Search PubMed⌕ Search

Biomedical subjects

Juerg Hodler

Publications and source records attributed to Juerg Hodler.

At least 55 records · Page 3Linked to original sources
PubMed2003

MR image-based grading of lumbar nerve root compromise due to disk herniation: reliability study with surgical correlation.

A system for grading lumbar nerve root compromise (no compromise, contact of disk material with nerve root, deviation of nerve root, and compression of nerve root) was tested in the interpretation of routine magnetic resonance images of 500 lumbar nerve roots in 250 symptomatic patients. Intra- and interobserver reliability was assessed for three independent observers. In the 94 nerve roots evaluated at surgery, surgical grading was correlated with image-based grading. kappa statistics indicated substantial agreement between different readings by the same observer and between different observers (for intraobserver agreement, kappa = 0.72-0.77; for interobserver agreement, kappa = 0.62-0.67). Correlation of image-based grading with surgical grading was high (r = 0.86). The image-based grading system enabled reliable evaluation and reporting of nerve root compromise.

Adult↗
PubMed2003

Suspected rotator cuff lesions: tissue harmonic imaging versus conventional US of the shoulder.

PURPOSE: To compare tissue harmonic imaging (THI) of the shoulder with conventional ultrasonography (US) in patients suspected of having rotator cuff lesions. MATERIALS AND METHODS: THI and conventional US images were obtained in 50 patients suspected of having rotator cuff lesions. Images were graded for visibility of acromioclavicular (AC) joint surfaces and rotator cuff tendon contours and substances: Grade 1 meant poor; grade 2, moderate; and grade 3, good visibility. Accuracy, sensitivity, and specificity of the diagnosis of AC joint osteoarthritis and accuracy of the diagnosis and rates of underestimation and overestimation of the extent of rotator cuff tears were evaluated. Visibility grade differences were evaluated with the Wilcoxon signed rank test. The McNemar test was used to assess differences in diagnoses. Magnetic resonance (MR) arthrography was the reference standard. RESULTS: Mean visibility grades for readers 1 and 2, respectively, were as follows: for AC joint bone surfaces, 2.1 and 2.0 with THI and 1.7 (P =.010) and 1.7 (P =.16) with conventional US; for AC joint capsule surfaces, 2.2 and 1.9 with THI and 1.8 (P =.005) and 1.8 (P =.34) with US; for supraspinatus tendon contour, 2.6 and 2.2 with THI and 2.1 (P =.001) and 1.9 (P =.055) with US; for supraspinatus tendon substance, 2.2 and 1.9 with THI and 2.0 (P =.036) and 1.7 (P =.070) with US; for subscapularis tendon contour, 2.4 and 2.1 with THI and 2.2 (P =.07) and 2.0 (P =.25) with US; and for subscapularis tendon substance, 1.8 and 1.7 with THI and 2.0 (P =.86) and 1.7 (P =.91) with US. Diagnostic accuracies for the supraspinatus tendon for readers 1 and 2, respectively, were 84% and 74% with THI and 86% and 70% with US (P >.99 for both readers). Corresponding values for the subscapularis tendon were 78% and 72% with THI and 64% (P =.27) and 52% (P =.006) with US. CONCLUSION: Joint and tendon surface visibility improves with THI, as compared with the visibility achieved with conventional US. THI is superior to conventional US for diagnosis of subscapularis tendon abnormalities.

Adult↗
PubMed2003

CT arthrography of the glenohumeral joint: CT fluoroscopy versus conventional CT and fluoroscopy--comparison of image-guidance techniques.

