Dean D. T. Maglinte

Comparison of Endoscopic Ultrasonography and Multidetector Computed Tomography for Detecting and Staging Pancreatic Cancer

Context Clinicians often use multidetector computed tomography or endoscopic ultrasonography to detect and stage pancreatic cancer. Contribution This prospective study found that, among 80 adults with proven pancreatic cancer, the sensitivity of multidetector computed tomography and endoscopic ultrasonography for detecting a pancreatic mass was 86% (CI, 77% to 93%) and 98% (CI, 91% to 100%), respectively. Among 53 patients undergoing surgery, endoscopic ultrasonography was more accurate for staging local tumor spread, but both tests showed similar accuracy for nodal staging and detecting resectability. Cautions Optimal strategies to detect and stage pancreatic cancer may vary across sites depending on the expertise of radiologists and endosonographers. The Editors In the United States for the year 2003, it was estimated that pancreatic cancer would be diagnosed in approximately 30700 patients and contribute to 30000 deaths (1). Complete surgical removal with negative histologic margins (R0 resection) is an independent predictor of postoperative survival (2-4) and remains the only potential curative treatment for pancreatic cancer. At surgical exploration, however, only 5% to 25% of the tumors are amenable to resection (5-8). Therefore, the principle goal of preoperative evaluation is to identify patients with potentially resectable disease while avoiding surgical exploration in those with unresectable disease. There is no evidence-based consensus on the optimal preoperative imaging assessment of patients with suspected pancreatic cancer. Because of widespread availability, helical computed tomography (CT) is usually the initial study for this indication (9, 10). Dual-phase helical CT, during which postinjection contrast image acquisition is obtained in both the pancreatic (arterial) and portal venous phases, has improved detection rate and assessment of resectability in patients with suspected pancreatic cancer (11, 12). Current state-of-the-art CT imaging uses a multiple-row detector with narrow detector collimation, wide x-ray beam, and rapid table translation; these features offer faster acquisition and thinner image slices compared with single-detector CT (13-15). Whether multidetector CT offers improved detection and staging of pancreatic cancer, however, is unknown. Endoscopic ultrasonography has been shown to be superior to conventional CT for the detection (16-20) and staging (19, 20) of pancreatic cancer. When compared with helical CT, however, endoscopic ultrasonography is reported to be either equivalent for detection (21, 22) or superior for detection or staging (23-25). To date, no comparative studies of multidetector CT with other imaging tests, including endoscopic ultrasonography, for suspected pancreatic cancer have been performed. Therefore, we conducted a prospective trial to compare endoscopic ultrasonography and multidetector CT for the detection, staging, and resectability of suspected locoregional pancreatic cancer. Methods Patients The institutional review board at Indiana University Medical Center approved this study, and all patients signed written informed consent. Eligible patients were referred to our hospital with clinically suspected or recently diagnosed solid or cystic pancreatic cancer within the previous 8 weeks. The referral base for our hospital consists of gastroenterologists and surgeons from Indiana and the surrounding contiguous states. Patients were eligible only if they agreed to undergo endoscopic ultrasonography, CT, and surgery (if necessary) at our institution. Patients were excluded if they had previously undergone endoscopic retrograde cholangiopancreatography or endoscopic ultrasonography at our institution for suspected pancreatic cancer; declined or remained undecided about potential surgical intervention; were referred to our institution by surgeons outside our hospital system. Patients were also excluded if they were pregnant, were incarcerated, could not independently provide informed consent, or were considered high surgical risk (American Society of Anesthesiology class III to V). In addition, we excluded patients with known or suspected periampullary masses, cholangiocarcinomas, or cancer with suspected locally advanced arterial (superior mesenteric, hepatic, or celiac) involvement or metastatic disease (ascites, suspicious liver or pulmonary lesions, distant enlarged lymph nodes) detected by previous imaging studies. Patients with suspected nonocclusive involvement of the superior mesenteric vein or portal vein were considered eligible for enrollment. Study Design This was a prospective, single-center, observational study. All enrolled patients had to respond to an initial health and medical questionnaire, which was followed by same-day endoscopic ultrasonography. Computed tomography was performed within 1 week. Within 3 weeks after CT, a surgeon examined the patient and reviewed