Karen M. Horton

Prevalence of unsuspected pancreatic cysts on MDCT.

OBJECTIVE Current generation MDCT technology facilitates identification of small, nonenhancing lesions in the pancreas. The objective of this study was to determine the prevalence of findings of unsuspected pancreatic cysts on 16-MDCT in a population of adult outpatients imaged for disease unrelated to the pancreas. MATERIALS AND METHODS Contrast-enhanced MDCT scans of the abdomen were reviewed from 2,832 consecutive examinations to identify pancreatic cysts. Patients with a history of pancreatic lesions or predisposing factors for pancreatic disease or who were referred for pancreatic CT were excluded. RESULTS A total of 73 patients had pancreatic cysts, representing a prevalence of 2.6 per 100 patients (95% CI, 2.0-3.2). Cysts ranged in size from 2 to 38 mm (mean, 8.9 mm) and were solitary in 85% of cases. Analysis of demographic information showed a strong correlation between pancreatic cysts and age, with no cysts identified among patients under 40 years and a prevalence of 8.7 per 100 (95% CI, 4.6-12.9) in individuals from 80 to 89 years. After controlling for age, cysts were more common in individuals of the Asian race than all other race categories, with an odds ratio of 3.57 (95% CI, 1.05-12.13). There was no difference by sex in the prevalence of cysts (p = 0.527); however, cysts were on average 3.6 mm larger (p = 0.014) in men than women. CONCLUSION In this outpatient population, the prevalence of unsuspected pancreatic cysts identified on 16-MDCT was 2.6%. Cyst presence strongly correlated with increasing age and the Asian race.

Application of CT in the investigation of angiogenesis in oncology

Tumor angiogenesis is the process by which new blood vessels are formed from the existing vessels in a tumor to promote tumor growth (1). Although angiogenesis is essential for tumor growth and metastasis, tumorigenesis and malignant transformation of the tumor are not dependent on angiogenesis. Angiogenesis is a complex process that is mediated by several angiogenic and antiangiogenic factors produced by the tumor cells, the blood, and the stroma of the host tissue (1-3). The balance in the production of these factors can help predict when angiogenesis will develop; angiogenesis develops when the proangiogenic factors overcome the antiangiogenic factors. The process of angiogenesis includes endothelial proliferation, breakdown of basement membranes of the capillaries, endothelial cell migration into the extravascular space in the stroma, formation of capillary tubes, communication with the postcapillary venules, and blood flow through the new blood vessels (4-7). Tumor angiogenesis is characterized morphologically by an increase in the number of blood vessels, including new capillaries, capillary sprouts, nonendothelialized capillaries, and arteriovenous shunts (5-9). Some of these vessels mal-

Prevalence of Significant Noncardiac Findings on Electron-Beam Computed Tomography Coronary Artery Calcium Screening Examinations

Background—Screening electron-beam computed tomography (EBCT) examinations for the detection and quantification of coronary artery calcification are being performed throughout the country. In addition to information about the heart, great vessels, and coronary arteries, these examinations include portions of the lungs, bony thorax, and upper abdomen. The purpose of this study was to determine the prevalence of significant noncardiac findings in a series of patients undergoing coronary artery calcification screening studies with EBCT scanning. Methods and Results—Between January 1, 2001, and October 1, 2001, 1326 consecutive patients underwent coronary artery calcification screening with EBCT (3-mm-thick slices were obtained at 3-mm intervals). Two board-certified radiologists reviewed the examinations on a workstation using standard mediastinal windows, lung windows, and bone windows. Significant extracardiac abnormalities were noted. Of 1326 patients, 103 (7.8%) had significant extracardiac pathology requiring clinical or imaging follow-up. These included 53 patients with noncalcified lung nodules <1 cm, 12 patients with lung nodules ≥1 cm, 24 patients with infiltrates, 7 patients with indeterminate liver lesions, 2 patients with sclerotic bone lesions, 2 patients with breast abnormalities, 1 patient with polycystic liver disease, 1 patient with esophageal thickening, and 1 patient with ascites. Conclusions—In this study, 7.8% of patients undergoing screening EBCT examinations for coronary artery calcification were found to have important extracardiac pathology requiring additional work-up. Therefore, it is essential that a radiologist review the entire examination.

The current status of multidetector row CT and three-dimensional imaging of the small bowel

Radiologists have played an important role in evaluation of patients with small bowel pathology. The small bowel series and, later, enteroclysis were the mainstays in radiologic diagnosis of many small bowel diseases, because the resolution and speed of CT was limited. Continued improvements in CT technology over the last 2 decades have resulted in a expanding role of CT for evaluation of the gastrointestinal tract, including the small intestine. Many conditions, such as small bowel obstruction and ischemia, that would traditionally be imaged with other modalities (small bowel series or angiography) are now routinely imaged with CT. The development of MDCT and improvements in 3D imaging systems have greatly improved the ability to examine the small bowel and mesenteric vasculature. With the introduction of new CT oral contrast agents and faster 32-detector row CT scanners, the diagnosis and evaluation of patients with small bowel disease will continue to improve.

