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ABSTRACT: To determine whether thromboembolic risk factor assessment could accurately indicate the pretest probability for pulmonary embolism (PE), and if so, computed tomographic (CT) angiography might be targeted more appropriately than in current usage, resulting in decreased costs and radiation exposure.
Institutional review board approval was obtained. Electronic medical records of 2003 patients who underwent CT angiography for possible PE during 1(1/2) years (July 2004 to February 2006) were reviewed retrospectively for thromboembolic risk factors. Risk factors that were assessed included immobilization, malignancy, hypercoagulable state, excess estrogen state, a history of venous thromboembolism, age, and sex. Logistic regressions were conducted to test the significance of each risk factor.
Overall, CT angiograms were negative for PE in 1806 (90.16%) of 2003 patients. CT angiograms were positive for PE in 197 (9.84%) of 2003 patients; 6.36% were Emergency Department patients, and 13.46% were inpatients. Of the 197 patients with CT angiograms positive for PE, 192 (97.46%) had one or more risk factors, of which age of 65 years or older (69.04%) was the most common. Of the 1806 patients with CT angiograms negative for PE, 520 (28.79%) had no risk factors. The sensitivity and negative predictive value of risk factor assessment in all patients were 97.46% and 99.05%, respectively. All risk factors, except sex, were significant in the multivariate logistic regression (P < .031).
In the setting of no risk factors, it is extraordinarily unlikely (0.95% chance) to have a CT angiogram positive for PE. This selectivity and triage step should help reduce current costs and radiation exposure to patients.
Radiology 08/2010; 256(2):625-32. · 5.73 Impact Factor
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Journal of the American Psychiatric Nurses Association 12/2009;
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Silvana C Faria,
Karthik Ganesan,
Irene Mwangi,
Masoud Shiehmorteza,
Barbara Viamonte,
Sameer Mazhar,
Michael Peterson,
Yuko Kono,
Cynthia Santillan, Giovanna Casola,
Claude B Sirlin
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ABSTRACT: Chronic liver disease is a major public health problem worldwide. Liver fibrosis, a common feature of almost all causes of chronic liver disease, involves the accumulation of collagen, proteoglycans, and other macromolecules within the extracellular matrix. Fibrosis tends to progress, leading to hepatic dysfunction, portal hypertension, and ultimately cirrhosis. Liver biopsy, the standard of reference for diagnosing liver fibrosis, is invasive, costly, and subject to complications and sampling variability. These limitations make it unsuitable for diagnosis and longitudinal monitoring in the general population. Thus, development of a noninvasive, accurate, and reproducible test for diagnosis and monitoring of liver fibrosis would be of great value. Conventional cross-sectional imaging techniques have limited capability to demonstrate liver fibrosis. In clinical practice, imaging studies are usually reserved for evaluation of the presence of portal hypertension or hepatocellular carcinoma in cases that have progressed to cirrhosis. In response to the rising prevalence of chronic liver diseases in Western nations, a number of imaging-based methods including ultrasonography-based transient elastography, computed tomography-based texture analysis, and diverse magnetic resonance (MR) imaging-based techniques have been proposed for noninvasive diagnosis and grading of hepatic fibrosis across its entire spectrum of severity. State-of-the-art MR imaging-based techniques in current practice and in development for noninvasive assessment of liver fibrosis include conventional contrast material-enhanced MR imaging, double contrast-enhanced MR imaging, MR elastography, diffusion-weighted imaging, and MR perfusion imaging.
Radiographics 10/2009; 29(6):1615-35. · 2.85 Impact Factor
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ABSTRACT: The purposes of this study were to determine the (1) frequency with which nonenhanced computed tomography (CT) (NECT) permits conclusive diagnosis of acute appendicitis, (2) accuracy of NECT when findings are conclusive, and (3) overall accuracy of a CT protocol consisting of NECT with selective use of contrast. Five hundred and thirty-six patients underwent a NECT protocol with selective use of contrast. Diagnostic accuracy was then determined separately for (1) patients with conclusive initial NECT, (2) patients with inconclusive initial NECT, and (3) all patients. NECT was conclusive on initial interpretation in 404/536 patients and inconclusive in 132/536. Of 132 inconclusive studies, 126 were repeated with contrast (intravenous, oral or rectal). Sensitivity, specificity, and positive and negative predictive value for diagnosis of acute appendicitis were (1) 90%, 96.0%, 84.8%, and 97.4% in patients with conclusive NECT (n = 404); (2) 95.6%, 92.3%, 73%, and 99% in patients with inconclusive NECT followed by repeat CT with contrast; and (3) 91.3%, 95%, 82%, and 98% in all patients. The initial diagnosis of appendicitis may be made by NECT in 75% of patients, with contrast administration reserved for inconclusive NECT studies.
