Christina A. LeBedis

Nontraumatic Orbital Conditions: Diagnosis with CT and MR Imaging in the Emergent Setting

Imaging provides crucial information regarding emergent orbital abnormalities, and the radiologist fulfills an important role in guiding patient care and contributing to favorable outcomes. Knowledge of the imaging features of nontraumatic orbital conditions commonly seen in the emergent setting-infections, inflammation, vascular abnormalities, and retinal and choroidal detachments-is necessary to achieve a prompt and accurate diagnosis, thereby avoiding permanent vision loss and other potentially devastating consequences. The ability to distinguish these entities from physiologic calcifications, posttherapeutic changes, and orbital devices allows optimal management without unnecessary further diagnostic work-up. For orbital imaging in the acute setting, computed tomography is the first-line modality, with magnetic resonance imaging playing an important secondary role.

Incidence of Contrast-Induced Nephropathy in Patients With Multiple Myeloma Undergoing Contrast-Enhanced CT

OBJECTIVE The purpose of this article is to evaluate the incidence of contrast-induced nephropathy (CIN) and the effects of associated risk factors in patients with multiple myeloma undergoing contrast-enhanced CT (CECT) with IV administration of nonionic iodinated contrast agent. MATERIALS AND METHODS This retrospective review of medical records identified patients with a diagnosis of myeloma who underwent a CECT examination of the chest, abdomen, or pelvis between January 1, 2005, and December 1, 2008. Analysis for CIN, as defined by an increase in creatinine level after the CECT examination of 25% or more, or of 0.5 mg/dL, compared with the level before the CECT examination, both within 48 hours and within 7 days, was performed. Statistical correlations between the development of CIN and creatinine level before CECT examination, patient location, type and amount of contrast agent, blood urea nitrogen-creatinine ratio, history of diabetes, hypercalcemia, Bence Jones proteinuria, β(2)-microglobulin level, albumin level, International Myeloma Staging System stage, and history of myeloma provided at the time the CT examination was ordered were calculated. RESULTS Forty-six patients who completed 80 unique examinations were included; their average creatinine level before CECT examination was 0.97 mg/dL. There was no significant difference in the average creatinine levels before CT examination between patients without and those with CIN. Four (5%) and 12 (15%) patients developed CIN within 48 hours and 7 days, respectively. Only serum β(2)-microglobulin level showed a statistically significant (p = 0.03) correlation with the development of CIN. CONCLUSION The incidence of CIN in patients with multiple myeloma with a normal creatinine level is low and correlates with β(2)-microglobulin levels. The administration of contrast agent in this patient population is safe but should be based on the potential benefit of the examination and the expected low risk of developing CIN.

Active Hemorrhage and Vascular Injuries in Splenic Trauma: Utility of the Arterial Phase in Multidetector CT

PURPOSE To determine whether the addition of arterial phase computed tomography (CT) to the standard combination of portal venous and delayed phase imaging increases sensitivity in the diagnosis of active hemorrhage and/or contained vascular injuries in patients with splenic trauma. MATERIALS AND METHODS The institutional review board approved this HIPAA-compliant retrospective study; the requirement to obtain informed consent was waived. The study included all patients aged 15 years and older who sustained a splenic injury from blunt or penetrating trauma and who underwent CT in the arterial and portal venous phases of image acquisition during a 74-month period (September 2005 to November 2011). CT scans were reviewed by three radiologists, and a consensus interpretation was made to classify the splenic injuries according to the American Association for the Surgery of Trauma splenic injury scale. One radiologist independently recorded the presence of contained vascular injuries or active hemorrhage and the phase or phases at which these lesions were seen. Clinical outcome was assessed by reviewing medical records. The relationship between imaging findings and clinical management was assessed with the Fisher exact test. RESULTS One hundred forty-seven patients met the inclusion criteria; 32 patients (22%) had active hemorrhage and 22 (15%) had several contained vascular injuries. In 13 of the 22 patients with contained injuries, the vascular lesion was visualized only at the arterial phase of image acquisition; the other nine contained vascular injuries were seen at all phases. Surgery or embolization was performed in 11 of the 22 patients with contained vascular injury. CONCLUSION The arterial phase of image acquisition improves detection of traumatic contained splenic vascular injuries and should be considered to optimize detection of splenic injuries in trauma with CT.

CT Imaging of Blunt Traumatic Bowel and Mesenteric Injuries

Delayed diagnosis of a bowel or mesenteric injury resulting in hollow viscus perforation leads to significant morbidity and mortality from hemorrhage, peritonitis, or abdominal sepsis. The timely diagnosis of bowel and mesenteric injuries requiring operative repair depends almost exclusively on their early detection by the radiologist on computed tomography examination, because the clinical signs and symptoms of these injuries are not specific and usually develop late. Therefore, the radiologist must be familiar with the often-subtle imaging findings of bowel and mesenteric injury that will allow for appropriate triage of a patient who has sustained blunt trauma to the abdomen or pelvis.

