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Although a broad spectrum of entities can induce acute pathologic changes in the small bowel, there are relatively few imaging features that are characteristic of a specific diagnosis on the basis of CT findings. Specific clinical information, including time course and onset of disease, patient risk factors, and any recent pharmacologic or radiation therapy, is often instrumental in refining the differential diagnosis. A wide spectrum of disorders is reviewed in this article; however, given the breadth of disorders associated with the small bowel, neoplastic and infectious conditions affecting the small bowel that can manifest acutely are not specifically discussed. Vascular diseases that can affect the small bowel regionally or diffusely, including thromboembolic and hypoperfusion phenomena, as well as a spectrum of vasculitides, are reviewed. Iatrogenic causes of small bowel disorders are discussed, including angiotensin-converting enzyme inhibitor-induced angioedema, and chemotherapy- and radiation therapy-associated patterns of disease. Autoimmune and hereditary conditions that can affect the small bowel, including systemic lupus erythematosus and genetic C1 esterase inhibitor deficiency, respectively, are reviewed. ©RSNA, 2018.

The purpose of this article is to describe arterial and venous thromboembolism in the abdomen, pelvis, and lower extremities in patients with coronavirus disease (COVID-19). Eighty-two patients with COVID-19 who underwent abdominal ultrasound or CT were retrospectively compared with 82 patients without COVID-19 for thromboembolism and solid-organ infarction. Nine (11%) patients with COVID-19 had thromboembolic findings, with medium to large arterial thrombi in five. One patient without COVID-19 had known portal vein thrombus on CT. Thromboembolic findings occurred more frequently in patients with than without COVID-19 (p = 0.02).

The placenta plays a crucial role throughout pregnancy, and its importance may be overlooked during routine antenatal imaging evaluation. Detailed systematic assessment of the placenta at ultrasonography (US), the standard imaging examination during pregnancy, is important. Familiarity with the normal and abnormal imaging appearance of the placenta along with the multimodality and methodical approach for evaluation of its related abnormalities is necessary, so that radiologists can alert clinicians regarding appropriate prompt management decisions. This will potentially decrease fetal and maternal morbidity and mortality. This article reviews early placental formation and the expected imaging appearance of the placenta during pregnancy, as well as variations in its morphology. It also discusses various placental diseases and their potential clinical consequences. Placental pathologic conditions include abnormalities of placental size, cord insertion, placental and cord location, and placental adherence. Other conditions such as bleeding in and around the placenta, as well as trophoblastic and nontrophoblastic tumors of the placenta, are also discussed. US with Doppler imaging is the initial imaging modality of choice for placental evaluation. Magnetic resonance (MR) imaging is reserved for equivocal cases or when additional information is needed. Computed tomography (CT) has a limited role in evaluation of placental abnormalities because of the ionizing radiation exposure and the relatively limited assessment of the placenta; however, CT can provide important information in specific circumstances, particularly evaluation of trauma and staging of choriocarcinoma. This article also addresses recent techniques and updates in placental imaging, including elastography, diffusion-weighted MR imaging, and blood oxygen level-dependent (BOLD) MR imaging. These advanced imaging techniques may provide additional information in evaluation of abnormal placental adherence and new insights into placental pathophysiology in selected patients. Online supplemental material is available for this article. ©RSNA, 2017.

Positive oral contrast agents, including barium suspensions and water-soluble iodinated solutions, have traditionally been used in conjunction with the CT evaluation of patients with abdominal and pelvic pain. Due to continued advancements in CT technology, and due to increasing obesity and correspondingly a general increase in the intra-abdominal and intra-pelvic fat separating bowel loops in North American patients and in patients in other parts of the world over the past few decades, the ability of radiologists to accurately evaluate the cause of acute symptoms has substantially improved. Recent research and evolving imaging society guidelines/systematic reviews increasingly support performing CT scans of the abdomen and pelvis without the need for positive oral contrast in these types of adult patient populations, in most clinical situations. Increased patient throughput, patient preference, patient safety, and most importantly, retention of high diagnostic accuracy, are reasons for this recent change in practice to routinely omit the use of enteric contrast agents for the majority of patients presenting with acute abdominal and pelvic pain whom are undergoing emergency CT.

While pelvic congestion syndrome and chronic pelvic pain are relatively common in women, no large- or medium-sized studies have been conducted to our knowledge to evaluate the frequency and severity of ovarian vein dilatation (OVD) on computed tomography (CT). The purpose of our study was therefore to analyze a large number of consecutive abdominal and pelvic CT scans in adult women to determine OVD frequency and severity.An IRB-approved, single-institution retrospective analysis of 1042 consecutive abdominal and pelvic CT scans in women ages 25-65 was performed. Scans were evaluated for the presence and severity of OVD and association with "nutcracker anatomy." A gradation scheme was developed based on quartile analysis.143 of the CT scans had OVD (13.7%). Of the positive scans, 96 were bilateral, 29 were left-side only, 18 were right-side only, and 18 had nutcracker-type compression of the left renal vein (14.4% of scans with left or bilateral OVD). In positive scans, the mean and median left OVD were 7.5 and 7 mm, respectively, and right-side were 7.2 and 7 mm, respectively. Based on quartile analysis, OVD grading was mild ( 6 mm), moderate (6-8 mm), or severe ( 8 mm), with moderate including the middle 50% of patients.OVD was found on 13.7% of 1042 consecutive female abdominal and pelvic CT scans, with "nutcracker anatomy" present in 14.4% of the scans with left OVD. Moderate dilatation was defined as an OVD of 6-8 mm at the iliac crests.

