James T. Rhea

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

OBJECTIVEnThe 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.nnnMATERIALS AND METHODSnWe 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.nnnRESULTSnOf 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%).nnnCONCLUSIONnPatients 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.

Imaging of blunt pancreatic trauma

Blunt pancreatic trauma is an exceedingly rare but life-threatening injury with significant mortality. Computed tomography (CT) is commonly employed as the initial imaging modality in blunt trauma patients and affords a timely diagnosis of pancreatic trauma. The CT findings of pancreatic trauma can be broadly categorized as direct signs, such as a pancreatic laceration, which tend to be specific but lack sensitivity and indirect signs, such as peripancreatic fluid, which tend to be sensitive but lack specificity. In patients with equivocal CT findings or ongoing clinical suspicion of pancreatic trauma, magnetic resonance cholangiopancreatography (MRCP) may be employed for further evaluation. The integrity of the main pancreatic duct is of crucial importance, and though injury of the duct may be strongly suggested upon initial CT, MRCP provides clear delineation of the duct and any potential injuries. This article aims to review and illustrate the CT and magnetic resonance imaging findings of blunt pancreatic trauma and delineate the integration of these modalities into the appropriate imaging triage of severely injured blunt trauma patients.

64 MDCT in multiple trauma patients: imaging manifestations and clinical implications of active extravasation.

The finding of active hemorrhage on computed tomography (CT) in trauma patients has been shown to have significant clinical implications and has been incorporated into numerous CT grading schema. As CT technology has advanced, the sensitivity for detection of active hemorrhage in the trauma population has significantly improved. Currently, with the improved spatial and temporal resolution afforded by 64 multidetector computed tomography (64 MDCT) technology, the clinical implications of the CT findings of active extravasation may need to be reconsidered. This article illustrates the various imaging manifestations of active extravasation throughout the body using 64 MDCT. Additionally, protocol issues specific to the findings of active hemorrhage using 64 MDCT are detailed, including novel interpretation techniques, which offer aid in detecting and characterizing hemorrhage. Finally, the clinical implication of active extravasation using this new technology is discussed. Although more sensitive to the detection of small hemorrhagic foci and with clinical implications highly dependent upon location, active bleeding remains as a salient finding that affects subsequent clinical management of trauma patients.

Use of 64-Row Multidetector CT Angiography in Blunt and Penetrating Trauma of the Upper and Lower Extremities

Computed tomographic (CT) angiography is rapidly becoming the preferred imaging test for the initial evaluation of patients suspected to have arterial injuries after blunt and penetrating trauma to the extremities. The increasingly widespread use of 64-row multidetector CT technology offers considerable benefits in extremity CT angiography in the trauma setting. These include the ability to generate isotropic data sets of long vascular territories, with the acquisition performed in a short time (10 seconds or less). Isotropic voxels make CT a fully multiplanar modality, a capability that is particularly useful for evaluating tortuous vessels. Sixty-four-row multidetector CT angiography of the extremities has the ability to demonstrate a variety of vascular injuries such as occlusion, pseudoaneurysm, active extravasation, and intimal dissection. Radiologists should be aware of the various potential pitfalls and limitations of extremity CT angiography in evaluation of trauma patients suspected to have extremity vascular injuries, including inadequate arterial enhancement, motion artifact, inadequate positioning, and streak artifact. By demonstrating the extent, location, and type of injury, CT angiography aids in the decision-making process to determine the appropriate management for each injury in each patient.

CT of blunt abdominal and pelvic vascular injury

Computed tomography (CT) has been shown to be increasingly useful in the evaluation of blunt trauma patients with suspected abdominopelvic vascular injuries. CT findings of abdominopelvic vascular insult may be broadly characterized as end-organ abnormalities or direct evidence of vascular injury. End-organ abnormalities implying an underlying vascular insult include identifying an area of relative hypoperfusion in solid organ injury. Direct evidence of a vascular injury includes identifying an irregular or thrombosed vessel or an area of active hemorrhage, among other findings. This review article aims to review and illustrate these findings of blunt abdominopelvic vascular trauma. Also, evolving lessons from our level I trauma center in the use of multiphasic imaging to further characterize sources of a vascular blush and the differentiation of arterial from venous sources of active hemorrhage are discussed.

Active extravasation of the abdomen and pelvis in trauma using 64MDCT

The objective of this study was to determine the clinical and management implications of the finding of active extravasation in blunt or penetrating trauma patients evaluated with abdomino-pelvic computed tomography (CT) using 64MDCT technology. This HIPAA compliant, retrospective study was IRB-approved, and the need for consent was waived. All adult patients scanned with 64MDCT who sustained blunt or penetrating abdomino-pelvic trauma and had findings of active extravasation at our Level I trauma center during a 30-month period were included. Two radiologists reviewed all abdomino-pelvic CT scans and characterized the active hemorrhage by location, extent, and attenuation on all available phases of imaging. Subsequent therapy and disposition were determined by reviewing the patients’ medical records. The relationship between the location of a source of extravasation and subsequent clinical outcome was evaluated using Fischer’s exact test. The relationship between the size and attenuation of the active hemorrhage and patient outcome were compared using the Wilcoxon rank sum test. One hundred and twenty-five patients with active extravasation were included. Patients with solid organ or pelvic injuries that were managed conservatively or had a negative digital subtraction angiogram had statistically significant smaller areas of active extravasation when compared to those that required intervention or died. When the attenuation values of extravasation are normalized to the intravascular attenuation achieved after intravenous contrast injection, no significant differences were seen based on subsequent clinical outcome. Based on location, those patients with solid organ, gastrointestinal/mesenteric, and pelvic sources of bleeding showed statistically significant higher likelihood of requiring subsequent intervention or dying, compared with those patients with subcutaneous, intramuscular, or retroperitoneal sources of active extravasation who were more likely to be managed conservatively (pu2009<u20090.0001, pu2009=u20090.005, pu2009=u20090.006, respectively). In blunt and penetrating trauma patients evaluated using 64MDCT technology, the location and size of the region of active extravasation are predictive of the type of subsequent clinical management. Normalized attenuation values of the active extravasation, however, are not predictive of subsequent management.