the results of endoscopic ultrasonography and CT to determine eligibility for potential resection. After surgery or the decision to pursue nonoperative management, we telephoned patients to assess quality of life at 1 month, 3 months, and every 6 months until death or until 24 months if clinical disease remained stable. Endoscopic Ultrasonography Technique Conscious sedation was performed with various combinations of intravenously administered propofol, meperidine, fentanyl, or midazolam. Initially, we examined all patients with a radial echoendoscope (Olympus GF-UM130 [Olympus America Inc., Melville, New York]). We then examined patients with a linear echoendoscope (using either Pentax FG-36UX [Pentax Precision Instruments, Orangeburg, New York] or Olympus GF-UC140P [Olympus America Inc.]). Unless cancer had been definitively confirmed previously, endoscopic ultrasonographyguided fine-needle aspiration was performed with a 22-gauge needle (Wilson-Cook Medical Inc., Winston-Salem, North Carolina) in all patients, when applicable. A cytotechnologist or cytopathologist was on-site for preliminary interpretations of all aspirations. One of 3 experienced gastroenterologists, each of whom had performed at least 1000 pancreatic examinations, performed all procedures. The operator was not blinded to previous radiographic data. Recorded information included the presence or absence, size, echocharacteristics, location, or locoregional extension of any visualized pancreatic mass, lymph nodes, or distant metastases. Lymph nodes that were not accessible to endoscopic ultrasonographyguided fine-needle aspiration were considered malignant if 3 or more of the following criteria were present: diffuse hypoechoic echogenicity, short-axis diameter of 5 mm or greater, well-defined borders, round shape, or location within 5 mm of the tumor. Well-defined hypoechoic or hyperechoic lesions within the liver with a short-axis diameter of 10 mm or greater and not accessible to fine-needle aspiration were defined as metastases. We considered vascular involvement by the tumor to be present if any 1 of the following were noted: loss of the normal hyperechoic interface between tumor and vessel for at least 5 mm (adherence), irregular tumor and vessel interface, tumor within vessel lumen (invasion), vessel encasement, and perigastric or periduodenal collaterals with associated venous occlusion. Immediately after the examination, any visualized mass was designated by the endosonographer as surgically resectable or unresectable and assigned a tumor, node, metastasis (TNM) staging according to the 1997 American Joint Committee on Cancer (AJCC) classification (Appendix Table) for staging of pancreatic cancer (26). Multidetector CT Technique We performed multidetector CT with a quad-channel scanner (MX 8000 Quad, Philips Medical Systems, Cleveland, Ohio) by using 0.5-second gantry rotation time and acquisition of 4 sections per rotation. All patients drank 500 mL of tap water as nonopaque oral intraluminal contrast media. A total of 150 mL (300 mg of iodine/mL) of low-osmolar contrast media (Isovue-300, Bracco Diagnostics, Princeton, New Jersey) was injected with a power injector (CT Envision Injector, Medrad, Pittsburgh, Pennsylvania) at a rate of 4.0 mL/s into an antecubital vein by using either an 18- or 20-gauge cannula. Examination was performed in a dual-phase mode. Image acquisition was first done during the pancreatic phase (35 seconds after the start of contrast infusion) from the top to the bottom of the pancreas with 4.0-mm beam collimation (nominal section thickness, 1.0 mm; effective section thickness, 1.3 mm), 0.5-mm reconstruction interval, 120 kVp, 205 mAs, and a pitch of 1.0 during a single breath-hold of 15 to 20 seconds. The second phase was performed during the portal venous phase (65 seconds after the start of contrast infusion) from the top of the liver to the iliac crests with 10-mm beam collimation (nominal section thickness, 2.5 mm; effective section thickness, 3.2 mm), 1.3-mm reconstruction interval, 120 kVp, 250 mAs, and a pitch of 0.875 during a single breath-hold of 15 seconds. Multiplanar (2-dimensional) reformatting was not routinely performed; however, when it was used, the entire data set was transferred to a workstation (MX View, Philips Medical Systems) for evaluation. No 3-dimensional (volume rendering) postprocessing was used in this study. One of 3 experienced gastrointestinal radiologists who were blinded to the results of the previous endoscopic ultrasonography examination interpreted all scans. Patient information provided to the interpreting radiologist included presenting symptoms; the size, location, and vascular involvement (if known) of any visualized pancreatic mass from previous CT; and the results of any previous endoscopic retrograde cholangiopancreatography (for example, presence or absence of ductal strictures) or pathology (for example, endoscopic brush cytology). Locoregional and distant adenopathy were considered malignant if they were greater than 10 mm in

