Biomedical subjects

Nancy M Major

Publications and source records attributed to Nancy M Major.

At least 19 recordsLinked to original sources

PubMed2007

Magnetic resonance imaging findings associated with surgically proven rotator interval lesions.

OBJECTIVE: To identify shoulder magnetic resonance imaging (MRI) findings associated with surgically proven rotator interval abnormalities. MATERIALS AND METHODS: The preoperative MRI examinations of five patients with surgically proven rotator interval (RI) lesions requiring closure were retrospectively evaluated by three musculoskeletal-trained radiologists in consensus. We assessed the structures in the RI, including the coracohumeral ligament, superior glenohumeral ligament, fat tissue, biceps tendon, and capsule for variations in size and signal alteration. In addition, we noted associated findings of rotator cuff and labral pathology. RESULTS: Three of three of the MR arthrogram studies demonstrated extension of gadolinium to the cortex of the undersurface of the coracoid process compared with the control images, seen best on the sagittal oblique images. Four of five of the studies demonstrated subjective thickening of the coracohumeral ligament, and three of five of the studies demonstrated subjective thickening of the superior glenohumeral ligament. Five of five of the studies demonstrated a labral tear. CONCLUSIONS: The MRI arthrogram finding of gadolinium extending to the cortex of the undersurface of the coracoid process was noted on the studies of those patients with rotator interval lesions at surgery in this series. Noting this finding-especially in the presence of a labral tear and/or thickening of the coracohumeral ligament or superior glenohumeral ligament-may be helpful in the preoperative diagnosis of rotator interval lesions.

Adult↗

PubMed2006

Upper extremity compartmental anatomy: clinical relevance to radiologists.

Malignant tumors of the upper extremity are uncommon, and their care should be referred to specialized facilities with experience treating these lesions. The Musculoskeletal Tumor Society (MSTS) staging system is used by the surgeon to determine appropriate surgical management, assess prognosis, and communicate with other healthcare providers. Magnetic resonance imaging (MRI) is employed pre-operatively to identify a lesion's compartment of origin, determine extent of spread, and plan biopsy and resection approaches. Involvement of neurovascular structures may result in devastating loss of upper extremity function, requiring amputation. Violation of high-resistance compartmental barriers necessitates more extensive surgical resection. Biopsy may be performed by the radiologist using imaging guidance. Knowledge of compartmental anatomy allows the radiologist or surgeon to use an easily excisable biopsy approach and prevent iatrogenic spread to unaffected compartments. Case examples are presented to illustrate the importance of compartmental anatomy in the management of benign and malignant upper extremity tumors.

Bone Neoplasms↗

PubMed2006

Evaluation of the acetabular labrum at 3.0-T MR imaging compared with 1.5-T MR arthrography: preliminary experience.

Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. The purpose of this study was to prospectively compare imaging of the acetabular labrum with 3.0-T magnetic resonance (MR) imaging and 1.5-T MR arthrography. Eight patients (four male, four female; mean age, 38 years) with hip pain suspicious for labral disease were examined at both MR arthrography and MR imaging. Presence of labral lesions, paralabral cysts, articular cartilage lesions, subchondral cysts, osteophytes, and synovial herniation pits was recorded. There was arthroscopic correlation of findings in five patients. MR imaging depicted four surgically confirmed labral tears that were identified at MR arthrography, as well as one that was not visualized at MR arthrography. MR imaging helped identify all other pathologic conditions that were diagnosed at MR arthrography and helped identify one additional surgically confirmed focal articular cartilage lesion. These results provide encouraging support for evaluation with 3.0-T MR imaging over 1.5-T MR arthrography.

Acetabulum↗

PubMed2006

Coracohumeral interval imaging in subcoracoid impingement syndrome on MRI.

