Coronary artery calcification is often not reported in pulmonary CT angiography in patients with suspected pulmonary embolism: an opportunity to improve diagnosis of acute coronary syndrome.

OBJECTIVE: In patients with suspected pulmonary thromboembolism (PTE), coronary artery calcification (CAC) can be an incidental finding on pulmonary CT angiography. We evaluated the frequency of CAC not being reported and its association with a diagnosis of acute coronary syndrome (ACS). MATERIALS AND METHODS: Data of 469 consecutive patients who were referred to the emergency radiology department for pulmonary CT angiography of suspected PTE were reviewed. Radiology reports were rechecked and positive CAC findings were recorded. All pulmonary CT angiograms were reevaluated by one radiologist and CAC findings were recorded. The rates of ACS and PTE as final diagnoses for that hospital admission were calculated. The association between CAC and ACS diagnosis was assessed in different subgroups of patients. RESULTS: Approximately 11.1% of patients had PTE and 43.8% had CAC. The incidence of CAC was significantly higher in patients with an ACS diagnosis than in those without ACS (56.2% vs 40.4%, respectively; odds ratio [OR] = 1.9). There was a strong positive association (OR = 3.5) between CAC and ACS in younger patients (men ≤ 45 years and women ≤ 55 years), patients without PTE (OR = 2.2), and those without cardiometabolic risk factors (OR = 3.8). CAC was not reported in 45% of patients (n = 98) with positive CAC findings on imaging. ACS was the final diagnosis in 31.6% of patients with unreported CAC. There was a significant association between CAC and ACS in patients with unreported CAC (OR = 2.2). This association was more prominent in the subgroups described. CONCLUSION: CAC is often not reported in pulmonary CT angiography studies. CAC is a significant predictor of ACS particularly in younger patients, patients without PTE, and those without cardiometabolic risk factors. Especially in these subgroups, radiologists should assess CAC findings.

Applications of justification and optimization in medical imaging: examples of clinical guidance for computed tomography use in emergency medicine.

Availability, reliability, and technical improvements have led to continued expansion of computed tomography (CT) imaging. During a CT scan, there is substantially more exposure to ionizing radiation than with conventional radiography. This has led to questions and critical conclusions about whether the continuous growth of CT scans should be subjected to review and potentially restraints or, at a minimum, closer investigation. This is particularly pertinent to populations in emergency departments, such as children and patients who receive repeated CT scans for benign diagnoses. During the last several decades, among national medical specialty organizations, the American College of Emergency Physicians and the American College of Radiology have each formed membership working groups to consider value, access, and expedience and to promote broad acceptance of CT protocols and procedures within their disciplines. Those efforts have had positive effects on the use criteria for CT by other physician groups, health insurance carriers, regulators, and legislators.

Looking back, moving forward: 1988-2013. The first 25 years of the American Society of Emergency Radiology.

The American Society of Emergency Radiology (ASER) was founded in 1988 and is celebrating its 25th Anniversary. ASER is thriving and emergency radiology has never enjoyed greater popularity than at present. This history describes the genesis of the Society, its growth and current state of affairs. It is based on the recollections and personal files of the authors, one Founder and both former ASER Presidents and Gold Medalists, the ASER archives, and interviews and correspondence with many ASER members. It is hoped that this brief review will be interesting to the reader, provide some insight into ASER evolution over the years, and hold some lessons moving forward.

The role of emergency MRI in the setting of acute abdominal pain.

Abdominal pain is one of the most common reasons for patients to present to the emergency department (ED) in the USA, with an estimated seven million visits in 2007-2008, a figure which represents 8 % (±0.2 %) [2] of all ED visits and a 31.8 % increase from 1999-2000. Abdominal pain has a broad differential diagnosis that encompasses multiple organ systems and can provide a significant diagnostic challenge to the ED physician. Although magnetic resonance imaging (MRI) currently plays a limited role in the assessment of abdominal pain presenting to the ED in the nongravid population, its utility in the pregnant and pediatric population has already been proven. A proven diagnostic track record, lack of ionizing radiation and the ability to provide excellent tissue contrast without the use of nephrotoxic iodinated contrast, makes MRI an attractive imaging modality. As physicians and patients become more aware of the potential risks associated with exposure to ionizing radiation, ED MRI utilization is likely to increase. In this article, we discuss the MRI appearance of some of the most common diagnoses, which present as abdominal pain to the ED.