Obesity is a growing problem around the world, and radiology departments frequently encounter difficulties related to large patient size. Diagnosis and management of suspected venous thromboembolism, in particular deep venous thrombosis (DVT) and pulmonary embolism (PE), are challenging even in some lean patients, and can become even more complicated in the setting of obesity. Many obstacles must be overcome to obtain imaging examinations in obese patients with suspected PE and/or DVT, and to ensure that these examinations are of sufficient quality to diagnose or exclude thromboembolic disease, or to establish an alternative diagnosis. Equipment limitations and technical issues both need to be acknowledged and addressed. Table weight limits and scanner sizes that readily accommodate obese and even morbidly obese patients are not in place at many clinical sites. There are also issues with image quality, which can be substantially compromised. We discuss current understanding of the effects of patient size on imaging in general and, more specifically, on the imaging modalities used for the diagnosis and treatment of DVT and PE. Emphasis will be placed on the technical parameters and protocol nuances, including contrast dosing, which are necessary to refine and optimize images for the diagnosis of DVT and PE in obese patients, while remaining cognizant of radiation exposure. More research is necessary to develop consistent high-level evidence regarding protocols to guide radiologists, and to help them effectively utilize emerging technology.

There has been a substantial increase in the utilization of imaging, particularly of multi-detector computed tomography (MDCT), for the evaluation of patients with suspected urolithiasis over the past 2 decades. While the diagnostic accuracy of computed tomography (CT) for urolithiasis is excellent, it has also resulted in substantial medical expenditures and increased ionizing radiation exposure. This is especially concerning in patients with known nephrolithiasis and in younger patients. This pictorial review will focus on recent trends and controversies in imaging of patients with suspected urolithiasis, including the current roles of ultrasound (US), MDCT, and magnetic resonance imaging, the estimated radiation dose from MDCT and dose reduction strategies, as well as imaging of suspected renal colic in pregnant patients. The current epidemiological, clinical, and practice management literature will be appraised.

To determine the yield of non-contrast multi-detector computed tomography (MDCT) of the abdomen and pelvis in diagnosing ureteral calculi as well as other alternative acute conditions in male vs in female adult patients presenting to the emergency department with new onset of symptoms.Our institutional review board approved a retrospective review of the official reports of the non-contrast MDCT examinations of the abdomen and pelvis performed on adults (18 years and older) presenting to our emergency department with a suspected ureteral calculus from October 1, 2011 to October 30, 2013. Patients with recently documented ureteral calculi, known urinary tract infection, malignancy, and trauma were excluded from the study. From a total of 1097 non-contrast MDCT examinations of the abdomen and pelvis over the 2-year period, 400 randomly selected examinations were reviewed (approximately one-third of all the examinations). We compared the prevalence of ureteral calculi between the male and female population. P values and confidence intervals were determined using software Stata 14. Other acute intra-abdominal and intra-pelvic findings amenable to prompt medical care were also documented and analyzed separately.The mean patient age was 55.2 years, with a range of 19-90 years. This included 170 female (mean age 56.8 years) and 230 male patients (mean age 54.2 years). Ureteral calculi were detected in 170 (42.5%) of the patients [111 males (48%) and 59 females (34.7%)] with a prevalence which was statistically significantly higher in the male patients compared to in the female patients (P0.01, confidence level of 95% and CI of 13.2-13.4). An alternative diagnosis was made based on the MDCT findings in 49 patient cases (12.25 %), including 26 females (15.29%) and 23 males (10.00%). There was no statistically significant difference in alternative acute findings in male compared to in female patients (P0.05). This was with the exception of acute pyelonephritis, which was statistically significantly higher in the female patients (P0.01).The likelihood of making the diagnosis of a ureteral calculus on non-contrast MDCT of the abdomen and pelvis was statistically significantly higher in male patients compared with female patients presenting to our emergency department. However, there was no statistically significant difference in the alternative diagnoses, with the exception of pyelonephritis, which was more common in women.

Imaging examinations are often performed in patients with Legionnaires' disease. The literature to date has documented that the imaging findings in this disorder are relatively nonspecific, and it is therefore difficult to prospectively differentiate legionella pneumonia from other forms of pneumonia, and from other noninfectious thoracic processes. Through a review of clinical cases and the literature, our objective is for the reader to gain a better understanding of the spectrum of radiographic manifestations of Legionnaires' disease.

