Ruedi F. Thoeni

The Revised Atlanta Classification of Acute Pancreatitis: Its Importance for the Radiologist and Its Effect on Treatment

An international working group has modified the Atlanta classification for acute pancreatitis to update the terminology and provide simple functional clinical and morphologic classifications. The modifications (a) address the clinical course and severity of disease, (b) divide acute pancreatitis into interstitial edematous pancreatitis and necrotizing pancreatitis, (c) distinguish an early phase (1st week) and a late phase (after the 1st week), and (d) emphasize systemic inflammatory response syndrome and multisystem organ failure. In the 1st week, only clinical parameters are important for treatment planning. After the 1st week, morphologic criteria defined on the basis of computed tomographic findings are combined with clinical parameters to help determine care. This revised classification introduces new terminology for pancreatic fluid collections. Depending on presence or absence of necrosis, acute collections in the first 4 weeks are called acute necrotic collections or acute peripancreatic fluid collections. Once an enhancing capsule develops, persistent acute peripancreatic fluid collections are referred to as pseudocysts; and acute necrotic collections, as walled-off necroses. All can be sterile or infected. Terms such as pancreatic abscess and intrapancreatic pseudocyst have been abandoned. The goal is for radiologists, gastroenterologists, surgeons, and pathologists to use the revised classifications to standardize imaging terminology to facilitate treatment planning and enable precise comparison of results among different departments and institutions.

Comparison of Barium Enema and Colonoscopy in the Detection of Small Colonic Polyps1

A total of 210 patients was examined by barium enema and colonoscopy. The authors found 219 polyps in 112 patients. Single-contrast barium enema missed 33 (45.2%) and double-contrast barium enema missed 17 (11.7%) polyps. Colonoscopy failed to detect 6 polyps (2.7%) and another 21 (10%) were not seen because the area could not be reached by the colonoscope. Malignancy was present in 5 small polyps. The authors conclude that the double-contrast barium enema offers a definite advantage in the right colon. In general, the two methods are complementary.

Value of computed tomography in the detection and staging of recurrent rectal carcinomas.

We studied a series of 39 patients who underwent computed tomog-raphy (CT) of the pelvis and abdomen following surgery for adenocarcinoma of the rectum. Based on the CT findings. recurrent rectal carcinoma was classi-fied into one of four stages: Stage I, intraluminal mass without colon wall thickening; Stage II. colon wall thickening (greater than 1 cm) without invasion of adjacent structures; Stage IIIA. thickening of the colon wall with direct invasion of adjacent organs but not the pelvic sidewalls; Stage IIIB, extension of mass to pelvic sidewalls; and Stage IV, distant metastatic disease. All 30 patients with recurrent rectal carcinoma had positive CT scans. Overall accuracy was 95% with 0% false negative and 5% false positive interpretations. Results indicate that CT is an accurate method of detecting and staging recurrent rectal carcinoma and for aiding the selection of appropriate therapy.

Ectopic pancreas: usual and unusual features.

Nine patients with ectopic pancreas in the stomach (8 patients) and duodenum (1 patient) were studied both radiographically and endoscopically. Correct diagnosis was made by radiography in six cases and by endoscopy in seven cases. Masses radiographically larger than 3 cm in diameter were seen in three patients. The incorrect radiographic diagnoses were related to the presence of a large mass in one patient and to the complications of severe bleeding and gastric outlet obstruction in the other two. Endoscopy and radiography are complementary modalities in the diagnosis of ectopic pancreas.

A multisite phase iii study of the safety and efficacy of a new manganese chloride-based gastrointestinal contrast agent for mri of the abdomen and pelvis

The purpose of this study was to evaluate the safety and efficacy of a manganese chloride‐based oral magnetic resonance (MR) contrast agent during a Phase III multisite clinical trial. Two hundred seventeen patients were enrolled who were already scheduled for MRI of the abdomen and/or pelvis. In this group of patients, it was postulated that the use of an oral agent would better allow discrimination of pathology from bowel. Patients with known gastrointestinal pathology including peptic ulcer disease, inflammatory bowel disease, obstruction, or perforation were excluded to minimize confounding variables that could affect the safety assessment. Of these 217 patients, 18 received up to 900 mL of placebo, and 199 patients were given up to 900 mL of a manganese chloride‐based oral contrast agent, LumenHance® (Bracco Diagnostics, Inc.). Safety was determined by comparing pre‐ and post‐dose physical examinations, vital signs, and laboratory examinations and by documenting adverse events. Efficacy was assessed by unblinded site investigators and two blinded reviewers who compared pre‐ and post‐dose T1‐ and T2‐weighted MRI scans of the abdomen and/or pelvis. In 111 (57%) of the 195 cases evaluated for efficacy by site investigators (unblinded readers), MRI after LumenHance provided additional diagnostic information. Increased information was found by two blinded readers in 52% and 51% of patients, respectively. In 44/195 cases (23%) unblinded readers felt the additional information would have changed patient diagnosis and in 50 patients (26%), it would have changed management and/or therapy. Potential changes in patient diagnosis or management/therapy were seen by the two blinded readers in 8–20% of patients. No clinically significant post‐dose laboratory changes were seen. Forty‐eight patients (24%) receiving LumenHance and four patients (22%) receiving placebo experienced one or more adverse events. Gastrointestinal tract side effects were most common, seen in 29 (15%) of LumenHance patients and in 3 (17%) of the placebo patients. LumenHance is a safe and efficacious oral gastrointestinal contrast agent for MRI of the abdomen and pelvis.J. Magn. Reson. Imaging 1999;10:15–24.

