MR imaging-based diagnosis and classification of meniscal tears.

Magnetic resonance (MR) imaging is currently the modality of choice for detecting meniscal injuries and planning subsequent treatment. A thorough understanding of the imaging protocols, normal meniscal anatomy, surrounding anatomic structures, and anatomic variants and pitfalls is critical to ensure diagnostic accuracy and prevent unnecessary surgery. High-spatial-resolution imaging of the meniscus can be performed using fast spin-echo and three-dimensional MR imaging sequences.

MR Appearance and Clinical Significance of Changes in the Hip Muscles and Iliopsoas Tendon After Arthroscopic Iliopsoas Tenotomy in Symptomatic Patients.

Background: Iliopsoas tenotomy is a treatment for snapping hip. Does this surgical procedure change the surrounding muscle and tendon anatomy?

Questions/purposes: This study seeks to evaluate the changes in the MR appearance of the hip muscles and iliopsoas tendon in patients following arthroscopic iliopsoas tenotomy.

Methods: One hundred sixty-nine consecutive adults were evaluated after iliopsoas tenotomy at the lesser trochanter.

High resolution ultrasound features of prostatic rib metastasis: a prospective feasibility study with implication in the high-risk prostate cancer patient.

Objective: In a prior study, high resolution ultrasound (US) was shown to be accurate for evaluating rib metastasis detected on bone scan. However, that study did not address the specific US appearance typical of osteoblastic rib metastasis. Our objective was to determine the specific US imaging appearance of osteoblastic prostate carcinoma rib metastasis using osteolytic renal cell carcinoma rib metastasis as a comparison group.

Is there an association between superolateral Hoffa fat pad edema on MRI and clinical evidence of fat pad impingement?

Objective: Patients with symptomatic Hoffa fat pad impingement often exhibit fat pad edema on MRI. We studied two patient groups to determine the association between MRI fat pad edema and clinical symptoms of Hoffa fat pad impingement.

Materials And Methods: We studied 34 consecutive patients with an MRI diagnosis of fat pad edema and no injury in the prior year (group 1) and 47 consecutive patients with a knee MRI examination and no injury in the prior year (group 2).

Imaging appearance of the normal and partially torn ligamentum teres on hip MR arthrography.

Objective: The purpose of this study was to evaluate the MR arthrographic appearance of the normal and partially torn ligament teres and to determine if there are imaging criteria for diagnosing partial tears of the ligamentum teres.

Materials And Methods: One hundred sixteen patients underwent preoperative MR arthrography and hip arthroscopy. Each MR examination was evaluated independently by two musculoskeletal radiologists for the following: size and width of the ligamentum teres in the proximal, mid, and distal thirds of the ligamentum teres; overall length of the ligamentum; number of bundles (1-3); signal intensity (SI) within the ligamentum teres (low, intermediate, high); ligamentum teres fibers (normal, attenuated, thickened, wavy); ligamentum teres integrity (not torn, degenerated, frayed, partial tear); and femoral head edema at the ligamentum teres origin.

How I diagnose meniscal tears on knee MRI.

Objective: The goal of this article is to summarize the literature about the diagnosis of meniscal tears on MRI including the normal appearance of the meniscus and the appearance of the various types of meniscal tears. In addition, I discuss my experience with the causes of errors in the MR diagnosis of meniscal abnormalities and the nuances of meniscal abnormalities that can mimic a meniscal tear.

Conclusion: MRI is a highly accurate imaging method for diagnosing meniscal tears.

Short-term clinical importance of osseous injuries diagnosed at MR imaging in patients with anterior cruciate ligament tear.

Purpose: To determine the association between osseous injuries and short-term clinical outcome in patients with anterior cruciate ligament (ACL) tear.

Materials And Methods: The retrospective study was performed with institutional review board approval, and the requirement to obtain informed consent was waived. The study group consisted of 114 patients (57 male and 57 female patients with a mean age of 26.

