Multidetector computed tomographic (CT) angiography is used in many institutions for initial evaluation of the cerebral circulation for acute stroke and subarachnoid hemorrhage as well as in various preoperative settings. A comprehensive CT examination that includes a review of three-dimensional and maximum intensity projection images of the intra- and extracranial arteries and axial images of the skull base (obtained with bone window settings) allows identification of most abnormalities and normal variants. Knowledge of the presence and clinical relevance of normal variants such as fenestrations, duplications, and persistent fetal arteries plays a crucial role in the diagnosis and management of acute stroke and subarachnoid hemorrhage and may aid in surgical planning. For example, the preoperative detection of a medial or intrasellar persistent trigeminal artery may help surgeons avoid a potentially life-threatening hemorrhage in a patient undergoing transsphenoidal surgery for pituitary adenoma. However, the significance of normal variants diverges widely: A clinically important association has been observed between fenestration and intracranial aneurysm formation, whereas early branching of the middle cerebral artery is not associated with an increased risk of aneurysm formation and has little clinical significance. Supplemental material available at http://radiographics.rsnajnls.org/cgi/content/full/29/4/1027/DC1.

Injuries to the lateral ligaments of the ankle are common in medical practice. The most commonly injured ligaments are the anterior talofibular (ATFL) and calcaneofibular (CFL) ligaments. When undertaking MRI evaluation of ankle injuries it is important to understand the normal dimensions, appearance and variations of these ligaments. Twenty-eight consecutive patients referred for MRI of the ankle underwent bilateral scanning. The thickness of normal and abnormal ATFL and CFL was determined. The mean thickness of the ATFL was 2.19 +/- 0.6 mm and the CFL measured 2.13 +/- 0.5 mm. One normal ankle had an extremely thin ATFL (0.8 mm) with an otherwise normal appearance, whereas two ankles had an ATFL with a high attachment, both of which were deemed to be normal variants. Nineteen per cent of normal CFLs were noted to consist of a lateral hypointense band with a medial isointense medial band. Two variations of normal ATFL, one normal variant CFL and a measurement of the normal thickness of the ATFL and CFL have been presented in this paper. These variations have not been described previously by other authors. It is envisaged that these findings will assist in the MRI assessment of the lateral ankle ligaments.

Objective: To assess the differences in the types of injuries sustained by surfboard and bodyboard riders and to identify common mechanisms of injury. Methods: Subjects were prospectively recruited to the study on presentation to one of the six hospital emergency departments. Consented subjects completed a questionnaire while in the emergency departments. Data regarding radiological investigations undertaken and their findings were collected retrospectively. Results: A total of 224 males and 28 females in the surfing group and 14 males in the bodyboard group were recruited. In surfers, the most common injured body parts were the head/face (115; 45.6%) and lower limb (69; 27.4%). Surfers were most commonly injured by a surfboard, either their own (178; 70.6%) or someone else's (18; 7.1%). Unfortunately, the small number of subjects recruited to the bodyboard group precluded meaningful comparison with the surfing group. Conclusions: The most common body part injured in surfers is the head/face compared with the lower limbs in bodyboard riders. Contact with a surfer's board (most commonly their own) is the most common cause of injury. Significant spinal fractures/injuries are sustained when the surfer (usually their head) strikes the seafloor. Head and facial fractures occur when the surfer is struck by their own board. Future research into surfboard design which incorporates softer compounds into the deck, rail, and fins is recommended. The need for local authorities and surf lifesavers to disseminate information relating to specific beaches to the general public regarding surf conditions, water depth, and the nature of the seafloor is also essential for injury prevention.

Flat foot (pes planus) is a progressive and disabling pathology that is treated initially with conservative measures and often followed by a variety of surgeries. This article briefly reviews the pathology in acquired flat foot deformity, the classification of posterior tibial tendon dysfunction, discusses surgical techniques for the management of adult flat foot deformity, and reviews potential complications and their relevant imaging appearances.