Biliary Imaging: Multimodality Approach to Imaging of Biliary Injuries and Their Complications

Although traumatic and iatrogenic bile leaks are rare, they have become more prevalent in recent years due to an increased propensity toward nonsurgical management of patients with liver trauma and an overall increase in the number of hepatobiliary surgeries being performed. Because clinical signs and symptoms of bile leaks are nonspecific and delay in the recognition of bile leaks is associated with high morbidity and mortality rates, imaging is crucial for establishing an early diagnosis and guiding the treatment algorithm. At computed tomography or ultrasonography, free or contained peri- or intrahepatic low-attenuation (low-density) fluid in the setting of recent trauma or hepatobiliary surgery should raise suspicion for a bile leak. Hepatobiliary scintigraphy and magnetic resonance (MR) cholangiopancreatography with hepatobiliary contrast agents can help detect active or contained bile leaks. MR cholangiopancreatography with hepatobiliary contrast agents has the added advantage of being able to help localize the bile leak, which in turn can help determine if endoscopic management is sufficient or if surgical management is warranted. Endoscopic retrograde cholangiopancreatography may provide diagnostic confirmation and concurrent therapy when nonsurgical management is pursued. A multimodality imaging approach is helpful in diagnosing traumatic or iatrogenic biliary injuries, accurately localizing a bile leak, and determining appropriate treatment.

Imaging of Pancreatic and Duodenal Trauma

Pancreatic and duodenal injuries are rare but life-threatening occurrences, often occurring in association with other solid organ injuries. Findings of pancreatic and duodenal trauma on computed tomography and MR imaging are often nonspecific, and high levels of clinical suspicion and understanding of mechanism of injury are imperative. Familiarity with the grading schemes of pancreatic and duodenal injury is important because they help in assessing for key imaging findings that directly influence management. This article presents an overview of imaging of blunt and penetrating pancreatic and duodenal injuries, including pathophysiology, available imaging techniques, and variety of imaging features.

Use of Magnetic Resonance Imaging Contrast Agents in the Liver and Biliary Tract

This article presents an overview of liver and biliary contrast agents including their mechanisms of action, dosage and elimination, current clinical indications, and potential future uses.

Use of Magnetic Resonance in Pancreaticobiliary Emergencies.

This article presents the magnetic resonance protocols, imaging features, diagnostic criteria, and complications of commonly encountered emergencies in pancreaticobiliary imaging. Pancreatic trauma, bile leak, acute cholecystitis, biliary obstruction, and pancreatitis are discussed. Various classifications and complications that can arise with these conditions, as well as artifacts that may mimic pathology, are also included.

Rotator Cuff Tear Arthropathy: Pathophysiology, Imaging Characteristics, and Treatment Options.

OBJECTIVE The purpose of this article is to review the biomechanical properties of the rotator cuff and glenohumeral joint and the pathophysiology, imaging characteristics, and treatment options of rotator cuff tear arthropathy (RCTA). CONCLUSION Although multiple pathways have been proposed as causes of RCTA, the exact cause remains unclear. Increasing knowledge about the clinical diagnosis, imaging features, and indicators of severity improves recognition and treatment of this pathologic condition.

Multidetector CT of Surgically Proven Blunt Bowel and Mesenteric Injury

Blunt traumatic injury is one of the leading causes of morbidity and mortality in the United States. Unintentional injury represents the leading cause of death in the United States for all persons between the ages of 1 and 44 years. In the setting of blunt abdominal trauma, the reported rate of occurrence of bowel and mesenteric injuries ranges from 1% to 5%. Despite the relatively low rate of blunt bowel and mesenteric injury in patients with abdominal and pelvic trauma, delays in diagnosis are associated with increased rates of sepsis, a prolonged course in the intensive care unit, and increased mortality. During the past 2 decades, as multidetector computed tomography (CT) has emerged as an essential tool in emergency radiology, several direct and indirect imaging features have been identified that are associated with blunt bowel and mesenteric injury. The imaging findings in cases of blunt bowel and mesenteric injury can be subtle and may be seen in the setting of multiple complex injuries, such as multiple solid-organ injuries and spinal fractures. Familiarity with the various imaging features of blunt bowel and mesenteric injury, as well as an understanding of their clinical importance with regard to the care of the patient, is essential to making a timely diagnosis. Once radiologists are familiar with the spectrum of findings of blunt bowel and mesenteric injury, they will be able to make timely diagnoses that will lead to improved patient outcomes. ©RSNA, 2017.