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Biomedical subjects

A Guermazi

Publications and source records attributed to A Guermazi.

At least 19 recordsLinked to original sources
PubMed2006

Cigarette smoking and the risk for cartilage loss and knee pain in men with knee osteoarthritis.

OBJECTIVE: To examine the effects of smoking on cartilage loss and pain at the knee in individuals with knee osteoarthritis. METHODS: 159 men with symptomatic knee osteoarthritis who participated in a 30-month, prospective, natural history study of knee osteoarthritis were examined. The more symptomatic knee was imaged using magnetic resonance imaging (MRI) at baseline, and again at 15 and 30 months of follow-up. Cartilage was scored using the Whole-Organ MRI Score semiquantitative method at the medial and lateral tibiofemoral joints and at the patellofemoral joint. At baseline and follow-up visits, the severity of knee pain was assessed using a Visual Analogue Scale pain score (0-100 mm). RESULTS: Among the 159 men, 19 (12%) were current smokers at baseline. Current smokers were younger (mean (standard deviation (SD)) age 62 (9) v 69 (9) years) and leaner (mean (SD) body mass index (BMI): 28.9 (3.2) v 31.3 (4.8) kg/m(2)) than men who were not current smokers. When adjusted for age, BMI and baseline cartilage scores, men who were current smokers were found to have an increased risk for cartilage loss at the medial tibiofemoral joint (odds ratio (OR) 2.3, 95% confidence interval (CI) 1.0 to 5.4) and the patellofemoral joint (OR 2.5, 95% CI 1.1 to 5.7). Current smokers also had higher adjusted pain scores at baseline (60.5 v 45.0, p<0.05) and at follow-up (59.4 v 44.3, p<0.05) than men who were not current smokers. CONCLUSIONS: Men with knee osteoarthritis who smoke sustain greater cartilage loss and have more severe knee pain than men who do not smoke.

Aged↗
PubMed2006

Urinary pentosidine does not predict cartilage loss among subjects with symptomatic knee OA: the BOKS Study.

OBJECTIVE: Age-related changes in articular cartilage are likely to play a role in the etiology of osteoarthritis (OA). One of the major changes in the extracellular matrix of cartilage is the age-related accumulation of advanced glycation end products (AGEs). Pentosidine, an AGE crosslink, is one of the few characterized AGEs and is considered an adequate marker for the many AGEs that are formed in vivo. We used data from a longitudinal observation study to determine if urinary pentosidine could serve as a marker to predict cartilage loss. METHODS: We conducted a prospective analysis of data from the Boston Osteoarthritis of the Knee Study (BOKS); a completed natural history study of knee OA. All subjects in the study met American College of Rheumatology (ACR) criteria for knee OA. Knee magnetic resonance (MR) images were scored for cartilage in 14 plates of the knee using the Whole Organ Magnetic Resonance Imaging Score (WORMS) semiquantitative grading scheme. Within the BOKS population, a nested sample of 127 subjects (39% of the whole sample) who had both baseline pentosidine and longitudinal magnetic resonance imaging (MRI) measurements (MRIs performed at baseline and 30 months later) was assessed. Urinary pentosidine was assayed and normalized to creatinine to account for differences in urine concentrations. We analyzed the data using three different methods to assess if baseline measures of pentosidine predicted subsequent cartilage loss on MRI. These were (1) analysis 1: logistic regression with the outcome cartilage loss in any plate; (2) analysis 2: proportional odds model where the outcome was defined as 0=no cartilage loss, 1=cartilage loss in one plate, 2=cartilage loss in two plates, and 3=cartilage loss in at least three plates; and (3) analysis 3: Poisson regression with the outcome the number of plates with cartilage loss. All analyses were adjusted for age, sex and Body Mass Index (BMI). RESULTS: At baseline the mean (standard deviation) age was 67 (9) years and 54% were male. The results for the three analytic steps are as follows: Analysis 1: the odds ratio for cartilage loss is 1.01 (95% confidence interval (CI) 0.93-1.09) with 1 unit increase in pentosidine. Analysis 2: the odds ratio for more cartilage loss is 0.99 (95% CI 0.92-1.06) with 1 unit increase in pentosidine. Analysis 3: the relative number of plates with cartilage loss decreased was 1.00 (95% CI 0.95-1.03) with a 1 unit increase in pentosidine. CONCLUSION: Urinary pentosidine does not predict knee cartilage loss. Previous studies have suggested that local content within cartilage of AGEs is elevated in persons at high risk for progression. Our data suggest that these changes are not measurable systemically. Alternatively, urinary pentosidine levels reflect cartilage degradation in all joints (thus whole body cartilage breakdown) and may therefore not relate to OA severity in a single knee joint.

