Brian C. Lucey

Abdominal 64-MDCT for suspected appendicitis: the use of oral and IV contrast material versus IV contrast material only

OBJECTIVE The objective of our study was to compare the diagnostic accuracy of IV contrast-enhanced 64-MDCT with and without the use of oral contrast material in diagnosing appendicitis in patients with abdominal pain. MATERIALS AND METHODS We conducted a randomized trial of a convenience sample of adult patients presenting to an urban academic emergency department with acute nontraumatic abdominal pain and clinical suspicion of appendicitis, diverticulitis, or small-bowel obstruction. Patients were enrolled between 8 am and 11 pm when research assistants were present. Consenting subjects were randomized into one of two groups: Group 1 subjects underwent 64-MDCT performed with oral and IV contrast media and group 2 subjects underwent 64-MDCT performed solely with IV contrast material. Three expert radiologists independently reviewed the CT examinations, evaluating for the presence of appendicitis. Each radiologist interpreted 202 examinations, ensuring that each examination was interpreted by two radiologists. Individual reader performance and a combined interpretation performance of the two readers assigned to each case were calculated. In cases of disagreement, the third reader was asked to deliver a tiebreaker interpretation to be used to calculate the combined reader performance. Final outcome was based on operative, clinical, and follow-up data. We compared radiologic diagnoses with clinical outcomes to calculate the diagnostic accuracy of CT in both groups. RESULTS Of the 303 patients enrolled, 151 patients (50%) were randomized to group 1 and the remaining 152 (50%) were randomized to group 2. The combined reader performance for the diagnosis of appendicitis in group 1 was a sensitivity of 100% (95% CI, 76.8-100%) and specificity of 97.1% (95% CI, 92.7-99.2%). The performance in group 2 was a sensitivity of 100% (73.5-100%) and specificity of 97.1% (92.9-99.2%). CONCLUSION Patients presenting with nontraumatic abdominal pain imaged using 64-MDCT with isotropic reformations had similar characteristics for the diagnosis of appendicitis when IV contrast material alone was used and when oral and IV contrast media were used.

Spontaneous hemoperitoneum: a bloody mess

Spontaneous hemoperitoneum may be a life-threatening occurrence. It most frequently presents with acute abdominal pain. Computed tomography (CT) is the most commonly used modality in the initial work up of these patients, but sonography and magnetic resonance imaging (MRI) play a role in the diagnosis. The etiology is varied, yet may be broadly classified into gynecologic, hepatic, splenic, vascular, and coagulopathic causes. This review will describe the common imaging findings of spontaneous hemoperitoneum, as it presents through the emergency room, and will detail the underlying causes and significance of spontaneous hemoperitoneum.

Impact of MDCT angiography on the use of catheter angiography for the assessment of cervical arterial injury after blunt or penetrating trauma.

OBJECTIVE The objective of our study was to assess the impact of the increasing use of MDCT angiography in the setting of blunt and penetrating neck trauma on the use of digital subtraction angiography (DSA) at our institution, a level 1 trauma center. MATERIALS AND METHODS From January 2001 to December 2003, 57 patients were referred for CT angiography or DSA of the neck after blunt or penetrating neck trauma. All CT angiograms were acquired with a 4-MDCT scanner. The patients were divided into three groups on the basis of consecutive 12-month periods (2001, 2002, and 2003), and the initial imaging technique was recorded. The results of CT and digital subtraction angiograms were compared with operative findings and with clinical course, when available. RESULTS In 2001, 12 patients were referred for imaging: nine patients were evaluated initially with DSA and three patients were evaluated with CT angiography and subsequently with DSA. In 2002 and 2003, 11 and 34 patients, respectively, underwent CT angiography as the initial imaging examination. During these 2 years, no patient underwent DSA as the initial diagnostic test, but five patients underwent DSA after CT angiography for the following indications: evaluation of nondiagnostic CT angiograms (n = 1), confirmation of findings when requested by the clinical service (n = 2), and catheter-guided therapy (n = 2). CONCLUSION CT angiography has essentially replaced DSA as the study of choice for the initial evaluation of the neck vessels in the setting of blunt or penetrating trauma at our institution. CT angiography is adequate for the initial evaluation, allows appropriate triage of patients to conventional angiography or surgery for appropriate treatment, and can guide conservative management when appropriate.