PURPOSE: To compare examination time with radiologist time and to measure radiation dose of computed tomographic (CT) fluoroscopy, conventional CT, and conventional fluoroscopy as guiding modalities for shoulder CT arthrography. MATERIALS AND METHODS: Glenohumeral injection of contrast material for CT arthrography was performed in 64 consecutive patients (mean age, 32 years; age range, 16-74 years) and was guided with CT fluoroscopy (n = 28), conventional CT (n = 14), or conventional fluoroscopy (n = 22). Room times (arthrography, room change, CT, and total examination times) and radiologist times (time the radiologist spent in the fluoroscopy or CT room) were measured. One-way analysis of variance and Bonferroni-Dunn posthoc tests were performed for comparison of mean times. Mean effective radiation dose was calculated for each method with examination data, phantom measurements, and standard software. RESULTS: Mean total examination time was 28.0 minutes for CT fluoroscopy, 28.6 minutes for conventional CT, and 29.4 minutes for conventional fluoroscopy; mean radiologist time was 9.9 minutes, 10.5 minutes, and 9.0 minutes, respectively. These differences were not statistically significant. Mean effective radiation dose was 0.0015 mSv for conventional fluoroscopy (mean, nine sections), 0.22 mSv for CT fluoroscopy (120 kV; 50 mA; mean, 15 sections), and 0.96 mSv for conventional CT (140 kV; 240 mA; mean, six sections). Effective radiation dose can be reduced to 0.18 mSv for conventional CT by changing imaging parameters to 120 kV and 100 mA. Mean effective radiation dose of the diagnostic CT arthrographic examination (140 kV; 240 mA; mean, 25 sections) was 2.4 mSv. CONCLUSION: CT fluoroscopy and conventional CT are valuable alternative modalities for glenohumeral CT arthrography, as examination and radiologist times are not significantly different. CT guidance requires a greater radiation dose than does conventional fluoroscopy, but with adequate parameters CT guidance constitutes approximately 8% of the radiation dose.

Adolescent↗
PubMed2003

Midterm outcome after vertebroplasty: predictive value of technical and patient-related factors.

PURPOSE: To evaluate different types of polymethylmethacrylate (PMMA) leakage and patient-related factors in relation to clinical midterm (1-24-month) outcome after vertebroplasty. MATERIALS AND METHODS: Standardized four-view radiographs obtained during 363 vertebroplasties in 181 treatment sessions in 152 patients were reviewed (121 patients with osteoporotic fractures, 30 with malignant disease, and one with hemangioma). Four types of PMMA leakage and other potential predictors (patient age and sex, treated region, number of vertebral levels injected, preprocedural pain, PMMA volume per vertebra) were related to postprocedural pain response and midterm outcome after vertebroplasty. chi2 and Kruskal-Wallis tests were used for statistical analysis. The mean follow-up period was 8.8 months (range, 1-24 months). RESULTS: At the time of discharge after the procedure, pain was absent after 106 of the 181 sessions (58.5%), better after 50 (27.6%), and the same after 25 (13.8%). In 258 of the 363 treated vertebral levels, at least one type of leakage was found. None of the evaluated factors were related significantly to postprocedural pain response, including PMMA leakage. Pain response at midterm outcome was strongly related to postprocedural treatment success, however (P <.001). CONCLUSION: Small to moderate amounts of PMMA may escape from the vertebral body with no significant effect on therapeutic success. Immediate postprocedural pain relief is the best predictor of midterm clinical outcome after vertebroplasty.

Aged↗
PubMed2003

Achilles tendons: clinical relevance of neovascularization diagnosed with power Doppler US.

PURPOSE: To evaluate the clinical relevance of neovascularization diagnosed with power Doppler ultrasonography (US) in Achilles tendons in patients with chronic achillodynia. MATERIALS AND METHODS: Forty consecutive patients (mean age, 52 years; age range, 30-72 years) were examined. US was performed bilaterally and repeated after 3 months. Shape and echogenicity were assessed with gray-scale US and vascularization with power Doppler US. All patients were treated conservatively. Clinical assessment was performed after 0, 3, and 6 months by using visual analogue scale (VAS) scores (0, no pain; 100, unbearable pain). The VAS scores were compared with the initial US findings, and analysis of variance was used for repeated measurements. RESULTS: Neovascularization was present in 30 of 55 painful tendons and in one of 25 asymptomatic tendons. The mean VAS scores at 0, 3, and 6 months, respectively, for tendons with neovascularization were 52, 26, and 20; those for tendons without neovascularization were 39, 19, and 18 (P =.15). Forty-eight painful and nine asymptomatic tendons were spindle shaped. The mean VAS scores at 0, 3, and 6 months, respectively, for the spindle-shaped tendons were 48, 25, and 20; those for normally shaped tendons were 33, 10, and 16 (P =.17). Thirty-five painful and four asymptomatic tendons were inhomogeneous. The mean VAS scores at 0, 3, and 6 months, respectively, for symptomatic inhomogeneous tendons were 54, 29, and 25; those for symptomatic homogeneous tendons were 32, 12, and 9 (P <.001). CONCLUSION: Although neovascularization is a specific sign for pain, it does not indicate an unfavorable outcome. Conversely, tendon inhomogeneity seems to be associated with an unfavorable outcome.

Achilles Tendon↗
PubMed2003

Morton neuroma: MR imaging in prone, supine, and upright weight-bearing body positions.

