Adjacent parenchymal abnormalities in peripheral bronchogenic carcinoma: correlation of thin-section CT with histology.

Our purpose is to correlate thin section CT of peripheral bronchogenic carcinomas with histologically detected lymphatic or vascular invasion. Retrospective 3-year database search revealed 186 surgical resections for primary bronchogenic carcinoma, of which 58 had available preoperative imaging performed at our institution. Cases with prior surgery, nonconfirmatory pathology, remote imaging, or central location were excluded, resulting in a study population of 42 patients, 25 men, 17 women, with a mean age of 69 years. Imaging with 1-3 mm collimation was performed within a mean of 32 days prior to surgery. Histologic diagnoses included adenocarcinoma (n = 24, 57%), squamous cell carcinoma (n = 13, 31%), large cell carcinoma (n = 4, 10%), and small cell carcinoma (n = 1, 2%), with a mean tumor size of 27 mm. Three radiologists blindly and independently recorded bronchovascular thickening, septal and nonseptal opacities, and the extent of each beyond tumor margins: 1) <5 mm, 2) 5-10 mm, and 3) >10 mm. Lymphangio-invasion was correlated with imaging findings, tumor size, and histology. Adjacent parenchymal abnormalities were recorded in 40 (95%) of 42 masses, with isolated nonseptal opacities representing the most frequent abnormality in 21 (50%), followed by bronchovascular thickening in 16 (38%), and septal opacities in 12 (29%). Lymphangio-invasion was present in 16 (38%) of cases. The frequency of lymphangio-invasion was highest (53%) in cases with 2 or more positive findings, and extension beyond 10mm from the tumor margin. This trend did not achieve statistical significance by ROC analysis. Lymphangio-invasion was positively correlated with tumor size, P =.03, but not histology.In conclusion, parenchymal abnormalities beyond tumor margins shown by CT may be due to lymphangio-invasion but imaging findings did not reliably distinguish cases with and without lymphangio-invasion.

Application of duplex US for characterization of endoleaks in abdominal aortic stent-grafts: report of five cases.

Endoleaks were detected with helical computed tomographic (CT) angiography in five patients after placement of an aortobiliac stent-graft. The leaks were subsequently evaluated with duplex ultrasonography (US) and, in four patients, with conventional aortography as well. CT angiography revealed a total of seven endoleaks, all of which were prospectively classified as reconstitution (type II) leaks. Duplex US demonstrated six of the seven endoleaks. At duplex US, two of the leaks were characterized as attachment-site (type I) leaks; these two diagnoses were confirmed during subsequent angiography and profoundly altered clinical care. As an adjunct to CT angiography in evaluating endoleaks, duplex US provides hemodynamic information that enables further characterization of the type of endoleak and facilitates appropriate clinical care.

Is unenhanced CT sufficient for evaluation of acute abdominal pain?

BACKGROUND: To determine whether intravenous contrast improves the ability of radiologists to establish the cause of acute abdominal pain after nondiagnostic or normal unenhanced CT. METHODS: Out of 164 consecutive emergency department patients presenting with less than 48 h of nontraumatic, acute abdominal pain, a confident diagnosis for cause of pain was made prospectively in 71/164 (43%) patients on these unenhanced scans by the monitoring radiologist. In the other 93 patients, our study sample, intravenous contrast-enhanced CT was obtained. At a later date, retrospectively, two experienced abdominal CT radiologists independently evaluated unenhanced CT scans alone for potential causes of pain and diagnostic confidence level on a 1-3 scale. At least 2 weeks later, intravenous enhanced and unenhanced scans were read side-by-side for the same assessment. RESULTS: There was no significant difference in diagnostic confidence levels comparing unenhanced CT alone (2.59) vs. intravenous enhanced and unenhanced CT together (2.64). Chi-square analysis found no significant difference in finding a cause for pain when intravenous contrast was added compared to the initial unenhanced scan alone. CONCLUSIONS: Intravenous contrast did not significantly improve the ability of CT to establish a cause of abdominal pain after a negative or nondiagnostic unenhanced CT.

The endometrium on routine contrast-enhanced CT in asymptomatic postmenopausal women: avoiding errors in interpretation.

We studied 54 asymptomatic postmenopausal women to characterize normal contrast-enhanced computed tomography (CT) appearance of endometrium. Endometrium was visualized in 26 out of 54 (48.1%) women, and when seen its mean short-axis thickness was 7.5 mm. The anteroposterior thickness varied directly with uterine angulation (P<.05). Endometrial attenuation was significantly less than that of the myometrium (P<.05). Endometrial thickness (short axis) and attenuation were inversely correlated to patient age and to years after menopause (P<.05). We believe that our findings will help prevent overdiagnosis of endometrial fluid or thickening in asymptomatic women.

Chronic inflammatory appendiceal conditions that mimic acute appendicitis on helical CT.

OBJECTIVE: Acute appendicitis is commonly diagnosed on CT, but chronic appendiceal processes can mimic acute appendicitis. The purpose of this study was to identify the frequency of these alternative conditions and their findings on helical CT. CONCLUSION: Chronic inflammatory conditions other than acute appendicitis were found in 9% of patients who underwent surgery after CT findings were interpreted as suspicious for appendicitis. These inflammatory conditions were indistinguishable from acute appendicitis when we used either primary or secondary CT signs.