Biomedical subjects

Marius R Schmid

Publications and source records attributed to Marius R Schmid.

At least 19 recordsLinked to original sources

PubMed2007

Peripheral tear of the triangular fibrocartilage: depiction with MR arthrography of the distal radioulnar joint.

OBJECTIVE: Although central tears of the triangular fibrocartilage are easily seen on imaging, peripheral tears of the ulnar attachment are frequently missed. The aim of this study was to evaluate the accuracy of MR arthrography of the distal radioulnar joint in depiction of peripheral tears of the triangular fibrocartilage. MATERIALS AND METHODS: Forty-one patients (18 women, 23 men; mean age, 38 years; age range, 18-60 years) underwent MR arthrography and wrist arthroscopy. For MR arthrography, iopamidol (300 mg I/mL) and gadopentetate dimeglumine (4 mmol/L) were injected into the distal radioulnar joint. Consensus review of both MR arthrograms and conventional arthrograms was performed by two experienced musculoskeletal radiologists. Presence or absence of communicating and noncommunicating tears of the ulnar attachment of the triangular fibrocartilage was recorded. Arthroscopy was used as the standard of reference for determining sensitivity, specificity, and accuracy in detection of tears of the ulnar attachment. RESULTS: At MR arthrography, communicating tear of the ulnar attachment was diagnosed in three patients, noncommunicating tear in 19 patients, and normal attachment in 19 patients. Arthroscopy revealed peripheral tear of the triangular fibrocartilage in all three patients with communicating tear, in 14 of 19 patients with noncommunicating tear, and in three of 19 patients with normal attachment. The sensitivity was 85% (17/20), specificity was 76% (16/21), and accuracy was 80% (33/41). CONCLUSION: MR arthrography of the distal radioulnar joint is accurate in depiction of peripheral tears of the ulnar attachment of the triangular fibrocartilage. These tears often appear as noncommunicating tears extending from the distal radioulnar joint into the triangular fibrocartilage.

Adolescent↗

PubMed2006

MR arthrography in calcific tendinitis of the shoulder: diagnostic performance and pitfalls.

The purpose was to assess the diagnostic performance of MR arthrography to diagnose calcific tendinitis of the shoulder and to assess the reasons for diagnostic errors. Standard MR arthrograms of 22 patients with calcific tendinitis and 61 controls were retrospectively analyzed by two independent and blinded radiologists. All cases were consecutively collected from a database. Conventional radiographs were available in all cases serving as gold standard. The supraspinatus was involved in 16, the infraspinatus in four and the subscapularis in two patients. All diagnostic errors were analyzed by two additional readers. Reader 1 correctly detected 12 of the 22 shoulders with and 42 of the 61 shoulders without calcific tendinitis (sensitivity 0.55, specificity 0.66). The corresponding values for reader 2 were 13 of 22 and 40 of 61 cases (sensitivity 0.59, specificity 0.69). Inter-rater agreement (kappa-value) was 0.42. Small size of the calcific deposits and isointensity compared to the surrounding tissue were the most important reasons for false negative results. Normal hypointense areas within the supraspinatus tendon substance and attachment were the main reason for false positive results. In conclusion, MR arthrography is insufficient in the diagnosis of calcific tendinitis. Normal hypointense parts of the rotator cuff may mimic calcific deposits and calcifications may not be detected when they are isointense compared to the rotator cuff. Therefore, MR imaging should not be interpreted without corresponding radiographs.

Adult↗

PubMed2006

Imaging findings predicting the outcome of cervical facet joint blocks.

To determine which cross-sectional imaging findings predict the short-term outcome of cervical facet joint blocks (FJB) and to evaluate the effect of combined intra-/periarticular versus periarticular injection on pain. Fifty facet joints in 37 patients were included in the study. Single, unilateral FJBs in 24 patients, and bilateral single level FJBs in 13 patients were performed, respectively. In all patients, pain relief was assessed using a visual analogue scale. All computed tomography (CT) examinations were blindly reviewed by two radiologists. Osteoarthritis was rated using the Kellgren classification. The presence of combined intra-/periarticular vs. sole periarticular injection of contrast was evaluated. Kellgren Grades 0 (n=23), 1 (n=5), 2 (n=3), 3 (n=9), and 4 (n=10) were found. Mean pain relief after injection was 35% (range: 0-100%). 40% of all injections were combined intra-/periarticular. There was neither a statistically significant difference between pain relief and combined intra-/periarticular versus sole periarticular injection (p=0.64) nor the grade of osteoarthritis (p=0.49). Pain relief after cervical FJBs does not correlate with morphologic alterations seen on CT. Periarticular FJBs are not less successful than combined intra-/periarticular FJBs.