PURPOSE: To assess the effect of prone, supine, and upright weight-bearing body positions on visibility, position, shape, and size of Morton neuroma during magnetic resonance (MR) imaging. MATERIALS AND METHODS: Eighteen patients with 20 Morton neuromas underwent MR imaging of the forefoot in prone (plantar flexion of the foot), supine (dorsiflexion of the foot), and upright weight-bearing positions. Visibility (3 = good, 2 = moderate, 1 = poor), position relative to the metatarsal bone, shape, and transverse diameter of Morton neuroma were assessed on transverse T1-weighted MR images. Associations between different body positions and variables of interest were calculated with Wilcoxon signed rank test, chi2 test, and paired Student t test. RESULTS: In the prone position, visibility of all 20 Morton neuromas was rated with a score of 3; visibility in the supine and weight-bearing positions was inferior (mean score, 2.4). All 20 (100%) Morton neuromas changed their position relative to the metatarsal bone between prone and supine and between prone and weight-bearing positions. When compared with the prone position, there was a difference in the shape of all 20 Morton neuromas in the weight-bearing position (P <.001). Between prone (mean transverse diameter of Morton neuroma, 8 mm) and supine (mean transverse diameter of Morton neuroma, 6 mm) positions, the transverse diameter of Morton neuroma significantly decreased by 2 mm (P =.03); between prone and weight-bearing positions, the decrease of the mean transverse diameter was also significant (difference, 2 mm; P =.03). CONCLUSION: Morton neuroma appears significantly different during MR imaging in prone, supine, or weight-bearing positions. The transverse diameter of Morton neuroma is significantly larger on images obtained in the prone position than it is on images obtained in the supine and upright weight-bearing positions. Visibility of Morton neuroma is best on MR images obtained in the prone position.

Adult↗
PubMed2003

Articular cartilage lesions of the glenohumeral joint: diagnostic effectiveness of MR arthrography and prevalence in patients with subacromial impingement syndrome.

PURPOSE: To determine the prevalence of articular cartilage lesions in patients with subacromial impingement syndrome and to assess the diagnostic effectiveness of magnetic resonance (MR) arthrography in detecting such cartilage abnormalities. MATERIALS AND METHODS: MR arthrographic images obtained in 52 consecutive patients (mean age, 45.8 years; age range, 17-73 years; 26 male and 26 female patients) were retrospectively evaluated for glenohumeral cartilage lesions. Two experienced musculoskeletal radiologists who were blinded to the arthroscopy report independently analyzed the articular cartilage. Humeral and glenoidal cartilage were assessed separately. The lesions were graded as either subtle or marked. Arthroscopic findings were the standard of reference. Sensitivity, specificity, accuracy, and interobserver agreement were calculated. RESULTS: At arthroscopy, humeral cartilage lesions were found in 15 patients (frequency, 29%). Four lesions were subtle, and 11 were marked. Cartilage lesions of the glenoid were less frequent (eight patients; frequency, 15%): Three were subtle, and five were marked. For reader 1 and reader 2, respectively, sensitivity of MR arthrography for humeral cartilage lesions was 53% and 100%, specificity was 87% and 51%, and accuracy was 77% and 65%; sensitivity for glenoidal cartilage lesions was 75% and 75%, specificity was 66% and 63%, and accuracy was 67% and 65%. Interobserver agreement for the grading of cartilage lesions with MR arthrography was fair (humeral lesions, kappa = 0.20; glenoidal lesions, kappa = 0.27). CONCLUSION: Glenohumeral cartilage lesions are found in up to one third of patients referred for MR arthrography for subacromial impingement syndrome. The performance of MR arthrography in the detection of glenohumeral cartilage lesions is moderate.

Adolescent↗
PubMed2003

Cartilage lesions in the hip: diagnostic effectiveness of MR arthrography.