Aged↗
PubMed2006

The relationship between specific tissue lesions and pain severity in persons with knee osteoarthritis.

INTRODUCTION: Pain is the most common symptom in knee osteoarthritis (OA), a leading cause of chronic disability, and a major source of the disability attributable to OA in general. Pain severity in knee OA is variable, ranging from barely perceptible to immobilizing. The knee lesions that contribute to pain severity have received little attention. OBJECTIVE: To examine whether worse pathology of specific knee tissues - i.e. cartilage, bone (attrition, cysts, bone marrow lesions, and osteophytes), menisci (tears and subluxation), ligaments, and synovium (synovitis/effusion) - is associated with more severe knee pain. METHODS: One hundred and forty-three individuals were recruited from the community with primary (idiopathic) knee OA, with definite tibiofemoral osteophytes in at least one knee, and at least some difficulty with knee-requiring activity. Knee magnetic resonance (MR) images were acquired using coronal T1-weighted spin-echo (SE), sagittal fat-suppressed dual-echo turbo SE, and axial and coronal fat-suppressed, T1-weighted 3D-fast low angle shot (FLASH) sequences. The whole-organ magnetic resonance imaging (MRI) scoring (WORMS) method was used to score knee tissue status. Since summing tissue scores across the entire joint, including regions free of disease, may dilute the ability to detect a true relationship between that tissue and pain severity, we used the score from the worst compartment (i.e. with the poorest cartilage morphology) as our primary approach. Knee pain severity was measured using knee-specific, 100 mm visual analogue scales. In analyses to evaluate the relationship between knee pain severity and lesion score, median quantile regression was used, adjusting for age and body mass index (BMI), in which a 95% CI excluding 0 is significant. RESULTS: The increase in median pain from median quantile regression, adjusting for age and BMI, was significant for bone attrition (1.91, 95% confidence interval (CI) 0.68, 3.13), bone marrow lesions (3.72, 95% CI 1.76, 5.68), meniscal tears (1.99, 95% CI 0.60, 3.38), and grade 2 or 3 synovitis/effusion vs grade 0 (9.82, 95% CI 0.38, 19.27). The relationship with pain severity was of borderline significance for osteophytes and cartilage morphology and was not significant for bone cysts or meniscal subluxation. Ligament tears were too infrequent for meaningful analysis. When compared to the pain severity in knees with high scores for both bone attrition and bone marrow lesions (median pain severity 40 mm), knees with high attrition alone (30 mm) were not significantly different, but knees with high bone marrow lesion without high attrition scores (15 mm) were significantly less painful. CONCLUSION: In persons with knee OA, knee pain severity was associated with subarticular bone attrition, bone marrow lesions, synovitis/effusion, and meniscal tears. The contribution of bone marrow lesions to pain severity appeared to require the presence of bone attrition.

Aged↗
PubMed2006

Responsiveness, effect size, and smallest detectable difference of Magnetic Resonance Imaging in knee osteoarthritis.

