Evangelos Perdikakis

Comparison of MR-arthrography and MDCT-arthrography for detection of labral and articular cartilage hip pathology

ObjectiveTo compare the diagnostic ability of MR arthrography (MRa) and MDCT arthrography (CTa) in depicting surgically proven hip labral tears and articular cartilage degradation.Materials and methodsLabral pathology and articular cartilage were prospectively evaluated with MRa and CTa in 14 hips of 10 patients. The findings were evaluated by two independent observers (a musculoskeletal fellow and one senior musculoskeletal radiologist). Sensitivity, specificity, accuracy, and positive predictive value were determined using arthroscopic and open surgery findings as the standard of reference. Interobserver agreement was recorded. All images were assessed for the presence of a labral tear (according to Czerny classification) and for cartilage erosion using a 3 point scale for both methods: 1 = complete visualization-sharp edges, 2 = blurred edges fissuring-partial defects, 3 = exposed bone. The same classification was applied surgically.ResultsDisagreement between the senior observer and the fellow observer was recorded in three cases of labral tearing with MRa and six with CTa. Disagreement was also found in four cases of cartilage erosion with both MRa and CTa. The percent sensitivity, specificity, accuracy, and positive predictive value for correctly assessing the labral tear were as follows for MRa/CTa, respectively: 100/15, 50/13, 90/14, and 90/13 (P < 0.05). The same values for cartilage assessment were 63/66, 33/40, 50/57 and 55/66 (P > 0.05).ConclusionInterobserver reproducibility with MRa is very good for labral tearing assessment. MRa is better for assessing labral tears. CTa shows better, but not statistically significant, demonstration of the articular cartilage.

Os naviculare: the multi-ossicle configuration of a normal variant

ObjectiveTo describe the multi-ossicle appearance of the os naviculare on MRI and CT examinations and to correlate this appearance with the published classification of this well-known skeletal variant.Materials and methodsWe retrospectively reviewed 148 patients, examined within a 2-year period (170 CT and MRI studies of the foot-ankle), for the presence of os naviculare. This variant was classified according to a widely used system (type I, II, III). In addition, each navicular variant was further reclassified according to the presence of one or more ossicles. The presence of bone marrow edema was also recorded.ResultsAccessory navicular bone was identified in 34 cases (20%) of the 170 exams. It was detected in 14 male and 14 female patients with the following incidence: 11.15% type I (19 cases), 4.11% type II (7 cases) and 4.74% type III (8 cases). In six cases the location was bilateral. Among patients with os naviculare, a multi-ossicle appearance with a total incidence of 14.7% (8.8% two ossicle configuration and 5.9% three ossicle configuration) was observed. In two type II cases studied with MRI, there was bone marrow edema suggesting a painful pseudarthrosis.ConclusionThe presence of multiple accessory navicular bone ossicles, not previously described with cross-sectional imaging, is reported herein. The pathogenesis and clinical relevance of this uncommon variant needs to be elucidated with further studies.

Symptomatic multipartite patella: imaging findings and pain relief. A description of two cases

Musculoskeletal injuries in the non-elite athletes are a clinical entity that is being seen more frequently nowadays. The term “weekend warriors” applies to amateur participants in sports activities and is related to an increasing number of musculoskeletal injuries mainly due to overuse. Concomitant skeletal variations may as well predispose to trauma. We add to the literature two cases of multipartite patella in which locally injected ropivacaine (ropivacaine hydrochloride) and steroid (betamethasone acetate-betamethasone sodium phosphate) relieved the symptoms completely. Here, we describe the clinical, imaging features and the course of treatment.

A 33-year-old male with a strenuous occupation and gradual inability to lift, pull, and push heavy weights during working: diagnosis and discussion.

