OBJECTIVE: The purpose of this study was to establish the normal range of wall thickness and the normal appearance of the gastric antrum on multidetector CT (MDCT). METHODS: AND MATERIALS. Soft-copy measurements of the gastric antrum and gastric body were performed on contrast-enhanced MDCT scans in 153 consecutive patients without gastric disease. For comparison, anatomic dissection of the stomach was performed in three cadavers. RESULTS: Smooth thickening of the distal gastric antrum relative to the proximal stomach on MDCT was seen in 152 (99%) of 153 patients and appeared concentric in 96% and eccentric in 4%. The mean (+/- SD) antral wall thickness was 5.1 +/- 1.6 mm. The longitudinal extent of antral wall thickening averaged 4.6 cm. At least one antral wall measurement (anterior or posterior) exceeded 5 and 10 mm in 85 patients (56%) and seven patients (5%), respectively. The anterior wall of the gastric body was significantly thinner at 2.0 +/- 0.4 mm (mean +/- SD) than the wall of the gastric antrum (p << 0.0001). The mean antral wall thickness when distention was characterized as grade 1 (least), 2, 3, and 4 (most) was 6.9, 5.1, 4.9, and 4.0 mm, respectively. Linear submucosal low attenuation (mural striation) of the thickened portion of the gastric antrum was noted in 36 patients (24%); fat attenuation was present in 14 cases. Cadaveric stomachs showed mild segmental thickening of the distal gastric antrum, but this thickening was less pronounced compared with in vivo MDCT findings. CONCLUSION: Smooth wall thickening of the distal gastric antrum relative to the proximal stomach on MDCT with or without submucosal low attenuation is a normal finding. Antral wall thickness commonly exceeds 5 mm and may measure up to 12 mm. Our MDCT findings, in conjunction with previous anatomic and physiologic observations, suggest that normal antral wall thickening consists of both static and dynamic components.

Adult↗

PubMed2003

Three-dimensional endoluminal CT colonography (virtual colonoscopy): comparison of three commercially available systems.

OBJECTIVE: The purposes of this study were to directly compare 3D endoluminal volume rendering and navigational capabilities of three different CT colonography systems and to assess feasibility of 3D evaluation for primary polyp detection. MATERIALS AND METHODS: Closely matched endoluminal images from three CT colonography software systems (Navigator, Vitrea 2, and V3D-Colon) and optical colonoscopy were obtained of eight pathologically proven colorectal polyps. All images were then reviewed by 25 physicians (12 radiologists and 13 gastroenterologists) who were not familiar with the three systems. For each polyp, the images yielded by the three systems were rated according to polyp conspicuity, 3D effect (depth), subjective quality, and likeness to optical colonoscopy. For comparison of endoluminal navigation capability, automated or semiautomated flight from rectum to cecum and cecum to rectum was attempted in 10 cases (20 flights) in which a continuous colonic air column could be identified on the 2D images. Additional 3D features were also compared. RESULTS: For polyp conspicuity, 3D effect, and likeness to optical colonoscopy, the V3D-Colon system was favored in 92.0% (184/200), 92.5% (185/200), and 92.5% (185/200) of responses, respectively (p < 0.001). For the same categories, the Navigator system ranked second in 73.0%, 74.0%, and 75.0% of cases, and the Vitrea 2 system ranked last in 79.0%, 77.5%, and 76.0% of cases, respectively. Automated or semiautomated navigation was successful in eight (40%) of 20 flights with Vitrea 2, in nine (45%) of 20 flights with Navigator, and in 20 (100%) of 20 flights with V3D-Colon (p < 0.001). The V3D-Colon system also had more navigational features than the other two systems. CONCLUSION: Pronounced subjective and objective differences in 3D endoluminal rendering and navigational capabilities exist among the systems evaluated. Of the three, effective time-efficient primary 3D evaluation appears to be feasible only with the V3D-Colon system.

Adenoma↗

PubMed2002

Acquired gastrointestinal fistulas: classification, etiologies, and imaging evaluation.

Fistulas are abnormal communications between two epithelial-lined surfaces. Gastrointestinal fistulas encompass all such connections that involve the alimentary tract, and they can be congenital or acquired in nature. This review focuses on acquired gastrointestinal fistulas. Development of an acquired gastrointestinal fistula can greatly affect patient outcome, yet the clinical manifestations are often protean in nature and the etiology, elusive. Imaging plays an important role in the detection and management of acquired gastrointestinal fistulas. The more routine use of cross-sectional imaging (especially computed tomography and magnetic resonance imaging) has altered the standard sequence of radiologic evaluation for possible fistulas, but fluoroscopic studies remain a valuable complement, especially for confirming and defining the anomalous communications. In this review, a classification scheme for gastrointestinal fistulas is provided, major causes are discussed, and individual fistula types are elaborated with an emphasis on contemporary imaging approaches.