OBJECTIVE: The aim of this study was to determine the responsiveness, effect size (ES) and smallest detectable difference (SDD) of two Magnetic Resonance Imaging (MRI) measures for osteoarthritis (OA) of the knee: a whole-organ semiquantitative evaluation and cartilage volume. DESIGN: This analysis was performed on a dataset from a randomized, double-blind trial (Roche NI-15713) conducted in 1998 of a novel therapy in subjects with mild-moderate knee OA, with MRI at baseline and 6-month follow-up. The trial measurements included (1) cartilage volume measured using a proprietary software method; and (2) semiquantitative scoring of other parameters important for "whole organ" evaluation of OA knee joint pathology, using the Whole-Organ MRI Score (WORMS). The analysis initially examined the distributional characteristics of WORMS items, such as cartilage morphology. Standardized response mean (SRM), ES, and SDD between baseline and 6-month follow-up were then calculated in the whole group and the placebo group alone. RESULTS: In general, the differences were small and this was reflected in the small ESs and SRMs. There was also a suggestion of a treatment effect with reduction in differences between baseline and follow-up in the treatment group. CONCLUSION: Of the MRI semiquantitative measures, cartilage morphology, synovitis and osteophytes appeared to be responsive to change and the focus of repeat measures should highlight these articular features. In general, the ESs and SRMs were small.

Adult↗
PubMed2006

Examining a whole-organ magnetic resonance imaging scoring system for osteoarthritis of the knee using Rasch analysis.

OBJECTIVE: The ability to reliably quantify all the structural abnormalities in osteoarthritis (OA) of the knee is a long-standing goal of OA research. On December 5 and 6, 2002, Outcome Measures in Rheumatology Clinical Trials and Osteoarthritis Research Society, International held a Workshop for Consensus on Osteoarthritis Imaging in Bethesda, MD, with the aim of providing a state-of-the-art review of imaging outcome measures for OA of the knee. As part of the Workshop, data from previous clinical trials and epidemiological studies of OA were analysed with respect to the metrological properties of the measurement methods used. The following report outlines the results of analyses aimed at evaluating the internal construct validity of a whole-organ, ordinal (semi-quantitative) magnetic resonance imaging score (WORMS) using Rasch analysis. The fit of data to the Rasch model offers a measure of the validity of summing different items into a subscale score and the degree to which this score behaves as a unidimensional, interval level measurement tool. METHODS: The Rasch model was applied in two OA studies. The first was a clinical cohort comprising OA knee subjects entering a clinical trial; study entry criteria included patients with at least moderate pain, radiographic osteophytes and a minimum of 1.5mm tibiofemoral joint-space width. The second cohort was from the Boston Osteoarthritis Knee Study, an observational cohort of subjects with symptomatic knee OA with pain on most days and a definite osteophyte in either the tibiofemoral or patellofemoral joints. Baseline WORMS scores from both studies were used for the Rasch analysis, performed with RUMM 2020 software. RESULTS: There was a substantial proportion of subjects in both study populations with zero scores in several of the subscales of WORMS. Few of the subscales met the requirements of the Rasch measurement model when summated across all sites, and summations of some postulated compartmentally based sites also failed to fit the Rasch model. The existing scoring categories also required rescoring at many sites. CONCLUSION: There remain important issues in constructing outcome measurements that summate different features across multiple anatomical sites. The whole-organ scoring system evaluated here is no exception. Resolving these issues will improve the ability of imaging studies to assess complex pathological structural change.

Adult↗
PubMed2006

High signal in knee osteophytes is not associated with knee pain.