Aim To describe perigastric appendagitis (PA) on CT as a new and distinct clinical entity to enable recognition and prevent additional unnecessary investigation or intervention. Materials and methods Institutional review board approval was obtained and informed consent was waived. Retrospective review of the clinical data and CT findings in eight patients with PA encountered over 10 years at one institution was performed. The English literature was reviewed and summarized. Two experienced abdominal radiologists reviewed the CT images by consensus. Results Seven of eight patients had moderate to severe epigastric pain for 1–7 days. All eight patients (four men, four women; mean age 44 years, range 33–81 years) had no fever or leukocytosis. All underwent abdominal CT which showed ovoid fat inflammation along the course of the perigastric ligaments (gastrohepatic, gastrosplenic, and falciform). Two had gastric wall thickening. Although the inflammation was correctly described, the specific diagnosis was not made on initial interpretation in five patients. Subsequently, they underwent further diagnostic testing [an upper gastrointestinal examination and hepatobiliary iminodiacetic acid (HIDA) cholescintigraphy, an upper endoscopy and MRI examination, HIDA cholescintigraphy, another CT, and an MRI examination, respectively]. The HIDA cholescintigraphy, upper GI examination, and upper endoscopy examinations were normal. No repeated examination was performed on the other three patients. Pain resolved spontaneously in all within two days. Conclusion Perigastric appendagitis can present with an acute abdomen, which is safely managed conservatively if diagnosed correctly. Radiologists should be aware of the entity to avoid unnecessary intervention, and recognize the CT findings of ovoid fat inflammation in the distribution of the perigastric ligaments.

Primary peritoneal mesothelioma is a rare neoplasm which carries a dismal prognosis. These highly aggressive tumors arise from mesothelial cells lining the peritoneum and are rapidly fatal. The neoplasm is typically associated with crocidolite asbestos exposure. We present the case of a 75-year-old man with primary peritoneal mesothelioma, with invasion into the right hepatic lobe.

Sonography is the primary imaging modality for the evaluation of pelvic pain in female patients, especially if gynaecological pathology is suspected. However, computed tomography (CT) is frequently used in patients who present to emergency departments (and elsewhere) with otherwise nonspecific abdominal and pelvic pain and may be the first imaging modality to demonstrate an acute gynaecological abnormality. Computed tomography can also be used prospectively in selected patients to further evaluate findings initially identified on sonography, although to reduce radiation exposure, magnetic resonance imaging is being used more frequently in this situation. The purpose of this article is to discuss the spectrum of gynaecological findings of the acute female pelvis that may be identified on CT by the emergency radiologist and by the general radiologist, with a brief review of the imaging literature of each specific diagnosis.

The purpose of this article is to familiarize radiologists and clinicians with a subset of common and uncommon incidental findings on abdominal and pelvic computed tomography examinations, including hepatic, splenic, renal, adrenal, pancreatic, aortic/iliac arterial, gynecological, and a few other miscellaneous findings, with an emphasis on "incidentalomas" discovered in the emergency setting. In addition, we will review the complex problem of diagnosing such entities, and provide current management recommendations. Representative case examples, which we have encountered in our clinical practices, will be demonstrated.

The placenta has a fundamental role in fetal health and functions as an important bridge to normal fetal development throughout pregnancy. A complete fetal ultrasound (US) survey should include full assessment of the placenta for any possible abnormalities. Placental diseases range from abnormal morphology, size, location, extent, and degree of placentation, to abruption and the presence of rare placental neoplasms of benign or malignant nature. Some of these conditions are associated with other diseases including aneuploidies, and their discovery should alert the radiologist to perform a very thorough fetal US examination. At times, a fetal karyotype may be needed to provide additional information. Timely detection of placental abnormalities can alert the clinician regarding the need to make important management decisions to reduce fetal and maternal morbidity and mortality. Familiarity with the normal and abnormal imaging appearance of the placenta is therefore necessary for the radiologist. Ultrasound with Doppler is the initial imaging modality of choice for placental assessment. Magnetic resonance imaging serves as a problem-solving examination in instances where the US findings are equivocal or where additional information is needed. Computed tomography has a limited role in the evaluation of placental disease because of its relatively limited tissue characterization and in particular because of the resultant direct radiation exposure of the fetus. However, in specific instances, particularly after trauma, computed tomography can provide invaluable information for patient management.

Implantation of an endometriotic lesion within a pelvic or abdominal wall scar is an uncommon but well-described condition that may be the underlying cause of acute or chronic recurrent abdominal or pelvic pain, especially after cesarean section. Radiologists may not consider scar endometriosis when it is encountered at cross-sectional imaging. Cesarean section scars are the most common site of extraovarian or extrauterine endometriosis. The condition also has been identified in other uterine surgery-related scars and in the skin, subcutaneous tissues, and abdominal and pelvic wall musculature adjacent to these scars. The most plausible cause of scar endometriosis is implantation of endometrial stem cells at the surgical site at the time of uterine surgery. Patients with scar endometriosis may be asymptomatic or present with cyclical pain corresponding to the menstrual cycle. Cross-sectional imaging findings vary from the nonspecific to those suggestive of the diagnosis when combined with clinical history. In particular, the presence of blood products in an anterior abdominal wall mass at magnetic resonance (MR) imaging with no other explanation is strongly suggestive of scar endometriosis. Ultrasonography, computed tomography, and MR imaging may be used to depict an endometriotic lesion, exclude endometriosis, or provide evidence for an alternative diagnosis.