Wireless Capsule Endoscopy Detects Small Bowel Ulcers in Patients With Normal Results From State of the Art Enteroclysis

BACKGROUND:Wireless capsule endoscopy (WCE) is a new technology for small bowel imaging.AIM:To report our initial experience with sensitivity of high quality enteroclysis in patients with small bowel ulcers detected by WCE.METHODS:Medical records of all patients referred for WCE from December, 2001 to April, 2002 at our institution were reviewed. All patients had negative upper and lower endoscopies and small bowel barium studies before WCE.RESULTS:There were 40 patients (19 female, mean age 57.3 yr) during this study period. Three patients had multiple small bowel ulcers detected by WCE. One with ileal ulcers and abdominal pain had an enteroclysis at another hospital before WCE. Review of the study at our institution showed that it was of excellent quality and was normal. Two patients with chronic iron deficiency anemia had multiple small bowel ulcers and were referred after WCE for a repeat small bowel barium study by biphasic enteroclysis performed by experienced GI radiologists. The radiologists were told in advance of the WCE findings. Both studies were considered technically to be of perfect quality. Despite this, both studies were negative. All 3 patients improved after therapy for Crohns disease.CONCLUSIONS:Our data indicates that WCE may be more sensitive for small bowel ulcers than the best enteroclysis available.

Correlation of CT Enteroclysis With Surgical Pathology in Crohn's Disease

BACKGROUND:The response to therapy in Crohns disease (CD) depends on the inflammatory or fibrostenotic nature of the underlying pathological process. Standard diagnostic tests cannot reliably distinguish between these two entities. Although CT enteroclysis (CTE) has shown promise in the evaluation of small bowel disorders, its accuracy for the differentiation of CD phenotypes is unknown.AIMS:To determine the accuracy of CTE compared with surgical pathology in patients with CD and to assess the association of CTE variables with inflammatory or fibrostenotic pathological lesions.METHODS:CTE studies from patients who underwent resective bowel surgery for CD were reviewed and compared with the pathological specimens using a standardized scoring system. Patients were excluded if they had incomplete studies, nonresective surgeries, or a diagnosis of malignancy. CTE variables, such as mucosal and mural enhancement, wall thickness, engorgement of vasa recta (comb sign), adenopathy, and the presence and severity of strictures were compared with the pathology results using Mantel-Haenszel χ2, Spearmans rank coefficient, and logistic regression analyses.RESULTS:Of the 54 patients enrolled, 10 were excluded. The remaining patients (61% female, 84% white) underwent 44 surgical interventions generating 47 bowel segments that were included in the analysis. The indications for surgery were: bowel obstruction in 21; perforating disease in 13; and refractory, nonobstructive disease in 15. The accuracy of CTE for inflammatory and fibrostenotic lesions was 76.6% and 78.7% using a four- and three-point grading system, respectively. There was good correlation between CTE and pathology in regards to inflammation (Spearmans r = 0.7, P < 0.0001) and fibrostenosis (Spearmans r = 0.6, P < 0.0001) scores. The pathological inflammation score was significantly associated with the CTE variables mucosal enhancement, wall thickness, comb sign, and adenopathy (Mantel-Haenszel χ2 P values 0.04, 0.04, <0.0001, and 0.016, respectively). The pathological fibrostenosis score was significantly associated with the presence and severity of stenosis on CTE (P = 0.001 and 0.007, respectively). By logistic regression analysis, the strongest association was seen with the comb sign (OR 5.52, P < 0.001) for inflammation and the presence of stenosis (OR 5.87, P = 0.006) for fibrostenosis. There was no interaction between the time interval from CTE to surgery and the strength of these associations.CONCLUSIONS:CTE may reliably differentiate between inflammatory and fibrostenotic lesions and may have an important role in the management of CD. Specific CTE variables correlate with each of these phenotypes and deserve further investigations in prospective studies.

Multidetector-row helical CT enteroclysis.

Currently, CT-E is not recommended as the first-line examination in patients when mucosal detail is required. Double-contrast barium air enteroclysis has advantages in demonstrating small mucosal abnormalities. The authors find CT-E of value in the work-up of patients with symptoms of intermittent small bowel obstruction, particularly those with a history of prior abdominal surgery; in the further work-up of selected patients with high-grade obstruction in whom general surgeons prefer initial conservative management (immediate postoperative small bowel obstruction, patients with history of prior abdominal surgery for malignant tumor, history of radiation treatment, and possible internal extraintestinal fistulae); in looking for complications of small bowel Crohns disease; and in the patient with unexplained anemia or gastrointestinal bleeding. In a series of patients who had both abdominal CT and barium enteroclysis done, each examination provided unique and complimentary diagnostic information. Because CT-E combines the advantages of both methods of examination, is it the optimum imaging work-up in the investigation of small bowel disease? Further research and clinical experience will define the precise role of CT-E in the investigation of small bowel disease. Experience with this method of examination is limited to a few institutions, performed by investigators with interest in small bowel diseases. The addition of cross-sectional display and multiplanar reformatting made possible by multidetector-row helical CT to enteral volume change and the use of multifunctional nasointestinal catheters make CT-E an important tool in the investigation of small bowel disease. Experience has shown the increased reliability of any method of examining the small bowel that challenges intestinal wall distensibility by fluid enteral volume infusion.

