computed tomographic (CT) scans in patients with silicosis correlate with pulmonary function test results. MATERIALS AND METHODS: Institutional review board approval and patient consent were obtained. Thirty-seven men (mean age, 71 years; range, 53-88 years) with silicosis were included. All patients had undergone inspiratory and expiratory thin-section CT and spirometry. Silicotic nodules, large opacity, emphysema, reticular opacities, bronchiectasis, and air trapping were graded subjectively on CT images. Emphysema was quantified on these images with built-in software. CT numbers were correlated with spirometric findings by using Spearman rank correlation analyses. Ten healthy volunteers (three men and seven women; mean age, 58 years) served as control subjects. RESULTS: After exclusion of three patients with inadequate image quality, 34 patients (mean age, 70 years; range, 53-88 years) were enrolled in the study group. Spirometric values did not differ significantly between patients with simple (n = 20) and patients with complicated (n = 14) silicosis but were significantly lower in patients than in control subjects. CT findings included air trapping (n = 33), emphysema (n = 26), nodules (n = 32), bronchiectasis (n = 22), large opacity (n = 19), and reticulation (n = 5). The extent of both air trapping and emphysema correlated negatively with spirometric values; the air trapping score showed the strongest correlation (ratio of forced expiratory volume in 1 second to forced vital capacity [FVC]: rho = -0.632, P < .001; forced expiratory flow at 50% of the FVC: rho = -0.576, P = .001). Silicotic nodule, large opacity, and bronchiectasis scores did not correlate with obstructive functional impairments. CONCLUSION: In comparison with the spirometric value, the extent of air trapping proved the best CT index in the assessment of obstructive derangement in workers with exposure to silica dust.

Aged↗

PubMed2004

Impact of lung volume on MR signal intensity changes of the lung parenchyma.

PURPOSE: To test the hypothesis that, in magnetic resonance (MR) imaging of healthy individuals, equal relative changes in lung volume cause equal relative changes in MR signal intensity of the lung parenchyma. MATERIALS AND METHODS: In two experimental runs, 10 volunteers underwent spirometrically monitored MR imaging of the lungs, with MR images acquired at 10 incremental lung volumes ranging from total lung capacity to 10% above residual volume. Average signal intensity, signal variability, and signal intensity integrals were calculated for each volunteer and for each lung volume. The effect of lung volume on signal intensity was quantified using linear regression analysis complemented by the runs test. Slopes and intercepts of regression lines were compared with an analysis of covariance. Slopes of the lines of best fit for lung volumes and signal intensities from the two runs were compared to the slope of the line of identity. Comparisons between the two runs were visualized using Bland and Altman plots. RESULTS: The slopes of the 10 individual regression lines yielded no significant differences (F = 1.703, P = 0.101; F = 1.321, P = 0.239). The common slopes were -0.556 +/- 0.027 (P = 0.0001) for the first and -0.597 +/- 0.0031 (P = 0.0001) for the second experimental run. Both slopes displayed no significant nonlinearity (P = 0.419 and P = 0.067). There was a strong association between changes in lung volumes (rs = 0.991, P = 0.0001) and changes in signal intensity (rs = 0.889, P = 0.0001) in the two experimental runs. Lines of best fit for lung volume and signal intensities were not significantly different from the slope of the line of identity (P = 0.321 and P = 0.212, respectively). CONCLUSION: Equal changes in lung volume cause equal changes in MR signal intensity of the lung parenchyma. This linear and reproducible phenomenon could be helpful in comparing pulmonary MR signal intensity between individuals.

Adult↗

PubMed2004

Treatment of osteonecrosis of the femoral head with implantation of autologous bone-marrow cells. A pilot study.