Adult↗

PubMed2006

Sympathetic skin response: monitoring of CT-guided lumbar sympathetic blocks.

PURPOSE: To prospectively evaluate accuracy of sympathetic skin response (SSR) for monitoring computed tomography (CT)-guided lumbar sympathetic blocks, with palpable temperature increase in the foot 30 minutes after injection serving as the reference standard. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained. Seventy individual lumbar sympathetic blocks were performed in 13 patients (six female, seven male; mean age, 45 years) with reflex sympathetic dystrophy of the foot. A 22-gauge needle was advanced to the sympathetic trunk at midlumbar level with CT fluoroscopic guidance, and 1 mL of iopamidol (200 mg of iodine per milliliter) and 5 mL of 0.5% bupivacaine were injected. SSR was monitored in both feet before and after bupivacaine injection. SSRs were activated with painless low-strength (5-20-mA) electrical stimuli. SSR ratio (SSR in the injected foot versus SSR in the contralateral foot) was calculated before injection and repeatedly at 1-minute intervals thereafter. Needle tip position and distribution of bupivacaine were measured on CT images. Receiver operating characteristic curves for SSR ratio were calculated until 7 minutes after injection. Logistic regression analyses adjusted for clustering were calculated for SSR ratio, injection parameters, needle tip position, and bupivacaine distribution. RESULTS: Thirty minutes after injection, 83% of procedures were considered clinically successful. An SSR cutoff ratio of 1:10 was used, and sensitivity, specificity, and accuracy of SSR for prediction of clinical success were 84%, 92%, and 86%, respectively, 4 minutes after injection and 95%, 92%, and 94%, respectively, 7 minutes after injection. Needle tip position (P = .19), medial and lateral borders of bupivacaine distribution (P = .11 and .056), and distance between bupivacaine distribution and the vertebral body (P = .41) were not significantly different between successful and unsuccessful injections. CONCLUSION: SSR can be used to correctly identify needle tip position in lumbar sympathetic blocks 6 and 7 minutes after injection.

Adolescent↗

PubMed2006

Cartilaginous defects of the femorotibial joint: accuracy of coronal short inversion time inversion-recovery MR sequence.

PURPOSE: To retrospectively assess the diagnostic performance of the short inversion time inversion-recovery (STIR) magnetic resonance (MR) sequence for depiction and classification of articular cartilaginous lesions in femorotibial joint, with arthroscopy as reference standard. MATERIALS AND METHODS: Institutional review board did not require approval and informed consent for review of patients' records or images. All patients (and parents of underage patients) agreed to use of their data. Two musculoskeletal radiologists independently analyzed femorotibial cartilage on coronal STIR images from 84 knee MR examinations in 83 patients (48 male patients [49 knees], 35 female patients; mean age, 39.5 years). Slightly modified Outerbridge classification was used: grade 0, normal cartilage; grade 1, softening or swelling; grade 2, partial-thickness defect; grade 3, fissuring to the level of the subchondral bone; and grade 4, exposed subchondral bone. Arthroscopy performed within 15 weeks was the standard of reference. Classification for arthroscopy differed only in definition of grade 1 (softening or swelling of cartilage). Sensitivity, specificity, accuracy, positive and negative predictive values, and weighted kappa values were calculated to assess interobserver reliability. RESULTS: At arthroscopy, 212 (63%) of 336 surfaces were classified as grade 0 (normal); 37 (11%), as grade 1 abnormalities; 30 (9%), as grade 2 lesions; 25 (7%), as grade 3 lesions; and 32 (10%), as grade 4 lesions. Grades 0 and 1 were considered normal; grades 2-4, as abnormal. For detection of contour defects of the cartilaginous surface, coronal STIR MR imaging had sensitivity values of 77% and 76%, specificity values of 96% and 89%, accuracy values of 91% and 85%, positive predictive values of 86% and 70%, and negative predictive values of 92% and 91% for readers 1 and 2, respectively. Weighted kappa value was 0.63. CONCLUSION: Contour defects of femorotibial cartilage can be detected with reasonable accuracy with routine STIR sequence.

