Efficacy of Barium-Based Fecal Tagging for CT Colonography: a Comparison between the Use of High and Low Density Barium Suspensions in a Korean Population - a Preliminary Study

OBJECTIVE: This preliminarily study was designed to determine and to compare the efficacy of two commercially available barium-based fecal tagging agents for CT colonography (CTC) (high-density [40% w/v] and low-density [4.6% w/v] barium suspensions) in a population in Korea. MATERIALS AND METHODS: In a population with an identified with an average-risk for colorectal cancer, 15 adults were administered three doses of 20 ml 40% w/v barium for fecal tagging (group I) and 15 adults were administered three doses of 200 ml 4.6% w/v barium (group II) for fecal tagging. Excluding five patients in group I and one patient in group II that left the study, ten patients in group I and 14 patients in group II were finally included in the analysis. Two experienced readers evaluated the CTC images in consensus regarding the degree of tagging of stool pieces 6 mm or larger. Stool pieces were confirmed with the use of standardized CTC criteria or the absence of matched lesions as seen on colonoscopy. The rates of complete fecal tagging were analyzed on a per-lesion and a per-segment basis and were compared between the patients in the two groups. RESULTS: Per-lesion rates of complete fecal tagging were 52% (22 of 42; 95% CI, 37.7-66.6%) in group I and 78% (28 of 36; 95% CI, 61.7-88.5%) in group II. The difference between the two groups did not reach statistical significance (p = 0.285). The per-segment rates of complete tagging were 33% (6 of 18; 95% CI, 16.1%-56.4%) in group I and 60% (9 of 15; 95% CI, 35.7%-80.3%) in group II; again, the difference between the two groups did not reach statistical significance (p = 0.171). CONCLUSION: Barium-based fecal tagging using both the 40% w/v and the 4.6% w/v barium suspensions showed moderate tagging efficacy. The preliminary comparison did not demonstrate a statistically significant difference in the tagging efficacy between the use of the two tagging agents, despite the tendency toward better tagging with the use of the 4.6% w/v barium suspension.

The Association of Anisakiasis in the Ascending Colon with Sigmoid Colon Cancer: CT Colonography Findings

The association of anisakiasis of the colon with colon cancer is rare and difficult to diagnose. Only one case of this type has been reported to date. In this study, we report a case of synchronous colon cancer and colonic anisakiasis. A 50-year-old woman was admitted for abdominal pain, and a volume-rendered surface-shaded image of CT colonography (CTC) revealed a concentric narrowing in the sigmoid colon and a segmental fold thickening in the ascending colon. A total colectomy was performed and the diagnosis of synchronous sigmoid colon cancer and anisakiasis of the ascending colon was confirmed. This case is the first reported visualization of synchronous colon cancer and colonic anisakiasis on a CTC.

Diagnostic Performance of CT Colonography for the Detection of Colorectal Polyps

OBJECTIVE: To investigate the diagnostic value of CT colonography for the detection of colorectal polyps. MATERIALS AND METHODS: From December 2004 to December 2005, 399 patients underwent CT colonography and follow-up conventional colonoscopy. We excluded cases of advanced colorectal cancer. We retrospectively analyzed the CT colonography findings and follow-up conventional colonoscopy findings of 113 patients who had polyps more than 6 mm in diameter. Radiologists using 3D and 2D computer generated displays interpreted the CT colonography images. The colonoscopists were aware of the CT colonography findings before the procedure. RESULTS: CT colonography detected 132 polyps in 107 of the 113 patients and conventional colonoscopy detected 114 colorectal polyps more than 6 mm in diameter in 87 of the 113 patients. The sensitivity of CT colonography analyzed per polyp was 91% (41/45) for polyps more than 10 mm in diameter and 89% (101/114) for polyps more than 6 mm in diameter. Thirteen polyps were missed by CT colonography and were detected on follow-up conventional colonoscopy. CONCLUSION: CT colonography is a sensitive diagnostic tool for the detection of colorectal polyps and adequate bowel preparation, optimal bowel distention and clinical experience are needed to reduce the rate of missing appropriate lesions.