European Radiology 09/2007; 17(8):2055-61. · 3.22 Impact Factor
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Radiology 12/2006; 241(2):627-8; author reply 628-9. · 5.73 Impact Factor
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ABSTRACT: To retrospectively determine the frequency and spectrum of findings and recommendations reported with whole-body computed tomographic (CT) screening at a community screening center.
This HIPAA-compliant study received institutional review board approval, with waiver of informed consent. The radiologic reports of 1192 consecutive patients who underwent whole-body CT screening of the chest, abdomen, and pelvis at an outpatient imaging center from January to June 2000 were reviewed. Scans were obtained with electron-beam CT without oral or intravenous contrast material. Reported imaging findings and recommendations were retrospectively tabulated and assigned scores. Descriptive statistics were used (means, standard deviations, and percentages); comparisons between subgroups were performed with univariate analysis of variance and chi(2) or Fisher exact tests.
Screening was performed in 1192 patients (mean age, 54 years). Sixty-five percent (774 of 1192) were men and 35% (418 of 1192) were women. Nine hundred three (76%) of 1192 patients were self referred, and 1030 (86%) of 1192 subjects had at least one abnormal finding described in the whole-body CT screening report. There were a total of 3361 findings, with a mean of 2.8 per patient. Findings were described most frequently in the spine (1065 [32%] of 3361), abdominal blood vessels (561 [17%] of 3361), lungs (461 [14%] of 3361), kidneys (353 [11%] of 3361), and liver (183 [5%] of 3361). Four hundred forty-five (37%) patients received at least one recommendation for further evaluation. The most common recommendations were for additional imaging of the lungs or the kidneys.
With whole-body CT screening, findings were detected in a large number of subjects, and most findings were benign by description and required no further evaluation. Thirty-seven percent of patients had findings that elicited recommendations for additional evaluation, but further research is required to determine the clinical importance of these findings and the effect on patient care.
Radiology 12/2005; 237(2):385-94. · 5.73 Impact Factor
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ABSTRACT: The aims of this study were to identify (1) the normal range of the appendix on computed tomography (CT), (2) the correlation of patient age and sex with the visibility and appearance of the appendix on CT, and (3) the normal variations in wall thickness, intraluminal content, and location of the appendix. Three hundred seventy-two outpatients underwent abdominopelvic CT. The scans were reviewed on the picture archiving and communication system and appendiceal outer-to-outer wall diameter, wall thickness, location, content and its correlation with appendix diameter were analyzed. The appendix was visualized in 305/372 patients. Its location relative to the cecum was highly variable. The diameter range was 3-10 mm; in 42% of cases the diameter was greater than 6 mm. When the intraluminal content (185/305) was visualized, the diameter was slightly superior to the mean (p=0.0156). In 329 CT scans in which oral contrast material was given, the appendix was filled by contrast material in 74/329 patients. The appendix wall thickness was measurable in 22/305 patients (average 0.15 cm). There is significant overlap between the normal and abnormal CT appearance of the appendix. Consequently the diagnosis of acute appendicitis should be based not only on the appearance of the appendix but also on the presence of secondary signs.
European Radiology 11/2005; 15(10):2096-103. · 3.22 Impact Factor
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ABSTRACT: To retrospectively identify and describe the imaging features that represent perivascular fatty infiltration of the liver.
The institutional review board approved the study and waived informed consent. The study complied with the Health Insurance Portability and Accountability Act. Ten patients (seven women, three men; mean age, 78 years; range, 31-78 years) with fatty infiltration surrounding hepatic veins and/or portal tracts were retrospectively identified by searching the abdominal imaging teaching file of an academic hospital. The patients' medical records were reviewed by one author. Computed tomographic (CT), magnetic resonance (MR), and ultrasonographic (US) imaging studies were reviewed by three radiologists in consensus. Fatty infiltration of the liver on CT images was defined as absolute attenuation less than 40 HU without mass effect and, if unenhanced images were available, as relative attenuation at least 10 HU less than that of the spleen; on gradient-echo MR images, it was defined as signal loss on opposed-phase images compared with in-phase images; and on US images, it was defined as hyperechogenicity of liver relative to kidney, ultrasound beam attenuation, and poor visualization of intrahepatic structures. Perivascular fatty infiltration of the liver was defined as a clear predisposition to fat accumulation around hepatic veins and/or portal tracts. For multiphase CT images, the contrast-to-noise ratio was calculated for comparison of spared liver with fatty liver in each imaging phase.
