Kirkland W. Davis

Knee Joint: Comprehensive Assessment with 3D Isotropic Resolution Fast Spin-Echo MR Imaging—Diagnostic Performance Compared with That of Conventional MR Imaging at 3.0 T

PURPOSE To determine whether a three-dimensional isotropic resolution fast spin-echo sequence (FSE-Cube) has similar diagnostic performance as a routine magnetic resonance (MR) imaging protocol for evaluating the cartilage, ligaments, menisci, and osseous structures of the knee joint in symptomatic patients at 3.0 T. MATERIALS AND METHODS This prospective, HIPAA-compliant, institutional review board-approved study was performed with a waiver of informed consent. FSE-Cube was added to the routine 3.0-T MR imaging protocol performed in 100 symptomatic patients (54 male patients with a median age of 32 years and 46 female patients with a median age of 33 years) who subsequently underwent arthroscopic knee surgery. All MR imaging studies were independently reviewed twice by two musculoskeletal radiologists. During the first review, the routine MR imaging protocol was used to detect cartilage lesions, ligament tears, meniscal tears, and bone marrow edema lesions. During the second review, FSE-Cube with multiplanar reformations was used to detect these joint abnormalities. With arthroscopic results as the reference standard, the sensitivity and specificity of FSE-Cube and the routine MR imaging protocol in the detection of cartilage lesions, anterior cruciate ligament tears, and meniscal tears were calculated. Permutation tests were used to compare sensitivity and specificity values. RESULTS FSE-Cube had significantly higher sensitivity (P = .039) but significantly lower specificity (P = .003) than the routine MR imaging protocol for detecting cartilage lesions. There were no significant differences (P = .183-.999) in sensitivity and specificity between FSE-Cube and the routine MR imaging protocol in the detection of anterior cruciate ligament tears, medial meniscal tears, or lateral meniscal tears. FSE-Cube depicted 96.2% of medial collateral ligament tears, 100% of lateral collateral ligament tears, and 85.3% of bone marrow edema lesions identified on images obtained with the routine MR imaging protocol. CONCLUSION FSE-Cube has similar diagnostic performance as a routine MR imaging protocol for detecting cartilage lesions, cruciate ligament tears, collateral ligament tears, meniscal tears, and bone marrow edema lesions within the knee joint at 3.0 T.

Correlation of MRI findings with clinical findings of trochanteric pain syndrome

ObjectiveGreater trochanter pain syndrome due to tendinopathy or bursitis is a common cause of hip pain. The previously reported magnetic resonance (MR) findings of trochanteric tendinopathy and bursitis are peritrochanteric fluid and abductor tendon abnormality. We have often noted peritrochanteric high T2 signal in patients without trochanteric symptoms. The purpose of this study was to determine whether the MR findings of peritrochanteric fluid or hip abductor tendon pathology correlate with trochanteric pain.Materials and methodsWe retrospectively reviewed 131 consecutive MR examinations of the pelvis (256 hips) for T2 peritrochanteric signal and abductor tendon abnormalities without knowledge of the clinical symptoms. Any T2 peritrochanteric abnormality was characterized by size as tiny, small, medium, or large; by morphology as feathery, crescentic, or round; and by location as bursal or intratendinous. The clinical symptoms of hip pain and trochanteric pain were compared to the MR findings on coronal, sagittal, and axial T2 sequences using chi-square or Fisher’s exact test with significance assigned as p < 0.05.ResultsClinical symptoms of trochanteric pain syndrome were present in only 16 of the 256 hips. All 16 hips with trochanteric pain and 212 (88%) of 240 without trochanteric pain had peritrochanteric abnormalities (p = 0.15). Eighty-eight percent of hips with trochanteric symptoms had gluteus tendinopathy while 50% of those without symptoms had such findings (p = 0.004). Other than tendinopathy, there was no statistically significant difference between hips with or without trochanteric symptoms and the presence of peritrochanteric T2 abnormality, its size or shape, and the presence of gluteus medius or minimus partial thickness tears.ConclusionsPatients with trochanteric pain syndrome always have peritrochanteric T2 abnormalities and are significantly more likely to have abductor tendinopathy on magnetic resonance imaging (MRI). However, although the absence of peritrochanteric T2 MR abnormalities makes trochanteric pain syndrome unlikely, detection of these abnormalities on MRI is a poor predictor of trochanteric pain syndrome as these findings are present in a high percentage of patients without trochanteric pain.

Percutaneous image-guided cryoablation of painful metastases involving bone: multicenter trial.

This study sought to describe the results of a single‐arm multicenter clinical trial using image‐guided percutaneous cryoablation for the palliation of painful metastatic tumors involving bone.