MDCT of Intraductal Papillary Mucinous Neoplasm of the Pancreas: Evaluation of Features Predictive of Invasive Carcinoma

OBJECTIVE The purpose of our study was to evaluate factors predictive of the presence of invasive carcinoma associated with intraductal papillary mucinous neoplasm (IPMN) of the pancreas on MDCT. MATERIALS AND METHODS Preoperative MDCT of 36 consecutive patients (23 men, 13 women; mean age, 66.6 years) who had undergone surgical resection and had a pathologic diagnosis of IPMN were retrospectively assessed. CT was performed with a 4-MDCT scanner with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Arterial and venous phase images were acquired at 25 and 50-60 sec from the start of IV contrast administration. Type of ductal involvement, location, tumor size in branch duct type and combined type lesions, caliber of the main pancreatic duct, caliber of the common bile duct or common hepatic duct, and solid appearance of the lesion were assessed on CT and correlated with pathologic findings for invasive carcinoma. RESULTS Pathologic analysis revealed carcinoma in situ in seven patients (19%) and invasive carcinoma in 15 patients (42%) arising from the IPMN. With invasive carcinoma, the size of the tumor in branch duct type and combined type, and the caliber of the main pancreatic duct were significantly larger compared with the lesions without invasive carcinoma (4.7 +/- 1.7 cm vs 2.6 +/- 1.4 cm [p = 0.0007] and 9.3 +/- 5.5 mm vs 4.6 +/- 4.1 mm [p = 0.006], respectively). A solid mass (p < 0.001), dilatation of the common bile duct or common hepatic duct (> or = 15 mm), and the presence of a stent (p = 0.0004) were correlated with the presence of associated invasive carcinoma. CONCLUSION MDCT helped to predict invasive carcinoma associated with IPMN.

Adrenal Mass Imaging with Multidetector CT: Pathologic Conditions, Pearls, and Pitfalls

The adrenal gland is involved by a range of neoplasms, including primary and metastatic malignant tumors; however, the most common tumor detected is the incidental benign adenoma. Although computed tomographic (CT) findings will not always yield a definitive diagnosis, attention to these findings provides a road map to guide image interpretation. Adenomas typically demonstrate rapid washout, which is defined as an absolute percentage washout (APW) of more than 60% and a relative percentage washout (RPW) of more than 40% on delayed images. Adrenocortical carcinoma typically has an RPW of less than 40%; however, large size and heterogeneity are more reliable indicators of the diagnosis than are washout values. Washout characteristics of pheochromocytoma are variable; in conjunction with high levels of dynamic enhancement, pheochromocytomas may mimic adenoma (ie, APW > 60%, RPW > 40%). Myelolipomas appear as well-defined masses with variable quantities of fat and soft tissue. After contrast material administration, metastases usually demonstrate slower washout on delayed images (APW < 60%, RPW < 40%) than do adenomas, although hypervascular metastases may enhance similarly to pheochromocytoma. Finally, a number of nonadrenal pathologic conditions have been reported to mimic adrenal masses at CT.

Thalidomide for the Treatment of Cough in Idiopathic Pulmonary Fibrosis: A Randomized Trial

BACKGROUND Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal disorder of unknown cause with no effective treatment. Cough affects up to 80% of patients with IPF, is frequently disabling, and lacks effective therapy. OBJECTIVE To determine the efficacy of thalidomide in suppressing cough in patients with IPF. DESIGN 24-week, double-blind, 2-treatment, 2-period crossover trial. (ClinicalTrials.gov registration number: NCT00600028) SETTING 1 university center. PARTICIPANTS 98 participants were screened, 24 were randomly assigned, 23 received treatment (78.3% men; mean age, 67.6 years; mean FVC, 70.4% predicted), and 20 completed both treatment periods. MEASUREMENTS The primary end point was cough-specific quality of life measured by the Cough Quality of Life Questionnaire (CQLQ). Secondary end points were visual analogue scale of cough and the St. Georges Respiratory Questionnaire (SGRQ). For all measures, lower scores equaled improved cough or respiratory quality of life. RESULTS CQLQ scores significantly improved with thalidomide (mean difference vs. placebo, -11.4 [95% CI, -15.7 to -7.0]; P < 0.001). Thalidomide also significantly improved scores on the visual analogue scale of cough (mean difference vs. placebo, -31.2 [CI, -45.2 to -17.2]; P < 0.001). In participants receiving thalidomide, scores from the total SGRQ, SGRQ symptom domain, and SGRQ impact domain improved compared with those of participants receiving placebo. Adverse events were reported in 74% of patients receiving thalidomide and 22% receiving placebo; constipation, dizziness, and malaise were more frequent with thalidomide. LIMITATION This was a single-center study of short duration and small sample size focused on symptom-specific quality of life. CONCLUSION Thalidomide improved cough and respiratory quality of life in patients with IPF. A larger trial is warranted to assess these promising results. PRIMARY FUNDING SOURCE Celgene Corporation.

Clinicopathological characteristics and molecular analyses of multifocal intraductal papillary mucinous neoplasms of the pancreas.