OBJECTIVE: Our understanding of the local source of pain in osteoarthritis (OA) remains unclear. We undertook this study to determine if the presence of high-signal osteophytes on magnetic resonance imaging (MRI) was associated with pain presence, location or severity. METHODS: Subjects were chosen from the Boston Osteoarthritis of the Knee Study, a natural history study of symptomatic knee OA. Assessments included knee MRI, pain assessments and information on weight and height. Osteophyte signal was defined as areas of increased signal intensity in the osteophyte on fat-suppressed T2 weighted images, and graded in the joint margins where osteophyte size is graded. All patients were evaluated with the frequent knee symptoms question for pain presence, the Western Ontario McMasters Osteoarthritis Index (WOMAC) for pain severity, and location of self-reported pain was recorded as present or absent based on locations identified on a standardized diagram. The osteophyte signal measures anywhere within one given knee were summed, creating an osteophyte signal aggregate. Logistic regression was conducted with quartile of osteophyte signal aggregate as the independent predictor and frequent knee symptom question as the dependent outcome. Association between quartile of osteophyte signal aggregate and pain severity on WOMAC was assessed using a linear regression. Logistic regression was used to evaluate the association between compartment-specific high-signal osteophytes aggregates (independent variable) and compartment-specific knee pain (dependent variable). Analyses were adjusted for gender, body mass index (BMI), and age. RESULTS: Two hundred and seventeen subjects were included in this analysis. They were predominantly male and 75% of subjects had radiographic tibio-femoral (TF) OA, and the remainder had patello-femoral (PF) radiographic OA. We did not find any association of high-signal osteophytes with presence of pain, pain severity or self-reported pain location. CONCLUSION: High-signal osteophytes detected on MRI are not associated with the presence of pain, pain severity or the self-reported location of pain.

Aged↗
PubMed2006

The association of meniscal pathologic changes with cartilage loss in symptomatic knee osteoarthritis.

OBJECTIVE: To explore the role of meniscal tears and meniscal malposition as risk factors for subsequent cartilage loss in subjects with symptomatic osteoarthritis (OA). METHODS: Study subjects were patients with symptomatic knee OA from the Boston Osteoarthritis of the Knee Study. Baseline assessments included knee magnetic resonance imaging (MRI) with followup MRI at 15 and 30 months. Cartilage and meniscal damage were scored on MRI in the medial and lateral tibiofemoral joints using the semiquantitative whole-organ magnetic resonance imaging score. Tibiofemoral cartilage was scored on MR images of all 5 plates of each tibiofemoral joint, and the meniscal position was measured using eFilm Workstation software. A proportional odds logistic regression model with generalized estimating equations was used to assess the effect of each predictor (meniscal position factor and meniscal damage as dichotomous predictors in each model) on cartilage loss in each of the 5 plates within a compartment. Models were adjusted for age, body mass index (BMI), tibial width, and sex. RESULTS: We assessed 257 subjects whose mean +/- SD age was 66.6 +/- 9.2 years and BMI was 31.5 +/- 5.7 kg/m2; 42% of subjects were female, and 77% of knees had a Kellgren/Lawrence radiographic severity grade > or = 2. In the medial tibiofemoral joint, each measure of meniscal malposition was associated with an increased risk of cartilage loss. There was also a strong association between meniscal damage and cartilage loss. Since meniscal coverage and meniscal height diminished with subluxation, less coverage and reduced height also increased the risk of cartilage loss. CONCLUSION: This study highlights the importance of an intact and functioning meniscus in patients with symptomatic knee OA, since the findings demonstrate that loss of this function has important consequences for cartilage loss.

Aged↗
PubMed2006

Lack of association between chondrocalcinosis and increased risk of cartilage loss in knees with osteoarthritis: results of two prospective longitudinal magnetic resonance imaging studies.

OBJECTIVE: To evaluate the relationship between chondrocalcinosis and the progression of knee osteoarthritis (OA) using longitudinal magnetic resonance imaging (MRI) assessments. METHODS: Longitudinal knee MRIs were obtained in the Boston OA Knee Study (BOKS) and in the Health, Aging and Body Composition (Health ABC) Study. Chondrocalcinosis was determined as present or absent on baseline knee radiographs. Cartilage morphology was graded on paired longitudinal MRIs using the Whole-Organ Magnetic Resonance Imaging Score in 5 cartilage subregions of each of the medial and lateral tibiofemoral joints. Cartilage loss in a subregion was defined as an increase in the cartilage score of > or = 1 (0-4 scale). The risk for change in the number of subregions with cartilage loss was assessed using Poisson regression, with generalized estimating equations to account for correlations. Analyses were adjusted for age, sex, body mass index, baseline cartilage score, and presence of damaged menisci. RESULTS: In BOKS, 23 of the 265 included knees (9%) had chondrocalcinosis. In Health ABC, 373 knees were included, of which 69 knees (18.5%) had chondrocalcinosis. In BOKS, knees with chondrocalcinosis had a lower risk of cartilage loss compared with knees without chondrocalcinosis (adjusted risk ratio [RR] 0.4, 95% confidence interval [95% CI] 0.2-0.7) (P = 0.002), and there was no difference in risk in Health ABC (adjusted RR 0.9, 95% CI 0.6-1.5) (P = 0.7). Stratification by intact versus damaged menisci produced similar results within each cohort. CONCLUSION: In knees with OA, the presence of chondrocalcinosis was not associated with increased cartilage loss. These findings do not support the hypothesis that chondrocalcinosis worsens OA progression.