Adolescent↗

PubMed2006

Fat content of lumbar paraspinal muscles in patients with chronic low back pain and in asymptomatic volunteers: quantification with MR spectroscopy.

PURPOSE: To prospectively evaluate the fat content of paraspinal muscles by using proton magnetic resonance (MR) spectroscopy in patients with chronic low back pain (LBP) and in asymptomatic volunteers matched with regard to age, sex, and body mass index. MATERIALS AND METHODS: The study was approved by the responsible institutional review board. Informed consent was obtained from each patient and each volunteer. Single-voxel proton MR spectroscopy was used to measure the fat content of the lumbar multifidus and longissimus muscles in 25 patients (13 women, 12 men; mean age, 40.5 years) with chronic LBP and in 25 matched asymptomatic volunteers (13 women, 12 men; mean age, 39.8 years). The fat content was also graded semiquantitatively (grades 0-4). The relationship between fat content and LBP duration, LBP intensity, and self-rated disability was assessed (Pearson correlation). RESULTS: The mean percentage fat content of the multifidus muscle was 23.6% (95% confidence interval [CI]: 17.5%, 29.7%) in patients with chronic LBP and 14.5% (95% CI: 10.8%, 18.3%) in the volunteers (P = .014). The corresponding values for the longissimus muscle were 29.3% (95% CI: 23.4%, 35.3%) in patients with LBP and 26.0% (95% CI: 21.9%, 30.0%) in the volunteers (P = .66). The semiquantitative grading of the fat content of the multifidus muscle was 0 in 12 (48%) of 25 patients and in 14 (56%) of 25 volunteers, 1 in 11 (44%) patients and in eight (32%) volunteers, and 2 in two (8%) patients and three (12%) volunteers. The semiquantitative grading of the fat content of the longissimus muscle was 0 in nine (36%) of 25 patients and 15 (60%) of 25 volunteers, 1 in 13 (52%) patients and nine (36%) volunteers, and 2 in three (12%) patients and one (4%) volunteer. Neither grade 3 nor grade 4 was assigned to any muscle. The grading differences were not significant between patients and volunteers. No significant correlation was found between fat content and pain intensity, pain duration, or self-rated disability. CONCLUSION: Proton MR spectroscopy demonstrates a significantly higher fat content in the multifidus muscle in patients with chronic LBP than in asymptomatic volunteers. No difference was detected with a semiquantitative grading system.

Adipose Tissue↗

PubMed2006

Association of a large lateral extension of the acromion with rotator cuff tears.

BACKGROUND: Factors predisposing to tearing of the rotator cuff are poorly understood. We have observed that the acromion of patients with a rotator cuff tear very often appears large on anteroposterior radiographs or during surgery. The purpose of this study was to quantify the lateral extension of the acromion in patients with a full-thickness rotator cuff tear and in patients with an intact rotator cuff. METHODS: The lateral extension of the acromion was assessed on true anteroposterior radiographs made with the arm in neutral rotation. The distance from the glenoid plane to the lateral border of the acromion was divided by the distance from the glenoid plane to the lateral aspect of the humeral head to calculate the acromion index. This index was determined in a group of 102 patients (average age, 65.0 years) with a proven full-thickness rotator cuff tear, in an age and gender-matched group of forty-seven patients (average age, 63.7 years) with osteoarthritis of the shoulder and an intact rotator cuff, and in an age and gender-matched control group of seventy volunteers (average age, 64.4 years) with an intact rotator cuff as demonstrated by ultrasonography. RESULTS: The average acromion index (and standard deviation) was 0.73 +/- 0.06 in the shoulders with a full-thickness tear, 0.60 +/- 0.08 in those with osteoarthritis and an intact rotator cuff, and 0.64 +/- 0.06 in the asymptomatic, normal shoulders with an intact rotator cuff. The difference between the index in the shoulders with a full-thickness supraspinatus tear and the index in those with an intact rotator cuff was highly significant (p < 0.0001). CONCLUSIONS: A large lateral extension of the acromion appears to be associated with full-thickness tearing of the rotator cuff.