Abdominopelvic CT increases diagnostic certainty and guides management decisions: a prospective investigation of 584 patients in a large academic medical center.

OBJECTIVE: The objective of our study was to prospectively determine how CT affects physicians' diagnostic certainty and management decisions in the setting of patients with nontraumatic abdominal complaints presenting to the emergency department. SUBJECTS AND METHODS: We included 584 patients presenting with nontraumatic abdominal complaints to the emergency department from November 2006 through February 2008. Emergency department clinicians were prospectively surveyed both before abdominal CT (pre-CT) and after abdominal CT (post-CT) to determine the leading diagnosis, the diagnostic certainty, and the management decisions. Changes were assessed by Fisher's exact test and the log likelihood ratio. RESULTS: The most common diagnoses were renal colic (119/584, 20.4%) and intestinal obstruction (80/584, 13.7%). CT altered the leading diagnosis in 49% of the patients (284/584, p < 0.00001) and increased mean physician diagnostic certainty from 70.5% (pre-CT) to 92.2% (post-CT) (p < 0.001; log likelihood ratio, 2.48). The management plan was changed by CT in 42% (244/583) (p < 0.0001). Physicians planned to admit 75.3% of the patients (440/584) to the hospital before CT; that plan was changed to hospital discharge with follow-up in 24.1% of patients (106/440) after CT. Surgery was planned for 79 patients before CT, whereas hospital discharge was planned for 25.3% of these patients (20/79) after CT. CONCLUSION: In the management of patients presenting to the emergency department with nontraumatic abdominal complaints, CT changes the leading diagnosis, increases diagnostic certainty, and changes potential patient management decisions.

Diagnosing cervical spine instability: role of the post-computed tomography scan out-of-collar lateral radiograph.

BACKGROUND: Cervical spine injuries may have devastating neurological consequences, which makes accurate diagnosis of injury a key part of the trauma evaluation. Imaging plays a significant role in making the diagnosis and guiding management. Current American College of Radiology Appropriateness Criteria guidelines recommend computed tomography (CT) of the cervical spine with multi-planar reformats as the highest-rated imaging examination for patients meeting clinical criteria, without subsequent need for further imaging with a negative scan in a neurologically intact and non-obtunded patient. Although CT is fast and accurate for evaluation of bony injury, it may overlook ligamentous injury. OBJECTIVE AND CASE REPORT: We report a case in which ligamentous instability was demonstrated as subluxation with an out-of-collar lateral radiograph after a CT scan showed no subluxation or fracture in a patient without neurological deficits. Our Radiology Department routinely performs an out-of-collar lateral radiograph after a negative CT scan, and this case suggests that there may be an important role for this practice. CONCLUSION: Magnetic resonance is the optimal study for soft tissue and ligamentous evaluation; however, a simple lateral out-of-collar radiograph after CT clearance, in an otherwise neurologically intact and non-obtunded patient, may be a quick and cost-effective means to assess for instability of the cervical spine.

Benefit of follow-up CT in emergency department patients with persistent non-traumatic abdominal pain.

To determine the benefit of a short-term follow-up abdominopelvic computed tomography (APCT) examination among emergency department (ED) patients with persistent abdominal pain and an initially negative CT. During a 5-year period from January 2004 to December 2008, our institution's radiology department performed approximately 56,000 APCTs examinations in the ED. Sixty-eight percent of the APCT examinations used intravenous contrast. Nine hundred fifty-seven patients received two APCTs within 1 week for non-traumatic abdominal pain in the ED. Sixty-four patients with initially negative APCTs presented to the ED within 1 week with persistent abdominal pain and received follow-up APCT imaging. The mean follow-up period was 2.6 days. The mean interval period in which the second APCT yielded a positive result was 2.0 days. Seventy-five percent of follow-up examinations were performed with intravenous contrast. Twenty-three percent of patients had positive findings on the follow-up examination. Seventy-three percent of the follow-up positive findings were referable to bowel pathology. The cause of abdominal pain remained elusive at 1 week in 23% of patients. Short-term follow-up APCT examinations in patients with persistent, unexplained abdominal pain may be of benefit if the second APCT is performed with intravenous contrast in patients suspected of having bowel pathology.