OBJECTIVE: The coracohumeral interval previously has been described as predictive of subcoracoid impingement on dynamic screening. The purpose of this study was to determine whether a coracohumeral interval acquired from routinely performed MRI can reliably diagnose subcoracoid impingement. MATERIALS AND METHODS: Preoperative MRI examinations of 19 patients (16 males, three females) with subsequent surgical confirmation of subcoracoid impingement were reviewed retrospectively and compared with MRI studies of 41 control subjects (22 males, 19 females). Axial and oblique sagittal coracohumeral interval measurements were taken. The morphology of the coracoid process and lesser tuberosity was assessed. Postanalysis application of the data to two smaller groups of patients was performed. The first group consisted of nine subjects (three males, six females) for whom subcoracoid impingement was diagnosed prospectively on the basis of abnormalities found by MRI. The second group consisted of seven patients (two males, five females) who were referred for MRI evaluation because of clinically suspected subcoracoid impingement. RESULTS: The average coracohumeral interval for females was 3 mm smaller than that for males. Using sex-adjusted data, we found a statistically significant difference between individuals with or without subcoracoid impingement in the axial coracohumeral interval (p = 0.01). This value, however, was poorly predictive (area under the receiver operating characteristic curve, 0.73). An 11.5-mm axial coracohumeral interval had 84% sensitivity but only 44% specificity. A 10.5-mm axial coracohumeral interval had 79% sensitivity and 59% specificity. The shoulder morphologic features assessed and intraarticular contrast use were not statistically significantly related to the coracohumeral interval. In postanalysis application of data, in the group of nine subjects without clinical diagnosis of subcoracoid impingement, all prospective MRI subcoracoid impingement diagnoses were falsely positive. However, if subcoracoid impingement was the referring diagnosis, prospective MRI evaluation more often was correct (n = 7 [three true-negatives, two true-positives, two false-negatives]). CONCLUSION: A sex-adjusted coracohumeral interval of 10.5-11.5 mm, although statistically significantly related to subcoracoid impingement, is poorly predictive of this diagnosis when acquired via routinely performed MRI. Subcoracoid impingement is primarily a clinical diagnosis that may be supported, but not established, by this means.

Adolescent↗

PubMed2006

Role of MRI in prevention of metatarsal stress fractures in collegiate basketball players.

OBJECTIVE: Metatarsal stress fractures are common and represent debilitating and potentially season-ending injuries for basketball players. Bone marrow edema is readily visualized on MRI and can be a sign of stress changes. Twenty-six asymptomatic male National Collegiate Athletic Association basketball players were imaged before the 2003-2004 season and 14 players were reimaged after the conclusion of the season with a screening study of long- and short-axis fat-suppressed T2-weighted images (TR/effective TE, 3,500/56) to identify bone marrow edema in the metatarsals. CONCLUSION: Six (12%) of 52 feet showed a signal indicating bone marrow edema in the metatarsals. MRI depicts bone marrow edema in the feet before a fracture becomes evident. Identification of this edema may reveal stress changes, allowing early treatment and prevention of debilitating stress fractures.

Adolescent↗

PubMed2006

Sensitivity of MR arthrography in the evaluation of acetabular labral tears.

OBJECTIVE: MRI has historically provided suboptimal visualization of tears of the acetabular labrum. Degenerative fraying and underlying cartilage abnormalities can often mimic tears of the labrum on conventional MRI. Administration of intraarticular gadolinium enhances the MRI appearance of the labrum to improve detection of labral abnormalities. This study examined the improved diagnostic sensitivity of MR arthrography compared with conventional MRI and the importance of confining the study to a small field of view. MATERIALS AND METHODS: Fifty-one hips were imaged in 48 patients. Fourteen hips underwent conventional MRI with a large field of view (30-38 cm). Seven hips underwent conventional MRI with a small field of view (14-20 cm). Thirty hips underwent MR arthrography with a small field of view (14-20 cm). Labral tears were diagnosed when contrast material was identified within the labrum or between the labrum and the acetabulum, when a displaced fragment was noted, or when a paralabral cyst was identified. All study results were compared with findings at the time of hip arthroscopy. RESULTS: Conventional MRI with a large field of view was 8% sensitive in detecting labral tears compared with findings at the time of arthroscopy. Diagnostic sensitivity was improved to 25% with a small field of view. MR arthrography with a small field of view was 92% sensitive in detecting labral tears. CONCLUSION: A combination of MR arthrography and a small field of view is more sensitive in detecting labral abnormalities than is conventional MRI with either a large or a small field of view.

