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.

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.

Pelvic CT angiography in blunt trauma: imaging findings and protocol considerations. [corrected].

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.

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.

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.

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.

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.

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.

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 (p < 0.0001, p = 0.005, p = 0.006, 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.

Detection of vascular injuries in patients with blunt pelvic trauma by using 64-channel multidetector CT.

Vascular injuries are a major source of morbidity and mortality in patients with blunt pelvic trauma. Digital subtraction angiography (DSA) has traditionally been used to detect pelvic arterial injuries and to treat active arterial hemorrhage. Improvements in the technology of computed tomography (CT) have facilitated the implementation of CT angiography, which is beginning to replace DSA in the evaluation of patients with acute trauma. Pelvic CT angiography can reliably depict various pelvic arterial injuries and can help differentiate arterial hemorrhage from venous hemorrhage on the basis of multiphasic acquisitions, a method that may be used to tailor the subsequent clinical approach. With the use of a 64-channel multidetector CT scanner, multiphasic pelvic CT angiography can be integrated into the evaluation of trauma patients by using 1.25-mm reconstructed section thickness, pitch of 1:0.987, and gantry revolution time of 0.5 second to achieve near-isotropic results. A standard dose of 100 mL intravenous contrast material is injected at a rate of 5 mL/sec, and 30 mL saline solution, also at 5 mL/sec, is injected as a "chasing" bolus to follow the contrast material.

MDCT evaluation of blunt abdominal trauma: clinical significance of free intraperitoneal fluid in males with absence of identifiable injury.

OBJECTIVE: The purpose of our study was to determine the clinical significance of the isolated finding of free intraperitoneal fluid on 64-MDCT in male patients who have undergone blunt trauma. MATERIALS AND METHODS: A retrospective study was performed of 669 consecutive male patients, ranging in age from 15 to 85 years, who underwent CT evaluation of the abdomen and pelvis at our level 1 trauma center over a 17-month period. Two radiologists evaluated the images for the presence of free intraperitoneal fluid and for an underlying cause. For patients with free intraperitoneal fluid, the mean attenuation and the size of the largest pocket of fluid on both portal venous and delayed phase images were measured for both those with and those without injury. For the patients who had free intraperitoneal fluid as an isolated finding, the electronic chart was reviewed to determine the clinical outcome, specifically whether these patients were observed, had short-interval follow-up imaging, or underwent exploratory laparotomy. RESULTS: Forty-eight of the 669 patients (7.2%) had free intraperitoneal fluid. Twenty-nine (4.3%) of these patients had an identifiable solid organ, bowel, bladder, or pelvic injury to explain the free fluid. In the remaining 19 (2.8%) patients, free fluid was an isolated finding. The size of the largest collection of fluid was smaller for patients without identifiable injury on portal venous phase (1,236 vs 348 mm(2)) and delayed phase (1,325 vs 298 mm(2)) images (p = 0.0015 and p < 0.0001, respectively). Fluid in patients without identifiable injury was also shown to be less dense. A statistically significant difference between the mean attenuation coefficients of the fluid in the patients with and without injury was also found on both the portal venous phase (45.1 vs 13.1 HU, p < 0.0001) and delayed phase (45.6 vs 20.8 HU, p < 0.0001) images. All 19 patients without identifiable injury were admitted for observation and discharged without surgical intervention. CONCLUSION: With 64 MDCT, the isolated finding of free intraperitoneal fluid in male patients who have undergone blunt trauma is seen in approximately 3% of patients. The size and mean attenuation coefficient measurements may add useful information regarding the clinical management of these patients, suggesting that small amounts of low-attenuation free fluid, in the absence of identifiable injury, may have no significant clinical implications.

Blunt trauma: feasibility and clinical utility of pelvic CT angiography performed with 64-detector row CT.

PURPOSE: To retrospectively evaluate the integration of pelvic computed tomographic (CT) angiography into the thoracoabdominal CT examination of blunt trauma by using 64-detector row CT to differentiate active arterial from active venous hemorrhage. MATERIALS AND METHODS: This study was institutional review board approved and HIPAA compliant; the requirement for informed patient consent was waived. Fifty-three patients (30 male, 23 female; mean age, 42 years) with multiple blunt trauma underwent pelvic CT angiography with 64-detector row CT at admission. Arterial phase and portal venous phase pelvic CT angiograms were evaluated for evidence of vascular injury. In patients with active extravasation, the size of the hemorrhaging area was measured on arterial, portal venous, and delayed phase images. The Fisher exact test was used to correlate presence of vascular injury with subsequent clinical management. The Wilcoxon rank sum test was used to test the association between size of active hemorrhage during the vascular enhancement phases and subsequent clinical outcome. Finally, the Fisher exact test was used to correlate presence of vascular injury with severity of osseous injury. RESULTS: At pelvic CT angiography, 21 of the 53 patients had evidence of vascular injury: 10 isolated active arterial extravasations, three isolated arterial occlusions, three cases of both arterial extravasation and occlusion, two cases of arterial and venous extravasations, and three isolated venous extravasations. Eleven of the 21 patients also underwent conventional angiography, with subsequent embolization performed in seven of these 11 patients. The remaining 10 patients were successfully treated conservatively. When the foci of active arterial extravasation were compared on arterial, portal venous, and delayed phase images, the mean areas of hemorrhage across all three phases were larger in patients who required conventional angiography than in those successfully treated with conservative management. CONCLUSION: With use of 64-detector row scanning, pelvic CT angiography was successfully integrated into the authors' CT protocols and enabled differentiation between active arterial and active venous hemorrhage, which may influence clinical management.