A broad spectrum of skin and subcutaneous (SQ) findings may be discovered in the emergency setting on CT examinations. There are some findings that are directly relevant to the reason or reasons why the patient has undergone the CT examination. However, other findings may be incidental. The skin and SQ tissues are by definition on the periphery of CT images and may be overlooked by the radiologist, although findings related to them can be of clinical importance. The purpose of this pictorial essay is to present a broad spectrum of skin and subcutaneous findings which may be identified on CT examinations in the emergency setting (and in some cases nonemergently), and to briefly review the relevant imaging literature, which surprisingly is relatively limited on this topic. Categories of cutaneous and subcutaneous abnormalities that will be covered include trauma and hemorrhage, iatrogenic findings, infection, neoplasms, calcification, and other miscellaneous entities, all of which may initially present on emergency CT examinations of the body.

We present a case of a 62-year-old man with a history of type II diabetes mellitus who presented to our emergency department with back pain and right upper quadrant abdominal pain associated with vomiting and weight loss. A computed tomographic scan of the abdomen and pelvis demonstrated a large adrenal mass, and subsequent biopsy showed primary adrenal lymphoma.

We present an 80-year-old man with multiple medical problems, and acute abdominal pain with feculent emesis. An unenhanced CT examination of the abdomen and pelvis demonstrated jejunal diverticulitis and findings of high-grade small bowel obstruction caused by a large enterolith. Enterolith ileus has rarely been reported in the radiology literature. This phenomenon has occasionally been reported in the surgical and gastroenterology literature. We highlight the CT findings associated with enterolith ileus in the setting of jejunal diverticulitis, to alert radiologists to this unusual diagnosis.

The purpose of this article is to retrospectively review the radiologic and clinical findings in patients with angiotensin-converting enzyme inhibitor (ACEI)-induced small-bowel angioedema, with an emphasis on CT findings.Imaging findings, with an emphasis on CT, and clinical characteristics of 20 patients (23 presentations) presenting to two institutions' emergency departments from 1996 through 2010 with ACEI-induced small-bowel angioedema were retrospectively reviewed by two abdominal radiologists who were aware of the diagnosis. Examinations were reviewed in consensus to determine common radiographic findings.Patient age range was 23-83 years (mean, 56 years). Sixteen of the 20 patients were women, and 15 of 20 were obese. All had acute onset of severe abdominal pain. The date of the initial episode prompting CT evaluation ranged from 2 days to 10 years after the start of ACEI therapy (average, 3.3 years). All patients underwent abdominal CT examinations while symptomatic; five patients also underwent a small-bowel series. Three patients underwent urgent surgery for presumed small-bowel ischemia. All patients had resolution of symptoms within 4 days of hospitalization. CT findings included ascites in all patients, small-bowel wall thickening (mean, 1.3 cm), mild dilatation (mean, 2.9 cm), and straightening. There was no small-bowel obstruction.ACEI-induced small-bowel angioedema should be included in the differential diagnosis when patients receiving ACEI therapy present with abdominal complaints and the following combination of findings on CT examination: ascites, small-bowel wall thickening, dilatation without obstruction, and straightening.

Colorectal cancer remains one of the most common causes of cancer death in this country. This malignancy is ideally suited for screening because the detection and removal of the precursor adenomatous polyp can prevent most colorectal cancers from ever forming. The choice of a test for screening involves consideration of various individual parameters, including patient age and the presence of risk factors for the development of colorectal cancer. Computed tomographic colonography (CTC) has emerged as the leading imaging technique for colorectal cancer screening in average-risk individuals on the basis of the evidence presented in this paper. The double-contrast barium enema is an alternative imaging test that is appropriate particularly when CTC is not available. In 2008, the American Cancer Society guideline for colorectal cancer screening was revised jointly with the US Multi-Society Task Force on Colorectal Cancer and the ACR to include CTC every 5 years as an option for average-risk individuals. Computed tomographic colonography is also the preferred test for colon evaluation after an incomplete colonoscopy. Imaging tests including CTC and the double-contrast barium enema are usually not indicated for colorectal cancer screening in high-risk patients with polyposis syndromes or inflammatory bowel disease. This paper presents the new colorectal cancer imaging test ratings and is the result of evidence-based consensus by the ACR Appropriateness Criteria ® Expert Panel on Gastrointestinal Imaging.

OBJECTIVE. The objectives of our study were to illustrate normal pancreatic anatomy using endoscopic ultrasound and to show the imaging findings of solid pancreatic masses on endoscopic ultrasound and CT.CONCLUSION. CT and endoscopic ultrasound have complementary roles in the diagnosis of solid pancreatic masses.

Lemierre Syndrome (LS) is relatively rare, and its clinical features are potentially confusing. Without proper therapy, LS is associated with significant morbidity and is potentially fatal. Recognition of the imaging features of LS in the chest and the neck may permit a timely diagnosis and lead to prompt institution of appropriate therapy. The emergency imaging features of LS in five cases are reviewed with emphasis on computed tomography of the chest and neck.