Comparison of 1.5- And 3.0-T MR imaging for evaluating the articular cartilage of the knee joint

PURPOSE To retrospectively compare the diagnostic performance of 1.5- and 3.0-T magnetic resonance (MR) imaging protocols for evaluating the articular cartilage of the knee joint in symptomatic patients. MATERIALS AND METHODS This HIPAA-compliant study was performed with a waiver of informed consent from the institutional review board. The study group consisted of 200 symptomatic patients undergoing MR examination of the knee at 1.5 T (61 men, 39 women; mean age, 38.9 years) or 3.0 T (52 men, 48 women; mean age, 39.1 years), who also underwent subsequent arthroscopic knee surgery. All MR examinations consisted of multiplanar fast spin-echo sequences with similar tissue contrast at 1.5 and 3.0 T. All articular surfaces were graded at arthroscopy by using the Noyes classification system. Three musculoskeletal radiologists retrospectively and independently graded all articular surfaces seen at MR imaging by using a similar classification system. The sensitivity, specificity, and accuracy of the 1.5- and 3.0-T MR protocols for detecting cartilage lesions were determined by using arthroscopy as the reference standard. The z test was used to compare sensitivity, specificity, and accuracy values at 1.5 and 3.0 T. RESULTS For all readers combined, the respective sensitivity, specificity, and accuracy of MR imaging for detecting cartilage lesions were 69.3%, 78.0%, and 74.5% at 1.5 T (n = 241) and 70.5%, 85.9%, and 80.1% at 3.0 T (n = 226). The MR imaging protocol had significantly higher specificity and accuracy (P < .05) but not higher sensitivity (P = .73) for detecting cartilage lesions at 3.0 T than at 1.5 T. CONCLUSION A 3.0-T MR protocol has improved diagnostic performance for evaluating the articular cartilage of the knee joint in symptomatic patients when compared with a 1.5-T protocol.

Cervical spine injury severity score. Assessment of reliability.

BACKGROUND Systems for classifying cervical spine injury most commonly use mechanistic or morphologic terms and do not quantify the degree of stability. Along with neurologic function, stability is a major determinant of treatment and prognosis. The goal of our study was to investigate the reliability of a method of quantifying the stability of subaxial (C3-C7) cervical spine injuries. METHODS A quantitative system was developed in which an analog score of 0 to 5 points is assigned, on the basis of fracture displacement and severity of ligamentous injury, to each of four spinal columns (anterior, posterior, right pillar, and left pillar). The total possible score thus ranges from 0 to 20 points. Fifteen examiners assigned scores after reviewing the plain radiographs and computed tomography images of thirty-four consecutive patients with cervical spine injuries. The scores were then evaluated for interobserver and intraobserver reliability with use of intraclass correlation coefficients. RESULTS The mean intraobserver and interobserver intraclass correlation coefficients for the fifteen reviewers were 0.977 and 0.883, respectively. Association between the scores and clinical data was also excellent, as all patients who had a score of > or =7 points had surgery. Similarly, eleven of the fourteen patients with a score of > or =7 points had a neurologic deficit compared with only three of the twenty with a score of <7 points. CONCLUSIONS The Cervical Spine Injury Severity Score had excellent intraobserver and interobserver reliability. We believe that quantifying stability on the basis of fracture morphology will allow surgeons to better characterize these injuries and ultimately lead to the development of treatment algorithms that can be tested in clinical trials.

MR Arthrography of the Hip: Comparison of IDEAL-SPGR Volume Sequence to Standard MR Sequences in the Detection and Grading of Cartilage Lesions

PURPOSE To compare the diagnostic performance of iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL)-spoiled gradient-recalled echo (SPGR) with that of standard magnetic resonance (MR) arthrography sequences for detecting and grading cartilage lesions within the hip joint during MR arthrography. MATERIALS AND METHODS Following institutional review board approval, 67 consecutive hip MR arthrograms were retrospectively reviewed independently by three musculoskeletal radiologists and one musculoskeletal fellow. IDEAL-SPGR images and the two-dimensional images, the latter from the routine MR arthrography protocol, were evaluated at separate sittings to grade each articular surface of the hip joint. By using arthroscopy as the reference standard, the sensitivity and specificity of the two techniques for detecting and grading cartilage lesions were determined. The McNemar test was used to compare diagnostic performance. Interreader agreement was calculated using Fleiss κ values. RESULTS For all readers and surfaces combined, the sensitivity and specificity for detecting cartilage lesions was 74% and 77%, respectively, for IDEAL-SPGR and 70% and 84%, respectively, for the routine MR arthrography protocol. IDEAL-SPGR had similar sensitivity (P = .12) to and significantly lower specificity (P < .001) than the routine MR arthrography protocol for depicting cartilage lesions. When analyzing the differences in sensitivity and specificity by reader, the two readers who had experience with IDEAL-SPGR had no significant difference in sensitivity and specificity for detecting cartilage lesions between the two sequences. For all readers and surfaces combined, IDEAL-SPGR had a higher accuracy in correctly grading cartilage lesion (P = .012-.013). Interobserver agreement for detecting cartilage lesions did not differ between the two techniques. CONCLUSION IDEAL-SPGR had similar sensitivity and significantly lower specificity for detecting cartilage lesions and higher accuracy for grading cartilage lesions than did a routine MR arthrography protocol; the lower specificity of IDEAL-SPGR for detecting cartilage lesions was not seen in experienced readers.