Pneumatosis Cystoides Intestinalis in Patients with Antinuclear Antibody Negative Systemic Lupus Erythematosus and Dermatomyositis: Report of Two Cases

Pneumatosis cystoides intestinalis (PCI) occurring in association with collagen vascular disease is an unusual combination that presents with intramural gas in the gastrointestinal tract. We report two cases of PCI, one with antinuclear antibody (ANA) negative SLE and the other with dermatomyositis, with a review of the relevant literature.

Malignant Fibrous Histiocytoma of Colon: A Case Report

Gastrointestinal malignant fibrous histiocytomas (MFH) are very rare and only about 30 cases have been reported in the English literature, among which 20 cases were from colorectal MFHs. A small bowel MFH with intussusception has been the only reported case in the Korean medical literature. A 52-year-old male presented with complaints of recently developed and aggravated right upper abdominal pain. We present the CT appearance and the clinico-pathologic findings of his primary inflammatory malignant fibrous histiocytoma, which arose from the subserosal layer of the ascending colon with tumor infiltration in all the layers. The colon showed extensive hemorrhagic necrosis and repetitive multifocal microperforations with resultant panperitonitis.

CT Findings of Locoregional Recurrence after Curative Resection of Colorectal Cancer

Postoperative recurrence is a major cause of mortality and morbidity for the patients suffering with colorectal cancer. Therefore, patients with colorectal cancer are routinely followed up with CT to detect the presence of locoregional recurrence and distant metastases. A central goal of postoperative surveillance for colorectal cancer is to improve survival through the earlier identification of tumor recurrence. Locoregional recurrence refers to tumor occurring at or adjacent to the surgical site and at the regional lymph nodes. It has been reported that metastatic spread based on the site of the primary tumor shows a relatively predictable pattern. Given the prevalence of colorectal cancer and the role of CT for postoperative surveillance, radiologists should be familiar with the CT findings of locoregional recurrence after curative resection for colorectal cancer.

The Usefulness of Air Insufflation Helical CT in Colorectal Cancer

PURPOSE: In patients with colorectal carcinoma, helical CT using air as a contrast agent provides axial images and a three-dimensional CT colonogram similar to that provided by barium enema. The purpose of this study was to assess the usefulness of air insufflation helical CT in colorectal cancer patients. MATERIALS AND METHODS: Thirty-three patients with colorectal carcinoma confirmed by surgery underwent air insufflation helical CT scanning after the infusion of air through the anus. In eleven who underwent barium studies, CT colonograms were also obtained. Two radiologists, who reached a consensus, analysed the detection rate, location and staging of the tumors; staging was based on the modified Dukes (Astler-Coller) classification. RESULTS: Using axial helical CT, the detection rate was 97%; staging was correct in 23 of the 33 patients, with an overall accuracy of 70%. Pathologic correlation was correct in 30 of the 33 cases (three were overestimated), and sensitivity, specificity and accuracy were 100%, 50%, and 91%, respectively. With regard to the involvement of lymph nodes, pathologic correlation was correct in 25 of the 33 patients; four were overestimated and four were underestimated. Sensitivity, specificity and accuracy were 69%, 80%, and 76%, respectively. The detection rate of CT colonography was 100%, but because in one case there was a discrepancy between CT colonography and barium enema as to the shape of the carcinoma, the agreement rate was 91%. CONCLUSION: Air insufflation helical CT, which provides a higher detection rate and more precise staging of colorectal carcinoma than the use of positive contrast materials and three dimensional depiction of tumor location, is helpful for the evaluation of colorectal carcinoma.