Aged↗
PubMed2006

Change in joint space width: hyaline articular cartilage loss or alteration in meniscus?

OBJECTIVE: To explore the relative contribution of hyaline cartilage morphologic features and the meniscus to the radiographic joint space. METHODS: The Boston Osteoarthritis of the Knee Study is a natural history study of symptomatic knee osteoarthritis (OA). Baseline and 30-month followup assessments included knee magnetic resonance imaging (MRI) and fluoroscopically positioned weight-bearing knee radiographs. Cartilage and meniscal degeneration were scored on MRI in the medial and lateral tibiofemoral joints using a semiquantitative grading system. Meniscal position was measured to the nearest millimeter. The dependent variable was joint space narrowing (JSN) on the plain radiograph (possible range 0-3). The predictor variables were MRI cartilage score, meniscal degeneration, and meniscal position measures. We first conducted a cross-sectional analysis using multivariate regression to determine the relative contribution of meniscal factors and cartilage morphologic features to JSN, adjusting for body mass index (BMI), age, and sex. The same approach was used for change in JSN and change in predictor variables. RESULTS: We evaluated 264 study participants with knee OA (mean age 66.7 years, 59% men, mean BMI 31.4 kg/m(2)). The results from the models demonstrated that meniscal position and meniscal degeneration each contributed to prediction of JSN, in addition to the contribution by cartilage morphologic features. For change in medial joint space, both change in meniscal position and change in articular cartilage score contributed substantially to narrowing of the joint space. CONCLUSION: The meniscus (both its position and degeneration) accounts for a substantial proportion of the variance explained in JSN, and the change in meniscal position accounts for a substantial proportion of change in JSN.

Aged↗
PubMed2006

Assessment of the radioanatomic positioning of the osteoarthritic knee in serial radiographs: comparison of three acquisition techniques.

OBJECTIVE: Recent studies using various standardized radiographic acquisition techniques have demonstrated the necessity of reproducible radioanatomic alignment of the knee to assure precise measurements of medial tibiofemoral joint space width (JSW). The objective of the present study was to characterize the longitudinal performance of several acquisition techniques with respect to long-term reproducibility of positioning of the knee, and the impact of changes in positioning on the rate and variability of joint space narrowing (JSN). METHODS: Eighty subjects were randomly selected from each of three cohorts followed in recent studies of the radiographic progression of knee osteoarthritis (OA): the Health ABC study (paired fixed-flexion [FF] radiographs taken at a 36-month interval); the Glucosamine Arthritis Intervention Trial (GAIT) (paired metatarsophalangeal [MTP] radiographs obtained at a 12-month interval), and a randomized clinical trial of doxycycline (fluoroscopically assisted semiflexed anteroposterior (AP) radiographs taken at a 16-month interval). Manual measurements were obtained from each radiograph to represent markers of radioanatomic positioning of the knee (alignment of the medial tibial plateau and X-ray beam, knee rotation, femorotibial angle) and to evaluate minimum JSW (mJSW) in the medial tibiofemoral compartment. The effects on the mean annualized rate of JSN and on the variability of that rate of highly reproduced vs variable positioning of the knee in serial radiographs were evaluated. RESULTS: Parallel or near-parallel alignment was achieved significantly more frequently with the fluoroscopically guided positioning used in the semiflexed AP protocol than with either the non-fluoroscopic FF or MTP protocol (68% vs 14% for both FF and MTP protocols when measured at the midpoint of the medial compartment; 75% vs 26% and 34% for the FF and MTP protocols, respectively, when measured at the site of mJSW; P<0.001 for each). Knee rotation was reproduced more frequently in semiflexed AP radiographs than in FF radiographs (66% vs 45%, P<0.01). In contrast, the FF technique yielded a greater proportion of paired radiographs in which the femorotibial angle was accurately reproduced than the semiflexed AP or MTP protocol (78% vs 59% and 56%, respectively, P<0.01 for each). Notably, only paired radiographs with parallel or near-parallel alignment exhibited a mean rate of JSN (+/-SD) in the OA knee that was more rapid and less variable than that measured in all knees (0.186+/-0.274 mm/year, standardized response to mean [SRM]=0.68 vs 0.128+/-0.291 mm/year, SRM=0.44). CONCLUSION: This study confirms the importance of parallel radioanatomic alignment of the anterior and posterior margins of the medial tibial plateau in detecting JSN in subjects with knee OA. The use of radiographic methods that assure parallel alignment during serial X-ray examinations will permit the design of more efficient studies of biomarkers of OA progression and of structure modification in knee OA.