Accuracy of MDCT in the diagnosis of choledocholithiasis.

OBJECTIVE Our purpose was to evaluate the diagnostic performance of contrast-enhanced and unenhanced MDCT, performed for various indications, in detecting choledocholithiasis. CONCLUSION Unenhanced and contrast-enhanced MDCT images, interpreted in PACS workstations with axial images, are moderately sensitive and specific for showing choledocholithiasis.

CT-guided intervention with low radiation dose: feasibility and experience.

OBJECTIVE The purpose of this study was to evaluate the feasibility of performing CT-guided interventional procedures with a very low radiation dose. MATERIALS AND METHODS We performed 291 CT-guided interventional procedures using a low dose of radiation. The subjects were 165 men and 126 women 22-89 years old with a mean age of 65 years. CT fluoroscopy was not used. The procedures were 201 percutaneous biopsies and 90 percutaneous aspiration or drainage procedures. Before the procedure, images were obtained with standard mAs of 175-250 mAs. All subsequent CT was performed at a reduced mAs. Technical success of catheter placement and biopsy was calculated, and the results were compared with those of procedures performed over the previous 12 months with standard radiation doses. Patient weight, lesion size, and number of CT acquisitions needed to complete the procedure were recorded. RESULTS All but three aspiration or drainage procedures performed at 30 mAs were successful, for a success rate of 96.7%. The technical success rate of biopsy performed at 30 mAs was 93.5%. In the cases of 13 patients undergoing biopsy, the masses were not identified with low-dose technique, and these procedures were completed at a higher dose. Results were independent of patient weight and lesion size. The technical success rate was 98% for percutaneous drainage performed at a standard radiation dose in the 12 months before introduction of the low-dose technique. The technical success rate was 87.5% for biopsy performed at a standard radiation dose in the 12 months before introduction of the low-dose technique. The complication rate of the low-dose technique was comparable to that of the standard-dose technique. CONCLUSION Low-dose radiation technique using 30 mAs results in technical success for both catheter placement and percutaneous biopsy comparable to standard radiation dose.

Development of Renal Scars on CT After Abdominal Trauma: Does Grade of Injury Matter?

OBJECTIVE The objective of our study was to determine whether there is an association between the grade of a traumatic renal injury and the subsequent development of renal parenchymal scars on CT. MATERIALS AND METHODS We performed a retrospective study encompassing all acute trauma patients admitted to our institution over a 42-month period found to have renal parenchyma injuries on initial MDCT and also to have undergone a follow-up CT performed at least 1 month after trauma. We identified 54 patients who sustained blunt (n = 44) or penetrating (n = 10) abdominal trauma. The renal injuries were graded by two radiologists according to the Organ Injury Scaling Committee of the American Association for the Surgery of Trauma (AAST), grades I through V. Follow-up CT was reviewed for the presence of parenchymal distortion, scarring, or perfusion defects. RESULTS Of the 54 patients, 12 had grade I injury, eight had grade II injury, 22 had grade III injury, 10 had grade IV injury, and two had grade V injury. Grades I and II traumatic renal injuries were undetectable on follow-up CT. Grade III injuries resulted in the development of renal scars in 14 of 22 (64%) patients. Scarring resulted in all patients with grades IV and V injuries. CONCLUSION Grades I and II renal injuries heal completely, whereas higher grades of renal trauma result in permanent parenchymal scarring. Hence, incidentally discovered renal scars in patients with a history of minor renal trauma should be attributed tentatively to other causes that may or may not require additional investigation.