Validation of MRI classification system for tibial stress injuries.

Objective: The purpose of our study was to compare an MRI classification system for tibial stress injuries with semiquantitative MR features of injury severity and clinical outcome.

Materials And Methods: Two musculoskeletal radiologists retrospectively reviewed in consensus the MR findings of 142 tibial stress injuries to quantify the degree of periosteal and bone marrow edema and grade the injuries using the Fredericson classification system (grade 1 = periosteal edema only, grade 2 = bone marrow edema visible on T2-weighted images, grade 3 = bone marrow edema visible on T1-weighted and T2-weighted images, grade 4a = multiple focal areas of intracortical signal abnormality, and grade 4b = linear areas of intracortical signal abnormality). Kruskal-Wallis tests were used to determine the relationship between the grade of stress injury and the degree of periosteal and bone marrow edema and the time to return to sports activity.

MRI appearance of the proximal hamstring tendons in patients with and without symptomatic proximal hamstring tendinopathy.

Objective: The purpose of our study was to determine if six MRI findings of the proximal hamstrings differ in frequency in hamstrings with and without symptoms of tendinopathy.

Materials And Methods: We reviewed the MRI examinations of 118 consecutive patients who had undergone pelvis MRI and evaluation by a musculoskeletal clinical specialist. The proximal hamstrings were evaluated at four consecutive axial locations for tendon size, internal T1 and T2 signal, peritendinous T2 signal, and ischial tuberosity edema.

MR arthrographic appearance of the postoperative acetabular labrum in patients with suspected recurrent labral tears.

Objective: The objective of our study was to evaluate the MR arthrographic appearance of the acetabular labrum in patients with a suspected recurrent acetabular labral tear after previous arthroscopic resection of a labral tear.

Conclusion: The labrum after excision will appear shortened on MR arthrography. A recurrent labral tear can be diagnosed by the identification on MR arthrography of a new line to the labral surface, an enlarged and distorted labrum, or a new paralabral cyst.

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.

Evaluation of the menisci of the knee joint using three-dimensional isotropic resolution fast spin-echo imaging: diagnostic performance in 250 patients with surgical correlation.

Objective: To compare the diagnostic performance of FSE-Cube, a three-dimensional isotropic resolution intermediate-weighted fast spin-echo sequence, with a routine magnetic resonance (MR) protocol at 3.0 T for detecting surgically confirmed meniscal tears of the knee joint in a large patient population.

Methods: FSE-Cube was added to a routine MR protocol performed at 3.

Arthroscopic partial meniscectomy: MR imaging for prediction of outcome in middle-aged and elderly patients.

Purpose: To determine whether preoperative magnetic resonance (MR) imaging could help identify factors associated with poor clinical outcome after arthroscopic partial meniscectomy (APM) in middle-aged and elderly patients with meniscal tears.

Materials And Methods: The prospective, institutional review board-approved, HIPAA-compliant study was performed with informed consent in 53 men and 47 women (average ages, 54.5 and 56.

Musculoskeletal mnemonics: differentiating features.

Mnemonics are often used in musculoskeletal radiology to help radiologists remember long differential diagnoses. However, unless the specific appearance of each entity on a differential is also recalled, mnemonics become useless. This article presents 8 mnemonics with their corresponding differential diagnoses and distinguishing features.

Association of parameniscal cysts with underlying meniscal tears as identified on MRI and arthroscopy.

Objective: Although patients with parameniscal cysts usually have underlying meniscal tears, we noted that this association was less common with anterior lateral cysts. We wished to determine whether the frequency of a meniscal tear underlying a parameniscal cyst varied with cyst location.

Materials And Methods: We reviewed a database of 7,771 knee MR examinations and identified 134 patients with an MR diagnosis of 138 parameniscal cysts and correlative arthroscopy in 78 patients.

Clinical usefulness of adding 3D cartilage imaging sequences to a routine knee MR protocol.

