Biomedical subjects

M Reiser

Publications and source records attributed to M Reiser.

At least 55 records · Page 3Linked to original sources

PubMed2002

Side differences of knee joint cartilage volume, thickness, and surface area, and correlation with lower limb dominance--an MRI-based study.

OBJECTIVE: To test the hypotheses that absolute side differences in knee joint cartilage morphology are substantially smaller than intersubject variability, and that systematic side differences are determined by (force) dominance of the lower limbs. METHODS: Fifteen healthy volunteers with definite dominance of one lower limb were studied. Knees were imaged sagittally with a validated, high-resolution MR sequence. Transverse MR images of the thigh and calf were acquired with a spin echo sequence. Knee joint cartilage volume, thickness and joint surface areas, as well as muscle cross sectional areas were determined with in house post-processing software. RESULTS: Absolute side differences amounted to 5.0+/-3.7% for the knee cartilage volume, 3.8+/-3.1% for cartilage thickness, and 3.4+/-1.7% for joint surface areas. The intersubject variability was 24.8%, 14.4%, and 14.1%, respectively. Volunteers with dominance of one of both lower limbs did not display significant side differences in cartilage morphology, but the side differences of the thigh musculature correlated positively with side differences of knee joint cartilage volume (r=+0.68; P< 0.01). CONCLUSIONS: The results advocate the use of cartilage parameters from the contra-lateral limb for retrospectively estimating cartilage loss in patients with unilateral osteoarthritis (OA), and for determining local risk factors of OA in cross-sectional epidemiological studies, which are specific to pre-morbid cartilage morphology. Functional (force) dominance of one of both lower limbs does not explain side differences of articular cartilage morphology, but side differences are positively associated with side differences in muscle cross sectional areas.

Adult↗

PubMed2002

Long-term and resegmentation precision of quantitative cartilage MR imaging (qMRI).

OBJECTIVE: Follow up of osteoarthritis (OA) and evaluation of structure modifying OA drugs require longitudinal data on cartilage structure. The aim of this study was to analyse the long term and resegmentation precision of quantitative cartilage analysis with magnetic resonance imaging (qMRI) in vivo, and to relate precision errors to the estimated cartilage loss in OA. METHOD: Sagittal MR images of the knee were obtained in 14 individuals, four datasets being acquired in a first imaging session. In 12 subjects, two further datasets were acquired over the next months. Image analysis was performed in the same session for image data obtained under short-term and long-term imaging conditions, and in three different sessions (months apart) for the first data set (resegmentation precision). RESULTS: Long-term precision errors ranged from 1.4% (total knee) to 3.9% (total femur) for cartilage volume and thickness and were only marginally higher than those under short term conditions. In the medial tibia, the error was 84 mm(3) compared with an estimated loss of >1,200 mm(3) in varus OA. Precision errors for resegmentation were somewhat higher, but considerably smaller than the intersubject variability. CONCLUSIONS: Scanner drift and changes in imaging or patient conditions appear not to represent a critical problem in quantitative cartilage analysis with magnetic resonance imaging (qMRI). In longitudinal studies, image analysis of sequential data should be performed within the same post-processing session. Under these conditions, qMRI promises to be a very powerful method to assess structural change of cartilage in OA.

Adult↗

PubMed2002

[Differentiation of benign osteoporotic and neoplastic vertebral compression fractures with a diffusion-weighted, steady-state free precession sequence].

PURPOSE: To evaluate the diagnostic accuracy of a diffusion-weighted, steady-state free precession (SSFP) sequence for the differentiation of acute benign osteoporotic and neoplastic vertebral compression fractures. METHODS: 85 patients with 102 vertebral compression fractures were examined with MR imaging using a spine array surface coil (Siemens, Vision, 1.5 Tesla). The following sequences were performed in sagittal orientation: T1-weighted spin echo (SE), short-tau inversion recovery (STIR) and a diffusion-weighted SSFP sequence (TR = 25 msec, diffusion pulse length delta = 3 msec). The SSFP images were evaluated qualitatively on a 5-grade scale from strongly hypointense to strongly hyperintense. Quantitative analysis was performed with region of interest measurements (ROI) and calculation of a bone marrow ratio. RESULTS: 60 fractures were due to osteoporosis and 42 fractures were caused by malignancy. "Hyperintensity" in a vertebral fracture on a SSFP sequence provided a sensitivity of 100 % and a specificity of 93 %. The positive predictive value was 91 %, the negative predictive value was 100 %. Quantitative analysis of the bone marrow ratio showed a statistically significant difference between the osteoporosis and the tumor group (p < 0.001). The mean value for the osteoporotic fractures was - 0.32 (SD 0.33) and + 2.07 (SD 1.37) for the tumor group. CONCLUSION: The SSFP sequence provides a high accuracy in the differentiation of benign osteoporotic and neoplastic vertebral compression fractures.