Acetabulum↗

PubMed2005

Lower extremity compartmental anatomy: clinical relevance to radiologists.

A thorough understanding of compartmental anatomy is necessary for the radiologist participating in the care of a patient with a lower extremity musculoskeletal malignancy. Localization of tumor to compartment of origin and identification of extracompartmental spread preoperatively are needed to correctly stage a tumor and determine the appropriate surgical management. An understanding of the locations of fascial boundaries, extracompartmental tissues, and neurovascular structures of the thigh and lower leg facilitates this diagnostic process. For the radiologist planning to biopsy a suspicious musculoskeletal lesion, consultation with the referring orthopaedic surgeon is recommended in order to jointly select an appropriate percutaneous biopsy approach. Adequate preprocedural planning ensures selection of an approach which prevents iatrogenic tumor spread beyond the compartment of origin, protects neurovascular structures, and allows complete resection of the biopsy tract and scar at the time of surgical resection without jeopardizing a potential limb-sparing procedure. Cross-sectional anatomic review and case examples demonstrate the importance of a detailed understanding of compartmental anatomy when approaching the patient with a lower extremity musculoskeletal tumor.

Adult↗

PubMed2005

MRI of internal impingement of the shoulder.

OBJECTIVE: Internal impingement is a condition that occurs in athletes in which the shoulder is put in extreme abduction and external rotation during overhead movements. During this motion, the posterior fibers of the supraspinatus tendon, anterior fibers of the infraspinatus tendon, or both can get impinged between the humeral head and the posterior glenoid. The purpose of this study was to evaluate the ability of MRI to show the findings of internal impingement of the shoulder. CONCLUSION: As opposed to our six patients with clinically and surgically diagnosed internal impingement, the control patients had isolated pathology in the rotator cuff, labrum, or humeral head. We found that the constellation of findings of undersurface tears of the supraspinatus or infraspinatus tendon and cystic changes in the posterior aspect of the humeral head associated with posterosuperior labral pathology is a consistent finding diagnostic of internal impingement.

Adolescent↗

PubMed2005

The "floating" meniscus: MRI in knee trauma and implications for surgery.

OBJECTIVE: We describe 21 cases involving meniscal injury in which the meniscus appears free-floating on MRI of the knee. In these cases, the meniscus is completely surrounded by fluid. Correlation with surgical reports shows that the "floating" meniscus corresponds to a meniscal avulsion or detachment from the tibial plateau with an associated disruption of the meniscotibial coronary ligaments, which attach the meniscus to the tibia, allowing fluid to encompass the meniscus. A floating meniscus on MRI may represent a new specific finding for an uncommon form of meniscal injury known as meniscal avulsion. CONCLUSION: The presence of a floating meniscus on MRI is a result of significant trauma to the knee leading to meniscal avulsion and is often associated with significant ligamentous injury. Alerting the surgeon to the presence of a meniscal avulsion facilitates appropriate surgical planning with meniscal reattachment to the tibial plateau.

Adolescent↗

PubMed2005

Comparison of fast spin-echo versus conventional spin-echo MRI for evaluating meniscal tears.

