MR Imaging and Clinical Characteristics of Diffuse Glioneuronal Tumor with Oligodendroglioma-like Features and Nuclear Clusters.

BACKGROUND AND PURPOSE: Diffuse glioneuronal tumor with oligodendroglioma-like features and nuclear clusters (DGONC) is a new, molecularly defined glioneuronal CNS tumor type. The objective of the present study was to describe MR imaging and clinical characteristics of patients with DGONC. MATERIALS AND METHODS: Preoperative MR images of 9 patients with DGONC (median age at diagnosis, 9.9 years; range, 4.2-21.8 years) were reviewed. RESULTS: All tumors were located superficially in the frontal/temporal lobes and sharply delineated, displaying little mass effect. Near the circle of Willis, the tumors encompassed the arteries. All except one demonstrated characteristics of low-to-intermediate aggressiveness with high-to-intermediate T2WI and ADC signals and bone remodeling. Most tumors (n = 7) showed a homogeneous ground-glass aspect on T2-weighted and FLAIR images. On the basis of the original histopathologic diagnosis, 6 patients received postsurgical chemo-/radiotherapy, 2 were irradiated after surgery, and 1 patient underwent tumor resection only. At a median follow-up of 61 months (range, 10-154 months), 6 patients were alive in a first complete remission and 2 with stable disease 10 and 21 months after diagnosis. The only patient with progressive disease was lost to follow-up. Five-year overall and event-free survival was 100% and 86±13%, respectively. CONCLUSIONS: This case series presents radiomorphologic characteristics highly predictive of DGONC that contrast with the typical aspects of the original histopathologic diagnoses. This presentation underlines the definition of DGONC as a separate entity, from a clinical perspective. Complete resection may be favorable for long-term disease control in patients with DGONC. The efficacy of nonsurgical treatment modalities should be evaluated in larger series.

[True thymic hyperplasia : Differential diagnosis of thymic mass lesions in neonates and children]. / "Echte Thymushyperplasie" : Differenzialdiagnose der Thymusvergrößerung bei Säuglingen und Kindern.

Reactive and neoplastic thymic pathologies are the main considerations in the case of masses in the anterior and middle part of the mediastinum, while neurogenic tumors are predominant in the posterior mediastinum (which are not dealt with here). In neonates and infants, the commonest pathologies in the anterior mediastinum comprise germ cell tumors (mainly teratomas), congenital thymic cysts and true thymic hyperplasia (TTH). In toddlers, teratomas, yolk sac tumors and cysts predominate. In children over 5 years of age, lymphomas are the commonest mass lesions whereas thymomas and thymic carcinomas are rare. In addition, inflammation-linked hyperplasia in myasthenia gravis and rebound thymic hyperplasia after chemotherapy must be considered. Although rare at all ages, sarcomas must be considered in the differential diagnosis from birth onwards and throughout adolescence. Based on the report of a rare case of recurrent TTH, the differential diagnosis of this benign but potentially life-threatening condition is discussed.

[Treatment of iatrogenic femoral pseudoaneurysms with thrombin injection--results in 54 patients]. / Die Behandlung iatrogener femoraler Pseudoaneurysmen durch Thrombininjektion -- Ergebnisse bei 54 Patienten.

PURPOSE: To evaluate ultrasound-guided percutaneous thrombin injection to treat iatrogenic femoral pseudoaneurysms following catheter interventions. MATERIALS AND METHODS: In a period of 2 years and 11 months, 55 iatrogenic femoral pseudoaneurysms were treated in 54 patients (male : female = 29 : 25) by percutaneous thrombin injection under continuous color Doppler control. Mean maximum diameter of the perfused lumen was 2.5 cm (SD +/- 1 cm). The injected thrombin doses varied between 10 and 2,000 U (median 200 U). RESULTS: Following thrombin injection, the pseudoaneurysm occlusion rate was 100 % (n = 55/55). Complete and persistent occlusion was achieved in 54 of 55 (98 %) pseudoaneurysms. A repeated procedure was necessary in 6 pseudoaneurysms. In one case (2 %), discrete signs of reperfusion were observed after primary occlusion within 24 hours of the initial procedure (lumen diameter 3 x 5 mm), followed by spontaneous thrombosis without further treatment. No complications, in particular no clinically manifest thromboembolic events, were observed. CONCLUSION: Ultrasound-guided percutaneous thrombin injection is an effective and safe method for the treatment of iatrogenic post catheterization femoral pseudoaneurysms.

Power Doppler sonography with and without echo-enhancing contrast agent and contrast-enhanced MRI for the evaluation of rheumatoid arthritis of the shoulder joint: differentiation between synovitis and joint effusion.

OBJECTIVE: To evaluate patients with clinically active rheumatoid arthritis (RA) of the shoulder for joint effusion and synovitis using conventional sonography, power Doppler (PD) sonography with and without echo-enhancing contrast agent, and contrast-enhanced MRI. DESIGN AND PATIENTS: Twenty-four patients (mean age 64 years) with known RA had one symptomatic shoulder evaluated by conventional gray-scale sonography and PD sonography before and after intravenous administration of the echo-enhancing contrast agent Levovist (300 mg/ml, 2.5 g). The degree and extent of the altered echo pattern in the subacromial bursa, axillary recess and glenohumeral joint seen by conventional gray-scale sonography and the intensity of vascular signals of PD sonography were compared with the findings of MRI obtained with T2-weighted turbo spin-echo sequences and contrast-enhanced T1-weighted fat-saturated spin-echo sequences. MRI was evaluated by two readers in consensus without knowledge of the sonographic findings. RESULTS: MRI, which was used as the reference examination, detected joint effusion in 71% (17/24) and synovitis in 92% (22/24) of the patients. Conventional sonography revealed an abnormal articular echo pattern in 96% (23/24) of the patients, especially in the axillary recess and subacromial bursa, but failed to attribute the altered echo pattern to either fluid or specific synovitis. PD sonography allowed a specific diagnosis of synovitis in 33% (8 patients), which increased to 50% (12 patients) after administration of an echo-enhancing contrast agent. In 42% (10/24) of the patients, the findings of synovitis demonstrated by MRI corresponded to an altered echo pattern by conventional sonography, but vascular signals were absent by PD sonography with or without echo-enhancing contrast agent. CONCLUSIONS: Using MRI as the "gold standard," PD sonography with and without echo-enhancing contrast agent cannot reliably identify synovitis or distinguish synovial inflammation from effusion in the shoulder joint.

Ultrasonography of acute musculoskeletal disease.

With technical improvements (higher frequency and extended field-of-view sonography) the ability of ultrasound to detect pathology in the musculoskeletal system has been greatly increased. As in MRI, and unlike conventional radiography, soft tissue lesions in muscles, tendons and occasionally in joints can be shown directly. An advantage is real-time imaging of joints during stress. A disadvantage is limited demonstration of internal structures within joints. This paper provides an overview of various pathologies with emphasis on acute disorders.