Fatty infiltration surrounded hepatic veins in three, portal tracts in five, and both hepatic veins and portal tracts in two patients. Six of the 10 patients had alcoholic cirrhosis, two reported regular alcohol consumption (one of whom had acquired immunodeficiency syndrome and hepatitis B), one was positive for human immunodeficiency virus, and one had no risk factors for fatty infiltration of the liver. In three of the 10 patients, fatty infiltration was misdiagnosed as vascular or neoplastic disease on initial CT images but was correctly diagnosed on MR images.
Perivascular fatty infiltration of the liver has imaging features that allow its recognition.
Radiology 11/2005; 237(1):159-69. · 5.73 Impact Factor
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ABSTRACT: To determine retrospectively the accuracy of screening ultrasonography (US) in patients with hypotension (systolic blood pressure <or= 90 mm Hg) after blunt abdominal trauma.
The investigational review board approved the study and waived informed consent. The study group consisted of 128 hypotensive patients with blunt abdominal trauma who underwent screening US over a 9-year period. Abdomens were scanned for free fluid and for parenchymal heterogeneity in visceral organs; scans that depicted these were considered positive. Prospective reports were used to calculate diagnostic performance. Patients were retrospectively given a fluid score according to the number of fluid pockets visualized (0, 1, or > or =2) (consensus by three readers) and were assigned to a low- or high-risk group according to the presence of hematuria and/or axial fracture on radiographs. Screening US results were compared with findings with the best available reference standard (computed tomography [CT]), repeat US, other diagnostic test, laparotomy, autopsy, clinical course). Data were compared by using chi(2) or Fisher exact test, depending on expected frequencies, with Bonferroni correction for multiple comparisons. Continuous variables were compared by using unpaired Student t test or Mann-Whitney U test, depending on data distribution.
The study included 77 male and 51 female patients (mean age, 42 years). Sensitivity was 85% (44 of 52) for detection of any injuries, 97% (30 of 31) for surgical injuries (ie, injuries requiring surgery), and 100% (10 of 10) for fatal injuries. Specificity was 96% (73 of 76), 82% (80 of 97), and 69% (81 of 118), and accuracy was 91% (117 of 128), 86% (110 of 128), and 71% (91 of 128), for respective injury categories. One nonfatal surgical injury was missed in a high-risk patient. For each injury category, frequency of injury in patients with a fluid score of 2 or more was nine times that in patients with a score of 0 (P < .001 for all comparisons). Frequency of false-negative US findings in high-risk patients was eight times that in low-risk patients (P < .01).
In patients who are hypotensive after blunt abdominal trauma and not hemodynamically stable enough to undergo diagnostic CT, negative US findings virtually exclude surgical injury, while positive US findings indicate surgical injury in 64% of cases.
Radiology 05/2005; 235(2):436-43. · 5.73 Impact Factor
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American Journal of Roentgenology 04/2005; 184(3 Suppl):S99-S101. · 2.78 Impact Factor
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ABSTRACT: The purpose of this study was to evaluate the accuracy of screening sonography for the detection of clinically significant abdominal injury in pregnant patients with blunt trauma.
We retrospectively reviewed the records of 5173 patients with blunt abdominal trauma who underwent screening sonography. Pregnant patients were identified, and the prospective sonographic interpretations were compared with surgical findings, computed tomography (CT), subsequent sonography, cystography, and the clinical course.
Of 1567 female patients with trauma, 947 were of reproductive age and, 102 (11%) of these 947 were pregnant. One patient was excluded because a truth standard was not available. Five (5%) of these 101 patients were found to have injuries at surgery. These injuries involved the placenta (2 injuries), spleen (2 injuries), liver (1 injury), and kidney (1 injury); all required surgery. Initial sonographic findings were positive in 4 of 5 patients with injuries. The missed injury was a placental injury detected 15 hours after screening sonography because of fetal bradycardia. After screening sonography, 6 patients underwent additional abdominal imaging: CT (3 patients), cystography (1 patient), and additional sonography (2 patients). Of 101 patients, 95 (94%) required no additional tests, and 97 (96%) required no test involving ionizing radiation. No pregnant patient underwent diagnostic peritoneal lavage. Sensitivity was 80% (95% confidence interval, 28%-100%), and specificity was 100% (96 of 96; 95% confidence interval, 96%-100%) for detecting major abdominal injury.