BACKGROUND: Aseptic nontraumatic osteonecrosis of the femoral head is a disorder that can lead to femoral head collapse and the need for total hip replacement. Since osteonecrosis may be a disease of mesenchymal cells or bone cells, the possibility has been raised that bone marrow containing osteogenic precursors implanted into a necrotic lesion of the femoral head may be of benefit in the treatment of this condition. For this reason, we studied the implantation of autologous bone-marrow mononuclear cells in a necrotic lesion of the femoral head to determine the effect on the clinical symptoms and the stage and volume of osteonecrosis. METHODS: We studied thirteen patients (eighteen hips) with stage-I or II osteonecrosis of the femoral head, according to the system of the Association Research Circulation Osseous. The hips were allocated to a program of either core decompression (the control group) or core decompression and implantation of autologous bone-marrow mononuclear cells (the bone-marrow-graft group). Both patients and assessors were blind with respect to treatment-group assignment. The primary outcomes studied were safety, clinical symptoms, and disease progression. RESULTS: After twenty-four months, there was a significant reduction in pain (p = 0.021) and in joint symptoms measured with the Lequesne index (p = 0.001) and the WOMAC index (p = 0.013) within the bone-marrow-graft group. At twenty-four months, five of the eight hips in the control group had deteriorated to stage III, whereas only one of the ten hips in the bone-marrow-graft group had progressed to this stage. Survival analysis showed a significant difference in the time to collapse between the two groups (p = 0.016). Implantation of bone-marrow mononuclear cells was associated with only minor side effects. CONCLUSIONS: Implantation of autologous bone-marrow mononuclear cells appears to be a safe and effective treatment for early stages of osteonecrosis of the femoral head. Although the findings of this study are promising, their interpretation is limited because of the small number of patients and the short duration of follow-up. Further study is needed to confirm the results.

Adult↗

PubMed2003

Predictive value of electrophysiology in children with hypoxic coma.

Assessment of prognosis of children in hypoxic coma is difficult. The value of clinical evaluation is often limited. The usefulness of electrophysiologic tests has been documented mostly in adults and neonates and in cases of traumatic coma. We reviewed retrospectively 39 consecutive children with nontraumatic hypoxic coma to assess the prognostic value of EEG, visual, and auditory evoked potentials. Correlation between electrophysiology and neurologic outcome after mean follow-up period of 30 months was significant (r(s) = 0.6, P < 0.001). In contrast there was no correlation between Pediatric Risk of Mortality score (PRISM) and outcome (r(s) = -0.42, P = 0.8). Combining magnetic resonance imaging with electrophysiology further enhanced their prognostic value (r(s) = 0.69, P < 0.001). Neuroimaging was highly sensitive but less specific, and electrophysiologic tests were highly specific but less sensitive. We conclude that early electrophysiology can contribute to predicting outcome in pediatric hypoxic coma.

Adolescent↗

PubMed2003

Air trapping in heart-lung transplant recipients: variability of anatomic distribution and extent at sequential expiratory thin-section CT.

PURPOSE: To evaluate the intrapatient reproducibility of the extent and anatomic distribution of air trapping at sequential expiratory thin-section computed tomographic (CT) examinations in heart-lung transplant recipients. MATERIALS AND METHODS: Nineteen heart-lung transplant recipients (eight with and 11 without bronchiolitis obliterans syndrome [BOS]) underwent three expiratory CT examinations within 1 hour. Residual volumes were measured at CT. Anatomic distribution and extent of air trapping were scored by two observers at two independent readings, and the reproducibility of observations was calculated for each feature. CT examination results were compared by using an analysis of variance that took into account interobserver and BOS and non-BOS effects. The Spearman rank correlation coefficient was calculated to test the association between variability of residual volumes and variability of the extent of air trapping. RESULTS: Residual volumes did not significantly differ between the three CT examinations (P =.556). Reproducibility values for findings of anatomic distribution of air trapping ranged from 84% to 95%, with a tendency toward improved reproducibility in patients without BOS. Mean reproducibility values for the extent of air trapping ranged from 97.1% to 97.7%, and no substantial difference in these values between patients with and those without BOS was observed. The Spearman rank coefficient for the correlation between variability of residual volumes and variability of extent of air trapping ranged from 0.382 to 0.568 (P =.105-.016). No interobserver effect was detected (P =.944). CONCLUSION: Anatomic distribution and extent are reproducible characteristics of air trapping. No substantial variability of air trapping occurs in functionally stable heart-lung transplant recipients.