Acromion↗

PubMed2006

Therapeutic efficacy of facet joint blocks.

OBJECTIVE: The objective of our study was to investigate outcome predictors of short- and medium-term therapeutic efficacy of facet joint blocks. MATERIALS AND METHODS: Forty-two patients with chronic lower back pain who were undergoing facet joint blocks at one (n = 29) or two (n = 13) levels were analyzed. All patients underwent MRI or CT of the lumbar spine within 5 months before the facet joint blocks. The facet joint blocks were performed under fluoroscopic guidance. A small amount (< 0.3 mL) of iodinated contrast agent, 0.5 mL of local anesthetics and 0.5 mL of steroids, were injected. The initial pain response was prospectively assessed using a visual analogue scale. Additional data, including short-term effect (> 1 week) and medium-term effect (> 3 months), were collected by a structured telephone interview. CT and MRI were reviewed with regard to the extent of facet joint abnormalities. Multiple logistic regression analyses were conducted to identify outcome predictor for efficacy of facet joint blocks. RESULTS: A positive immediate effect was seen in 31 patients (74%). A positive medium-term effect was found in 14 patients (33%). Pain alleviated by motion (p = 0.035) and the absence of joint-blocking sensation (p = 0.042) predicted pain relief. However, the extent of facet joint osteoarthritis on MRI and CT was not a significant predictor for outcome (p = 0.57-0.95). CONCLUSION: Facet joint blocks appear to have a beneficial medium-term effect in one third of patients with chronic lower back pain and may therefore be a reasonable adjunct to nonoperative treatment. However, outcome appears to depend on clinical, not on morphologic, imaging findings.

Adult↗

PubMed2006

Association between rotator cuff abnormalities and reduced acromiohumeral distance.

OBJECTIVE: The purpose of this study was to evaluate the association between rotator cuff abnormalities and reduced acromiohumeral distance. MATERIALS AND METHODS: Acromiohumeral distance was measured on conventional radiographs and on MR images. Three age- and sex-matched patient groups each including 21 patients were stratified according to acromiohumeral distance on conventional radiographs (group 1, 10 mm). Acromiohumeral distance was related to the presence, location, and size of a rotator cuff tear and the degree of fatty degeneration of the muscle assessed on MR arthrography. The relative influence on acromiohumeral distance of the various MR arthrographic findings was assessed. Spearman's rank correlation and stepwise regression were used for statistical analysis. RESULTS: In group 1 (acromiohumeral distance <or= 7 mm) full-thickness supraspinatus tendon tears were present in 90% (19/21) of the patients, infraspinatus tendon tears in 67% (14/21) of the patients, and subscapularis tendon tears in 43% (9/21) of the patients. The size of rotator cuff tendon tears and the degree of fatty degeneration in all rotator cuff muscles showed a significant negative correlation with acromiohumeral distance (p < 0.05). After stepwise regression, a significant relative influence on acromiohumeral distance remained for size of rotator cuff tear (p < 0.0001) and for degree of fatty degeneration of the infraspinatus muscle (p = 0.013). CONCLUSION: Tendon tears and fatty muscle degeneration in the rotator cuff correlate with reduced acromiohumeral distance. Size of rotator cuff tear and degree of fatty degeneration of the infraspinatus muscle have the most pronounced influence on acromiohumeral distance.

Acromion↗

PubMed2005

Clinical course of knees with asymptomatic meniscal abnormalities: findings at 2-year follow-up after MR imaging-based diagnosis.