Sonography is an effective screening examination that can obviate more hazardous tests such as CT, cystography, and peritoneal lavage in most pregnant patients with trauma requiring objective evaluation of the abdomen.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 03/2005; 24(2):175-81; quiz 183-184. · 1.25 Impact Factor
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American Journal of Roentgenology 10/2004; 183(3):681-90. · 2.78 Impact Factor
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ABSTRACT: To assess clinical and surgical outcomes in patients with blunt abdominal trauma and negative screening ultrasonographic (US) scans.
From a database of 4,000 patients who underwent screening US for suspected blunt abdominal trauma at a level 1 trauma center, the authors retrospectively identified 3,679 patients with negative US findings. In these patients, outcome was determined by means of retrospective review of the trauma registry and all radiologic, surgical, and autopsy reports. In patients with false-negative findings at screening US, all imaging studies and medical charts were also reviewed. Proportions were statistically compared by means of the Pearson chi(2) and Fisher exact tests. Monte Carlo estimation was applied when expected frequencies were low.
Among the 3,679 patients with negative findings at screening US, 99.9% (n = 3,641) had no injuries (true-negative findings). Differences in true-negative rates as a function of year (P >.5) or time of day (P >.3) were not significant. Among the 3,641 patients with true-negative findings, 93.6% (n = 3,407) required no additional tests and 6.4% (n = 234) underwent computed tomography or other tests. The percentage of patients who underwent additional tests was significantly higher in the 1st year of the study (19.2%) than in subsequent years (all comparisons, P <.001). Thirty-eight patients had false-negative US findings for abdominal injury. The injuries that were missed in 24 patients were nonsurgical (those that were treated successfully without intervention or were considered minor at autopsy) and those in 14 patients were surgical (required surgical intervention). Cumulatively, 65 injuries were missed. The six most common injuries included retroperitoneal hematoma (n = 13) and injuries in the spleen (n = 10), liver (n = 9), kidney (n = 8), adrenal gland (n = 8), and small bowel (n = 7). Twenty-five of the 38 patients had no or trace hemoperitoneum. Mean diagnostic delay until recognition of missed injury was 16.8 hours +/- 4.3 (standard error of the mean). The missed injury was identified within 12 hours in 19 of the 38 patients and within 24 hours in 34.
The combination of negative US findings and negative clinical observation virtually excludes abdominal injury in patients who are admitted and observed for at least 12-24 hours.
Radiology 03/2004; 230(3):661-8. · 5.73 Impact Factor
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ABSTRACT: To determine the risk for missed injury in patients with blunt abdominal trauma and negative findings at screening ultrasonography (US) and with coexistent hematuria or fracture of the sixth through 12th ribs, lumbar spine, or pelvis.
From a database of 4,000 patients screened with US for blunt abdominal trauma at a level 1 trauma center, the 3,679 patients with negative US findings were retrospectively classified by consensus of two authors into high-risk (n = 494) and low-risk (n = 3,185) groups based on the presence of hypothetical predictors of missed injury: hematuria (n = 96) or fracture of the sixth through 12th ribs (n = 216), lumbar spine (n = 105), or pelvis (n = 174). Outcome in each patient was determined by the same two authors consensually after retrospective review of the trauma registry and all radiologic, surgical, and autopsy reports. The risk for missed abdominal injury was determined for each patient risk group and for each hypothetical predictor. Risks were statistically compared by using the Pearson chi2, Fisher exact, or Fisher-Freeman-Halton exact test, depending on expected frequencies.
High-risk patients were 24 times more likely to have abdominal injuries after negative US findings (30 [6.1%] of 494) than were low-risk patients (eight [0.25%] of 3,185) (P <.001). Among high-risk patients, the absolute risks for missed abdominal injury associated with specific predictors were 15.6% (15 of 96 patients) for hematuria, 6.0% (13 of 216) for lower rib fractures, 7.6% (eight of 105) for lumbar spine fractures, and 5.2% (nine of 174) for pelvic fractures. Each of these risks was significantly higher for patients in the high-risk group than for those in the low-risk group (P <.001).
Hematuria and fracture of the lower ribs, lumbar spine, or pelvis are objective predictors of missed abdominal injury in patients with blunt abdominal trauma and negative US findings, and such patients may benefit from additional screening with computed tomography.
Radiology 12/2003; 229(3):766-74. · 5.73 Impact Factor
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ABSTRACT: Contact dissolution with MTBE is an effective and safe method to treat symptomatic patients with cholesterol gallstones. Personnel, time, and safety factors have limited widespread use of the procedure. With current competing methods to treat gallstones, it is likely that MTBE use will be reserved for those patients who elect percutaneous therapy due to fear of surgery or anesthesia and in those elderly patients who are compromised by underlying medical conditions.
