Tears of the supraspinatus tendon: assessment with indirect magnetic resonance arthrography in 67 patients with arthroscopic correlation.

BACKGROUND: Magnetic resonance (MR) arthrography is generally regarded as the gold standard for shoulder imaging. As an alternative to direct MR arthrography, the less invasive indirect MR arthrography technique was proposed, offering logistic advantages because fluoroscopic or ultrasonographic guidance for joint injection is not required. PURPOSE: To assess the diagnostic performance of indirect MR arthrography in the diagnosis of full- and partial-thickness supraspinatus tears in a symptomatic population. MATERIAL AND METHODS: Two radiologists with different levels of experience independently and retrospectively interpreted indirect MR (1.5T) arthrograms of the shoulder obtained in 67 symptomatic patients who underwent subsequent arthroscopy. On MR, the supraspinatus tendon was evaluated for full- or partial-thickness tear. With arthroscopy as the standard of reference, sensitivity, specificity, and diagnostic accuracy of indirect MR arthrography in the detection of full- and partial-thickness tears of the supraspinatus tendon was calculated. Kappa (kappa) statistics were used for the assessment of the agreement between arthroscopic and imaging findings and for the assessment of interobserver agreement. RESULTS: For full-thickness tears of the supraspinatus tendon, sensitivities, specificities, and accuracies exceeded 90% for both observers, with excellent interobserver agreement (kappa = 0.910). For partial-thickness tears, sensitivities (38-50%) and accuracies (76-78%) were poor for both reviewers, and interobserver agreement was moderate (kappa = 0.491). Discrepancies between MR diagnosis and arthroscopy were predominantly observed with small partial-thickness tears. CONCLUSION: Indirect MR arthrography is highly accurate in the diagnosis of full-thickness rotator cuff tears. However, the diagnosis of partial-thickness tears with indirect MR arthrography remains faulty, because exact demarcation of degenerative change and partial rupture is difficult. On the basis of the above findings, we do not recommend indirect MR arthrography on patients for whom rotator cuff disease is suspected clinically.

Imaging of femoroacetabular impingement: pictorial review.

Femoroacetabular impingement (FAI) is a cause of progressive osteoarthritis of the hip in younger patients. Three types of FAI have been described: a cam-type, a pincer-type and a mixed type. Early recognition of the morphologic hip features of each type of impingement is important, because arthroscopic treatment is still successful in the initial stage to prevent or delay further hip degeneration. This article reviews the imaging features of the different types of FAI. Magnetic resonance arthrography (MRA) is the preferred modality to detect, localise and characterise the type of FAI and the resulting injuries of the acetabular hyaline cartilage and fibrocartilaginous labrum.

Magnetic resonance imaging of variants of the knee.

Magnetic resonance imaging has become the imaging modality of choice for evaluation of internal derangements of the knee. Anatomical variants are often an incidental finding on these examinations. Knowledge and recognition of variants is important, not only to avoid misdiagnosis but also to avoid additional imaging and over-treatment. This pictorial essay provides an overview of variants encountered during a review of 1,873 magnetic resonance imaging examinations of the knee. Emphasis is laid on these variants that are clinically important.

The effectiveness of diagnostic imaging methods for the assessment of soft tissue and articular disorders of the shoulder and elbow.

There are no clear guidelines for diagnostic imaging of articular and soft tissue pathologies of the shoulder and elbow. Several methods are used, including magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA) and ultrasound (US). Their cost-effectiveness is still unclear. We performed a meta-analysis of the relevant literature and discussed the role of MR imaging of the shoulder and elbow compared with other diagnostic imaging modalities. For the shoulder impingement syndrome and rotator cuff tears, MRI and US have a comparable accuracy for detection of full-thickness rotator cuff tears. MRA and US might be more accurate for the detection of partial-thickness tears than MRI. Given the large difference in cost of MR and US, ultrasound may be the most cost-effective diagnostic method for identification of full-thickness tears in a specialist hospital setting (Evidence level 3). Both MRA and CT arthrography (CTA) are effective methods for the detection of labrum tears. More recently, multidetector CTA has offered the advantages of thinner slices than with MRA in a shorter examination time. Still, MRA has the advantage towards CTA to directly visualize the affected structures with a better evaluation of extent and location and to detect associated capsuloligamentous injuries. For the elbow pathologies, plain MRI or MRA have the advantage towards CTA to detect occult bone injuries. CTA is better for the assessment of the thin cartilage of the elbow. Both US and MRI are reliable methods to detect chronic epicondylitis; US is more available and far more cost-effective (Evidence level 2). MRA can differentiate complete from partial tears of the medial collateral ligament. US or MRI can detect partial and complete biceps tendon tears and/or bursitis. MRI can provide important diagnostic information in lesions of the ulnar, radial, or median nerve.

Imaging of lipomatous soft tissue tumors.

The purpose is to give an overview of the imaging features of benign and malignant lipomatous tumors. Imaging characteristics which are helpful in the differential diagnosis between benign and malignant subtypes are highlighted.

