Clare J. Roche

The urachus is a fibrous tube extending from the umbilicus to the anterosuperior bladder dome that usually obliterates at week 12 of gestation, becoming the median umbilical ligament. Urachal pathology occurs when there is incomplete obliteration of this channel during foetal development, resulting in the formation of a urachal cyst, patent urachus, urachal sinus or urachal diverticulum. Patients with persistent urachal remnants may be asymptomatic or present with lower abdominal or urinary tract symptoms and can develop complications. The purpose of this review is to describe imaging features of urachal remnant pathology and potential benign and malignant complications on ultrasound, CT, positron emission tomography CT and MRI.

Certain pathologic conditions have classic radiologic manifestations that resemble various types of food. These "food signs" are highly memorable and easily recognizable and include findings that resemble various fruits and vegetables; meat, fish, and egg dishes; pasta, rice, grains, and bread (carbohydrates); desserts, cakes, and candy; and dishes, cutlery, condiments, and so on. It is important that radiologists recognize these classic signs, which will allow confident diagnosis on the basis of imaging findings alone or narrowing of the differential diagnosis.

We report a case where fetal MRI using a low-field-strength magnet (0.5 T) accurately confirmed a large extracranial vascular malformation, which was suspected on antenatal US. Fetal MRI enabled better counselling of the parents and allowed suitable plans to be made regarding method of delivery and early management of the neonate. To our knowledge this is the first case of an extracranial vascular malformation imaged using fetal MRI.

Vascular injuries resulting from closed fractures of the humerus are rare. We describe two patients who developed unsuspected pseudoaneurysms following closed humeral fracture. Both patients presented with a mass, suspicious for malignancy. In each case, diagnosis was made by magnetic resonance imaging.