Cutaneous Fistula↗

PubMed2002

Primary neoplasms of the appendix manifesting as acute appendicitis: CT findings with pathologic comparison.

PURPOSE: To evaluate the computed tomographic (CT) findings in patients with acute appendicitis related to an underlying appendiceal neoplasm. MATERIALS AND METHODS: Clinical and pathologic data obtained over a 10-year period in 65 patients with primary appendiceal neoplasms were reviewed. Preoperative CT studies in patients who presented clinically with symptoms of acute appendicitis were analyzed retrospectively and in consensus by three radiologists. The appendix was evaluated on CT scans for morphology, location, presence of calcification, maximal diameter, and wall thickness. RESULTS: Twenty-six (40%) of the 65 patients with appendiceal neoplasms had presented with symptoms of acute appendicitis. Preoperative CT studies available in 22 patients showed increased appendiceal diameter, wall thickening, and periappendiceal fat stranding in 22 (100%), 22 (100%), and 21 (95%) patients, respectively. The appendiceal diameter was greater than 15 mm (mean diameter, 2.9 cm) in 19 patients (86%). Morphologic changes of concern for neoplasm were present in 19 patients (86%) and included cystic dilatation in nine patients and presence of a soft-tissue mass without dilatation in 10 patients. An appendiceal diameter greater than 15 mm and/or a morphologic abnormality were present in 21 of 22 cases (95%). CONCLUSION: CT findings strongly suggest the presence of underlying neoplasm in the majority of patients with secondary appendicitis.

Acute Disease↗

PubMed2002

Non-Hodgkin's lymphoma of the appendix: clinical and CT findings with pathologic correlation.

OBJECTIVE: The purpose of this report is to describe the clinical, CT, and pathologic features of non-Hodgkin's lymphoma of the vermiform appendix. CONCLUSION: Non-Hodgkin's lymphoma of the appendix typically manifests with acute symptoms in patients who have no prior history of lymphoma. Most patients with the disease present clinically with signs and symptoms suggestive of acute appendicitis. On CT, lymphomatous infiltration of the appendix produces markedly diffuse mural soft-tissue thickening (range of diameters, 2.5-4.0 cm; mean diameter, 3.2 cm). The vermiform morphology of the appendix is usually maintained, and aneurysmal dilatation of the lumen is sometimes seen. Stranding of the periappendiceal fat seen on CT may represent superimposed inflammation or even direct lymphomatous extension. Coexisting abdominal lymphadenopathy is not seen in all patients. Although appendiceal lymphoma is rare, the characteristic CT appearance could lead to a preoperative diagnosis.

Adult↗

PubMed2002

Stomal metastases complicating percutaneous endoscopic gastrostomy: CT findings and the argument for radiologic tube placement.

OBJECTIVE: This article describes the CT appearance of metastatic implantation at the percutaneous endoscopic gastrostomy (PEG) tract in patients with malignancy of the upper aerodigestive tract. Cumulative data from previous case reports are also considered for insight into causes of metastasis and the implications for gastrostomy placement in these patients. CONCLUSION: CT showed lobulated soft tissue involving the entire abdominal wall PEG tract in all proven cases. CT is an effective method for evaluation because the tumor burden lies predominately in the abdominal wall and not at the entry or exit site. The stomal implant is often the only site of metastatic disease at presentation. In general, CT findings of mildly increased soft tissue along the PEG tract are nonspecific, but a lobulated mass is highly suspicious for tumor implantation, especially if the one-sided thickness exceeds 1 cm. The preponderance of evidence from the existing literature points to direct tumor implantation during endoscopic placement as the likely cause (rather than hematogenous spread). This conclusion would support the alternative of radiologic tube placement in these patients.

Abdominal Muscles↗

PubMed2002

Intestinal malrotation in adolescents and adults: spectrum of clinical and imaging features.

Explore the source record for details and available documents.

Acute Disease↗

PubMedDate not supplied

Primary neoplasms of the appendix: radiologic spectrum of disease with pathologic correlation.