OBJECTIVE: We compare sensitivities of conventional spin-echo and fast spin-echo sequences in the evaluation of meniscal tears. Furthermore, we reevaluate the results from prior studies comparing these two sequences to understand why there are differing conclusions regarding the efficacy of fast spin-echo sequences as a commensurate replacement for conventional spin-echo sequences. MATERIALS AND METHODS: We used records from a control group of 64 patients (128 menisci) who had undergone arthroscopy to determine the sensitivity of conventional spin-echo sequences for detecting meniscal tears. Two hundred sixteen consecutive patients (432 menisci) were then imaged using conventional spin-echo and fast spin-echo sequences to evaluate for meniscal tears. Both sequences were proton density-weighted with fat suppression. RESULTS: Of the 432 menisci, 170 tears were detected on conventional spin-echo imaging. Only 128 tears were detected on the fast spin-echo sequence. The sensitivities of conventional spin-echo and fast spin-echo imaging were found to be 93% and 80%, respectively. In addition, findings from conventional spin-echo and fast spin-echo sequences were discordant for 72 menisci (17%, p < 0.01). CONCLUSION: The sensitivities of conventional spin-echo and fast spin-echo imaging for detecting meniscal tears have been shown to be greater than 90% and approximately 80%, respectively. However, some authors advocate substituting conventional spin-echo imaging with fast spin-echo imaging. We urge the abandonment of fast spin-echo imaging for evaluating meniscal tears because a loss of greater than 10% in sensitivity is unacceptable.

Adult↗

PubMed2004

MR imaging appearance of 180-360 degrees labral tears of the shoulder.

Glenoid labral tears exceeding 180 degrees are an uncommon entity in which characteristic clinical and MR imaging features can lead to a more accurate preoperative diagnosis. We provide a description of glenoid labral tears that exceed 180 degrees, and their characteristic magnetic resonance imaging features. In the young, heavily muscled male athlete, the identification of multiple sites of labral pathology and isolated, extensive posterior labral injuries are features that should raise suspicion for labral tears that exceed 180 degrees.

Adolescent↗

PubMed2004

Pathologic conditions mimicking osteonecrosis.

MRI has become increasingly helpful in establishing an early diagnosis of avascular necrosis(AVN). AVN often demonstrates a classic pattern on MRI; findings earlier in the course of the disease are less specific. Many pitfalls can complicate interpretation, and a number of pathologic conditions can share features of early AVN on MRI and plain radiographs. These entities should be distinguished from AVN, because treatment and prognosis may differ significantly.

Bone Cysts↗

PubMed2004

Magnetic resonance imaging of the coracoclavicular ligaments: its role in defining pathoanatomy at the acromioclavicular joint.

Four patients with acromioclavicular joint injuries (one type II, two type III, one type V), two patients without acromioclavicular joint injury, and a fresh-frozen cadaver underwent magnetic resonance imaging (MRI) and plain radiographs. The normal conoid and trapezoid ligaments were easily identified in the cadaver and the two uninjured patients. Magnetic resonance imaging revealed disruption of both coraclavicular ligaments in the three patients with type II and type III injuries. However, the patient with the type V injury had disruption of the trapezoid ligament alone. Thus, the grade of injury, as determined by the change in the coracoclavicular interval onplain radiography and defined by the Rockwood classification system, failed to correlate with the pathoanatomy seen on MRI in two of the four injured patients. These findings suggest that improvements in the classification of these injuries may be necessary.

Acromioclavicular Joint↗

PubMed2003

Cytopathology of mesenchymal chondrosarcomas: a report and comparison of four patients.

BACKGROUND: Mesenchymal chondrosarcoma (MC) is an infrequent neoplasm, representing approximately 1% of all chondrosarcomas. Cytologic descriptions of MCs have been confined to rare case reports. In the current report, the authors describe their experience with the cytologic features of four MCs: two primary tumors and two metastatic lesions. METHODS: Four patients were diagnosed with MC at the authors' institution from 1994 to 2002. Three of four patients underwent fine-needle aspiration (FNA) biopsy as part of their diagnosis; in the fourth patient, imprint cytology was performed. Each tumor also received histologic confirmation. RESULTS: The patients studied included three females and one male. In three patients, the tumor presented initially as a soft tissue mass; whereas, in the remaining patient, the MC presented in the tibia. FNA results demonstrated small, oval-to-spindled cells with high nuclear-to-cytoplasmic ratios. Cells occurred singly and in clumps in a background of basophilic extracellular matrix. Histologic examination of each lesion demonstrated biphasic tumors, including focal areas of relatively mature cartilage formation as well as a small cell population. CONCLUSIONS: MC is a rare soft tissue tumor that occurs frequently in extraskeletal locations. FNA of these tumors can be diagnostic if the tumor is sampled appropriately and of critical features, such as the background extracellular matrix, are recognized. Given the propensity of these tumors to metastasize and the poor prognosis of patients with MC, early identification by FNA biopsy may allow earlier, more aggressive interventions.