Seminars in Roentgenology 08/1991; · 0.66 Impact Factor
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Western Journal of Medicine 02/1990; 152(1):64-5.
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ABSTRACT: Fat accumulation is one of the most common abnormalities of the liver depicted on cross-sectional images. Common patterns include diffuse fat accumulation, diffuse fat accumulation with focal sparing, and focal fat accumulation in an otherwise normal liver. Unusual patterns that may cause diagnostic confusion by mimicking neoplastic, inflammatory, or vascular conditions include multinodular and perivascular accumulation. All of these patterns involve the heterogeneous or nonuniform distribution of fat. To help prevent diagnostic errors and guide appropriate work-up and management, radiologists should be aware of the different patterns of fat accumulation in the liver, especially as they are depicted at ultrasonography, computed tomography, and magnetic resonance imaging. In addition, knowledge of the risk factors and the pathophysiologic, histologic, and epidemiologic features of fat accumulation may be useful for avoiding diagnostic pitfalls and planning an appropriate work-up in difficult cases.
Radiographics 26(6):1637-53. · 2.85 Impact Factor
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ABSTRACT: Abdominal wall hernias are a common imaging finding in the abdomen and may be complicated by strangulation, incarceration, or trauma. Because of the risk of developing complications, most abdominal wall hernias are surgically repaired, even if asymptomatic. However, post-surgical complications are also common and include hernia recurrence, infected and noninfected fluid collections, and complications related to prosthetic material. Multi-detector row computed tomography (CT) with its multiplanar capabilities is particularly useful for the evaluation of unrepaired and surgically repaired abdominal wall hernias. Multi-detector row CT provides exquisite anatomic detail of the abdominal wall, thereby allowing accurate identification of wall hernias and their contents, differentiation of hernias from other abdominal masses (tumors, hematomas, abscesses), and detection of pre- or postoperative complications. These findings improve the communication of imaging results to clinicians and help optimize treatment planning. Knowledge of multi-detector row CT findings in unrepaired and surgically repaired abdominal wall hernias and their complications is essential for making the correct diagnosis and may help guide clinical management.
Radiographics 25(6):1501-20. · 2.85 Impact Factor
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ABSTRACT: The differential diagnosis of extrahepatic abdominopelvic masses is wide. Demonstration of fat within a lesion at noninvasive imaging is an important clue for narrowing the differential diagnosis. Macroscopic fat is readily identified with both computed tomography (CT) and magnetic resonance (MR) imaging. Demonstration of microscopic fat is more difficult and may require special techniques. Identification of fat with CT is based on x-ray resorption and therefore on the attenuation (typically less than -20 HU). Several MR imaging techniques have been developed for fat suppression. Two of the most widely available are spectroscopic fat saturation and chemical shift (in-phase/opposed-phase) imaging. Entities with predominantly macroscopic fat include myelolipoma, angiomyolipoma, teratoma, liposarcoma, lipoma, epiploic appendagitis, omental infarction, and mesenteric panniculitis. Lesions with predominantly microscopic fat include adrenal adenoma and some teratomas. Other fat-containing entities involve the mesentery and bowel wall; these include fibrofatty mesenteric proliferation and submucosal fat deposition.
Radiographics 25(1):69-85. · 2.85 Impact Factor
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ABSTRACT: Fat stranding adjacent to thickened bowel wall seen at computed tomography (CT) in patients with acute abdominal pain suggests an acute process of the gastrointestinal tract, but the differential diagnosis is wide. The authors observed "disproportionate" fat stranding (ie, stranding more severe than expected for the degree of bowel wall thickening present) and explored how this finding suggests a narrower differential diagnosis, one that is centered in the mesentery: diverticulitis, epiploic appendagitis, omental infarction, and appendicitis. The characteristic CT findings (in addition to fat stranding) of each of these entities often lead to a final diagnosis. Diverticulitis manifests with mild, smooth bowel wall thickening and no lymphadenopathy. Epiploic appendagitis manifests with central areas of high attenuation and a hyperattenuated rim, in addition to its characteristic location adjacent to the colon. In contrast, omental infarction is always centered in the omentum. The most specific finding of appendicitis is a dilated, fluid-filled appendix. Correct noninvasive diagnosis is important because treatment approaches for these conditions range from monitoring to surgery.
Radiographics 24(3):703-15. · 2.85 Impact Factor