The state of radiographic technique in the examination of the colon: a survey in 1987.

Results of an extensive multiple-choice questionnaire sent to 175 leading medical centers in the world were analyzed and compared with those of a similar survey from 1976. One hundred sixty-two (93%) responses were received. Both single- and double-contrast enema procedures are still employed, but the use of the double-contrast technique has markedly increased. Preparation of the colon is even more meticulous than in 1976 and is equal for both techniques. Pharmacologic aids are used more often but preparatory enemas less frequently than in 1976. The use of fluoroscopic equipment has not significantly changed. The decision on the appropriate sequence for the barium enema examination and colonoscopy is based on the individual clinical problem in the majority of cases, and the time interval between the barium enema examination and lower endoscopy with or without biopsy is significantly shorter than in 1976. The use of computed tomography and magnetic resonance imaging has increased since 1976, but angiography is used less often and mostly for unknown causes of bleeding and to stop bleeding.

Safe and easy power injection of contrast material through a central line

Abstract. Power-assisted injection of contrast material into an antecubital vein is commonly used in CT and has been proven superior to manual injection. Power-assisted injection through a central line bares the risk of rupturing the line because manual control over the pressure applied by the power injector is lacking. We present a simple safety device which allows manual control of the pressure by means of an interposed three-way stopcock combined with a small syringe for pressure equalization.

The Radiographic Appearance of Complications Following Nissen Fundoplication

Seventy patients had an upper gastrointestinal examination following Nissen fundoplication for reflux esophagitis associated with hiatal hernia. Thirty-nine were asymptomatic and the fundoplication appeared normal. Of the 31 patients with symptoms (dysphagia, pain, or vomiting), 15 had spontaneous relief and demonstrated a normal postsurgical radiographic appearance of the stomach. The other 16 had both persistent symptoms and radiographic abnormalities, including 5 stenoses, 3 recurrent hernias, and 8 pouch deformities of the fundus. The roentgenographic features and etiology of these surgical failures are discussed and the importance of the radiographic examination in discerning successful surgical repair from failure despite similar postsurgical symptoms is stressed.

CT for the evaluation of carcinomas in the colon and rectum

The role of conventional CT in assessing patients with colorectal tumors is well established. The low accuracy of CT for identifying early stages of primary colorectal cancers prevents the routine use of CT for preoperative staging. Nevertheless, CT is useful in examining patients suspected of having extensive disease, in deciding whether a patient will benefit from preoperative radiation, in designing radiation ports, and in detecting complications related to the neoplasm. For recurrent colorectal neoplasm, CT has the premier role. CT surpasses colonoscopy in detecting early masslike tumor recurrence at the anastomotic site because of its extrinsic component, and CT and MRI are the only methods that can fully evaluate cases of total abdominoperineal resection. After total abdominoperineal resection, however, CT cannot determine with certainty that a soft tissue density in the surgical bed represents recurrent tumor. In patients with colorectal neoplasms, preliminary results with multiplanar and three-dimensional reconstructions of helical CT images are promising, but their role needs further investigation.

CT detection of asymptomatic pancreatitis following ERCP.

Presence or absence of pancreatitis without symptoms attributable to pancreatitis was assessed by computed tomography (CT) in 31 patients who underwent CT following endoscopic retrograde cholangiopancreatography (ERCP) within a time interval of 0–9 days. Presence or absence of pancreatitis was proven by elevated or normal amylase, and/or surgery, and by symptoms related to pancreatitis. Twenty-five of the patients underwent ERCP without and six with sphincterotomies. Among the six patients, additional procedures included two stent placements, two balloon dilatations, and one basket retrieval. Eleven of 31 patients developed pancreatitis following ERCP. The incidence of pancreatitis was higher in the group with maneuvers (four of six patients or 66.7%) than that without maneuvers (seven of 25 or 28%). Asymptomatic pancreatitis was present in five of 31 patients or 16.1%, and three of these had CT evidence of severe pancreatitis. CT demonstration of pancreatitis following ERCP with or without maneuvers may not always indicate clinically relevant disease.