Scapulothoracic stabilization and motion is mainly carried out by the synergic and antagonistic action of three muscles: the serratus anterior, the trapezius, and the rhomboid [1, 2]. The serratus anterior is innervated by the long thoracic nerve (LTN), the trapezius by the spinal accessory nerve, and the rhomboid muscles by the dorsal scapular nerve [1–3]. Direct or indirect trauma, iatrogenic injuries, or idiopathic processes such as the Parsonage– Turner syndrome may result in nerve injury and eventually paresis of the affected muscle [1–3]. The LTN is formed from the anterior rami of the 5th, 6th, and 7th cervical nerves. It passes between the clavicle and the first rib and then enters a fascial sheath and descends along the lateral aspect of the thoracic wall innervating the muscle fibers of serratus anterior [4]. Due to its lengthy course (24 cm in average), its delicate and thin nature (2–3 mm) and the fact that it traverses the middle scalene muscle and descends between the clavicle and the first rib, the nerve is easily susceptible to injuries [4]. In the vast majority of cases, the mechanism of traumatic nerve injury is either overstretchingtraction or compression and constriction of nerve fascicles and the clinical result is serratus anterior muscle denervation, which is demonstrated as medial scapular winging [1–4]. Clinical examination provides valuable information for a correct diagnosis. Serratus anterior paresis results in medial scapular winging whereas lateral winging is the consequence of trapezius and rhomboid paresis [1–5]. In our case, the physical examination revealed medial winging of the right scapula, which became more pronounced when the patient was asked to perform active forward or upward elevation and abduction of his arms (Fig. 1). Since the diagnosis is easily made during clinical examination and visual inspection of the scapula, the need for MR imaging evaluation is limited [6–9]. MR imaging was requested in order to exclude a disk disease-radiculopathy and rule out a possible mass lesion either in the spinal canal or more peripherally. The anatomical distribution of the signal changes on MR aided in the correct diagnosis. The MR imaging findings of uniform muscle edema and the absence of fatty infiltration correlated well with the onset of symptoms and suggested a subacute phase of aponeurositis. This finding is considered essential in treatment planning. Due to imaging findings, electromyographic testing and nerve conduction studies were not performed. The electromyographic testing could have provided the degree of denervation, but according to the literature, the initial degree of denervation cannot be used to predict the extent of nerve recovery [10]. The isolated serratus anterior paresis and the associated medial scapular winging has been shown to respond well to The case presentation can be found at doi:10.1007/s00256-011-1231-2. E. Perdikakis : L. Palladas :A. Karantanas Department of Radiology, University of Crete, Stavrakia, Heraklion, Crete, Greece

Metastatic lung angiosarcoma from a femoral subperiosteal origin

Primary malignant vascular bone tumors are unusual and include hemangioendothelioma, epitheloid hemangioendothelioma and angiosarcoma. Although few cases of primary bone angiosarcomas have been reported, those of femoral origin are even more infrequent. Such tumors diagnosis may be challenging due to their radiographic and histologic variety. We present a case of a 24-yearold woman with a subperiosteal diaphyseal angiosarcoma originating from the femoral bone and metastatic to the lung at the time of diagnosis. The clinical, histological and radiological features of this extremely rare lesion are presented.

Thalidomide-induced phocomelia: “An old wound that still hurts”

A case of a female patient with thalidomide-induced phocomelia and additional dermal complications associated with the prosthesis itself is presented herein.

Pelvic hemangiopericytoma: the role of diffusion weighted imaging in targeting the biopsy site and in monitoring the tumour response to radiotherapy

Pelvic hemangiopericytoma: the role of diffusion weighted imaging in targeting the biopsy site and in monitoring the tumour response to radiotherapy Background. Despite advances in imaging, the accurate characterization of soft tissue tumours remains a challenging task. Furthermore, the interpretation of post treatment changes and evaluation of tumour response to therapy is another complicating issue regarding soft tissue tumour imaging. Case report. Herein, a patient with a pelvic hemangiopericytoma, by whom different diagnostic imaging methods were used, is presented. Conclusions. Diffusion weighted imaging (DWI) might provid useful information in guiding biopsy and enabled monitoring of the radiation therapy results.

Assessment of a postoperative anastomotic stricture following correction surgery of a type IVa choledochal cyst using Gd-EOB-DTPA-enhanced magnetic resonance cholangiography

Choledochal cyst is a relatively uncommon disease which is characterized by congenital dilatation of the intra and/or extrahepatic part of the biliary tree. Type IVa choledochal cysts are managed surgically through total excision of the entire extrahepatic part of the abnormal bile ducts and a simultaneous hepaticoenterostomy. Postoperative anastomotic stricture after excision of choledochal cysts and hepaticojejunostomy is a well-known late complication. We report a case of a 17-year-old female in whom gadoxetic acid-enhanced magnetic resonance cholangiography assisted in the evaluation of a biliary stricture following bile duct procedures after choledochal cyst correction surgery.

Stieda process versus Haglund's deformity: An uncommon presentation of posterior ankle impingement

Posterior ankle impingement syndrome represents an important cause of chronic ankle pain and has been extensively described in the orthopaedic and radiology literature. A rare case of this painful hindfoot disorder that resulted from two concurrent developmental anomalies is presented herein.

Bilateral lipoma arborescens of the knee: a case report

Lipoma arborescens, a diffuse articular lipomatosis, is a rare disorder characterized by marked villiform synovial proliferation and diffuse replacement of the subsynovial tissue by mature adipocytes. Unilateral joint involvement is the usual presentation while bilateral joint involvement is more uncommon. We reported a case of bilateral lipoma arborescens in a male patient with associated marked patellofemoral osteoarthritis and described the MR imaging findings.