Are cervical spine radiograph examinations useful in patients with low clinical suspicion of cervical spine fracture? An experience with 254 cases.

Trauma patients with low clinical suspicion of cervical spine fracture are often examined with a plain X-ray cervical spine series rather than with cervical spine computed tomography (CT). The authors have been concerned by the absence of fractures in the group of patients examined with plain X-ray. The objective of this investigation was to determine the usefulness of plain X-ray examinations in suspected cases of cervical spine fracture compared to CT. A retrospective review was performed of all trauma patients undergoing imaging for suspected cervical spine fracture in our Emergency Department over a one-year period (January 1, 2007 to December 31, 2007). During the study period, 254 cervical spine plain X-ray and 3,080 cervical spine CT examinations were performed. Of the 254 plain X-ray examinations, 237 were interpreted as negative for fracture, 11 were suboptimal examinations, and six were interpreted as possible fractures (later ruled out by further imaging). Of the 3,080 CT examinations, 2,884 were interpreted as negative for fracture and 196 as positive. The overall positivity rates for acute cervical spine fracture were 0.0% in plain X-ray and 6.4% in CT examinations. These data confirm the authors' concern that plain X-ray imaging for patients with low clinical suspicion for cervical spine trauma in our hospital may have too low a yield to justify its use. However, the 6.4% positivity rate in the group of patients selected for CT examination justifies its use in this group.

MDCT for automated detection and measurement of pneumothoraces in trauma patients.

OBJECTIVE: The size of a pneumothorax is an important index to guide the emergency treatment of trauma patients--chest tube drainage. The purpose of this study was to develop and validate an automated computer-aided volumetry scheme for detection and measurement of pneumothoraces for trauma patients imaged with MDCT. MATERIALS AND METHODS: Three pigs and 68 trauma patients with at least one diagnosed occult pneumothorax (23 women and 45 men; age range, 14-89 years; mean age, 41 +/- 19 years) were selected for the development and validation of our computer-aided volumetry scheme for pneumothorax. Computer-aided volumetry of pneumothorax consisted of five automated steps: extraction of pleural region, detection of pneumothorax candidates, delineation of the detected pneumothorax candidates, reduction of false-positive findings, and report of the volumetric measurement of pneumothoraces. RESULTS: In the animal study, our computer-aided volumetry scheme yielded a mean value of 24.27 +/- 0.64 mL (SD) compared with 25 mL of air volume manually injected in each scan. The correlation coefficients were 0.999 and 0.997 for the in vivo and ex vivo comparison, respectively. In the patient study, the sensitivity of our computer-aided volumetry scheme was 100% with a false-positive rate of 0.15 per case for 32 occult pneumothoraces > or = 25 mL. The correlation coefficient was 0.999 for manual volumetry comparison. This automated computer-aided volumetry scheme took approximately 3 minutes to finish the detection and measurement per case. CONCLUSION: The results show that our computer-aided volumetry scheme provides an automated method for accurate and efficient detection and measurement of pneumothoraces in MDCT images of trauma patients.

Emergency MRI of acute pelvic pain: MR protocol with no oral contrast.

The aim of this study was to evaluate the efficacy of magnetic resonance (MR) without oral contrast in the assessment of suspected acute pathologies of the pelvis in pregnant and non-pregnant patients. Sixty-seven patients who had MR of the lower abdomen and pelvis for acute abdomen were included in the study. The MR examinations were evaluated for indication of the study, type of MR sequences, and sensitivity of MR in diagnosing the disease. T2 single shot fast spin echo (SS-FSE), T2 FSE, short tau inversion recovery, pre-gadolinium T1, and post-gadolinium T1 sequences were utilized. There were 30 pregnant and two postpartum women in the study group. Positive pelvic MR findings were seen in 73% (49/67). Final diagnoses were acute appendicitis (n = 12), ovarian torsion (n = 6), abscess (n = 3), tubo-ovarian abscess (n = 2), ovarian tumor (n = 2), degenerating fibroid (n = 3), and perianal fistula (n = 2). For acute appendicitis, sensitivity was 100% (12/12), and positive predictive value was 92% (12/13). Post-gadolinium T1-weighted sequences and T2 SS-FSE with FS were the sequences, which were most likely to best demonstrate the acute appendicitis. For ovarian torsion, the sensitivity was 86% (6/7), and positive predictive value was 100% (6/6). MR imaging is an efficacious means of diagnosing acute appendicitis, ovarian torsions, and other adnexal diseases in the acute setting. The four sequence protocol without oral contrast offers an excellent means of investigating the cause of acute lower abdominal and pelvic pain.