Imaging of vascular soft tissue tumors.

Most tumors of the vascular system are benign, cutaneous or subcutaneous lesions that are usually readily diagnosed without significant differential diagnosis. On the other hand, lesions that arise in deep soft tissues have to be differentiated from malignant neoplasms. In these cases, further imaging work-up is necessary for local staging and planning therapy. Vascular lesions of intermediate malignancy and malignant vascular tumors are very rare and demonstrate nonspecific imaging findings. This manuscript aims to give a brief overview of vascular soft-tissue tumors and to discuss the imaging appearances.

Accuracy of radiography in grading and tissue-specific diagnosis--a study of 200 consecutive bone tumors of the hand.

OBJECTIVE: To determine the usefulness of radiography and magnetic resonance imaging in differentiating benign from malignant bony tumors of the hand and in making a tissue-specific diagnosis. DESIGN: Two hundred consecutive bony tumors of the hand, the details of which originated from a national databank, were studied in a prospective way by radiography (100%) and by MRI (25%). All tumors were graded on a five-point scale, from certainly benign to certainly malignant, using location and morphology as diagnostic parameters. For all tumors a tissue-specific diagnosis was made, by the proposal of three possibilities in decreasing order of probability. Histological diagnosis was made by peer review, according to the WHO classification. RESULTS: By the combining of "certainly" and "probably" benign (grades I and II) and "certainly" and "probably" malignant (grades IV and V), a correct grading was obtained in 165 (82.5%) of the cases (154 of the 173 benign and 11 of the 27 malignant tumors). A correct tissue-specific diagnosis was included in the three proposed differentials in 87.5%. MRI confirmed a correct diagnosis made on radiography in 72% and improved the grading capability by correctly upgrading malignant tumors and downgrading benign tumors in, respectively, 8% and 12%. The capability to obtain a tissue-specific diagnosis improved with change of an incorrect diagnosis on radiography to a correct one on MRI in 12 cases (24%). CONCLUSION: Subjective (semiquantitative) grading on radiography by an expert group proved to be excellent when compared with the results of a quantitative analysis of individual grading parameters. Multiple logistic regression analysis of these parameters resulted in a grading formula containing only six variables. The additional value of MRI in grading was amply demonstrated. Already high accuracy of radiography, in making a tissue-specific diagnosis, improved substantially after the performance of MRI.

MR imaging in the diagnosis and management of inheritable musculoskeletal disorders.

Although the initial identification of a congenital skeletal malformation is usually made by a combination of clinical examination, conventional radiology and genetic tests, this review illustrates the additional value of magnetic resonance imaging (MRI) in the diagnosis, determination of the extent of the disease, demonstration of associated abnormalities, therapy planning, disease monitoring and prognosis evaluation.

Imaging of tumours of the foot and ankle.

The general presentation of osseous and soft-tissue neoplasms of the foot and ankle is not different from lesions encountered in other parts of the body and imaging features may be nonspecific. Some lesions, however, have a predilection for the foot and ankle and may have typical imaging features, such as plantar fibromatosis or intraosseous lipoma. This presentation aims to give an overview of bone and soft-tissue tumours of the foot and ankle and to discuss the strength of each imaging modality in the diagnosis.

Soft tissue aneurysmal bone cyst.

A soft tissue aneurysmal bone cyst located in the right gluteus medius of a 21-year-old man is reported. On conventional radiography, the lesion demonstrated a spherically trabeculated mass with a calcific rim. On CT scan, it showed a well-organized peripheral calcification resembling a myositis ossificans. On MRI, it presented as a multilocular, cystic lesion with fluid-fluid levels. The lesion had no solid components except for intralesional septa. Although findings on imaging and histology were identical to those described in classical aneurysmal bone cyst, diagnosis was delayed because of lack of knowledge of this entity and its resemblance to the more familiar post-traumatic heterotopic ossification (myositis ossificans).

Pictorial essay. Myositis ossificans circumscripta.

Myositis ossificans circumscripta (MOC) is a localized, non-neoplastic, heterotopic ossification within the muscle. Despite advances in medical imaging, it remains difficult to distinguish it from other disorders. As a consequence, a biopsy is frequently performed. We illustrate some common findings and non-specific imaging features of MOC with respect to radiography, computed tomography, bone scintigraphy, ultrasonography, and magnetic resonance imaging. The differentiation among MOC and its mimics is also presented in order to help the radiologists to make an appropriate diagnostic decision.

Recurrent arthritis as presenting symptom of osteomyelitis.

We present a patient who had one episode of prepatellar bursitis and subsequently several episodes of arthritis of his right knee. Cultures of several punctures of his knee remained sterile, but the patient had been taking oral antibiotics on each of these occasions against our medical advice. Ultimately a diagnostic puncture revealed growth of Staphylococcus aureus. An X-ray demonstrated an osteolytic lesion of the patella, but no defect in the articular surface of the patella could be visualised. MRI demonstrated a communication between the osteomyelitic focus through the medial retinaculum to the bursa suprapatellaris and the knee joint. Osteomyelitis of the patella is mainly a disease of childhood. This case is, to our knowledge, the first report on the association between bursitis, osteomyelitis of the patella and recurrent septic arthritis of the knee in an adult. The literature is reviewed and discussed briefly.