Lipohyperplasia of the Ileocecal Valve Mimicking Malignant Neoplasm on CT: A Case Report

We report a case in which CT scanning revealed lipohyperplasia of the ileocecal (IC) valve and cecum with acute inflammation and ulceration mimicking malignant neoplasm. At unenhanced CT, lesion attenuation was lower than that of back muscle, and at contrast-enhanced CT, the lesion was seen as a lobulated polypoid mass with inhomogeneous enhancement, pericecal fat infiltration, and pericecal lymphadenopathy. Although these findings mimick those of malignant neoplasm, the typical location of the mass, involving the IC valve, and the low attenuation observed at unenhanced CT, can help distinguish it from other masses.

Ruptured Mucinous Adenocarcinoma of the Colon in a Child: A Case Report

Carcinoma of the colon is extremely rare in pediatric patients, and due to the preponderance of poor histological characteristics and the difficulty of diagnosis, the prognosis in children is quite unfavorable. We describe a case of ruptured and disseminated mucinous adenocarcinoma of the descending and sigmoid colon in a 14-year-old boy with abdominal pain, diarrhea and fever. Ultrasonography and computed tomography revealed a large soft tissue mass containing tiny calcifications and poorly enhanced hypodense portions in the thickened descending and sigmoid colon, as well as abundant ascites. Where images reveal a mass with low attenuation, calcifications, and aggressive dissemination, mucinous adenocarcinoma may be preferentially included in the differential diagnosis of a pedriatic colon tumor.

Colitis Cystica Profunda Causing Intussusception: A Case Report

Colitis cystica profunda is a benign disorder in which a mucous cyst is located in the submucosal layer of, primarily, the pelvic colon and rectum. Radiologic reports of the condition are rare. We report the radiological findings of a case of colitis cystica profunda arising from the proximal ascending colon near the ileocecal valve, and causing intussusception. We also review the literature.

Primary Lymphoma of the Colon: Radiologic and Pathologic Findings

Compared with the stomach and small intestine, the colon and rectum are uncommon sites of lymphomatous involvement. Primary colorectal lymphoma is diagnosed when the lesion is confined to the colorectal area and regional lymph nodes, without involvement of other organs including the upper gastrointestinal tract, bone marrow, and distant lymph nodes. The radiologic appearance of primary lymphoma of the stomach and small bowel is well known, but in cases involving the colorectal area, this is not so. In this article, we categorize and illustrate the radiologic manifestations of primary colorectal lymphoma according to the findings of double-contrast barium enema and CT images, and describe the pathologic findings.

CT Findings and Clinical Characteristics of Colorectal Mucinous Adenocarcinoma

PURPOSE: To establish the CT findings and clinical characteristics of colorectal mucinous adenocarcinoma. MATERIALS AND METHODS: The CT features of 26 surgically proven cases of colorectal mucinous adenocarcinoma were reviewed. The subjects were selected from among 262 patients with colorectal cancer, of whom 40 with non-mucinous adenocarcinoma were included as a control group. Contrast-enhaneed CT images were analyzed for tumor location, the presence or absence of tumoral calcification, tumor shape (circumferential or eccentric, polypoid or infiltrative), tumor thickness-to-length ratio, and attenuation and homogeneity. In each group, the TNM stage of pathologic specimens was compared. During follow-up, the incidence of recurrence, and outcome, were also compared. RESULTS: CT images of mucinous adenocarcinoma revealed intratumoral calcification in three patients (12%, p < 0.01). Tumors were eccentric and polypoid-shaped, with a high tumoral thickness/length ratio (p < 0.01). On contrast-enhanced images, most were seen as a heterogenous hypoattenvuted mass. No differences in T-NM stage were found in surgical specimens. In patients with mucinous adenocarcinoma, recurrence during the early follow-up period is more common than in patients with non-mucinous cancer. CONCLUSION: Contrast-enhanced CT reveals mucinous adenocarcinoma as an eccentric polypoid mass with heterogeneous hypoattenuation. In patients with mucinous colorectal cancer, careful follow-up is required because tumors tend to recur early in the follow-up period.