Fournier gangrene: role of imaging.

Fournier gangrene is a rapidly progressing necrotizing fasciitis involving the perineal, perianal, or genital regions and constitutes a true surgical emergency with a potentially high mortality rate. Although the diagnosis of Fournier gangrene is often made clinically, emergency computed tomography (CT) can lead to early diagnosis with accurate assessment of disease extent. CT not only helps evaluate the perineal structures that can become involved by Fournier gangrene, but also helps assess the retroperitoneum, to which the disease can spread. Findings at CT include asymmetric fascial thickening, subcutaneous emphysema, fluid collections, and abscess formation. Subcutaneous emphysema is the hallmark of Fournier gangrene but is not seen in all cases. Compared with radiography and ultrasonography, CT provides a higher specificity for the diagnosis of Fournier gangrene and superior evaluation of disease extent; however, diagnosis and evaluation can also be performed with these other modalities. The administration of broad-spectrum antibiotics and aggressive surgical débridement of the nonviable tissue are both essential for successful treatment. An awareness of the CT features of Fournier gangrene is imperative for prompt diagnosis and effective treatment planning.

Multidetector CT of blunt thoracic trauma.

Thoracic injuries are significant causes of morbidity and mortality in trauma patients. These injuries account for approximately 25% of trauma-related deaths in the United States, second only to head injuries. Radiologic imaging plays an important role in the diagnosis and management of blunt chest trauma. In addition to conventional radiography, multidetector computed tomography (CT) is increasingly being used, since it can quickly and accurately help diagnose a wide variety of injuries in trauma patients. Furthermore, multiplanar and volumetric reformatted CT images provide improved visualization of injuries, increased understanding of trauma-related diseases, and enhanced communication between the radiologist and the referring clinician.

Multidetector CT of carpal injuries: anatomy, fractures, and fracture-dislocations.

Fractures and dislocations of the carpal bones are more common in young active patients. These injuries can lead to pain, dysfunction, and loss of productivity. Conventional radiography remains the primary imaging modality for evaluation of suspected carpal fractures and dislocations. However, multidetector computed tomography (CT) is playing an increasingly important role, especially in the following situations: (a) when results from initial radiographs are negative in patients with suspected carpal fractures, (b) when initial radiographic findings are indeterminate, and (c) when knowledge of the extent of carpal fractures or dislocations is required before surgical treatment. The advantages of multidetector CT include quick and accurate diagnosis with availability in most emergency centers. Multidetector CT can easily display the extent of carpal fractures and dislocations, often depicting fractures that are occult at radiography. In addition, with multiplanar (two-dimensional) and volumetric (three-dimensional) reformation, pathologic conditions and anatomic relationships are better perceived. This information can be easily conveyed to orthopedic and trauma surgeons and can be crucial for surgical treatment and planning.

Cemento-osseous dysplasia, a radiological mimic of periapical dental abscess.

In the imaging evaluation of Emergency Department patients presenting with facial pain, there is a condition that can mimic the radiographic appearance of a periapical dental abscess. This condition, cemento-osseous dysplasia, may appear similar on dental X-rays, panoramic radiographs, and computed tomography examinations to and must be distinguished from the more common periapical abscess in order to avoid inappropriate intervention. This review highlights the easy confusion of these two entities based on radiographic appearance and the clinical implications of such a mistake and suggests some approaches to avoid this error.

Magnetic resonance of acute appendicitis: pearls and pitfalls.

Acute appendicitis is the most common surgical abdominal emergency. Although the clinical diagnosis can be made accurately in typical cases, imaging plays an important role in improving diagnostic accuracy of this condition, especially when the clinical diagnosis is uncertain. Magnetic resonance imaging is an emerging promising technique for the diagnosis of acute appendicitis, especially in patients with nondiagnostic ultrasound and in patients where radiation is a clinical concern. In the following review, the role of magnetic resonance in the diagnosis of appendicitis will be discussed.

MR imaging of the acute abdomen and pelvis: acute appendicitis and beyond.

