Periapical lucency around the tooth: radiologic evaluation and differential diagnosis.

Periapical lucencies are often seen incidentally at head and neck imaging studies performed for indications not related to the teeth. These lesions are, however, occasionally manifestations of diseases that have a wide range of effects and may at times represent the source of symptoms that prompted the study. The vast majority of periapical lucencies are the result of apical periodontal or pulpal disease. If found in an advanced state or left untreated, disease related to the tooth may spread to adjacent tissues, including the sinuses, orbits, deep fascial spaces of the neck, and intracranial structures, and result in a significant increase in patient morbidity and mortality. Although the majority of periapical lucencies seen on radiographs and computed tomographic images occur secondary to apical periodontal or pulpal disease, not all lucencies near the tooth root are due to infection. Lucency near the tooth root may be seen in the setting of other diseases of odontogenic and non-odontogenic origin, including neoplasms. Although imaging findings for these lesions can include periapical lucent components, awareness of the varied secondary imaging features can aid the radiologist in developing an accurate differential diagnosis. Familiarity with the imaging features and differential diagnoses of diseases or conditions that cause lucency around the tooth root results in appropriate referral and prompt diagnosis, management, and treatment, and can prevent unnecessary additional imaging or intervention. In addition, early recognition and appropriate treatment of infectious processes will result in improved clinical outcomes and a decrease in morbidity and mortality.

Radiologic techniques and effectiveness of angiography to diagnose and treat acute upper gastrointestinal bleeding.

The use of catheter-based techniques to treat upper gastrointestinal hemorrhage has evolved considerably over the past few decades. At present, the state-of-the-art interventional suites provide optimal imaging. Coupled with advanced catheter technology, the two may be used to manage and treat the patient with acute upper gastrointestinal hemorrhage. This article summarizes these techniques and, when possible, compares them with other methods such as surgery and endoscopy. The specific role of transcatheter embolotherapy is highlighted, alongside an additional discussion on pharmacologic infusion of vasopressin.