Pancreatic cysts include inflammatory lesions, low-grade neoplasms, and malignant neoplasms. Cystic neoplasms may prompt investigation because of symptoms such as abdominal pain, distension, jaundice, or nausea, but they are usually incidentally discovered. In the older literature, pseudocysts related to acute and chronic pancreatitis accounted for the majority of pancreatic cysts, but it is difficult to differentiate pancreatic cystic neoplasms from pseudocysts even with high-resolution modalities including computed tomography (CT) and magnetic resonance imaging (MRI) scans. Additionally, the more recent literature has shown that small pancreatic cystic lesions are relatively common as incidental findings on cross-sectional imaging examinations that are performed for other reasons, typically in older patients without prior episodes of pancreatitis; these are often low-grade mucinous lesions or occasionally epithelial cysts. Endoscopic ultrasound with fine-needle aspiration has emerged as a prime modality in delineating such cystic lesions. There has been an exponential increase in the more recent literature regarding pancreatic cystic lesions. The purpose of this review article is to provide a concise overview of these pancreatic cystic lesions.

F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) has been shown to be useful in the evaluation of many tumors due to its high sensitivity and specificity. However, false-positive interpretations may occur from benign subcutaneous and cutaneous etiologies. At our institution we have encountered FDG-PET scans which demonstrated a variety of cutaneous and subcutaneous lesions including stomas, hernias, rhinophyma, dose infiltrations, physiologic muscle uptake, and tophaceous gout. Additionally, malignant cutaneous and subcutaneous malignant lesions may also demonstrate substantial F-18 FDG uptake on PET scans, including lymphoma, skin metastases, and melanoma. The purpose of this atlas article is to demonstrate and review key features of various cutaneous and subcutaneous lesions, both benign and malignant, which can result in hypermetabolism on FDG-PET or PET-CT scans.

OBJECTIVE. Associations between pleural and pericardial effusions have been described in malignancy and autoimmune disorders. Bacterial pneumonia is the most frequent cause of parapneumonic effusion; however, knowledge of the relationship between parapneumonic effusion and the presence of pericardial fluid in children is limited. We examined this relationship. METHODS. We performed a retrospective chart review of pediatric patients who were admitted to our institution during a 6-year period with a diagnosis of either parapneumonic effusion or empyema and who had undergone an echocardiogram, a computed tomography scan of the thorax, or both. All demographic, clinical, radiographic, and laboratory data of these patients were collected, and statistical analysis was done with Student's t tests and χ2 analyses. RESULTS. We reviewed the charts of 59 children with parapneumonic effusions. Forty-eight underwent 2-dimensional echocardiography, chest computed tomography scan, or both. Of these 48 patients, 54.2% (n = 26) were found to have a concomitant pericardial effusion. The majority of patients with pericardial effusions had left-sided pleural disease. Patients with pericardial effusions had more symptomatic days before hospitalization, lower pleural fluid albumin levels, elevated serum white blood cell counts, elevated pleural fluid white blood cell and absolute neutrophil counts, and an increased incidence of surgical intervention. One patient had evidence of hemodynamic compromise that required pericardiocentesis. CONCLUSIONS. We found a high incidence of pericardial effusions in pediatric patients with parapneumonic effusions. Leukocytosis, higher pleural fluid leukocyte and neutrophil counts, and a propensity for surgical intervention suggest a prognostic relationship between pericardial effusions and more severe parapneumonic disease. The majority of these pericardial collections resolve with treatment of the underlying pleural disease.

There is a wide variety of uncommon and unusual gastrointestinal causes of acute abdominal and pelvic pain that may be prospectively diagnosed on computed tomography. We demonstrate 10 such diagnoses and briefly review the current computed tomography and clinical literature on intussusception occurring beyond early childhood, small bowel obstruction from internal hernia, cecal volvulus, intramural small bowel hemorrhage, Boerhaave's syndrome, gastrointestinal luminal foreign bodies, small bowel diverticulitis, hemoperitoneum secondary to abdominal tumor; gallstone ileus, and gallbladder torsion. Radiologists and clinicians need to be aware of these disorders, particularly with the widespread utilization of computed tomography (CT) in the management of patients with acute abdominal pain.

OBJECTIVE. Our objective was to describe the CT features of spontaneous isolated celiac artery dissection in a series of six otherwise healthy patients with acute abdominal pain.CONCLUSION. Although once believed rare, isolated spontaneous celiac artery dissection should be considered in the diagnosis of acute abdominal pain, especially in middle-aged adults.