Adult↗

PubMed2003

Dose reduction in multidetector CT using attenuation-based online tube current modulation.

OBJECTIVE: This study was designed to quantify the radiation dose saved by attenuation-based online tube current modulation applied to multidetector CT (MDCT) of the adult trunk as a function of effective milliampere-second (mAs) presets, sex, and body habitus. SUBJECTS AND METHODS. One hundred twenty patients underwent MDCT of the trunk (60 thoracic, 60 abdominal) with an attenuation-based online tube current modulation. Consecutive acquisitions at standard and two lower effective mAs presets were obtained in each patient. Mean percentage effective mAs reductions were compared for each effective mAs preset, taking into account sex and body mass index. RESULTS: Mean effective mAs reduction was 16.9% and 20.0% for the chest and the abdomen, respectively. Mean percentage effective mAs reductions were found to be significantly different for sex (chest, p = 0.003; abdomen, p = 0.002) but not significantly different for the different effective mAs presets or body mass index. CONCLUSION: Attenuation-based online tube current modulation used with MDCT should be considered as a secondary tool of radiation dose reduction because it saves as much as 20% of the radiation dose on the adult trunk, regardless of initial mAs preset. However, initial decreases of mAs presets by the physician should be considered the primary tool for radiation dose reduction.

Adult↗

PubMed2003

Comparison between low-dose and standard-dose multidetector CT in patients with suspected chronic sinusitis.

OBJECTIVE: This study was designed to compare low- and standard-dose multidetector CT (MDCT) findings in patients with suspected chronic sinusitis. SUBJECTS AND METHODS. Fifty patients underwent MDCT at 10 and 150 effective mAs. The low-dose MDCT protocol delivered a radiation dose of 0.047 mSv in men and 0.051 mSv in women, whereas the standard-dose MDCT protocol delivered a radiation dose of 0.70 mSv in men and 0.76 mSv in women. Scans of the right and left sides of sinonasal cavities were reviewed by three radiologists, with each physician reviewing a scan twice over an interval of more than 2 weeks. The reviewers were asked to evaluate the scans for eight mucosal and two bone abnormalities. We calculated the number of discrepancies in observed abnormalities between pairs of reviewers, among all three reviewers, and between findings on scans acquired with the two radiation doses. RESULTS: The mean number of discrepancies in observed abnormalities on scans acquired with different radiation doses ranged from 0 to 5.2. Discrepancies between pairs of reviewers ranged from 1.0 to 12.8 for low-dose scans and from 1.0 to 13.0 for standard-dose scans. Discrepancies among all reviewers ranged from 1.0 to 10.3 for low-dose scans and from 1.0 to 8.7 for standard-dose scans. In analyzing cases of significant discrepancies in observations, we found greater variation between pairs of reviewers and among all three reviewers than between findings obtained with different dose levels. CONCLUSION: Dose reduction played a far less important role in discrepancies of detected abnormalities than did the human element of reviewer observation. Given this finding and the fact that low-dose MDCT delivers a radiation dose that is no higher than that delivered by a four-view radiographic examination, low-dose MDCT should be considered the imaging method of choice in patients with suspected chronic sinusitis.

Adolescent↗

PubMed2002

The evaluation by magnetic resonance imaging of hepatic periportal fibrosis in infants with neonatal cholestasis: preliminary report.

