The soft-tissue manifestations of neurofibromatosis type 1.

The radiological appearances of neurofibromatosis type 1 (NF-1) are numerous and variable, because of the widespread presence of peripheral nerves. Knowledge of this variability can prevent unnecessary intervention. For example, occasionally lesions can be misinterpreted and biopsies performed unnecessarily. Thus, familiarity with the manifestations of this disease and the spectrum of associated abnormalities is an important part of the radiologist's armamentarium. This paper explores the manifold radiological appearances of extracranial NF-1 as experienced by the Sarcoma and Soft Tissue Tumour Unit at the Royal Marsden Hospital.

MRI features of posterior ankle impingement syndrome in ballet dancers: a review of 25 cases.

AIM: To describe the magnetic resonance imaging (MRI) features of posterior ankle impingement syndrome (PAIS) in classical ballet dancers. MATERIALS AND METHODS: A retrospective review was undertaken of 25 MRI examinations of the ankle performed on 23 ballet dancers over a 26-month period. Images were examined for the presence of osseous and soft-tissue anatomical variants at the posterior ankle and imaging signs of PAIS. All patients presented with symptoms and signs suggestive of PAIS including posterior ankle pain, swelling and stiffness during plantar flexion. RESULTS: Anatomical variants predisposing to PAIS including as os trigonum and tuberosity arising from the superior calcaneum were clearly depicted. The most common imaging feature of PAIS in our series was high T2 signal posterior to the talocalcaneal joint indicating synovitis (n = 25). Thickening of the posterior capsule (n = 13) and tenosynovitis of flexor hallucis longus (n = 17) were also common. An os trigonum was an infrequent finding (n = 7). Bone marrow oedema, commonly in the posterior talus (n = 10) or in a patchy distribution (n = 10) was often noted. CONCLUSION: MRI is a useful diagnostic tool in PAIS, and in the present series, clearly demonstrates the anatomical variants and range of osseous and soft-tissue abnormalities associated with this condition. Prospective studies are needed to understand the significance and importance of individual MRI findings in producing the symptoms of PAIS.

Imaging features of multicentric Castleman's disease in HIV infection.

AIM: To describe the computed tomography (CT) features of human immunodeficiency virus (HIV)-associated Castleman's disease. MATERIALS AND METHODS: Nine HIV-positive patients with biopsy-proven Castleman's disease were studied. Clinical and demographic data, CD4 count, histological diagnosis and human herpes type 8 (HHV8) serology or immunostaining results were recorded. CT images were reviewed independently by two radiologists. RESULTS: CT findings included splenomegaly (n=7) and peripheral lymph node enlargement (axillary n=8, inguinal n=4). All nodes displayed mild to avid enhancement after intravenous administration of contrast material. Hepatomegaly was evident in seven patients. Other features included abdominal (n=6) and mediastinal (n=5) lymph node enlargement and pulmonary abnormalities (n=4). Patterns of parenchymal abnormality included bronchovascular nodularity (n=2) consolidation (n=1) and pleural effusion (n=2). On histological examination eight patients (spleen n=3, lymph node n=9, lung n=1, bone marrow n=1) had the plasma cell variant and one had mixed hyaline-vascular/plasma cell variant. The majority had either positive immunostaining for HHV8 or positive serology (n=8). CONCLUSION: Common imaging features of multicentric Castleman's disease in HIV infection are hepatosplenomegaly and peripheral lymph node enlargement. Although these imaging features may suggest the diagnosis in the appropriate clinical context, they lack specificity and so biopsy is needed for diagnosis. In distinction from multicentric Castleman's disease in other populations the plasma cell variant is most commonly encountered, splenomegaly is a universal feature and there is a strong association with Kaposi's sarcoma.

Pictorial review: MRI features of foot and ankle injuries in ballet dancers.

Foot and ankle pain is common in ballet dancers. Although clinical examination often points to the underlying cause, imaging is often necessary to confirm the diagnosis and thus ensure appropriate future management. Factors predisposing to the increased incidence of injuries in this population include the classical position in which ballet dancers stand, which is on the tips of the toes in the en pointe position or on the balls of the feet in the demi-pointe position. Furthermore, the repetitious nature of ballet and the long hours spent rehearsing cause over-use injuries. The causes of foot and ankle pain can be thought of in four different groups: the impingement syndromes; tendon abnormalities; osseous pathology; and ligament abnormalities. These will be discussed and illustrated.

Trainee reporting of computed tomography examinations: do they make mistakes and does it matter?

AIM: To determine the accuracy of trainees reporting computed tomography (CT) examinations. MATERIAL AND METHODS: Over a 6-month period a single consultant reviewed all the CT examinations reported by registrars in one radiology department. After recording a provisional registrar report each examination was jointly reviewed by the consultant and registrar. The consultant's opinion was regarded as the gold standard. Data collected included: the error rate, whether an error was significant, leading to a change in patient management, and whether the mistake was a false-negative or positive. RESULTS: Three hundred and thirty-one patients were included in the study. There was an overall error rate of 21.5%. A significant error leading to a change in management was made in 10% of reports, and a significant error that did not lead to a change in management was made in 9.3%; 2.1% of reports had insignificant errors; and 69% of errors were false-negatives. CONCLUSION: Registrars make a significant number of errors affecting patient management when reporting CT and ideally all examinations should be reviewed by a consultant.