Adult↗

PubMed2002

[Detection of tibial condylar fractures using 3D imaging with a mobile image amplifier (Siemens ISO-C-3D): Comparison with plain films and spiral CT].

PURPOSE: To analyze a prototype mobile C-arm 3D image amplifier in the detection and classification of experimental tibial condylar fractures with multiplanar reconstructions (MPR). METHOD: Human knee specimens (n = 22) with tibial condylar fractures were examined with a prototype C-arm (ISO-C-3D, Siemens AG), plain films (CR) and spiral CT (CT). The motorized C-arm provides fluoroscopic images during a 190 degrees orbital rotation computing a 119 mm data cube. From these 3D data sets MP reconstructions were obtained. All images were evaluated by four independent readers for the detection and assessment of fracture lines. All fractures were classified according to the Müller AO classification. To confirm the results, the specimens were finally surgically dissected. RESULTS: 97 % of the tibial condylar fractures were easily seen and correctly classified according to the Müller AO classification on MP reconstruction of the ISO-C-3D. There is no significant difference between ISO-C and CT in detection and correct classification of fractures, but ISO-CD-3D is significant by better than CR. CONCLUSION: The evaluation of fractures with the ISO-C is better than with plain films alone and comparable to CT scans. The three-dimensional reconstruction of the ISO-C can provide important information which cannot be obtained from plain films. The ISO-C-3D may be useful in planning operative reconstructions and evaluating surgical results in orthopaedic surgery of the limbs.

Humans↗

PubMed2002

[Sedation analgesia in interventional radiology].

PURPOSE: Development of a save and effective protocol for analgosedation of patients undergoing painful interventional procedures. MATERIAL AND METHODS: In a prospective trial a consecutive series of 72 adult patients underwent analgosedation during painful interventions. A radiologist performed the analgosedation, the patients received a combination of a shortly effective piperidine derivative (Alfentanil [Rapifen(R)]; 7.5 - 15 microgram/kg body weight) and Benzodiazepine (midazolam [Dormicum(R)]; 20 microgram/kg body weight). After pre-procedure oxygenation patients were continuously monitored. Pain and discomfort were scored using an established visual-analog pain score (0 - 10). A control group (n = 24) had received midazolam, pentazocine or fentanyl according to the study protocol. RESULTS: All procedures could be carried out by an interventional radiologist and a nurse and/or technologist only. In 69/72 cases adequate analgosedation could be achieved. Injection of alfentanil was titrated, with a rapid onset and short acting effect of the analgesia. Patients reported an average pain score of 2.6 vs. 4.5 in the control group. Over 55 % experienced no or mild pain (score 0 - 3), in the control group only 8 % reached this level. CONCLUSION: A combination of shortly effective alfentanil and midazolam allows interventional radiologists to perform major procedures alone under effective analgosedation. This medication scheme is superior to the medication upon demand.

Adjuvants, Anesthesia↗

PubMed2002

[Studies on image quality, high contrast resolution and dose for the axial skeleton and limbs with a new, dedicated CT system (ISO-C-3 D)].

PURPOSE: Evaluation of 3D-CT imaging of the axial skeleton and different joints of the lower and upper extremities with a new dedicated CT system (ISO-C-3D) based on a mobile isocentric C-arm image amplifier. MATERIAL AND METHODS: 27 cadaveric specimes of different joints of the lower and upper extremities and of the spinal column were examined with 3D-CT imaging (ISO-C-3D). All images were evaluated by 3 radiologists for image quality using a semiquantitative score (score value 1: poor quality; score value 4: excellent quality). In addition, dose measurements and measurements of high contrast resolution were performed in comparison to conventional and low-dose spiral CT using a high contrast phantom (Catphan, Phantom Laboratories). RESULTS: Adequate image quality (mean score values 3 - 4) could be achieved with an applied dose comparable to low-dose CT in smaller joints such as wrist, elbow, ankle and knee. A remarkably inferior image quality resulted in imaging of the hip, lumbar and thoracic spine (mean score values 2 - 3) in spite of almost doubling the dose (dose increased by 85 percent). The image quality of shoulder examinations was insufficient (mean score value 1). Phantom studies showed a high-contrast resolution comparable to helical CT in the xy-axis (9 lp/cm). CONCLUSION: Preliminary results show, that image quality of C-arm-based CT-imaging (ISO-C-3D) seems to be adequate in smaller joints. ISO-C-3D images of the hip and axial skeleton show a decreased image quality, which does not seem to be sufficient for diagnosing subtle fractures.