Objective: To examine the clinicopathologic features and clonal relationship of multifocal intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. Background: Intraductal papillary mucinous neoplasms are increasingly diagnosed cystic precursor lesions of pancreatic cancer. Intraductal papillary mucinous neoplasms can be multifocal and a potential cause of recurrence after partial pancreatectomy. Methods: Thirty four patients with histologically documented multifocal IPMNs were collected and their clinicopathologic features catalogued. In addition, thirty multifocal IPMNs arising in 13 patients from 3 hospitals were subjected to laser microdissection followed by KRAS pyrosequencing and loss of heterozygosity (LOH) analysis on chromosomes 6q and 17p. Finally, we sought to assess the clonal relationships among multifocal IPMNs. Results: We identified 34 patients with histologically documented multifocal IPMNs. Synchronous IPMNs were present in 29 patients (85%), whereas 5 (15%) developed clinically significant metachronous IPMNs. Six patients (18%) had a history of familial pancreatic cancer. A majority of multifocal IPMNs (86% synchronous, 100% metachronous) were composed of branch duct lesions, and typically demonstrated a gastric-foveolar subtype epithelium with low or intermediate grades of dysplasia. Three synchronous IPMNs (10%) had an associated invasive cancer. Molecular analysis of multiple IPMNs from 13 patients demonstrated nonoverlapping KRAS gene mutations in 8 patients (62%) and discordant LOH profiles in 7 patients (54%); independent genetic alterations were established in 9 of the 13 patients (69%). Conclusions: The majority of multifocal IPMNs arise independently and exhibit a gastric-foveolar subtype, with low to intermediate dysplasia. These findings underscore the importance of life-long follow-up after resection for an IPMN.

Multidetector-row computed tomography and 3-dimensional computed tomography imaging of small bowel neoplasms: current concept in diagnosis.

The diagnosis of small bowel neoplasms can present a difficult challenge to the radiologist because the tumors are uncommon, often small, and may be difficult to detect radiographically. The most common small bowel neoplasms include adenocarcinoma, carcinoid, lymphoma, and gastrointestinal stromal tumors. The location and computed tomography (CT) appearance of the small bowel tumors may aid in the diagnosis. For instance, small bowel adenocarcinoma occurs more frequently in the duodenum and may result in obstruction. Carcinoid tumors are more common in the ileum and are typically hypervascular submucosal masses that produce a characteristic mesenteric mass when they spread to the mesenteric nodes. Lymphoma can occur anywhere along the gastrointestinal tract and have a variable CT appearance. It may appear as a single mass, multiple masses, an infiltrating lesion resulting in aneurysmal dilatation of the bowel, or as an exophytic mass. Gastrointestinal stromal tumors are more common in the jejunum and ileum and usually appear exophytic and bulky often with ulceration. Traditionally, small bowel series and enteroclysis have been used for imaging patients with suspected small bowel tumors. More recently, CT is beginning to play a more important role for this clinical indication. The thinner collimation possible with multidetector CT (MDCT) along with water as oral contrast and a good intravenous contrast bolus may improve the sensitivity of CT for detecting small bowel tumors. In addition, MDCT scanners improve the quality of the 3-dimensional CT (3D CT) images that are valuable to the clinicians and surgeons for surgical planning. It is important for the radiologist to be familiar with the CT appearance of these neoplasms and the potential role of MDCT and 3D imaging in their diagnosis and surgical planning.

Predicting resectability of periampullary cancer with three-dimensional computed tomography.

The radiographic assessment of extent of tumor burden and local vascular invasion appears to be enhanced with three-dimensional computed tomography (3D-CT). The purpose of this study was to evaluate the impact of preoperative 3D-CT in determining the resectability of patients with periampullary tumors. Intraoperative findings from exploratory laparotomy were gathered prospectively from 140 patients who were thought to have periampullary tumors and were deemed resectable after undergoing preoperative 3D-CT imaging. CT findings were compared to intraoperative findings, and the accuracy of 3D-CT in predicting tumor resectability and, ultimately, the likelihood of obtaining a margin-negative resection were assessed. Of the 140 patients who were thought to have resectable periampullary tumors after preoperative 3D-CT, 115 (82%) were subsequently determined to have periampullary cancer. The remaining 25 patients had benign disease. Among the patients with periampullary cancer, the extent of local tumor burden involving the pancreas and peripancreatic tissues was accurately depicted by 3D-CT in 93 % of the patients. 3D-CT was 95% accurate in determining cancer invasion of the superior mesenteric vessels. Preoperative 3D-CT accurately predicted periampullary cancer resectability and a margin-negative resection in 98% and 86% of patients, respectively. For patients with pancreatic adenocarcinoma (n=85), preoperative 3D-CT resulted in a resectability rate and a margin-negative resection rate of 79% and 73%, respectively. The ability of 3 D-CT to predict a margin-negative resection for periampullary cancer, including pancreatic adenocarcinoma, relies on its enhanced assessment of the extent of local tumor burden and involvement of the mesenteric vascular anatomy.