Extremity CT angiography: application to trauma using 64-MDCT

Evolving multi-row detector computed tomography (MDCT) technology has resulted in increasing utility of CT angiography (CTA) in extremity vascular trauma diagnosis and characterization. Given the widespread availability as well as the ease of acquiring CTA in the trauma setting, CTA is increasingly being used as the initial diagnostic evaluation in extremity vascular trauma, replacing digital subtraction angiography in many institutions. One of the significant advantages of the application of 64-MDCT to extremity vascular trauma is the ability to integrate CTA into routine trauma torso protocols. This ultimately yields an efficient, tailored examination to evaluate the multi-trauma patient in a timely manner, a critical concern in this patient population. Although 64-MDCT offers increasing improvement in image quality, technical quality hinges on strict attention to protocol considerations in its implementation. This review article aims to detail the myriad injuries, which may be detected and characterized with CTA. Protocol considerations in the application of 64-MDCT technology to extremity vascular trauma are discussed, drawing from our experience in an urban, Level I trauma center. Finally, the advantages and techniques of integrating extremity CTA into torso trauma protocols will be described.

Imaging colorectal trauma using 64-MDCT technology.

Computed tomography has evolved to become the principal imaging modality in the evaluation of colorectal trauma. Direct signs of colorectal trauma are usually highly specific but relatively insensitive and, therefore, indirect signs are important in the diagnostic of colorectal injuries. In addition, prompt recognition of colorectal injury is crucial as even short delays in its diagnosis have been shown to significantly increase both morbidity and mortality. All these things make colorectal injury a challenge for radiologists. The purpose of this review is to describe and analyze the various computed tomography (CT) findings of colorectal injuries in both penetrating and blunt trauma using 64-multirow detector computed tomography technology, based on our experience in a level I trauma center. Additionally, the CT protocol methods specific to colorectal injuries are detailed.

Influence of body habitus and use of oral contrast on reader confidence in patients with suspected acute appendicitis using 64 MDCT.

The purpose of this study is to evaluate how body habitus affects reader confidence in diagnosing acute appendicitis and appendiceal visualization using 64 MDCT technology with and without oral contrast. We conducted a HIPAA compliant, IRB approved study of adult patients presenting to the Emergency Department with nontraumatic abdominal pain. Subjects were randomized to two groups: 64 MDCT scans performed with oral and intravenous contrast or scans performed solely with intravenous contrast. Three radiologists established their confidence about the presence of appendicitis as well as recording whether the appendix was visualized. Reader confidence in diagnosing acute appendicitis was compared between the two groups for the three readers. The impact of patient BMI and estimated intra-abdominal fat on reader confidence in diagnosing appendicitis was determined. Finally, a comparison of the effect of BMI and intra-abdominal fat on appendiceal visualization between the two groups was carried out. Three hundred three patients were enrolled in this study. There was a statistically significant difference in confidence based on BMI for reader 2, group 1 in diagnosing appendicitis. No further statistically significant differences in reader confidence for diagnosing appendicitis based on BMI or intra-abdominal fat were identified. There was no influence of BMI or intra-abdominal fat on appendiceal visualization. Increasing BMI was seen to improve reader confidence for one of three readers in patients that received both oral and intravenous contrast. No further effects of BMI or intra-abdominal fat on confidence in diagnosing or excluding appendicitis were seen. Neither BMI nor intra-abdominal fat were seen to influence appendiceal visualization.

Pelvic CT angiography: application to blunt trauma using 64MDCT

The evolution of multi-row detector computed tomography (MDCT) technology has resulted in evolving applications of CT angiography (CTA) in the trauma setting. In patients with significant blunt pelvic injuries, the immediate diagnosis and characterization of vascular injuries are of significant import given their morbidity and mortality in this patient population. The application of MDCT technology, specifically 64MDCT, to pelvic CTA is useful in evaluating for potential vascular injuries and may be integrated into admission trauma imaging in order to triage patients with blunt pelvic trauma to appropriate emergent intervention. This review will discuss the use of pelvic CTA in blunt pelvic trauma and its utility in detecting and characterizing vascular injury, including the differentiation of arterial from venous hemorrhage. Protocol considerations in pelvic CTA using 64MDCT technology will be detailed as well as the integration of pelvic CTA into torso CT trauma protocols.The evolution of multi-row detector computed tomography (MDCT) technology has resulted in evolving applications of CT angiography (CTA) in the trauma setting. In patients with significant blunt pelvic injuries, the immediate diagnosis and characterization of vascular injuries are of significant import given their morbidity and mortality in this patient population. The application of MDCT technology, specifically 64MDCT, to pelvic CTA is useful in evaluating for potential vascular injuries and may be integrated into admission trauma imaging in order to triage patients with blunt pelvic trauma to appropriate emergent intervention. This review will discuss the use of pelvic CTA in blunt pelvic trauma and its utility in detecting and characterizing vascular injury, including the differentiation of arterial from venous hemorrhage. Protocol considerations in pelvic CTA using 64MDCT technology will be detailed as well as the integration of pelvic CTA into torso CT trauma protocols.