Evaluation of Blunt Abdominal Trauma Using PACS-Based 2D and 3D MDCT Reformations of the Lumbar Spine and Pelvis

OBJECTIVE The purpose of this study was to show the value of 2D and 3D reformations of CT data from abdominal and pelvic CT performed immediately at the workstation using a PACS-based software program to evaluate the lumbar spine and pelvis in patients with blunt abdominal trauma. MATERIALS AND METHODS We reviewed the abdominopelvic CT scans and conventional radiographs of the lumbar spine or pelvis of 156 consecutive patients with blunt abdominal trauma. The CT data were compared with the radiographic findings and also with the findings of dedicated repeat CT of the spine or pelvis, when performed. RESULTS CT depicted 80 fractures of the lumbar spine and 178 pelvic fractures. Radiography showed 40 fractures of the lumbar spine and 138 pelvic fractures. No additional fractures were identified on dedicated repeat CT. CONCLUSION Conventional radiographs to clear the lumbar spine are no longer required when abdominopelvic CT data are available. CT and reformatted CT data show more fractures than radiography and miss no fractures compared with dedicated CT of the lumbar spine or pelvis. Having these images immediately available through the PACS workstation saves time for the trauma team in the management of critically ill patients.

MRI of Complicated Pouchitis

OBJECTIVE The purpose of this study is to assess the ability of MRI to identify the presence of inflammation related to the pouch reservoir in symptomatic patients with an ileal pouch-anal anastomosis who present with clinically suspected complicated pouchitis. CONCLUSION Initial results suggest that MRI should be considered in patients who have undergone ileal pouch-anal anastomosis and present a clinical impression of complicated pouchitis. MRI showed abnormalities consistent with complicated pouchitis in seven of nine examinations, with findings including pouch wall thickening, abnormal wall enhancement, peripouch fluid collection, sinus and fistula tract formation, lymphadenopathy, and peripouch stranding and fatty proliferation. MRI findings of complicated pouchitis should raise the suspicion of Crohns disease and should prompt further investigation.

Acute pancreatitis: the role of imaging and interventional radiology.

Acute pancreatitis can manifest as a benign condition with minimal abdominal pain and hyperamylasemia or can have a fulminant course, which can be life-threatening usually due to the development of infected pancreatic necrosis, and multisystem organ failure [1, 2]. Fortunately, 70–80% of patients with acute pancreatitis have a benign self-limiting course (Figs. 1, 2, 4). The initial 24-48 hours after the initial diagnosis is usually the period that determines the subsequent course, and for many of the 20–30% of patients who subsequently have a fulminant course, this becomes apparent within this time frame. With reference to long-term outcome following acute pancreatitis, most cases recover without long-term sequelae with only a minority of cases progressing to chronic pancreatitis [5]. In the initial management of acute pancreatitis, assessment of metabolic disturbances and systemic organ dysfunction is critical. However, the advent and continued refinement of cross-sectional imaging modalities over the past two decades has led to a prominent role for diagnostic imaging in assessing acute pancreatitis. Furthermore, these cross-sectional imaging modalities have enabled the development of diagnostic and therapeutic interventional techniques in the hands of radiologists. In this article we review the diagnostic features of acute pancreatitis, the clinical staging systems, complications and the role of imaging. The role of interventional radiology techniques in the management of acute pancreatitis will be discussed as well as potential complications associated with these treatments.

Radiologic management of cysts in the abdomen and pelvis

OBJECTIVE Few abdominal or pelvic cystic lesions come to the attention of the interventional radiologist, and those that do are symptomatic. Differentiation of cysts from cystic-appearing masses is not difficult when a multitechnique imaging approach is used. Our objective is to summarize the principles and specifics for management of symptomatic cysts through percutaneous catheter techniques. CONCLUSION Percutaneous aspiration of cysts can relieve symptoms without the need for surgery. A sound knowledge of the various types of cysts that may be found in the abdomen and pelvis enables the radiologist to select those patients who will benefit the most from percutaneous management.