PURPOSE: The aim of this study was to evaluate the potential role of magnetic resonance (MR) imaging cholangiography for the assessment of periportal fibrosis associated with neonatal cholestasis. METHODS: The authors have compared the findings on MR imaging cholangiography and on pathology in 10 infants evaluated because of neonatal cholestasis. The series included 3 patients with biliary atresia (BA), 3 patients with choledocal cyst, 2 with a neonatal hepatitis, and 2 with an inspissated bile syndrome. MR examinations were performed on a 0.5 Tesla magnet unit using Turbo Field Echo T1 and Turbo spin echo T2 sequences. A periportal hyposignal paralleling the portal vein branches and disappearing after Gadolinium injection was considered consistent with periportal fibrosis. The final type of hepatobiliary anomaly was established based on surgery (n = 6) or on laparoscopic cholangiogram (n = 10). The degree of periportal fibrosis was evaluated on pathology using a grading system from grade 0 (no fibrosis) to 4 (fibrosis with cirrhosis). The relationship between periportal hyposignal and fibrosis was tested using the exact chi2 test. RESULTS: MR imaging assessed correctly and more completely than ultrasound scan the morphology of the biliary tract in all 10 patients. A periportal hyposignal was present in the 3 patients with BA (2 patients displayed a grade 3 and one a grade 4 fibrosis on pathology) and in one with choledocal cyst (grade 3 fibrosis on pathology). No hyposignal was visualized in the 2 other patients with a choledocal cyst (grades 1 and 2), in the 2 patients with neonatal hepatitis (grades 1 and 2), or in the 2 patients with inspissated bile syndrome (both grade 0). A relationship between the hyposignal seen on MR and the degree of fibrosis seen on pathology was confirmed by the exact chi2 test (P =.019). CONCLUSIONS: This preliminary series confirms the potential role of MR imaging for the assessment of the morphology of the abnormal biliary tract and of the degree of periportal fibrosis. The presence of an hyposignal on an echo gradient TFE T1 sequence suggests an advanced fibrosis (grade 3 and higher).

Biliary Atresia↗

PubMed2002

Value of MR imaging of the brain in children with hypoxic coma.

BACKGROUND AND PURPOSE: The contribution of MR imaging to identify hypoxic-ischemic injuries has been studied mostly in neonates or adults. The purpose of this study was to describe the MR imaging findings of toddlers and older children with hypoxic coma and to analyze the prognostic value of an MR imaging scoring system. METHODS: The conditions of 40 children with hypoxic coma (age range, 6 weeks to 18 years) were clinically graded according to the pediatric risk of mortality score, and MR imaging studies were performed. Sixty-four MR imaging studies were distributed in five categories according to their timing relative to the hypoxic event: days 1 through 3, 4-7, 8-15, 16-50, and after day 50. These were evaluated retrospectively by using an eight-point scoring system based on two lesion categories assessing watershed areas and basal ganglia involvement, including signal intensity and morphologic features with respect to maturation-related norms. Two age groups (< or =1 year and >1 year) were considered. The surviving children were grouped according to neurologic outcome. RESULTS: The occurrence of watershed areas or basal ganglia involvement was not significantly different in association with age. Sixteen children died. Twelve children had moderate to severe sequelae resulting from neurodevelopmental disabilities, and 12 had good neurologic outcomes. There was no correlation between pediatric risk of mortality score and neurologic evolution. There was a strong correlation between first MR imaging score (P <.001) and neurologic outcome. The sensitivity of the first MR imaging score was high (96%), even when obtained during the first 3 days, with a specificity of 50% and a positive predictive value of 82%. Six patients with definite abnormal MR imaging findings experienced good neurologic outcomes. CONCLUSION: The MR imaging scoring system proposed in this study can be used to establish an early prognosis in a significant proportion of children with hypoxic coma. It is helpful, even during the first 3 days after the event. However, some patients with definite abnormal MR imaging findings may experience good neurologic evolution.

Adolescent↗

PubMed2002

Impact of dental and skeletal movements on the facial profile within the framework of orthodontic and surgical treatments.

The impact of dental and skeletal movements on the soft tissues during orthodontic and surgical treatments is widely known. Most studies are limited to examining the repercussions of a dental or skeletal movement on a given soft tissue point. The uniqueness of the present study, carried out on 95 patients, lies in the examination of the impact of movements of various landmarks--2 dental points (incision superius and incision inferius) and 4 skeletal points (anterior nasal spine, point A, point B, andpogonion)--on 7 soft tissue landmarks (from the tip of the nose to soft tissue pogonion). The study was carried out with the purpose of providing a simple, practical, and accurate tool for clinical use to assist in treatment planning. This article outlines the main aspects of the tool while specifying its limitations and error margins.

Adolescent↗