PURPOSE: To evaluate the diagnostic performance of magnetic resonance (MR) arthrography in the detection of articular cartilage lesions in patients suspected of having femoroacetabular impingement and/or labral abnormalities. MATERIALS AND METHODS: Forty-two MR arthrograms obtained in 40 patients with a clinical diagnosis of femoroacetabular impingement and/or labral defect were retrospectively analyzed. Two readers independently interpreted the images for cartilage lesion location, depiction, and characteristics. Within 6 months after MR arthrography, each patient underwent open hip surgery, during which the entire cartilage of the hip joint was inspected. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated. kappa values were calculated to quantify the level of interobserver agreement. RESULTS: At surgery, most (37 [88%] of 42) cartilage defects were identified in the anterosuperior part of the acetabulum. In 23 (55%), 12 (29%), 10 (24%), and 10 (24%) hips, lesions were found in the posterosuperior acetabulum, anteroinferior acetabulum, posteroinferior acetabulum, and femoral head, respectively. The sensitivities and specificities of MR arthrographic detection of cartilage damage in all regions combined were 79% (73 of 92 regions) and 77% (91 of 118 regions), respectively, for reader 1 and 50% (46 of 92 regions) and 84% (99 of 118 regions), respectively, for reader 2. At interobserver comparison, agreement was fair (kappa = 0.31) for detection of cartilage lesions in the femoral head and poor (kappa <or= 0.2) for detection of lesions in all acetabular regions. CONCLUSION: Cartilage lesions are common in young and middle-aged patients with femoroacetabular impingement and/or labral abnormalities and are most frequently found in the anterosuperior part of the acetabulum. 2003

Adult↗
PubMed2003

Prevalence and size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections in asymptomatic knees on MR imaging.

OBJECTIVE: The purposes of this study were to evaluate the prevalence and determine the size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections on MR images of asymptomatic knees. MATERIALS AND METHODS: MR images of 102 asymptomatic knees were evaluated with regard to the prevalence of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections. The MR examinations were performed in patients (mean age, 42.8 years; age range, 18-73 years) with clinically suspected meniscal lesions in the contralateral knee. The craniocaudal, anteroposterior, and mediolateral diameters of detectable abnormal fluid collections were measured. RESULTS: Medial meniscal cysts (mean size [craniocaudal x anteroposterior x mediolateral], 9 x 6 x 13 mm) were found in four asymptomatic knees. Neither lateral meniscal cysts nor ganglionic cysts of the cruciate ligaments were identified. Twenty-six synovial cysts of the popliteal space (Baker's cyst)-consisting of 11 gastrocnemius portions (mean size, 19 x 8 x 10 mm) and 15 semimembranosus portions (mean size, 20 x 7 x 9 mm)-were found in 19 knees. Twenty-four (92%) of these cysts had a maximal diameter of 30 mm or less. Fluid-filled bursae were found in 49 knees. The deep infrapatellar bursa was most commonly involved (42 knees; mean size, 6 x 3 x 5 mm). Fluid-filled anserine bursae (mean size, 27 x 12 x 10 mm) were detected in five knees. CONCLUSION: Meniscal cysts may be present in asymptomatic knees, at least on the medial side. Synovial cysts of the popliteal space can be found in approximately one fifth of asymptomatic knees. Their maximal diameter is usually smaller than 30 mm.

Adult↗
PubMed2003

Patients with suspected meniscal tears: prevalence of abnormalities seen on MRI of 100 symptomatic and 100 contralateral asymptomatic knees.

OBJECTIVE: The purpose of this study was to evaluate the prevalence of MR abnormalities of the knee on the symptomatic and contralateral asymptomatic sides in patients with suspected meniscal tears. SUBJECTS AND METHODS. One hundred patients (mean age, 42.7 years; range, 18-73 years) referred for suspected meniscal tears were prospectively examined with MRI of both knees when the contralateral knee was asymptomatic. The prevalence of various types of meniscal tears and other MR abnormalities was determined. RESULTS: Meniscal tears were found in 57 symptomatic knees and in 36 contralateral asymptomatic knees. In those 57 patients with a meniscal tear on the symptomatic side, the prevalence of asymptomatic tears in the contralateral side was 63% (36/57). Horizontal or oblique meniscal tears were found medially in 32 and laterally in 11 symptomatic knees, and medially in 29 and laterally in eight asymptomatic knees. Radial, vertical, complex, or displaced tears were found medially in 18 and laterally in five symptomatic knees, and medially in five and laterally in none of the asymptomatic knees. Collateral ligament abnormalities were found in 53 symptomatic knees and in six asymptomatic knees. Pericapsular soft-tissue abnormalities were found in 64 symptomatic and in 12 asymptomatic knees. Edema-like bone marrow abnormalities were found in 36 symptomatic and in three asymptomatic knees. CONCLUSION: Horizontal or oblique meniscal tears are frequently encountered in both asymptomatic and symptomatic knees and may not always be related to symptoms. However, radial, vertical, complex, or displaced meniscal tears and abnormalities of the collateral ligaments, pericapsular soft tissues, and bone marrow are found almost exclusively on the symptomatic side and appear to be clinically more meaningful.