Arm↗

PubMed2002

Transjugular intrahepatic portosystemic shunting is not superior to endoscopic variceal band ligation for prevention of variceal rebleeding in cirrhotic patients: a randomized, controlled trial.

BACKGROUND: The aim of the present study was to compare the transjugular intrahepatic portosystemic shunt (TIPS) with variceal band ligation (VBL) in the prophylaxis of variceal rebleeding in patients with cirrhosis of the liver. METHODS: Fifty-four cirrhotic patients (21 Child-Pugh class A, 27 class B, 6 class C) were randomized to TIPS (n = 28) or VBL (n = 26) within 2 months after control of esophageal variceal hemorrhage. Statistical analysis was performed on the intention-to-treat principle. RESULTS: Mean follow-up was 2 years. Mortality risk at 1 and 2 years of follow-up was 7.8% +/- 5.3% and 19.9% +/- 8.8% in the TIPS group and 16.5% +/- 7.6% and 16.5% +/- 7.6% in the VBL group, respectively (n.s.); actuarial probability of remaining free from rebleeding was 83.7% +/- 77.4% and 71.4% +/- 10.4% in the TIPS group and 83.9% +/- 7.3% and 78.1% +/- 8.8% in the VBL group at 1 and 2 years, respectively (n.s.). Hepatic encephalopathy within 1 month after randomization was observed in 2 patients in the TIPS group and in 1 in the VBL group. CONCLUSION: TIPS is not superior to VBL in the prevention of variceal rebleeding. Furthermore, similar mortality rates in patients treated with TIPS or VBL negate TIPS as the preferred strategy for prevention of variceal rebleeding.

Endoscopy↗

PubMed2002

T-cell non-Hodgkin's lymphoma in adults: clinicopathological characteristics, response to treatment and prognostic factors.

T-cell NHL represent 10-15% of all malignant lymphomas making systematic prospective clinical trials difficult. Therefore, the prognostic significance of the T-cell phenotype has been a matter of controversy in recent years. In a retrospective analysis of 681 patients (pts) with NHL accrued from 1992 to 1997 at a single institution, 66 patients with T-cell NHL were identified. According to the REAL classification, histologies were as follows: 28 peripheral T-cell lymphomas (PTCL), 19 large cell anaplastic lymphoma (LCAL), 12 precursor lymphoblastic lymphoma (Lb), and seven AILD. Multiagent anthracycline containing regimens were used as initial therapy in 91% of cases. T-cell NHL represent 9.8% of all NHL patients at our institution accrued over a 6-year period. Overall response rate was 76%, 21% had progressive disease and 3% died during first line treatment. Mean overall survival (OS) was 8.22 +/- 0.94 years. There was a significant difference in OS between the four different histological subgroups (log rank P=0.0288). LCAL: mean OS 11.05 +/- 1.55 years (95% CI 8.00-14.09); LB: mean OS 7.09 +/- 1.40 years (95% CI 4.33-9.84); PTCL: mean 6.62 +/- 1.17 years (95% CI 4.33-8.90); AILD: 1.54 +/- 0.44 years (95% CI 0.67-2.40). OS was also significantly different for patients classified according to the International Prognostic Index (IPI)-score (log rank P = 0.002). Mean OS for patients with low risk, intermediate low risk, intermediate high risk and high risk was 10.46 +/- 1.02, 6.46 +/- 1.79, 4.50 +/- 1.20 and 1.15 +/- 0.46 years, respectively. Univariate analysis (log-rank test) for prognostic factors also revealed elevated LDH, B-symptoms and extranodal involvement as significant factors for OS. The presence of bulky disease (>7.5 cm), advanced stage III/IV and bone marrow involvement did not influence OS. In conclusion, it is evident that histological subtype and IPI-score have a strong prognostic impact on OS in pts with T-cell NHL. Thus, the distribution of risk factors in patients with T-cell NHL may be more important for OS than T-cell histology per se.