Current concepts in imaging of small bowel obstruction

The diagnosis and treatment of small bowel obstruction continue to evolve. The imaging approach in the work-up of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this disease have undergone considerable changes over the past two decades. This article examines the current concepts related to the use of imaging technology in the diagnosis and management of patients with small bowel obstruction. The meaning of frequently used but poorly defined terms in describing intestinal obstruction is clarified and illustrated.

Malignant melanoma: Patterns of metastasis to the small bowel, reliability of imaging studies, and clinical relevance

Abstract OBJECTIVES: The aims of this study were to determine the frequency of different patterns of melanoma metastases to small bowel on radiological examination, and to assess the reliability of the most commonly used radiological methods for detecting these lesions. METHODS: The records of cases archived as melanoma metastatic to the small bowel of the Armed Forces Institute of Pathology were reviewed. The clinical information, type of imaging procedure performed, and radiological features were analyzed and compared to the findings at surgery and at autopsy. RESULTS: A total of 32 patients had clinical and surgical data with pathological confirmation. Seven patients had metastasis involving the duodenum, 22 had jejunal involvement, and 11 had ileal involvement. Metastases were categorized as polypoid, cavitary, infiltrating, or exoenteric. The polypoid pattern was seen in 20 patients (63%), six of whom showed multiple polypoid lesions (>10), referred to as polyposis. The “target lesion,” a discrete polypoid mass with a central ulceration, was observed in only three (9%) of the 32 patients. Eight patients (25%) demonstrated a cavitary pattern, a circumferential mass with inner marginal necrosis, and five (16%) showed an infiltrating pattern. One patient (3%) had an exoenteric lesion with a fistulous tract. The small bowel follow-through demonstrated 32 of 55 metastases (sensitivity 58%). Contrast-enhanced CT demonstrated 32 of 48 masses (sensitivity 66%). Of the six cases of malignant polyposis, none were identified using CT, and only two were diagnosed by small bowel follow-through. CONCLUSIONS: The polypoid pattern, equally distributed between the jejunum and ileum, is the most common manifestation of metastatic melanoma to the small bowel. The target lesion was infrequently seen in this series. Small bowel follow-through and conventional CT seem to be unreliable in demonstrating melanoma metastases to the small bowel.

Enteroclysis in the evaluation of suspected small intestinal bleeding

One hundred twenty-five consecutive enteroclysis studies performed for the indication of gastrointestinal bleeding were reviewed. The overall yield of positive studies was low (10%) but important lesions were found. Patients with unequivocally normal evaluations of the upper gastrointestinal tract and colon had the highest yield of positive enteroclysis studies (20%). Neither the specific type of bleeding, the presence or absence of abdominal symptoms or physical examination findings, nor the results of laboratory tests were associated with a positive or negative enteroclysis study.

Efficacy of venous reconstruction in patients with adenocarcinoma of the pancreatic head

Pancreaticoduodenectomy is often avoided in patients with portal or superior mesenteric venous involvement due to the perception that venous resection is complex, morbid, and carries a poor longterm survival. Our recent experience using state-of-the-art imaging and strict resection criteria show that venous reconstruction increases operative time, transfusion requirements, intensive care unit stay, and total hospital length of stay, but has no significant impact on operative morbidity rates, mortality rates, or the incidence of positive histologic margins. Kalpan-Meier life table analysis shows similar survival curves when compared to a contemporary cohort of patients who do not undergo venous reconstruction.

Radiology of small bowel obstruction: contemporary approach and controversies

The radiologic workup of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this complex situation have undergone considerable changes over the past two decades. The diagnosis and treatment of small bowel obstruction, a common clinical condition often associated with signs and symptoms similar to those seen in other acute abdominal disorders, continue to evolve. This article examines the changes related to the use of imaging in the diagnosis and management of patients with this potentially dangerous problem and revisits pertinent controversies.

Radiologic Investigations Complement and Add Diagnostic Information to Capsule Endoscopy of Small-Bowel Diseases

OBJECTIVE The purpose of our study was to review how commonly performed radiologic examinations compare with capsule endoscopy in the investigation of small-bowel diseases, to analyze the limitations of capsule imaging, and to propose an algorithm for use of specific radiologic examinations to complement wireless capsule endoscopy. CONCLUSION The diagnostic yield of capsule endoscopy is superior to that of radiologic examinations except air double-contrast enteroclysis for mucosal details. Radiologic investigations find new applications in clinical practice by complementing capsule endoscopy to overcome its limitations.