Adolescent↗
PubMed2003

MRI features of the acromioclavicular joint that predict pain relief from intraarticular injection.

OBJECTIVE: Our objective was to evaluate the predictive value of various MRI findings in the acromioclavicular joint for pain relief after intraarticular injection. MATERIALS AND METHODS: The acromioclavicular joint of 50 patients (20 women, 30 men; mean age, 51 years; range, 25-75 years) was evaluated on MRIs of the shoulder. Osteophytes, subchondral cysts and irregularities, bone marrow edema, joint effusion, and joint capsule hypertrophy were assessed by two musculoskeletal radiologists in consensus. Local anesthetics were injected into the acromioclavicular joint with fluoroscopic guidance. Patients graded pain relief on a visual analogue scale (0-100%) after 15 min. The relationship between pain relief and MRI findings was assessed with the Mann-Whitney U test. Pain relief equal to or greater than 70% was rated as a positive response to the injection. This cutoff value was used to calculate sensitivity, specificity, accuracy, and predictive values of the various MRI findings in determining which acromioclavicular joints were responsive to joint injections. RESULTS: Mean pain relief after injection was 38%. Pain relief was significantly related to capsular hypertrophy (p = 0.007) and was equal to or greater than 70% in 11 patients. The sensitivity in diagnosing a successful injection (range, 9-82%) was highest for caudal osteophytes (82%) and capsular hypertrophy (73%). The specificity (range, 51-97%) was highest for subchondral cysts (97%), subchondral bone marrow edema (95%), and joint effusion (92%). CONCLUSION: Pain relief after intraarticular injection is significantly related to capsular hypertrophy diagnosed on MRI. MRI findings have a reasonable sensitivity and a high specificity in predicting relevant short-term pain relief after intraarticular injection.

Acromioclavicular Joint↗
PubMed2002

Risk factors for lumbar disc degeneration: a 5-year prospective MRI study in asymptomatic individuals.

STUDY DESIGN: A longitudinal magnetic resonance imaging investigation of lumbar disc degeneration in asymptomatic individuals was conducted. OBJECTIVE: To investigate risk factors for the development or deterioration of lumbar disc degeneration. SUMMARY OF BACKGROUND DATA: Numerous studies have explored the significance of certain risk factors for the development or progression of disc degeneration, but no comprehensive longitudinal magnetic resonance imaging-based study has been reported that simultaneously considers clinical, morphologic, physical, psychosocial, and occupational risk factors. METHODS: In the 5-year follow-up evaluation of 41 asymptomatic individuals, the risk factors for the development of lumbar disc degeneration and its progression were investigated. All 41 individuals had a magnetic resonance imaging scan at baseline and at the minimum 5-year follow-up assessment using the same scanner and protocol. The magnetic resonance images were analyzed independently by two radiologists with regard to disc degeneration. Various predictor variables were assessed both at baseline and follow-up, with special emphasis on physical job characteristics, sports activities, and magnetic resonance image-based morphologic findings. RESULTS: Of the 41 individuals, 17 (41%) exhibited a deterioration of the disc status. In 10 individuals, the progression of disc degeneration was one grade or more. Only a weak correlation existed between progressive disc degeneration and low back pain development during a 5-year follow-up period. Multiple logistic regression analysis demonstrated that the extent of disc herniation (odds ratio [OR], 12.63; confidence interval [CI], 1.24-128.49), the lack of sports activities (OR, 2.71; CI, 1.04-7.07), and night shift work (OR, 23.01; CI, 1.26-421.31) were significant predictors for disc degeneration during follow-up evaluation when control was used for the number of degenerated discs at baseline, gender, age, and body mass index. CONCLUSIONS: The results indicate that the extent of disc herniation, the lack of sports activities, and night shift work are significant risk factors for the development of lumbar disc degeneration and its progression.

Adult↗
PubMed2002

MR imaging of the forefoot under weight-bearing conditions: position-related changes of the neurovascular bundles and the metatarsal heads in asymptomatic volunteers.