Aged↗

PubMed2002

Time-intensified dexamethasone/cisplatin/cytarabine: an effective salvage therapy with low toxicity in patients with relapsed and refractory Hodgkin's disease.

BACKGROUND: An important variable affecting outcome in relapsed and refractory Hodgkin's disease (HD) is the potential of conventional salvage chemotherapy to reduce tumor volume before high-dose chemotherapy (HDCT) and autologous stem cell transplantation. Currently, the optimal salvage chemotherapy regimen for these patients is unclear. Since dexamethasone/cisplatin/cytarabine (DHAP) given at 3-4 week intervals has been shown to be very effective in patients with relapsed aggressive non-Hodgkin's lymphoma, we evaluated this regimen given at a median of 16-day intervals in patients with relapsed and refractory HD. PATIENTS AND METHODS: Patients with relapsed or refractory HD were treated with two cycles of DHAP [dexamethasone 40 mg intravenously (i.v.) day 1-4, cisplatin 100 mg/m(2) i.v. as 24-h continuous infusion day 1, and cytarabine 2 g/m(2) i.v. 12q day 2]. Granulocyte colony-stimulating factor (G-CSF) was given at a dose of 5 micro g/kg from day 4 until day 13. Patients with partial remission (PR) or complete remission (CR) after two cycles of DHAP received sequential HDCT. RESULTS: The median age of the 102 patients included was 34 years (range 21-64 years). Forty-two percent of the patients had late relapse, 29% early relapse, 12% multiple relapse and 16% primary progressive/refractory disease. The response rate (RR) after two cycles of DHAP was 89% (21% CR, 68% PR). The RRs for patients with late, early, multiple and progressive HD were 91%, 93%, 92% and 65%, respectively. Using the chi-square test for independence, remission status (relapsed HD versus progressive HD) and stage at relapse (stage I/II versus stage III/IV) were significant factors for response to DHAP. WHO grade 4 leukocytopenia and thrombocytopenia were the main toxic- ities occurring in 43% (mean duration 1.1 days, range 0-6) and 48% (mean duration 1.4 days, range 0-11) of all courses, respectively. Neither severe infections nor treatment-related deaths occurred. Peripheral blood stem cells (PBSCs) were collected after the first cycle DHAP in eight patients. The hematopoietic progenitors showed a very rapid increase from day 10 with a synchronous and impressive peak on day 12. A mean of 6.1 x 10(6)/kg CD34(+) cells were collected per apheresis. As originally recommended in the protocol, PBSCs were routinely collected during sequential HDCT in the remaining patients. CONCLUSIONS: A brief tumor-reducing program with two cycles of DHAP given in short intervals supported by G-CSF is effective and well-tolerated in patients with relapsed and refractory HD. This regimen can be used to mobilize stem cells and select those patients with chemosensitive relapse who should subsequently be treated with HDCT.

Adolescent↗

PubMed2001

[Virtual large intestine imaging with multi-level CT. Pain free coloscopy--that works!].

Provided that the bowel is carefully cleansed, virtual colonoscopy permits a safe, reliable and painfree diagnosis of the large bowel. It requires distension of the bowel with ambient air. Contraindications include pregnancy, acute inflammation of the bowel and recent surgery. Tumors and large polyps (10 mm and more) can be diagnosed with certainty, while polyps measuring 5 mm and more are detected with a high degree of sensitivity. It goes without saying that virtual colonoscopy does not allow for the taking of biopsy material or the performance of therapeutic measures, so that positive or suspicious findings must be clarified by conventional colonoscopy. In principle, virtual colonoscopy is also suitable for use as a screening procedure. Whether the radiation exposure associated with the conventional examination protocol can be considered acceptable for screening purposes is questionable. However, using mathematical means, the radiation dose can be reduced to one-tenth of the usual dose.

Colon↗

PubMed2001

Case-oriented computer-based-training in radiology: concept, implementation and evaluation.

BACKGROUND: Providing high-quality clinical cases is important for teaching radiology. We developed, implemented and evaluated a program for a university hospital to support this task. METHODS: The system was built with Intranet technology and connected to the Picture Archiving and Communications System (PACS). It contains cases for every user group from students to attendants and is structured according to the ACR-code (American College of Radiology) 2. Each department member was given an individual account, could gather his teaching cases and put the completed cases into the common database. RESULTS: During 18 months 583 cases containing 4136 images involving all radiological techniques were compiled and 350 cases put into the common case repository. Workflow integration as well as individual interest influenced the personal efforts to participate but an increasing number of cases and minor modifications of the program improved user acceptance continuously. 101 students went through an evaluation which showed a high level of acceptance and a special interest in elaborate documentation. CONCLUSION: Electronic access to reference cases for all department members anytime anywhere is feasible. Critical success factors are workflow integration, reliability, efficient retrieval strategies and incentives for case authoring.