Doxycycline↗
PubMed2005

The dural tail sign--beyond meningioma.

There have been somewhat conflicting reports published about the significance of linear meningeal thickening and enhancement adjacent to peripherally located cranial mass lesions on contrast-enhanced magnetic resonance (MR) images. Most of the authors consider this so-called "dural tail sign" or "flare sign" almost specific for meningioma. This review illustrates the MR imaging findings of a wide spectrum of disorders that show this dural sign. Causes include other extra-axial lesions and also peripherally located intra-axial lesions such as neuromas, chloromas, metastases, lymphoma, gliomas, pituitary diseases, granulomatous disorders, and also cerebral Erdheim-Chester disease. The dural tail sign is not specific to a particular pathological process. Nevertheless, useful conclusions can be drawn from the morphology of the lesion, its enhancement pattern, and its solitary or multifocal presentation. The final diagnosis must be based on cerebrospinal fluid studies or histological studies after biopsy.

Adolescent↗
PubMed2005

Imaging of diffuse metastatic and dystrophic pulmonary calcification in children after haematopoietic stem cell transplantation.

The authors describe three cases of diffuse pulmonary calcification; two metastatic in children with acute transitory renal failure and the other dystrophic in a child with leukaemia. All three patients underwent haematopoietic stem cell transplantation (HSCT). Chest radiographs disclosed diffuse calcification within the lungs. The distribution of this calcification was bilateral but asymmetric. Diagnosis was made in two cases by high resolution computed tomography (HRCT) and in one case by HRCT and bone scan. Radiological characteristics, scintigraphic features, pathological mechanism and clinical outcome of such pulmonary calcification are discussed.

Acute Disease↗
PubMed2004

Whole-Organ Magnetic Resonance Imaging Score (WORMS) of the knee in osteoarthritis.

OBJECTIVES: To describe a semi-quantitative scoring method for multi-feature, whole-organ evaluation of the knee in osteoarthritis (OA) based on magnetic resonance imaging (MRI) findings. To determine the inter-observer agreement of this scoring method. To examine associations among the features included in the scoring method. METHODS: Nineteen knees of 19 patients with knee OA were imaged with MRI using conventional pulse sequences and a clinical 1.5 T MRI system. Images were independently analyzed by two musculoskeletal radiologists using a whole-organ MRI scoring method (WORMS) that incorporated 14 features: articular cartilage integrity, subarticular bone marrow abnormality, subarticular cysts, subarticular bone attrition, marginal osteophytes, medial and lateral meniscal integrity, anterior and posterior cruciate ligament integrity, medial and lateral collateral ligament integrity, synovitis/effusion, intraarticular loose bodies, and periarticular cysts/bursitis. Intraclass correlation coefficients (ICC) were determined for each feature as a measure of inter-observer agreement. Associations among the scores for different features were expressed as Spearman Rho. RESULTS: All knees showed structural abnormalities with MRI. Cartilage loss and osteophytes were the most prevalent features (98% and 92%, respectively). One of the least common features was ligament abnormality (8%). Inter-observer agreement for WORMS scores was high (most ICC values were >0.80). The individual features showed strong inter-associations. CONCLUSION: The WORMS method described in this report provides multi-feature, whole-organ assessment of the knee in OA using conventional MR images, and shows high inter-observer agreement among trained readers. This method may be useful in epidemiological studies and clinical trials of OA.