CT Findings and Clinical Characteristics of Colorectal Mucinous Adenocarcinoma

PURPOSE: To establish the CT findings and clinical characteristics of colorectal mucinous adenocarcinoma. MATERIALS AND METHODS: The CT features of 26 surgically proven cases of colorectal mucinous adenocarcinoma were reviewed. The subjects were selected from among 262 patients with colorectal cancer, of whom 40 with non-mucinous adenocarcinoma were included as a control group. Contrast-enhaneed CT images were analyzed for tumor location, the presence or absence of tumoral calcification, tumor shape (circumferential or eccentric, polypoid or infiltrative), tumor thickness-to-length ratio, and attenuation and homogeneity. In each group, the TNM stage of pathologic specimens was compared. During follow-up, the incidence of recurrence, and outcome, were also compared. RESULTS: CT images of mucinous adenocarcinoma revealed intratumoral calcification in three patients (12%, p < 0.01). Tumors were eccentric and polypoid-shaped, with a high tumoral thickness/length ratio (p < 0.01). On contrast-enhanced images, most were seen as a heterogenous hypoattenvuted mass. No differences in T-NM stage were found in surgical specimens. In patients with mucinous adenocarcinoma, recurrence during the early follow-up period is more common than in patients with non-mucinous cancer. CONCLUSION: Contrast-enhanced CT reveals mucinous adenocarcinoma as an eccentric polypoid mass with heterogeneous hypoattenuation. In patients with mucinous colorectal cancer, careful follow-up is required because tumors tend to recur early in the follow-up period.

Comparative Study between Gastro g rafin Enema and Air Enema CT: Evaluation of the Diagnostic Accuracy of Lesion Detection and Staging of Colorectal Cancer

PURPOSE: We compared the use of diluted gastrografin enema- and air enema CT for the evaluation of the diagnostic accuracy of preoperative lesion detection and the staging of colorectal carcinoma. MATERIALS AND METHODS: Forty-two patients (43 lesions) with colorectal carcinoma, diagnosed by barium enema and/or colonoscopy, underwent preoperative diluted (2.5%) gastrografin enema CT, and in another 26 patients (27 lesions) with colorectal carcinoma, air enema CT was performed. The presence or absence of lesion, its spread (T), and peritumoral lymph node (N) were analyzed. All patients underwent surgery and pathologic confirmation was obtained. RESULTS: Gastrografin enema CT and air enema CT demonstrated the primary tumor in 97.7% (42 of 43) and 96.3% of cases (26 of 27), respectively. A comparison of gastrografin enema CT and the pathologic results showed that the disease was correctly staged as T2 in five of six cases, as T3 in 28 of 31, and as T4 in two of five. Using air enema CT, the disease was correctly staged as T2 in three of three cases, as T3 in 17 of 21, and as T4 in one of two. Overall, carcinoma was correctly staged by gastrografin enema CT in 83% of cases (35 of 42) and by air enema CT in 81% (21 of 26). Nodal involvement was accurately detected in 64% of cases (27 of 42) using gastrografin enema CT and in 69% (18 of 26) using air enema CT. CONCLUSIONS: These findings suggest that the use of gastrografin enema or air enema CT does not significantly affect the diagnostic outcome.

Comparative Study between Gastro g rafin Enema and Air Enema CT: Evaluation of the Diagnostic Accuracy of Lesion Detection and Staging of Colorectal Cancer

PURPOSE: We compared the use of diluted gastrografin enema- and air enema CT for the evaluation of the diagnostic accuracy of preoperative lesion detection and the staging of colorectal carcinoma. MATERIALS AND METHODS: Forty-two patients (43 lesions) with colorectal carcinoma, diagnosed by barium enema and/or colonoscopy, underwent preoperative diluted (2.5%) gastrografin enema CT, and in another 26 patients (27 lesions) with colorectal carcinoma, air enema CT was performed. The presence or absence of lesion, its spread (T), and peritumoral lymph node (N) were analyzed. All patients underwent surgery and pathologic confirmation was obtained. RESULTS: Gastrografin enema CT and air enema CT demonstrated the primary tumor in 97.7% (42 of 43) and 96.3% of cases (26 of 27), respectively. A comparison of gastrografin enema CT and the pathologic results showed that the disease was correctly staged as T2 in five of six cases, as T3 in 28 of 31, and as T4 in two of five. Using air enema CT, the disease was correctly staged as T2 in three of three cases, as T3 in 17 of 21, and as T4 in one of two. Overall, carcinoma was correctly staged by gastrografin enema CT in 83% of cases (35 of 42) and by air enema CT in 81% (21 of 26). Nodal involvement was accurately detected in 64% of cases (27 of 42) using gastrografin enema CT and in 69% (18 of 26) using air enema CT. CONCLUSIONS: These findings suggest that the use of gastrografin enema or air enema CT does not significantly affect the diagnostic outcome.