Computer Communication Networks↗

PubMed2001

Usefulness of calcium scoring using electron beam computed tomography and noninvasive coronary angiography in patients with suspected coronary artery disease.

The aim of this study was to investigate the reliability of calcium scoring (CS) and electron beam computed tomographic angiography (EBCTA) as a noninvasive tool in the diagnosis of coronary artery disease (CAD): 93 consecutive patients (aged 59 +/- 9 years) with symptoms suspicious for CAD underwent CS. In 87 of these subjects, an additional EBCTA investigation was performed. Using receiver-operating characteristic curve analysis, we determined a calcium score cut point providing an overall sensitivity of 80% and a specificity of 72% in detecting patients with CAD. For clinical purposes the use of cut points is difficult. We therefore determined score ranges providing >80% specificity (high score range) and >85% sensitivity (low score range) and determined the scores between these ranges as equivocal borderline scores. Calculated on a per-segment basis in assessable proximal and midcoronary segments, the sensitivity for detecting coronary stenoses >50% was 78%, and the specificity was 93%. Thus, 32 of 44 patients with significant CAD and 24 of 49 patients without CAD were correctly classified. The combination of CS and EBCTA predicted CAD in 77% (72 of 93) of patients. No or low calcium scores provided high specificity for ruling out CAD. The addition of EBCTA in those patients improved sensitivity. In patients with high calcium scores, accuracy of EBCTA was not significantly different from CS alone (72% vs 83%), whereas in patients with borderline scores it was significantly superior (80% vs 58%, p <0.03). Thus, the complementary use of CS and EBCTA appears beneficial, particularly in patients with borderline scores, and could improve sensitivity in the low score range. In the presence of high scores, no major diagnostic gain from an additional EBCTA versus CS alone could be observed.

Calcinosis↗

PubMed2001

[Screening lowers breast cancer mortality. Motivate your patients for mammography].

Breast cancer is the most common malignant disease in women under 70, and the most common cause of death in those under 50. Causal prophylaxis is unknown. Only early diagnosis prior to the onset of lymphogenic or hematogenic metastasization improves the prognosis. Since the early nineteen-sixties, large-scale studies have shown that screening mammography can reduce mortality. Furthermore, early diagnosis enables breast-conserving treatment in up to 70% of cases. Disadvantages of screening mammography currently under discussion are the radiation burden, the number of false-positive diagnoses prompting biopsy and incurring costs. In Germany, the cost of screening mammography in women with no relevant history or clinical symptoms is not borne by the state-affiliated health insurance carriers. Currently, ongoing pilot projects are investigating quality-controlled early diagnosis with mammography.

Adult↗

PubMed2001

Contrast-enhanced MR angiography in patients after kidney transplantation.

The aim of this study was to investigate the value of a contrast-enhanced 3D MR angiography in detecting postoperative vascular complications after kidney transplantation in comparison with digital subtraction angiography (DSA). Forty-one patients who underwent a kidney transplantation were examined with MR angiography and DSA. Contrast-enhanced MR angiography was performed as a dynamic measurement with one precontrast and three postcontrast measurements. Maximum intensity projection reconstructions were performed for all postcontrast data sets after DSA. The results were evaluated by two independent observers who were unaware of the DSA results. Twenty-three hemodynamically significant arterial stenoses were identified with DSA in the iliac arteries ( n=7), the renal allograft arteries ( n=12), and in their first branches ( n=4). For a patient-based analysis the sensitivity and specificity, respectively, for observer 1 were 100 and 97%, and for observer 2, 100 and 93%. Respective data were 100 and 100% after a consensus evaluation by two observers. Complications involving the renal veins were detected in 2 cases and perfusion defects of the kidney parenchyma were detected in 4 cases. Contrast-enhanced MR angiography is a reliable method in identifying postoperative arterial stenoses after kidney transplantation. In addition, dynamic MR angiography can be helpful in detecting venous complications and perfusion defects in kidney allografts.

Adult↗

PubMed2001

[Brain protective interstitial laser thermotherapy. Therapy of brain tumors without secondary damage].

