Acute gastrointestinal bleeding: emerging role of multidetector CT angiography and review of current imaging techniques.

Acute gastrointestinal bleeding is a common cause of hospitalization, morbidity, and mortality in the United States. The evaluation and treatment of acute gastrointestinal bleeding are complex and often require a multispecialty approach involving gastroenterologists, surgeons, internists, emergency physicians, and radiologists. The multitude of pathologic processes that can result in gastrointestinal bleeding, the length of the gastrointestinal tract, and the often intermittent nature of gastrointestinal bleeding further complicate patient evaluation. In addition, there are multiple imaging modalities and therapeutic interventions that are currently being used in the evaluation and treatment of acute gastrointestinal hemorrhage, each with its own strengths and weaknesses. Initial experience indicates that multidetector computed tomographic angiography is a promising first-line modality for the time-efficient, sensitive, and accurate diagnosis or exclusion of active gastrointestinal hemorrhage and may have a profound impact on the evaluation and subsequent treatment of patients who present with acute gastrointestinal bleeding.

Sonography of the acute scrotum: the four T's of testicular imaging.

The scrotum is frequently imaged on an emergent basis. The differential diagnosis of the acute scrotum can be divided into four categories-torsion, trauma, tumor, and "testiculitis" (epididymo-orchitis). Although testicular neoplasms are not imaged emergently, 15% are detected incidentally when performing an emergent scrotal ultrasound. Therefore, the emergent sonographic examination of the testicles should include a thorough search for malignancy. Images demonstrating the sonographic and color Doppler appearances of each of the "four T's" will be reviewed. The radiographic review will focus on the imaging features, which are the keys to arriving at the correct diagnosis.