PURPOSE: To prospectively evaluate the clinical course of asymptomatic meniscal lesions diagnosed by using magnetic resonance (MR) imaging. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. The clinical courses of meniscal lesions in 84 asymptomatic knees (in 48 men and 36 women; mean age, 43.6 years; age range, 18-73 years) were assessed. Thirty-one asymptomatic meniscal lesions were depicted among the 84 knees at MR imaging. The follow-up period was at least 2 years (mean, 29.8 months; range, 24-36 months). Knee pain, stiffness, and function during daily and sports activities were assessed by using a visual analogue scale (VAS), on which a score of 0 indicated no pain or complaints and a score of 100 indicated maximal pain and/or complaints. The chi2 test was used for statistical analysis. RESULTS: At follow-up, 12 (39%) of the 31 patients with and 10 (19%) of the 53 patients without meniscal lesions reported having knee pain (P = .046). Nine (29%) patients with and five (9%) patients without meniscal lesions reported having knee stiffness (P = .02). Ten (32%) patients with and five (9%) patients without meniscal lesions reported having impaired function during daily activities (P = .008). Thirteen (42%) patients with and 15 (28%) patients without meniscal lesions reported having impaired function during sports activities (P = .20). Mean VAS scores ranged from 22 to 30; mean VAS scores for pain, stiffness, impaired daily function, and impaired sports function were 26, 22, 27, and 30, respectively. None of the initially asymptomatic knees was treated with surgery during the follow-up period. CONCLUSION: The clinical course of knees with initially asymptomatic meniscal lesions, compared with the clinical course of knees without meniscal lesions, is characterized by an increased frequency of complaints. However, severities of pain and knee function impairment remain low.

Activities of Daily Living↗

PubMed2005

Prospective evaluation of two different injection techniques for MR arthrography of the hip.

The aim of the study was to evaluate prospectively the technical feasibility and discomfort of two different injection techniques for MR arthrography of the hip. Sixty-one consecutive patients undergoing MR arthrography of the hip (68 hips) were randomly injected either at the femoral head (36 hips) or the femoral neck (32 hips). The patients rated discomfort during and 0-72 h after arthrography using a visual analogue scale (VAS, 0="did not feel anything", 100="unbearable"). The volume injected, the distance between the needle tract and the neurovascular bundle, the duration of the procedure and the extra-articular contrast leakage were measured. No significant differences were found for the volume injected, the distance between the needle tract and the neurovascular bundle, or the procedure duration. Volume of extra-articular contrast leakage was statistically significantly different (head 1+/-2 cm(3), neck 3+/-5 cm(3), P=0.024). The VAS score for needle advancement was significantly different (head 25+/-20, neck 19+/-23, P=0.031). No significant differences were found for the VAS score regarding delayed discomfort. Before the examination the arthrography-related discomfort was overestimated by 74% (50/68), correctly anticipated by 22% (15/68) and underestimated by 4% (3/68) of the patients. MR-related discomfort was overestimated by 32% (22/68), correctly anticipated by 57% (39/68) and underestimated by 10% (7/68) of the patients. Both hip puncture techniques were well tolerated. The neck injection technique produced less discomfort and was associated with greater extra-articular contrast leakage.

Adolescent↗

PubMed2005

Lumbar disk herniation: do MR imaging findings predict recurrence after surgical diskectomy?

PURPOSE: To retrospectively evaluate if the degree of disk degeneration and disk herniation volume at magnetic resonance (MR) imaging are risk factors for recurrent disk herniation. MATERIALS AND METHODS: The institutional review board permits such retrospective studies, and individual informed consent was not required. MR imaging findings obtained before initial diskectomy in 30 patients (mean age, 42.8 years; 10 women, 20 men) with recurrent disk herniation (study group) and 30 patients (mean age, 42.2 years; nine women, 21 men) without recurrence for at least 2 years after surgery (control group) were compared. Disk degeneration was assessed on T2-weighted sagittal MR images with a five-point grading system (grade I indicated no degeneration; grade II, horizontal hypointense bands within disk; grade III, inhomogeneous disk with intermediate signal intensity; grade IV, no distinction between inner and outer parts of disk; and grade V, collapsed hypointense disk). Disk herniation was classified as representing protrusion, extrusion, or sequestration. The volume of both the affected intervertebral disk and the herniated disk material was measured. Qualitative and quantitative analyses were performed by two readers. The chi(2) test was used for comparison of categorical variables. For comparison of disk degeneration and volumes between patients with and those without recurrence, a paired two-tailed t test was used. Odds ratios based on the extent of disk degeneration were calculated for the entire sample. RESULTS: Advanced disk degeneration (grades IV and V) was significantly less frequent in the study group than in the control group (P < .006). The risk of recurrent disk herniation decreased by a factor of 3.4 for each increase in grade of disk degeneration (odds ratio: 3.58; 95% confidence interval: 1.3, 9.6; P = .011). Mean disk herniation volume as a percentage of intervertebral disk volume was 10.59% +/- 3.41 in the study group and 11.56% +/- 3.84 in the control group. This difference was not significant (P = .31). CONCLUSION: Minor disk degeneration but not herniation volume represents a risk factor for the recurrence of disk herniation after diskectomy.