Acute abdominal and pelvic processes account for more than half of all surgical procedures performed in the emergency setting. Rapid and accurate diagnosis in the emergency department is essential for the appropriate management of these acute conditions. Magnetic resonance (MR) imaging is an attractive modality for diagnostic imaging in patients for whom the risks of radiation or the potential nephrotoxicity of iodinated contrast agents is a major concern, such as pregnant and pediatric patients. MR imaging is most useful for evaluating pregnant patients with acute lower abdominal pain believed to have an extra-uterine cause, such as appendicitis or ovarian torsion. Other patients with other conditions commonly seen in the emergency setting may be better evaluated with another cross-sectional imaging modality. Imaging protocols should be adapted to the constraints of acute illness, with emphasis placed on minimizing the duration of image acquisition, and should include strategies to decrease motion-related artifacts. A prudent approach is to select the imaging modalities that can best depict a particular subset of clinical conditions to help narrow the differential diagnosis. Disadvantages of MR imaging include its high cost, the limited availability of MR imaging systems and trained radiologists, and the incompatibility of MR imaging systems and the equipment used for intensive care and monitoring of patient status.

CT cystography with multiplanar reformation for suspected bladder rupture: experience in 234 cases.

OBJECTIVE: CT cystography has replaced conventional cystography in the evaluation of patients with suspected bladder rupture in most trauma centers. We performed this retrospective review to determine the accuracy of CT cystography and the role of multiplanar reformation in the diagnosis of bladder injury. MATERIALS AND METHODS: The patient cohort was composed of trauma patients with clinically or CT-suspected bladder ruptures who were evaluated with CT cystography using two different MDCT scanners at our level 1 trauma center. The patients were identified through Folio, a radiology research tool software system. The CT cystography results were compared with the findings at surgery, clinical follow-up, or both. RESULTS: Between January 1, 2000, and December 31, 2004, 234 patients were examined in our level 1 trauma center with CT cystography. From the total of 234 examinations, 216 (92.3%) were interpreted as negative and 18 examinations (7.7%) were interpreted as positive. On the 18 positive examinations, 11 were extraperitoneal bladder rupture, five were intraperitoneal bladder rupture, and two were combined intraperitoneal and extraperitoneal bladder rupture. Surgical bladder exploration and repair were performed in nine of the 18 cases. Seven (77.8%) of the nine cases had operative findings consistent with the CT cystogram findings. The overall sensitivity and specificity of CT cystography in diagnosing bladder rupture were each 100%. For extraperitoneal bladder rupture, the sensitivity and specificity were 92.8% and 100%, respectively. For intraperitoneal rupture, the sensitivity and specificity were 100% and 99%, respectively. CONCLUSION: CT cystography is accurate for diagnosing bladder rupture. Sagittal and coronal multiplanar reformations may be helpful in identifying most sites of bladder rupture.

Acute epiploic appendagitis and its mimics.

Acute epiploic appendagitis most commonly manifests with acute lower quadrant pain. Its clinical features are similar to those of acute diverticulitis or, less commonly, acute appendicitis. The conditions that may mimic acute epiploic appendagitis at computed tomography (CT) include acute omental infarction, mesenteric panniculitis, fat-containing tumor, and primary and secondary acute inflammatory processes in the large bowel (eg, diverticulitis and appendicitis). Whereas the location of acute epiploic appendagitis is most commonly adjacent to the sigmoid colon, acute omental infarction is typically located in the right lower quadrant and often is mistaken for acute appendicitis. It is important to correctly diagnose acute epiploic appendagitis and acute omental infarction on CT images because these conditions may be mistaken for acute abdomen, and the mistake may lead to unnecessary surgery. The CT features of acute epiploic appendagitis include an oval lesion 1.5-3.5 cm in diameter, with attenuation similar to that of fat and with surrounding inflammatory changes, that abuts the anterior sigmoid colon wall. The CT features of acute omental infarction include a well-circumscribed triangular or oval heterogeneous fatty mass with a whorled pattern of concentric linear fat stranding between the anterior abdominal wall and the transverse or ascending colon. As CT increasingly is used for the evaluation of acute abdomen, radiologists are likely to see acute epiploic appendagitis and its mimics more often. Recognition of these conditions on CT images will allow appropriate management of acute abdominal pain and may help to prevent unnecessary surgery.