PURPOSE: To assess practicability of weight-bearing magnetic resonance (MR) imaging of the forefoot, and to demonstrate position-related changes of the neurovascular bundles and the metatarsal heads in asymptomatic volunteers. MATERIALS AND METHODS: With an open-configuration MR system, 32 feet of 32 asymptomatic individuals aged 20-60 years were studied in supine and weight-bearing body positions. Transverse T1-weighted spin-echo MR images were performed. MR images were evaluated qualitatively with regard to image quality, visibility, and position-dependent changes of the neurovascular bundle. In addition, the position of the metatarsal heads was analyzed quantitatively. RESULTS: Weight-bearing MR imaging was feasible in all 32 feet. Quality of MR images obtained in the weight-bearing position was superior to that obtained in the supine position (P < 0.05). A change in the position of the neurovascular bundle from below a virtual line paralleling the plantar cortical line to above this line was present in 50 of 61 instances (82%) between the supine and the weight-bearing positions. When changing from the supine to the weight-bearing position, there was a significant decrease in the distance between the plantar skin and the metatarsal heads for the second (mean 4.5 mm), third (mean 4.4 mm), and fourth metatarsal heads (mean 3.7 mm) (P < 0.0001). However, the difference for the first (mean 0.5 mm) and fifth (mean 0.9 mm) metatarsal heads was not significant. CONCLUSION: Weight-bearing MR imaging of the forefoot is feasible using an open-configuration MR system and demonstrates position-related changes of the neurovascular bundles relative to the metatarsal heads, as well as position-related changes of the metatarsal heads themselves.

Adult↗
PubMed2002

Joint magnetic resonance imaging: normal variants and pitfalls related to sports injury.

MR imaging abnormalities, such as increased signal within normally hypointense structures, form and attachment abnormalities, fluid collections in joints, tendon sheaths and bursa, or even tumors, such as Morton's neuromas, are common in asymptomatic volunteers. They may be explained by normal physiology, anatomic variability, MR imaging artifacts, or true abnormalities without clinical importance. Although it is not always possible to differentiate such variants or artifacts from clinically relevant findings, it is important to know their potential cause and clinical importance and not to over-report them as abnormality requiring additional imaging or treatment. Thorough knowledge of normal anatomy is crucial in this situation.

Ankle Joint↗
PubMed2002

Evaluation of complex joint motion with computer-based analysis of fluoroscopic sequences.

RATIONALE AND OBJECTIVES: To develop a computer-assisted analysis of complex joint motion based on standard fluoroscopic sequences. MATERIALS AND METHODS: Fluoroscopic sequences of 10 normal shoulders and 20 patients after total shoulder arthroplasty were recorded during abduction and adduction. The analysis of the shoulder motion was based on automated tracking of selected components (models) of the shoulder joint. After processing the digitized images with an edge-detection procedure, visible edges were defined as base models. These models were tracked frame by frame. Several automated postprocessing evaluation procedures were developed and tested. RESULTS: The amounts of rotation and translation of the glenohumeral joint can be quantified and related. The mean translation parallel to the glenoid in the normal shoulder joints was 2.8 mm and 1.9 mm in joints after shoulder arthroplasty. The mean translation perpendicular to the glenoid was 0.9 mm and 0.8 mm, respectively. In complex motion patterns (ie, combined glenohumeral and thoracoscapular motion), electronic stabilization of an object (ie, stabilization of scapula) and, thus, separate analysis of each component. CONCLUSION: Computer assisted analysis allows automated evaluation of complex joint motion based on standard fluoroscopic sequences.

Algorithms↗
PubMed2002

Laser-induced thermotherapy of the vertebral body: preliminary assessment of safety and real-time magnetic resonance monitoring in an animal model.

RATIONALE AND OBJECTIVES: To evaluate the safety of percutaneous laser-induced thermotherapy (LITT) of vertebral bodies and the feasibility of monitoring the thermal effects with real-time magnetic resonance (MR) imaging. MATERIALS AND METHODS: Laser fibers were placed in nine vertebral bodies of two minipigs under CT-guidance. LITT was performed in an open 0.5 T MR scanner using an Nd: YAG laser source. A T1-weighted MR sequence was used for continuous color-coded temperature monitoring. Histology of the vertebral body and spinal cord were subsequently obtained. RESULTS: Thermal lesions of the vertebral bodies measured 8 to 11 mm (mean 9.3 mm) in diameter. Thermal injuries of the spinal cord were observed in all four levels in which cortical bone surrounding the spinal canal was damaged during needle placement and in none with intact cortical bone. MR monitoring of the thermal effect was possible only if acquired in breath-hold technique. CONCLUSIONS: An intact cortical bone seems to be a prerequisite for safe LITT of the vertebral body. Real-time MR-monitoring of the thermal effect in vertebral bodies and the spinal canal was feasible with breath-hold acquisition. Larger studies are necessary to further evaluate accuracy of real-time MR imaging.

Animals↗