Although uncommon, primary appendiceal neoplasms often result in clinical symptoms that may lead to abdominal imaging. Acute appendicitis from luminal obstruction is the most common manifestation for most tumor types. Other manifestations include intussusception, a palpable mass, gastrointestinal bleeding, increasing abdominal girth (from pseudomyxoma peritonei), and secondary genitourinary complications. Asymptomatic appendiceal neoplasms may be discovered incidentally. Mucoceles from either benign or malignant mucinous neoplasms represent the majority of appendiceal tumors detected at imaging but are the least likely to manifest as appendicitis. Pseudomyxoma peritonei is a common manifestation of mucinous adenocarcinoma. Colonic-type (nonmucinous) adenocarcinoma of the appendix is much less common than mucinous tumors and typically manifests as a focal mass without mucocele formation. Carcinoid tumor is the most common appendiceal neoplasm but is less often detected radiologically because it is typically small and relatively asymptomatic. Goblet cell carcinoid tumor and non-Hodgkin lymphoma of the appendix are rare and usually infiltrate the entire appendix. Cross-sectional imaging, particularly computed tomography (CT), is effective in the evaluation of these neoplasms. CT appears to be the modality of choice whenever an appendiceal mass is suspected. CT will help rule out or confirm an appendiceal tumor and may suggest a more specific diagnosis.

Appendiceal Neoplasms↗

PubMedDate not supplied

Differential diagnosis of polypoid lesions seen at CT colonography (virtual colonoscopy).

Computed tomographic (CT) colonography, also referred to as virtual colonoscopy, holds significant promise for effective large-scale colorectal cancer screening. Two-dimensional (2D) and three-dimensional (3D) displays of the CT data are employed, both of which are critical for proper evaluation. Although many radiologists continue to use the 2D images for polyp detection, more emphasis on the 3D images for primary detection of polyps has yielded the best results for screening detection. The primary target lesion for colorectal screening is the adenomatous polyp, since detection and removal of all larger or advanced lesions could potentially prevent approximately 95% or more of all colon cancers. Frankly invasive adenocarcinoma is rarely encountered in an average-risk asymptomatic screening population, but it is of course another important target. In addition to these clinically significant epithelial neoplasms, however, a host of additional lesions and pseudolesions may be encountered that appear polypoid at CT colonography. A subset of "don't touch" lesions, which should not be confused with potential neoplasms, can also be recognized at CT colonography. A variety of useful techniques and observations can be used to increase the specificity of CT colonography for distinguishing false polyps from true polyps.

Colonic Polyps↗

PubMedDate not supplied

Unusual nonneoplastic peritoneal and subperitoneal conditions: CT findings.

Peritoneal disease can manifest at computed tomography (CT) as fluid accumulation within the peritoneal cavity (ascites) or soft-tissue infiltration of the various peritoneal ligaments and mesenteries. Beyond the commonly encountered cases of typical ascites and peritonitis, there is a wide spectrum of uncommon nonneoplastic conditions that may involve the peritoneal and subperitoneal spaces. For example, systemic or organ-based diseases that occasionally involve the peritoneum include eosinophilic gastroenteritis, amyloidosis, extramedullary hematopoiesis, Erdheim-Chester disease, sarcoidosis, and mesenteric cavitary lymph node syndrome. Tumorlike conditions that may affect the peritoneum include aggressive fibromatosis (desmoid), inflammatory pseudotumor, retractile mesenteritis, and Castleman disease. Atypical peritoneal infections include tuberculosis, actinomycosis, echinococcosis, Whipple disease, and mesenteric adenitis. Conditions involving the subperitoneal fat include epiploic appendagitis, mesenteric panniculitis, and segmental omental infarction, all of which have characteristic CT findings. CT is an excellent imaging modality for detection and characterization of peritoneal involvement from these unusual diseases.

Adult↗

PubMedDate not supplied

Primary neoplasms of peritoneal and sub-peritoneal origin: CT findings.

Peritoneal carcinomatosis is a common metastatic manifestation of many organ-based malignancies, particularly carcinomas of the gastrointestinal tract and ovaries. Primary neoplasms of peritoneal and sub-peritoneal origin occur much less frequently than metastatic peritoneal involvement from a known or occult primary tumor; however, these rare primary lesions (peritoneal mesothelioma, papillary serous carcinoma, desmoplastic small round cell tumor, benign and malignant mesenchymal tumors, lymphoproliferative disorders) are often first detected at computed tomography (CT) and should be considered in the absence of a known or suspected organ-based malignancy. A precise diagnosis based on imaging findings alone is often not possible. Furthermore, distinguishing a benign from a malignant process and a primary from a metastatic process is also challenging. Nevertheless, CT features combined with the patient's relevant clinical and demographic data can help narrow the differential diagnosis for a peritoneum-based neoplasm in many cases. CT is useful not only for the detection, characterization, and staging of primary neoplasms of peritoneal and subperitoneal origin, but also for guiding biopsy for tissue diagnosis.

Humans↗