Adult↗

PubMed2005

Interosseous ligament tears of the wrist: comparison of multi-detector row CT arthrography and MR imaging.

PURPOSE: To compare the accuracy of multi-detector row computed tomographic (CT) arthrography and magnetic resonance (MR) imaging in depicting tears of dorsal, central, and palmar segments of scapholunate (SL) and lunotriquetral (LT) ligaments in cadavers. MATERIALS AND METHODS: Cadaver wrists were obtained and used according to institutional guidelines and with informed consent of donors prior to death. Nine cadaver wrists of eight subjects were evaluated. MR images were obtained with a 1.5-T MR unit. Imaging protocol included intermediate-weighted coronal and transverse fast spin-echo and coronal three-dimensional gradient-echo sequences. Multi-detector row CT arthrography was performed after tricompartmental injection of 3-6 mL of contrast material with a concentration of 160 mg per milliliter of iodine. Palmar, dorsal, and central segments of both ligaments were analyzed on transverse and coronal MR images and multiplanar multi-detector row CT reconstructions by two musculoskeletal radiologists working independently. Open inspection of the wrists was the reference standard. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated from the imaging and gross pathologic readings. Statistical significance was calculated with the McNemar test. Weighted kappa values for interobserver agreement were calculated for both imaging modalities. RESULTS: All ligament segments could be visualized in all cases with both imaging modalities. CT arthrography was more sensitive (100%) than MR imaging (60%) in detection of palmar segment tears (P = .62); specificity of both imaging modalities was 77%. Sensitivity (CT arthrography, 86%; MR imaging, 79%) and specificity (CT arthrography, 50%; MR imaging, 25%) for detection of the central segment tears were determined. Dorsal segment tears were detected only with CT arthrography, while all tears were missed with MR imaging (P = .02). Interobserver agreement was better for multi-detector row CT arthrography (kappa = 0.37-0.78) than for MR imaging (kappa = -0.33 to -0.10). CONCLUSION: Performance in depiction of palmar and central segment tears of SL and LT ligaments is almost equal for multi-detector row CT arthrography and MR imaging, with much higher interobserver reliability for CT arthrography. CT arthrography is significantly superior to MR imaging in the detection of dorsal segment tears of SL and LT ligaments.

Aged↗

PubMed2005

Imaging of patellar cartilage with a 2D multiple-echo data image combination sequence.

OBJECTIVE: We sought to evaluate the diagnostic value of a 2D multiple-echo data image combination (MEDIC) MRI sequence in the detection of patellar cartilage defects. MATERIALS AND METHODS: Our study included 52 consecutive patients who had knee surgery within 4 months of undergoing an MRI examination including an axial 2D MEDIC (TR/TE, 884/26; flip angle, 30 degrees ) sequence. Cartilage was surgically graded on a 5-point scale: 0, normal; 1, softening or swelling; 2, partial thickness defect; 3, fissuring to the level of the subchondral bone; or 4, exposed subchondral bone. Cartilage was graded on MRI according to a scale that was almost identical to the surgical scale except that grade 1 lesions were defined as signal alteration or swelling of cartilage. Two blinded reviewers independently analyzed patellar cartilage. Sensitivity, specificity, accuracy, and weighted kappa values for interobserver variability were calculated. RESULTS: Low-grade cartilage lesions predominated in our study group. When grade 2 or higher was considered the threshold for relevance, the sensitivity, specificity, and accuracy for the MEDIC sequence was as high as 79%, 82%, and 81%, respectively. Increasing the threshold of relevance to grade 3 increased the sensitivity, specificity, and accuracy to as high as 83%, 91%, and 90%, respectively. Interobserver agreement for the MEDIC sequence was good (weighted kappa = 0.68). CONCLUSION: The 2D MEDIC sequence performs comparably to previously described sequences optimized for cartilage imaging such as the 3D double-echo steady-state or 3D spoiled gradient-recalled sequences with good interobserver agreement, high sensitivity, and excellent specificity for revealing low- to intermediate-degree cartilage defects.

Adult↗

PubMed2004

Assessment of fat content in supraspinatus muscle with proton MR spectroscopy in asymptomatic volunteers and patients with supraspinatus tendon lesions.