This study aims to review the imaging findings of distal (thoracic and abdominal) complications related to ventriculo-peritoneal (VP), ventriculo-pleural (VPL), and ventriculo-atrial (VA) cerebrospinal fluid (CSF) shunt catheter placement. Institution review board-approved single-center study of patients with thoracic and abdominal CSF catheter-related complications on cross-sectional imaging examinations over a 14-year period was performed. Clinical presentation, patient demographics, prior medical history, and subsequent surgical treatment were recorded. The presence or absence of CSF catheter-related infection and/or acute hydrocephalus on cross-sectional imaging was also recorded. There were 81 distal CSF catheter-related complications identified on 47 thoracic or abdominal imaging examinations in 30 patients (age 5-80 years, mean 39.3 years), most often on CT (CT = 42, MRI = 1, US = 4). Complications included 38 intraperitoneal and 11 extraperitoneal fluid collections. Extraperitoneal collections included nine abdominal wall subcutaneous (SC) pseudocysts associated with shunt migration and obesity, an intrapleural pseudocyst, and a breast pseudocyst. There were also two large VPL-related pleural effusions, a fractured catheter in the SC tissues, and a large VA shunt thrombus within the right atrium. Ten patients (33.3 %) had culture-positive infection from CSF or shunt catheter samples. Ten patients (33.3 %) had features of temporally related acute or worsening hydrocephalus on neuroimaging. In four of these patients, the detection of thoracic and abdominal complications on CT preceded and predicted the findings of acute hydrocephalus on cranial imaging. Thoracic and abdominal complications of CSF shunts, as can be identified on CT, include shunt infection and/or obstruction, may be both multiple and recurrent, and may be predictive of concurrent acute intracranial problems.

The purpose of our study was to retrospectively evaluate the prevalence and clinical relevance of positive abdominal and pelvic CT findings for patients 65 years of age and older, when compared with all other scanned adult Emergency Department (ED) patients, at a single tertiary care hospital. Our hypothesis was that there is an increased prevalence and clinical relevance of positive abdominal/pelvic CT findings in senior patients. A research ethics board-approved retrospective review of all adult patients who underwent an emergency CT of the abdomen and pelvis for acute nontraumatic abdominal and/or pelvic signs and symptoms was performed. Two thousand one hundred two patients between October 1, 2011, and September 30, 2013, were reviewed. Six hundred thirty-one patients were included in the65 group (298 men and 333 women; mean age 46, age range 18-64), and 462 were included in the65 group (209 men and 253 women; mean age 77.6, age range 65-99). Overall, there were more positive CT findings for patients65 (389 positive cases, 61.6 %) compared with the65 group (257 positive cases, 55.6 %), which was a statistically significant difference (p 0.03). Moreover, with the exception of complicated appendicitis cases, which were more common in the65 group, there were no statistically significant differences in the clinical/surgical relevance of the positive CT findings between the two groups. The findings of our retrospective study therefore refute our hypothesis that there is an increased prevalence of positive abdominal CT findings in patients65. This may be related to ED physicians at our institution being more hesitant to order CT examinations for the younger population, presumably due to radiation concerns. However, older patients in our series were more likely to present with complicated appendicitis, and a lower threshold for ordering CT examinations of the abdomen and pelvis in this patient population should therefore be considered.

With massive pulmonary embolism (PE) being the first or second leading cause of unexpected death in adults, protection against PE is critical in appropriately selected patients. The use of inferior vena cava (IVC) filters has increased over the years, paralleling the increased detection of deep venous thrombosis (DVT) and PE by improved and more available imaging techniques. The use of IVC filters has become very common as an alternative and/or as a supplement to anticoagulation, and these filters are often seen on routine abdominal CT, including in the emergency setting; therefore, knowledge of the normal spectrum of findings of IVC filters by the radiologist on CT is critical. Additionally, CT can be used specifically to identify complications related to IVC filters, and CT may alternatively demonstrate IVC filter-related problems which are not specifically anticipated clinically. With multiple available IVC filters on the US market, and even more available outside of the USA, it is important for the emergency and the general radiologist to recognize the different models and various appearances and positioning on CT, as well as their potential complications. These complications may be related to venous access, but also include thrombosis related to the filter, filter migration and penetration, and problems associated with filter deployment. With the increasing number of inferior vena cava filters placed and their duration within patients increasing over time, it is critical for emergency and other radiologists to be aware of these findings on CT.

Sclerosing hemangioma (SH) is a relatively rare, benign neoplasm of the lung. Although there are relatively characteristic imaging findings, biopsy remains the definitive diagnostic test. We report the radiology and pathology of a patient with a SH, with emphasis on the computed tomographic and (18)F-fluorodeoxyglucose positron emission tomography findings, and review the literature on this unusual tumor.

This article reviews the research to date, as well as our clinical experience from two institutions, on gadolinium-enhanced computed tomographic angiography (gCTA) for imaging the body. gCTA may be an appropriate examination for the small percentage of patients who would benefit from noninvasive vascular imaging, but who have contraindications to both iodinated contrast and magnetic resonance imaging. gCTA is more expensive than CTA with iodinated contrast, due to the dose of gadolinium administered, and gCTA has limitations compared with CTA with iodinated contrast, in that parenchymal organs are not optimally enhanced at doses of 0.5 mmol/kg or lower. However, in our experience, gCTA has been a very useful problem-solving examination in carefully selected patients. With the advent of 16-64 detector CT, in combination with bolus tracking, we believe that the overall dose of gadolinium needed for diagnostic CTA examinations, while relatively high, can be safely administered.

Carcinosarcomas are very uncommon tumors, which are comprised of both malignant epithelial and mesenchymal elements. They occur most commonly in the head and neck, respiratory tract, and female reproductive organs. In the gastrointestinal tract, they are most often found in the oropharynx, esophagus, and, to a lesser extent, in the stomach. Carcinosarcomas rarely originate from the colon, but when they do, they are extremely aggressive malignancies. We report the radiologic and pathologic findings of a patient with a carcinosarcoma believed to have arisen from the colon and which involved the adjacent mesentery and omentum.