Objective: The objective of our study was to determine whether 3D sequences can improve the diagnostic performance of a routine MR protocol for detecting cartilage lesions within the knee joint at 3 T.

Subjects And Methods: An iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) spoiled gradient-recalled echo (SPGR) sequence (n = 75 patients) or an IDEAL gradient-recalled acquisition in a steady state (GRASS) sequence (n = 75 patients) was added to routine 3-T knee MR protocol to examine 150 patients who subsequently underwent arthroscopic knee surgery. Each articular surface of the knee joint was graded at arthroscopy.

Hip injuries in athletes.

Hip injuries are common in athletes, and there is an extensive differential diagnosis of potential causes. This article reviews the anatomy of the hip, and discusses the imaging findings of hip pathology in athletes including skeletal, intraarticular, and extra-articular abnormalities. The role of radiography, computed tomography (CT), magnetic resonance (MR) imaging, MR arthrography, CT arthrography, and sonography in evaluating each condition is discussed.

Magnetic resonance imaging of the meniscus.

Magnetic resonance imaging has evolved into a highly accurate modality in detecting meniscal injuries and provides the essential anatomic detail to help guide treatment options in this age of meniscal preservation. Accurate interpretation requires a thorough understanding of meniscal anatomy and function, anatomic variants, technical factors, typical appearance of tear patterns on magnetic resonance imaging, associated ligamentous injuries, causes of misdiagnoses, and the importance of correlation with the clinical examination.

3.0-T evaluation of knee cartilage by using three-dimensional IDEAL GRASS imaging: comparison with fast spin-echo imaging.

Purpose: To compare the diagnostic performance of iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) gradient-recalled acquisition in steady-state (GRASS) imaging with a routine magnetic resonance (MR) imaging protocol for evaluating knee cartilage at 3.0 T in patients by using arthroscopy as the reference standard.

Materials And Methods: This prospective Health Insurance Portability and Accountability Act-compliant study was performed with a waiver of informed consent from the institutional review board.

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.

Ultrasound imaging of normal displacement of the extensor carpi ulnaris tendon within the ulnar groove in 12 forearm-wrist positions.

Objective: Instability of the extensor carpi ulnaris (ECU) tendon can be a difficult clinical diagnosis because of normal changes in tendon position during wrist motion. Our goal was to determine the normal variation of ECU tendon displacement in 12 forearm-wrist positions.

Subjects And Methods: Ultrasound imaging of the ECU tendons of 40 symptom-free wrists of healthy volunteers (13 women, seven men; mean age, 22.

Comparison of the accuracy rates of 3-T and 1.5-T MRI of the knee in the diagnosis of meniscal tear.

Objective: The purpose of this study was to compare the accuracy of 3-T MRI with that of 1.5-T MRI of the knee in the diagnosis of meniscal tear and to analyze the causes of diagnostic error.

Materials And Methods: We reviewed the medical records and original MRI interpretations of 100 consecutive patients who underwent 3-T MRI of the knee and of 100 consecutive patients who underwent 1.

Comparison of standard hip MR arthrographic imaging planes and sequences for detection of arthroscopically proven labral tear.

Objective: The purpose of this study was to compare multiple imaging planes and two pulse sequences for detection of arthroscopically proven labral tears.

Materials And Methods: From March 2004 through June 2007, acetabular labral tear was diagnosed at hip arthroscopy of 189 patients. Preoperative MR arthrography of the affected hip was performed on 144 patients at our institution.

Vastly undersampled isotropic projection steady-state free precession imaging of the knee: diagnostic performance compared with conventional MR.

Purpose: To compare a vastly undersampled isotropic projection steady-state free precession (VIPR-SSFP) sequence and routine magnetic resonance (MR) imaging for evaluating the cartilage, ligaments, menisci, and osseous structures of the knee in symptomatic patients.

Materials And Methods: All subjects signed written informed consent prior to participation in this prospective, HIPAA-compliant, institutional review board-approved study. VIPR-SSFP was added to the routine 1.