PURPOSE: To evaluate proton magnetic resonance (MR) spectroscopy in the assessment of lipid content of the supraspinatus muscle in asymptomatic volunteers and patients with supraspinatus tendon lesions. MATERIALS AND METHODS: Single-voxel proton MR spectroscopy was used to assess lipid content of the supraspinatus muscle in asymptomatic volunteers (n = 30) and patients with partial-thickness supraspinatus tendon tears (n = 30), newly diagnosed full-thickness supraspinatus tendon tears (n = 30), and chronic full-thickness supraspinatus tendon tears (n = 30). The apparent lipid content of the supraspinatus muscle measured with proton MR spectroscopy was related to its appearance on sagittal-oblique T1-weighted spin-echo MR images (grades 0-4). One-way analysis of variance was performed to test for significant differences, and the Tukey honestly significant difference procedure was performed for post hoc comparisons. RESULTS: Mean apparent lipid content was 13.7% (95% confidence interval [CI]: 11.5%, 15.8%) for asymptomatic volunteers, 29.5% (95% CI: 25.1%, 34.0%) for patients with partial-thickness tears, 48.6% (95% CI: 41.3%, 55.9%) for patients with full-thickness tears, and 66.1% (95% CI: 57.7%, 74.5%) for patients with chronic tears. Values were significantly different (analysis of variance, P <.001; P <.001-.002 for all post hoc pairwise comparisons). Mean apparent lipid content for the supraspinatus muscle was as follows: grade 0, 19.6% (95% CI: 16.7%, 22.6%); grade 1, 36.8% (95% CI: 33.2%, 40.4%); grade 2, 53.6% (95% CI: 43.1%, 64.2%); grade 3, 67.5% (95% CI: 52.6%, 82.3%); and grade 4, 79.2% (95% CI: 73.2%, 85.3%). With analysis of variance (P <.001), all post hoc pairwise comparisons were significant (P </=.001) except between grades 2 and 3 (P =.112) and between grades 3 and 4 (P =.261). In 14 (25%) subjects who had grade 0 appearance on T1-weighted images, lipid content values were greater than the upper range of values in the volunteers. CONCLUSION: Proton MR spectroscopy is suitable in the assessment of apparent lipid content of rotator cuff muscles.

Adult↗

PubMed2004

MR arthrography of the hip: diagnostic performance of a dedicated water-excitation 3D double-echo steady-state sequence to detect cartilage lesions.

OBJECTIVE: The objective of our study was to compare the diagnostic performance of a dedicated cartilage MR sequence (water-excitation 3D double-echo steady-state) with a standard MR sequence (T1-weighted spin-echo) in detecting articular cartilage lesions of the hip after intraarticular injection of gadopentetate dimeglumine. MATERIALS AND METHODS: In 50 MR arthrograms of the hip joint obtained in 47 consecutive patients, a sagittal 3D double-echo steady-state sequence (TR/TE, 24/6.5; flip angle, 25 degrees ) was compared with a sagittal T1-weighted spin-echo sequence (350/14). Two musculoskeletal radiologists independently evaluated articular cartilage. Sensitivity and specificity for detecting cartilage defects were calculated for those hips that underwent open surgery (n = 21). Lesion conspicuity was retrospectively reviewed and graded between 1 (not visible) and 5 (well defined). RESULTS: At surgery, a total of 26 lesions of the acetabular (n = 20) and femoral (n = 6) cartilage were found. For the 3D double-echo steady-state and T1-weighted spin-echo sequences, sensitivities and specificities for cartilage lesion detection were 58% and 88% and 81% and 81% for reviewer 1 and 62% and 94% and 62% and 100% for reviewer 2, respectively. Lesion conspicuity was significantly superior (p = 0.036) for the 3D double-echo steady-state sequence (mean grade, 3.4) compared with the T1-weighted spin-echo sequence (mean grade, 3.0). The kappa value was fair for the 3D double-echo steady-state sequence (kappa = 0.40) and moderate for the T1-weighted spin-echo sequence (kappa = 0.55). CONCLUSION: The 3D double-echo steady-state sequence optimized for cartilage imaging improves lesion conspicuity but does not improve diagnostic performance.

Adult↗

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

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↗