[MR imaging accuracy in the prediction of bone graft healing potential in scaphoid non-union]. / Valeur de l'IRM dans l'evaluation du potentiel de guérison des pseudarthroses du scaphoïde traitées par greffe osseuse.

PURPOSE: To determine the accuracy of MR imaging in predicting bone graft healing in patients with scaphoid non-union. MATERIAL AND METHODS: 21 patients with scaphoid non-union were examined with MR imaging prior to bone grafting (conventional bone graft in 14 cases and vascularized bone graft in 7 cases). The protocol included unenhanced and Gadolinium-enhanced sequences. Signal intensity and homogeneity of the proximal fragment was analysed by two independent radiologists. MRI findings were then correlated to the postoperative rate of union. RESULTS: Healing occurred in 17 cases and failed in 4 cases with a mean follow up of 14 months. Intraobserver agreement in MR reading was respectively 0.92 et 0.86. Interobserver agreement was 0.88. On Tl-wi, the proximal fragment was hyperintense in 1 case (with positive surgical result), heterogeneous low signal intensity in 7 cases (healing in n = 7) and homogeneous low signal intensity in 13 cases (healing in n = 9). On T2-wi, the proximal fragment was hypointense in 4 cases (healing in n = 3), homogeneous high signal in 5 cases (healing in n = 4) and heterogeneous high signal intensity in 12 cases (healing in n = 10). After Gadolinium injection, enhancement was homogeneous in 4 cases (healing in n = 4), heterogeneous in 8 cases (healing in n = 7) and absent in 9 cases (healing in n = 6). In the group with no enhancement, 5 patients were treated with vascularized bone graft (healing in n = 4) and 4 with conventional bone graft (healing in n = 2). CONCLUSION: The absence of enhancement of the proximal scaphoid fragment leads to poor surgical results except for vascularized bone graft.

[Value of volume rendering in musculo-skeletal disorders]. / Intérêt de la technique de rendu volumique en pathologie ostéo-articulaire.

Three dimensional imaging is increasingly important for evaluation of anatomic relationships and extent of disease, for treatment planning and for follow-up evaluation. The volume rendering technique allows creation of accurate 3D images that can be used for several clinical applications especially in musculo-skeletal disorders such as evaluation of tumors or fractures. This article describes the methods used for volume rendering technique and focuses on the specific aspects of volume rendering applied to musculo-skeletal applications.

[MR-arthrography: general principles and applications]. / L'arthro-IRM: principes et applications.

The recent approval by the French Ministry of Health of the use of intra-articular Gadolinium could promote the increasing use of MR-arthrography in France. Although useful in specific pathologies, it should not be overly prescribed and should be considered only if it provides a more accurate diagnosis than other less invasive techniques. The technical aspects and medico-legal implications of MR-arthrography as well as its various indications are reviewed in this article. There are three possible techniques: indirect MR-arthrography with IV Gadolinium injection, direct MR-arthrography with intra-articular Gadolinium injection and lastly, direct MR-arthrography with intra-articular injection of iodinated contrast media (or saline solution). Indirect MR-arthrography cannot be recommended because of insufficient contrast enhancement and the absence of joint filling. Conversely, direct MR-arthrography allows joint expansion which smooths out capsule and ligaments, better delineates articular surfaces and yields a homogeneous high intensity signal of the entire joint. Direct MR-arthrography with iodinated contrast media combines standard arthrography with conventional MRI. Direct MR-arthrography with intra-articular injection of dilute Gadolinium is associated with T1WI, usually of higher quality than T2WI, even though the latter remains part of the protocol. Although, the last two techniques yield higher image quality and are often performed for various articular pathologies, they should not be randomly carried out in the evaluation of joint pathology. However, they should be recommended as the first step in the diagnosis of painful shoulders or hips in young adults and athletes.

[Lipomatous tumors of soft tissues in the extremities and the waist in adults]. / Tumeurs graisseuses des parties molles des membres et des ceintures de l'adulte.

Lipomatous tumors of the upper and lower extremities in adults are frequent and lipoma is the most common soft tissue tumor. Most have a typical appearance at imaging but presentation and management may vary based on the exact histological subtype. The purpose of this paper is to review the main clinical, radiological and histological features of the different benign and malignant lipomatous tumors.