E2742. Emphysematous Infections: What the Radiologist Needs to Know
  1. Ilana Warsofsky; Brigham and Women's Hospital
  2. Daniel Souza; Brigham and Women's Hospital
Emphysematous (gas-forming) infections within the solid organs and walls of hollow viscera can be seen in different pathologic or benign conditions. Identification of these findings in patients presenting with acute abdominal pain is important due to the high rate of mortality and morbidity. It is important to be able to recognize these entities across modality in order to help referring clinicians provide the best management given the high mortality and morbidity. Gas in abnormal locations can be related to gas forming bacteria, tissue infarction with necrosis, fistula, iatrogenic or reflux from adjacent organs. As these patients often have comorbid conditions and possible limited physical exam findings, radiologists play a crucial role in helping to improve patient outcomes based on prompt diagnosis and accurate communication of findings to allow for early treatment and management of these conditions.

Educational Goals / Teaching Points
The goals of this educational exhibit are to illustrate the characteristic imaging findings of emphysematous infections across modality when applicable, discuss the clinical manifestations, illustrate imaging features, and review relevant risk factors, potential differential diagnosis as well as current management.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
It is important to understand the pathophysiologic characteristics and predisposing conditions (such as diabetes mellitus or depressed immune response) in order to administer the correct treatment for gas forming infections in the genitourinary system, gallbladder, stomach, pancreas and abdominopelvic wall. The case examples which will be presented in this educational exhibit will discuss potential etiologies of the abnormal gas identified. Types of infections to be aware of include: emphysematous pyelonephritis, endometritis, cystitis, cholecystitis, pancreatitis, gastritis, as well as abdominal wall and Fournier gangrene. Most diagnoses are best made on CT; however, when available additional imaging modalities will be illustrated.

Emphysematous infections of the abdomen and pelvis are often life threatening requiring urgent medical and surgical management. Patients often present with insidious symptoms and can progress quickly to sepsis. Often patients are evaluated by x-ray or ultrasound. CT is highly sensitive and specific for detection of gas in abnormal locations. It is important to integrate findings from each scan in conjunction with patient history. It is This case-based format was designed to review for radiologists the pathophysiologic mechanisms, risk factors, and typical imaging features in the gastrointestinal, genitourinary and abdominal wall to make early diagnosis of these conditions.