Cartilage morphology at 3.0T: assessment of three-dimensional magnetic resonance imaging techniques.

To compare six new three‐dimensional (3D) magnetic resonance (MR) methods for evaluating knee cartilage at 3.0T.

MRI Appearance of the Pectinofoveal Fold

OBJECTIVE The pectinofoveal fold is an intraarticular structure of the hip that has had only limited study in the clinical and anatomic literature. This fold may resemble a hip plica; however, symptomatic hip plicae are now being recognized and treated at hip arthroscopy. We wished to determine the frequency and appearance of the pectinofoveal fold on hip MR arthrography. By defining the variations in its appearance, the normal pectinofoveal fold can be distinguished from pathologic hip plicae. MATERIALS AND METHODS One hundred fifty-two hip MR arthrography examinations of patients who subsequently underwent hip arthroscopy were retrospectively reviewed. Each MR examination was reviewed for the presence of a pectinofoveal fold. If present, the fold was measured in the anteroposterior, mediolateral, and superior-inferior dimensions; evaluated for smooth or irregular contour; and evaluated for a femoral or capsular site of insertion. RESULTS The pectinofoveal fold was visualized on hip MR arthrograms in 144 of the 152 (95%) patients and visualized at hip arthroscopy in 150 of the 152 (99%) patients. The average thickness of the fold was 2.6 mm (range, 1-13 mm) in the mediolateral dimension and 17 mm (range, 1-32 mm) in the anteroposterior dimension. The average length of the fold in the superior-inferior dimension was 23.3 mm (range, 7-44 mm). The pectinofoveal fold had a smooth contour in 75 of the 144 (52%) patients with examinations that showed the fold and an irregular contour in 69 of 144 (48%) patients. The fold was found to insert onto the capsule in 108 of 144 (75%) patients and onto the femur in the remaining 36. CONCLUSION The pectinofoveal fold should almost always be visualized at MR arthrography. The fold can have various appearances and attachment sites, and these normal variations should not be mistaken for fold abnormalities. These findings should be useful in distinguishing this normal structure from normal and pathologic plicae.

Imaging of the Hamstrings

The hamstring muscles, located in the posterior thigh, include the biceps femoris, the semimembranosus, and the semitendinosus. The proximal portions of the hamstring muscles are subject to a variety of injuries and pathology. Many of these entities affect the origin of the hamstrings, including the tendinous enthesis, the underlying ischial tuberosity, and the surrounding tissues. Tendinosis and small partial tears at the origin are the result of chronic attrition. They may be accompanied by bursitis or hamstring syndrome. Apophysitis occurs in teenagers prior to complete fusion of the ischial apophysis and results from repeated traction injuries on the apophysis without discrete displacement. Abrupt injury at the origin from forced flexion of the hip results in osseous avulsions of the apophysis in teenagers and proximal tendon ruptures in adults. Other entities affect the muscles distal to the tendon origins. These injuries include strains and partial tears of the musculotendinous junction from acute indirect trauma, delayed onset muscle soreness from overuse of the muscle group without discrete remembered injury, and contusions and myositis ossificans from direct blunt impact. The imaging features of these injuries and pathology are fairly specific and diagnostic, with the exception of some cases of myositis ossificans and chronic ischial avulsions.

Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material.

OBJECTIVE Several previous studies reported that the signal contacting the meniscal surface in a recurrent tear on MR arthrography had intensity equal to that of intraarticular contrast material. Because we failed to diagnose recurrent tears using this criterion, we reviewed our knee MR arthrograms in patients who had prior meniscal surgery. CONCLUSION On knee MR arthrograms, the signal contacting the surface of a recurrent meniscal tear may be equal to or less than that of adjacent intraarticular gadolinium contrast material.