We report the radiology and pathology of a pediatric patient with lymphomatoid granulomatosis (LG) and review the literature, with an emphasis on the radiological findings and on the small subset of pediatric patients with this rare condition.

Pulmonary embolism (PE) and deep venous thrombosis (DVT) are a continuum and are difficult to diagnose clinically. Combined CT venography and pulmonary angiography (CTVPA) is a single examination that combines multidetector CT pulmonary angiography (CTPA) and CT venography (CTV) of the abdomen, pelvis, and lower extremities, providing "one-stop shopping" for venous thromboembolism without additional venipuncture or i.v. contrast, and it adds only a few additional minutes to scanning time. CTVPA rapidly and accurately examines the deep veins, reveals the presence, absence, and extent of deep venous thrombosis, serves as a baseline, and helps guide patient management. Multiple investigators have reported a high degree of accuracy when CTV is compared with venous ultrasound. There are some pitfalls in image interpretation, especially with regard to mixing artifacts, and there are continuing controversies as to exactly which parts of the abdomen, pelvis, and legs should be scanned routinely, the ideal timing of CTV acquisition relative to contrast injection, and the slice thickness and gap, if any, that should be used.

We present the case of a 53-year-old woman after thyroidectomy with metastatic multifocal papillary carcinoma and encapsulated focal Hurthle cell carcinoma. Postoperatively, an I-131 whole-body scan revealed uptake in the low midline anterior neck. She was treated with 151.5 mCi of I-131. The 1-year follow-up I-131 whole-body scan revealed a new pelvic mass with I-131 uptake. Pelvic CT showed bilateral complex ovarian masses. She underwent surgical excision, revealing a right ovarian endometriotic cyst and a left ovarian cystadenofibroma, without thyroid tissue involvement. I-131 uptake in a cystadenofibroma is extremely rare and has been reported only once to our knowledge.

Ewing's sarcoma/primitive neuroectodermal tumor is a rare entity belonging to a family of neoplasms of neuroectodermal origin. These highly aggressive neoplasms overwhelmingly affect children and young adults. A quarter of Ewing's sarcomas occur principally in the soft tissues with primary involvement of the perinephric fat and kidney being exceptionally rare. We present a 38-year-old man with primary Ewing's sarcoma of the perinephric fat and kidney diagnosed 2 years earlier who subsequently developed an infiltrating left renal and perinephric mass.

The combination of computed tomographic (CT) venography and pulmonary angiography (CTVPA) was initially described in 1998 as a single comprehensive noninvasive imaging examination for suspected thromboembolic disease. It allowed the identification of pulmonary embolism as well as deep venous thrombosis (DVT) in the abdomen, pelvis, thighs, and calves. The venographic portion of CTVPA has now been studied by multiple researchers and has been shown to be an accurate imaging study for the thigh veins in comparison with lower extremity sonography. In contrast to sonography, however, CTVPA readily and rapidly permits evaluation of the inferior vena cava, the pelvic veins, the calf veins, and all of the superficial venous system. Complex venous anatomy can be surveyed, an additional sonographic study is not required, and only a few extra minutes and images are required over and above CT pulmonary angiography. A review of 957 recent cases of suspected pulmonary embolism examined with CTVPA revealed an overall 10.5% frequency of DVT, with a nearly equal distribution of thrombosis at the common femoral, superficial femoral, popliteal, and deep calf veins. Although a variety of protocols for CTVPA may be implemented, including a contiguous helical acquisition, obtaining 5- or 10-mm-thick images every 4 cm provides a high degree of accuracy and decreases overall radiation dose.

Rationale and Objectives The purpose of this study was to determine whether a simple rapid blood test can obviate computed tomography (CT) in a sizable percentage of patients suspected of having pulmonary embolism, based on the hypothesis that negative d -dimer results could eliminate any further search for pulmonary embolism. Materials and Methods At the authors' institution, 2,121 sequential patients underwent a whole-blood antibody agglutination test for cross-linked fibrin degradation products ( d -dimer). Of these patients, 844 had positive test results and were not further considered. A retrospective review included reports of all multisection combined CT venographic and pulmonary angiographic studies obtained within 48 hours of the d -dimer assay for the 1,277 patients with negative d -dimer results; 229 (18%) of these 1,277 patients underwent combined CT venography and pulmonary angiography, usually within 24 hours. Results Retrospective review of the imaging examinations that were discrepant with the d -dimer results revealed only three false-negative d -dimer results. Of the 229 patients in whom combined CT venography and pulmonary angiography was performed for suspected pulmonary embolism, 226 (98.7%) had no evidence of acute pulmonary embolism or deep venous thrombosis. The negative predictive value of a negative d -dimer result was therefore 98.7% (confidence interval, 96.2%–99.7%). Conclusion The d -dimer assay is a simple rapid blood test that is sensitive to the presence of acute thrombosis. Very few patients with negative results have acute deep venous thrombosis or pulmonary embolism, with combined CT venography and pulmonary angiography used as the reference standard.