An unusual case of generalized oedema.

We present the case of a 66-year-old woman with generalized oedema and pain in the four limbs. Physical examination revealed a diffuse, painful, partly pitting, oedema of forearms, hands, lower legs and feet. There were no signs of synovitis. Laboratory investigation was non relevant, except for mild eosinophilia, which normalized subsequently. Cardiac, nephrological and venous disturbances were excluded. More uncommon disorders, such as eosinophilic fasciitis, early stage of scleroderma and polymyositis were considered. MRI scanning of the right forearm revealed an increased signal intensity in the superficial muscle fibers and thickening of the fascia (figure 1). Subsequently a full thickness biopsy of the musculus flexor digitorum superficialis was performed, revealing an inflammatory infiltration of lymphocytes and eosinophils, localized in the fascia. There was no necrosis of muscle fibers. No signs of scleroderma were found. The biopsy confirmed the diagnosis of eosinophilic fasciitis. Clinical and MRI findings suggested an early stage of disease and the patient was treated with low-dose corticosteroids.

Paraspinal cervical calcifications associated with scleroderma.

Although soft tissue calcifications are well known to occur as a late manifestation in scleroderma, symptomatic paraspinal calcinosis is very rare. Clinically, patients present with focal neck pain, weakness or radiculopathy, and decreased range of motion of the neck. We describe the imaging features of a rare case of cervical paraspinal calcinosis in a 74-year-old woman with long-standing scleroderma. Standard radiography is usually sufficient to confirm the diagnosis, but CT-scan allows a more precise location of the calcifications around the facet joints, sometimes with associated erosions. The advantage of MRI is to evaluate the possible intraspinal extension of the calcifications in case of focal neurological symptomatology.

Additional value of magnetic resonance with spin echo T1-weighted imaging with fat suppression in characterization of soft tissue tumors.

OBJECTIVE: The aim of the study was to describe the signal intensity (SI) behavior of soft tissue tumors (STT) on spin echo (SE) T1 weighted images (WI) with fat suppression (FS) and to assess its additional value in tissue characterization. METHODS: MRI signal characteristics of 53 histological proven STT were discussed. Signal intensity behavior of STT could be classified in 4 types, representing specific tissues or tissue components. Type 1 was defined as low SI on both SE T1-WI and SE T1-WI with FS. Type 2 was defined as high SI on both sequences. Type 3 consisted of high SI on T1-WI and low SI on T1-WI with FS. Type 4 was defined as SI comparable with SI of normal muscle on T1-WI and SI higher than normal muscle on T1-WI with FS. The additional information concerning contrast enhancement is described. RESULTS: Type 1 SI behavior was noted in fibrous lesions, in hemosiderotic components, cysts, and myxoma. Type 2 was noted in lesions containing methemoglobin or melanin. Type 3 was specific for fatty tissue. Type 4 was noted in highly cellular parts and in lesions of vascular origin. The use of SE T1-WI with FS improved lesion conspicuity on T1-WI. CONCLUSIONS: E T1-WI with FS has additional value in the characterization of fibrous and hemosiderotic parts from cellular parts of lesions. It gives more confidence in characterization of neurogenic tumors and hemangioma's. Presence of methemoglobin and melanin are clearly discriminated from fatty tissue. Tumor conspicuity and inhomogeneity evaluation is improved. The use of SE T1-WI FS not only improves tumor conspicuity, but as tumor homogeneity and SI are important parameters in staging and characterization of STT, the use of SE T1-WI with FS will certainly be helpful. This may obviate the need for gadolinium administration.

Gamma-probe-directed lymphatic mapping and sentinel lymphadenectomy in primary cutaneous melanoma.

BACKGROUND: Radiotracer and blue-dye lymphatic mapping is a recommended combined method to guide sentinel lymphadenectomy and full regional lymph node dissection in selected patients with cutaneous melanoma. OBJECTIVE: To evaluate the diagnostic accuracy and the prognostic value of gamma-probe-directed lymphatic mapping in cutaneous melanomas. METHODS: Sixty-five stage I and II melanoma patients underwent gamma-probe-directed lymphatic mapping. Sentinel lymph nodes were studied by both conventional and immunohistochemical stainings. The median follow-up was 11 months. RESULTS: Sensitivities of preoperative and intraoperative sentinel lymph node detection were 100 and 98%, respectively. Only 1 failure of detection and 1 missed same-basin metastasis were experienced in the axillary and cervical areas, respectively. Eleven patients (16.9%) had sentinel node metastases leading to adjuvant therapy. CONCLUSION: Gamma-probe-directed lymphatic mapping is useful for staging melanoma. However, in the expectation of a more specific identification of the sentinel lymph node, the standard protocol remains recommended for exploring the axillary and cervical areas. The histological examination supported in some cases by immunohistochemistry remains mandatory in all cases.