The purpose of interstitial radiosurgery is to deliver a necrotizing dose of heat to an accurately defined focal area without damaging adjacent healthy brain tissue. To achieve this, heat at a temperature of 60-100 degrees C is applied via a laser fiber placed stereotactically in the center of the tumor. With the aid of thermosensitive magnetic resonance imaging (MRI), not only can the heat distribution within and around the tumor be measured during treatment, but also the extent of the lesion produced assessed. Interstitial laser thermotherapy (ILTT) performed under MRI monitoring, could become an important interdisciplinary minimally invasive treatment option for patients with brain tumors. Experimental data on the biological effects of interstitial laser therapy on normal brain tissue are not yet available, and only preliminary clinical studies investigating the effects of laser energy on brain tumors have so far been carried out. This overview presents a description of our own initial results, discusses the present state of our knowledge and current possibilities and limitations of this new treatment modality.

Brain↗

PubMed2001

Magnetic resonance imaging-based assessment of cartilage loss in severe osteoarthritis: accuracy, precision, and diagnostic value.

OBJECTIVE: To examine the in vivo accuracy and precision of magnetic resonance imaging (MRI)-based assessment of cartilage loss in patients with severe osteoarthritis (OA) of the knee. METHODS: High-resolution MRI images of the tibial cartilage were obtained in 8 patients prior to total knee arthroplasty, using a water-excitation gradient-echo MRI sequence (acquisition time 6 minutes 19 seconds; spatial resolution 1.2 x 0.31 x 0.31 mm3). The MRI measurements were repeated after joint repositioning. The precision of the cartilage volume and thickness computations was determined after 3-dimensional reconstruction. During surgery, the tibial plateaus were resected, and the MRI data were compared with water displacement of surgically retrieved cartilage. RESULTS: The standard deviation (coefficient of variation) of repeated tibial cartilage volume measurements was 56 mm3 (5.5%) medially and 59 mm3 (3.8%) laterally. The deviation from surgically removed tissue was -13%, on average, with a high linear correlation between both methods (r = 0.98). In patients with varus OA, the tissue loss was estimated to be 1,290 mm3 in the medial tibia and 1,150 mm3 in the lateral tibia, compared with the data in healthy volunteers. CONCLUSION: Noninvasive quantitative MRI-based analysis of cartilage morphometry in severe OA is accurate, precise, and displays high potential diagnostic value.

Aged↗

PubMed2001

Age-related changes in the morphology and deformational behavior of knee joint cartilage.

OBJECTIVE: Alterations of cartilage morphology and mechanical properties occur in osteoarthritis, but it is unclear whether similar changes also take place physiologically during aging, in the absence of disease. In this in vivo study, we tested the hypothesis that thinning of knee joint cartilage occurs with aging and that elderly subjects display a different amount of cartilage deformation than do young subjects. METHODS: We evaluated 30 asymptomatic subjects ages 50-78 years. Morphologic parameters for the knee cartilage (mean and maximum thickness, surface area) were computed from magnetic resonance imaging data. Results were compared with those in 95 young asymptomatic subjects ages 20-30 years. Deformation of the patellar cartilage was determined after the subjects performed 30 knee bends. RESULTS: There was a significant reduction of patellar cartilage thickness in elderly women (-12%; P < 0.05), but not in elderly men (-6%). Femoral cartilage was significantly thinner in both sexes (-21% in women, -13% in men; P < 0.01), whereas tibial cartilage thickness displayed only nonsignificant trends (-10% in women, -7% in men). Patellar cartilage deformation was -2.6% in elderly women and -2.2% in elderly men. These values were significantly lower (P < 0.05) than those in young subjects. CONCLUSION: We confirmed the hypothesis that knee cartilage becomes thinner during aging, in the absence of cartilage disease, but that the amount of reduction differs between sexes and between compartments of the knee joint. We show that under in vivo loading conditions, elderly subjects display a lower level of cartilage deformation than do healthy young subjects.

Adult↗

PubMed2001

MR lung imaging at 0.2 T with T1-weighted true FISP: native and oxygen-enhanced.

An inversion recovery true fast imaging with steady precession (FISP) pulse sequence was developed to carry out fast imaging of the lungs at 0.2 T. Using this sequence, oxygen-enhanced magnetic resonance (MR) lung imaging was performed on healthy volunteers. The lungs showed signal enhancement (11.7% +/- 3.8%) when breathing 100% oxygen. Using inversion recovery, true FISP at low field may prove promising for MR lung imaging.

Artifacts↗