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.

Suspected aortic dissection and other aortic disorders: multi-detector row CT in 373 cases in the emergency setting.

PURPOSE: To retrospectively review the authors' experience with multi-detector row computed tomography (CT) for detection of aortic dissection in the emergency setting. MATERIALS AND METHODS: The investigation was institutional review board approved, did not require informed patient consent, and was HIPAA compliant. In 373 clinical evaluations in the emergency setting, 365 patients suspected of having aortic dissection and/or other aortic disorders underwent multidetector CT. Criteria for acute aortic disorder were confirmed by using surgical and pathologic diagnoses or findings at clinical follow-up and any subsequent imaging as the reference standard. Positive cases were characterized according to type of disorder interpreted. Resulting sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated by using two-way contingency tables. All cases found to be negative for acute aortic disorders were grouped according to alternative CT findings. RESULTS: Sixty-seven (18.0%) of the 373 cases were interpreted as positive for acute aortic disorder. One hundred twelve acute aortic disorders were identified in these 67 cases: 23 acute aortic dissections, 14 acute aortic intramural hematomas, 20 acute penetrating aortic ulcers, 44 new or enlarging aortic aneurysms, and 11 acute aortic ruptures. Three hundred five (81.8%) cases were interpreted as negative for acute aortic disorder. In 48 negative cases, multidetector CT depicted alternative findings that accounted for the clinical presentation. Of these, three included both acute aortic disorders and alternative findings, and 45 included only alternative findings. One (0.3%) case was indeterminate for acute aortic disorder. Overall, 112 findings were interpreted as positive for acute aortic disorder, an alternative finding, or both at CT. No interpretations were false-positive, one was false-negative, 67 were true-positive, and 304 were true-negative. Sensitivity, specificity, PPV, NPV, and accuracy were 99% (67 of 68), 100% (304 of 304), 100% (67 of 67), 99.7% (304 of 305), and 99.5% (371 of 373), respectively. CONCLUSION: The positivity rate for acute aortic dissection or other acute aortic disorder in 373 cases examined at multi-detector row CT was 18.0%.

Emergency department abdominal computed tomography for nontraumatic abdominal pain: optimizing utilization.

OBJECTIVES: To identify predictors of positive computed tomographic (CT) yield and to measure the impact of CT yield on the disposition of patients referred for computed tomography after presenting to an emergency department with nontraumatic abdominal pain. MATERIALS AND METHODS: Computed tomographic reports, laboratory data, and emergency department and hospital records were retrospectively analyzed in 604 consecutive patients undergoing CT examinations. Computed tomographic yield was correlated to age, gender, leukocyte count, specified precomputed-tomography clinical diagnosis, and patient disposition. RESULTS: Forty-eight percent of CT scans (298 of 621) had positive results. Computed tomographic results were positive in 76% of children (13 of 17) and 47% of adults (285 of 604) (P < .03) and in 45% of female patients (155 of 343) and 51% of male patients (143 of 278) (P < .2). Fifty-two percent of CT scans (223 of 426) with and 38% (75 of 195) without specified precomputed-tomography clinical diagnoses had positive results (P < .01). Fifty-eight percent of CT scans (161 of 278) with elevated and 40% of CT scans (135 of 336) with normal patient leukocyte counts had positive results (P < .001). Sixty-seven percent of patients (171 of 256) admitted and 35% of patients (127 of 365) discharged had positive CT results (P < .001). Computed tomography revealed unsuspected diagnoses in 27% of patients (165 of 621). Thirteen percent of patients (12 of 93) without any clinical predictors for positive CT yield were admitted after positive CT results. Thirty-eight percent of patients (104 of 273) with clinically suspected diagnoses requiring admission were discharged after negative CT results. CONCLUSION: Clinical indicators of positive CT yield include pediatric age, leukocytosis, and a specified precomputed-tomography diagnosis. Positive CT results are a predictor for hospital admission. In one quarter of cases, computed tomography identifies clinically unsuspected diagnoses and thereby adds information important for patient management, even after clinical evaluation.

The status of appendiceal CT in an urban medical center 5 years after its introduction: experience with 753 patients.