Aged↗
PubMed2004

Idiopathic systemic capillary leak syndrome: cutaneous involvement can be misleading.

BACKGROUND: Systemic capillary leak syndrome (SCLS) is a severe disorder characterized by unexplained rapid transfer of considerable volumes of plasma from the intravascular to the extravascular compartment. For some cases of SCLS, no aetiology is evident and these cases are reported as idiopathic (ISCLS). OBJECTIVES: To describe the cutaneous findings in 3 patients with ISCLS. RESULTS: Cutaneous involvement consisted in sclerosis, livedo, purpura and photodistributed maculopapular erythematous rash. Dermal mucinosis was proven by biopsy in 1 patient. No underlying disease was diagnosed during follow-up. CONCLUSION: The above-mentioned cutaneous findings can be present during acute attacks of ISCLS. They seem specifically related to the ISCLS and not indicative of an underlying disease.

Aged↗
PubMed2003

Metallic artefacts in MR imaging: effects of main field orientation and strength.

AIM: To determine the effect of metallic implant positioning on magnetic resonance (MR) imaging artefacts, and to determine the optimal imaging parameters for minimization of metallic artefacts. MATERIALS AND METHODS: In a phantom and in three joints with non-ferromagnetic metallic implants imaged at 1.5 and/or at 0.2 T, we examined the influence of the static magnetic field (B(0)) strength and orientation, frequency-encoding direction, and type of imaging sequence on metallic artefacts. RESULTS: The impact of artefacts caused by metallic objects depends mainly on the relationship between the anatomy of interest and the orientation of the object relative to the direction of B(0). The main field strength plays a less important role, but its orientation depends on the type of MR imager. CONCLUSION: MR artefacts can be easily minimized by optimally positioning patients with metallic implants in the magnet. Knowledge of how this influences MR imaging is helpful in patient selection and guiding limb positioning.

Artifacts↗
PubMed2003

Imaging in antiangiogenesis trial: a clinical trials radiology perspective.

Traditional approaches for treating cancer have largely focused on the ability of chemotherapy, and to a lesser extent radiation therapy, to destroy tumour cells. Recent developments in antiangiogenesis treatments require a fundamental shift in the radiological and imaging paradigms associated with evaluating response. Proper design and execution of any clinical trial involving imaging angiogenesis requires satisfactory consideration of a number of strategies and an in-depth understanding of different imaging techniques such as dynamic contrast enhanced MRI and CT, contrast-enhanced ultrasound and positron emission tomography. In particular, for imaging, the strategies can be divided into issues that need to be addressed during the protocol planning phase, and strategies that need to be addressed during the execution phase. Furthermore, clinical trials are usually subject to stringent regulations surrounding traceability and reproducibility that need to be followed before the regulatory authorities will accept the integrity of the data. This paper elaborates on the above strategies and outlines certain aspects, or tactics, that need to be considered while preparing for a multicentre clinical trial that involves imaging angiogenesis.

Angiogenesis Inhibitors↗
PubMed2003

[Fatty replacement of the pancreas in a patient with asymptomatic pulmonary cystic fibrosis].

The authors report the case of a 26-year-old woman with hepatomegaly, who had recurrent and progressive nausea and abdominal pain. Computed tomography and magnetic resonance imaging demonstrated fatty replacement of the entire pancreas resulting from cystic fibrosis. The pulmonary disease was totally asymptomatic. Fatty replacement of the pancreas is the most frequent pattern in older patients with cystic fibrosis. This pattern correlates with pancreatic exocrine dysfunction.

Adipose Tissue↗