Adolescent↗

PubMed2003

MR imaging of ankylosing spondylitis.

Ankylosing spondylitis (AS) is one of a group of disorders characterized by association with HLA-B27 histocompatibility complex, seronegativity for rheumatoid factor, and propensity for inflammation at entheses, synovial articulations, and cartilaginous articulations. The radiographic hallmark of the disease is ankylosis, and the principle sites of involvement are the sacroiliac joints and spine, with less frequent involvement of other joints, including the pubic symphysis, hips, shoulders, knees, hands, feet, and sternoclavicular, acromioclavicular, sternomanubrial, and temporomandibular joints. Following a brief discussion of the basic pathophysiology and typical clinical findings of AS, we describe the typical magnetic resonance imaging features of the disease as it is manifests in the axial skeleton. Finally, a brief mention of special considerations in the radiographic evaluation of the AS patient in the setting of trauma is made.

Bone and Bones↗

PubMed2003

Accuracy of MR imaging of the knee in adolescents.

OBJECTIVE: A report in the orthopedics literature states that MR imaging for internal derangement of the knee has a lower accuracy in adolescents than in adults and may even provide spurious information that alters clinical management. This assertion has not been specifically addressed in the radiology literature. The purpose of our study was to determine the accuracy of MR imaging in adolescents with regard to injury of the cruciate ligaments and menisci. MATERIALS AND METHODS: A database search of our institution's records from January 1998 to July 2000 yielded 2140 MR examinations of the knee, all of which had been performed with a standard knee protocol on a 1.5-T magnet. Of these 2140 examinations, 156 included patients younger than 18 years. Fifty-nine of these patients underwent surgery, and the orthopedic surgeons' operative reports were used as the gold standard with which the MR imaging results were compared. Thirty-four boys and 25 girls who ranged in age from 11 to 17 years (mean age, 15 years) were examined. The clinical notes for the remaining 97 patients were evaluated for information about management and clinical improvement. RESULTS: The sensitivity and specificity values for MR imaging of the menisci and cruciate ligaments in adolescents were as follows: medial meniscus, 92% sensitivity and 87% specificity; lateral meniscus, 93% sensitivity and 95% specificity; anterior cruciate ligament, 100% sensitivity and 100% specificity; and posterior cruciate ligament, 0% sensitivity and 100% specificity. CONCLUSION: Our data suggest that MR imaging of the knee in adolescents is sensitive, specific, and accurate.

Adolescent↗

PubMed2003

MR imaging of complications of loose surgical tacks in the shoulder.

OBJECTIVE: Loose surgical tacks in the shoulder joint are a potential cause of new-onset shoulder pain after arthroscopic repair of an anterior-to-posterior lesion of the superior labrum. We report the MR imaging appearance of loose surgical tacks in this anatomic location. CONCLUSION: MR imaging is valuable in the evaluation of postoperative shoulder pain. Synovitis is a commonly considered clinical diagnosis; our report illustrates that loose tacks are another potential complication after shoulder surgery

Adolescent↗

PubMed2003

MR imaging of infrapatellar plica injury.

OBJECTIVE: Injury to the infrapatellar plica (ligamentum mucosum) has not been previously described in the radiology literature to our knowledge. This article shows the MR imaging appearance of injury to the infrapatellar plica. CONCLUSION: Injury to the infrapatellar plica is uncommon but should be considered as a potential source of knee pain, especially if no other evidence indicates internal derangement. MR imaging can reveal a typical appearance for infrapatellar plica injury.

Adolescent↗