OBJECTIVE: Appendiceal CT was introduced at our hospital in 1996 and now is used in most patients. The use of appendiceal CT has generated controversy and mixed results in various investigations. Our purpose was to determine the percentage of patients for whom CT was performed, incidence of appendicitis, accuracy of CT, percentage of equivocal interpretations, and negative appendectomy rates for those patients who did and did not undergo CT. MATERIALS AND METHODS: Patient records from 2001 that included clinical or CT preoperative examination were analyzed, with follow-up through 2003. Patient age and sex, clinical presentation, CT techniques, CT interpretations, operative reports, pathology reports, and patient disposition were determined. Final diagnoses were provided by pathologic criteria, patient follow-up, or patient survey. Statistical analysis included Fisher's exact test and receiver operating characteristic (ROC) curves. RESULTS: Of 753 patients, 663 (88%) were examined on CT for suspected appendicitis and 90 had an appendectomy without undergoing CT. The incidence of appendicitis in the patients who underwent CT was 39.2%. The sensitivity and specificity of CT were 99% and 95%, respectively; the area under the ROC curve was 0.9896; and the percentage of equivocal CT interpretations was 3.3%. The false-negative appendectomy rates were 3.0% and 5.6% for patients with and without CT, respectively (for all patients, p = 0.326; for female pediatric patients, p = 0.030). CONCLUSION: Five years ago, the negative appendectomy rate dropped from 20% to 7%, and it is now 3.0%. The incidence of appendicitis in patients who are examined on CT is stable compared with similar cohorts from prior investigations. Patients who do not undergo CT also have a low negative appendectomy rate, but this relatively small group is selected on the basis of a convincing clinical presentation. Female pediatric patients likely would have a lower negative appendectomy rate with greater use of CT.

How to simplify the CT diagnosis of Le Fort fractures.

OBJECTIVE: The numerous components seen in the Le Fort fractures make classification difficult. Our objective is to simplify the task of classifying Le Fort fractures. CONCLUSION: Each of the Le Fort fractures has at least one unique component that is easily recognizable: I, the anterolateral margin of the nasal fossa; II, the inferior orbital rim; and III, the zygomatic arch. Classification of the Le Fort fractures is simplified by using these unique components to establish a tentative classification that is then confirmed.

Trends in the use of CT and radiography in the evaluation of facial trauma, 1992-2002: implications for current costs.

OBJECTIVE: CT has replaced conventional radiography of the face in many trauma centers. Concern exists that increased costs are associated with increased use of CT. Our goal was to compare the amount of CT and radiography performed for facial trauma at a level 1 trauma center in 1992 and in 2002 and to determine hospital costs for the imaging of these patients. MATERIALS AND METHODS: The changes in volume and types of facial imaging examinations were determined comparing 1992 and 2002. Hospital costs of different imaging examinations were determined for 2002. Current costs of imaging facial trauma were compared with what 2002 costs would have been if the practice pattern in 1992 had continued. RESULTS: In 1992, 890 patients were evaluated for facial trauma. Six hundred seventy-one had only radiography, 153 only CT of the face, and 66 both CT and radiography. In 2002, 828 patients were evaluated. Five hundred eighty-four patients had only CT of the face; 228, only radiography; and 16, both CT and radiography. The number of facial imaging examinations per patient in 1992 and 2002 was 1.23 and 1.03, respectively. The 2002 hospital cost of a facial CT examination was $121 and of a facial radiography series was $154. Using CT instead of radiography for evaluating facial injury resulted in an overall cost savings of 22% per patient in 2002. CONCLUSION: The availability of CT has not resulted in increased use of facial imaging. The increased use of CT from 1992 to 2002 results in decreased current costs for the hospital.

Computed tomography evaluation of diverticulitis.

Acute diverticulitis is a frequent and important diagnosis in gastrointestinal disease, most commonly involving the colon. It is estimated that approximately 15% to 30% of patients with diverticulosis develop symptomatic diverticulitis at some point in the natural history of the condition, often requiring medical and/or surgical therapy. The clinical diagnosis is often difficult to make, and several radiological studies have been used over the past decades to assist in the diagnosis of acute diverticulitis. These include barium enema, ultrasound, and computed tomography (CT). A number of studies over the past decade have shown CT to be the preferable initial examination because of its ability to demonstrate not only the extent of intramural inflammation but also the degree of pericolic disease, including intraperitoneal inflammation, perforation, and abscess formation. Additional benefits of CT imaging include guiding therapeutic interventions in complicated forms of diverticular disease and providing an alternative diagnosis in patients without diverticulitis. The accuracy, techniques, criteria for diagnosis, and staging and applications of CT imaging in acute diverticulitis are discussed.

Controversies in emergency radiology. CT versus ultrasound in the evaluation of blunt abdominal trauma.

There has been controversy regarding ultrasonography (US) versus CT in blunt abdominal trauma (BAT). Each modality has its strengths and weaknesses. US is fast and allows resuscitative efforts to proceed while the patient is being scanned. However, the sensitivity of US is inferior to that of CT, and there is user variability. CT is better at determining the extent, type, and grade of injury, resulting in a more tailored therapeutic plan and safe conservative management of many patients. However, CT involves ionizing radiation, cannot be performed portably, and requires only visual monitoring while scanning. Given each modality's strengths and weaknesses we conclude that CT is the preferred examination when the BAT patient is stable or moderately stable, enough to be taken to CT. If a BAT patient is unstable, US is beneficial in screening for certain injuries or large hemoperitoneum prior to an exploratory laparotomy.