Objectives. To determine the utility of hematuria testing in a large series of patients with suspected renal colic using unenhanced helical computed tomography (CT) as the reference standard. Methods. A retrospective review of the CT reports of all patients who underwent unenhanced helical CT for suspected renal colic at one institution during a 3.5-year period and who also underwent a formal microscopic urinalysis within 24 hours of the CT study was conducted. The sensitivity, specificity, positive predictive value, and negative predictive value of the presence of any blood on the urinalysis for renal colic were calculated. Results. Urolithiasis was present in 587 (62%) of the 950 patients, and 363 patients had negative examinations for renal colic, including 69 with significant alternative diagnoses in the latter group. Of the urinalyses, 492 were true-positive, 174 were true-negative, 189 were false-positive, and 95 were false-negative, yielding a sensitivity, specificity, positive predictive value, and negative predictive value of 84%, 48%, 72%, and 65%, respectively. Forty-six percent of the urinalysis results were negative for blood in the subset of patients with significant alternative diagnoses. Conclusions. The sensitivity of hematuria on microscopic urinalysis for renal colic using unenhanced CT as the reference standard was 84%, and the specificity and negative predictive value was low. The presence or absence of blood on urinalysis cannot be used to reliably determine which patients actually have ureteral stones.

The purpose of this study was to evaluate the clinical significance of the "flat cava" sign on abdominal CT scans in hospitalized patients without trauma.CT scans of the abdomen of 500 inpatients imaged for a wide variety of nontraumatic indications were retrospectively reviewed for a flat cava sign. Two radiologists measured the maximal anteroposterior and transverse diameters of the inferior vena cava at four predetermined levels. The medical records of the subset of patients with a flat cava sign--defined as a maximal transverse-to-anteroposterior ratio of 3:1 or greater at one or more of the four levels--were reviewed for evidence of hypovolemia or hypotension.Seventy patients (14%; 48 women, 22 men) had a flat inferior vena cava present on at least one of the four levels. Of these 70 patients, 21 had definite and three had possible clinical evidence of hypotension or hypovolemia. A flat cava sign isolated to only one level was seen in 22 of the 70 patients, most commonly at the level just below the renal veins, and only four of these 22 patients had evidence of hypotension or hypovolemia.Of the 500 inpatients, 14% had a flat cava sign on at least one of the four levels examined on abdominal CT scans. The majority of these patients with a flat cava sign did not have hypotension or evidence of hypovolemia, but a minority (30%) did.

The most common cause of acute right lower quadrant (RLQ) pain requiring surgery is acute appendicitis (AA). This narrative's focus is on imaging procedures in the diagnosis of AA, with consideration of other diseases causing RLQ pain. In general, Computed Tomography (CT) is the most accurate imaging study for evaluating suspected AA and alternative etiologies of RLQ pain. Data favor intravenous contrast use for CT, but the need for enteric contrast when intravenous contrast is used is not strongly favored. Radiation exposure concerns from CT have led to increased investigation in minimizing CT radiation dose while maintaining diagnostic accuracy and in using algorithms with ultrasound as a first imaging examination followed by CT in inconclusive cases. In children, ultrasound is the preferred initial examination, as it is nearly as accurate as CT for the diagnosis of AA in this population and without ionizing radiation exposure. In pregnant women, ultrasound is preferred initially with MRI as a second imaging examination in inconclusive cases, which is the majority.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

The rate of cesarean deliveries continues to rise, while the rate of vaginal delivery after cesarean birth continues to decline. Many women now tend to undergo multiple cesarean deliveries, and therefore the associated chronic maternal morbidities are of growing concern. Accurate diagnosis of these conditions is crucial in maternal and fetal well-being. Many of these complications are diagnosed by imaging, and radiologists should be aware of the type and imaging appearances of these conditions.

To determine the frequency and location of deep venous thrombosis at computed tomographic (CT) venography after CT pulmonary angiography in a large series of patients clinically suspected of having pulmonary embolism and to compare the accuracy of CT venography with lower-extremity venous sonography.Venous phase images were acquired from the diaphragm to the upper calves after completion of CT pulmonary angiography in 650 patients (373 women, 277 men; age range, 18-99 years; mean age, 63 years) to determine the presence and location of deep venous thrombosis. Results of CT venography were compared with those of bilateral lower-extremity venous sonography in 308 patients.A total of 116 patients had pulmonary embolism and/or deep venous thrombosis, including 27 patients with pulmonary embolism alone, 31 patients with deep venous thrombosis alone, and 58 patients with both. Among 89 patients with deep venous thrombosis, thrombosis was bilateral in 26, involved the abdominal or pelvic veins in 11, and was isolated to the abdominal or pelvic veins in four. In patients in whom sonographic correlation was available, CT venography had a sensitivity of 97% and a specificity of 100% for femoropopliteal deep venous thrombosis.Combined CT venography and pulmonary angiography can accurately depict the femoropopliteal deep veins, permitting concurrent testing for venous thrombosis and pulmonary embolism. CT venography also defines pelvic or abdominal thrombus, which was seen in 17% of patients with deep venous thrombosis.