CT Findings of Non-specific Colonic Edema in Liver Cirrhosis

PURPOSE: To evaluate the CT findings and clinical significance of colonic edema in liver cirrhosis. MATERIALS AND METHODS: We retrospectively reviewed the CT scans of 221 cases of clinically diagnosed liver cirrhosis in 173 patients. In 30 of these [23 men and six women aged between 35 and 67 (mean, 54) years], colonic edema was present. We evaluated its distribution (ascending, transverse or descending colon), analysed serum albumin and bilirubin levels, and in both the colonic edema and non-colonic edema group, determined whether ascites was present. Thus, we sought correlation between the presence of colonic edema, the severity of liver cirrhosis, and each parameter. RESULTS: CT revealed colonic edema in 30 of 221 cases (14 %). Of the 30, 13 cases (43 %) were diffuse colonic edema and 17 (57 %) were regional edema. Among these 17 cases, 12 (71 %) were seen only in the ascending colon, while five (29 %) were seen in both the ascending and transverse colon. In the group with colonic edema, the mean level of serum albumin was 2.6 g/dl, and that of serum bilirubin was 4.9 mg/dl; 20 patients ( 67 %) had ascites. In the group without colonic edema, mean levels of serum albumin and serum bilirubin were 3.0 g/dl and 4.1 mg/dl, respectively ; 43 patients (30 %) had ascites. There was no significant statistical difference in serum albumin and bilirubin levels between the colonic edema and non-colonic edema group (p>0.05), though ascites was more common among the former group. CONCLUSION: In cases of liver cirrhosis, CT evidence of colonic edema is not uncommon. The ascending colon is most frequently involved, though disease severity does not vary significantly according to site. When CT reveals the presence of colonic edema, further diagnostic evaluation is not necessary if there is no evidence of clinical symptoms.

Comparison of CT & MRI Findings in the Staging of Rectosigmoid Carcinoma According to New AJCC Classification

PURPOSE: To evaluate the diagnostic accuracy of computed tomography(CT) and magnetic resonance imaging(MRI)in the staging of rectosigmoid carcinoma according to the new AJCC classification. MATERIALS AND METHODS: BetweenAugust 1997 and October 1998, 36 patients with pathologically proven rectosigmoid carcinoma who underwent preoperative CT and MRI were evaluated. CT scans were performed with spiral CT in 27 cases and with conventional CT in nine. In all cases, MR images were obtained using a 1.5T unit and a body arrayed coil. T1- and T2-weightedimages were obtained in axial, sagittal, and coronal planes. On the basis of the results of CT scanning and MRI,tumor stage was determined by two radiologists using the AJCC cancer staging manual(1997). They reached aconsensus and compared their results with the pathologic stage. The T-stage was T1 in three cases, T2 in two, T3in 26, and T4 in five. The N-stage was N0 in 16 cases, N1 in seven, and N2 in 13. RESULTS: In the case of CT, thediagnostic accuracy of T-staging was 67%, and that of N-staging, 44%. For MRI, the corresponding figures were 83%and 67%. For T-staging, MRI was more accurate than CT(P=0.006), but for N-staging, the diagnostic accuracy of CT and MRI was statistically equivalent (P>0.05). CONCLUSION: MRI using a body arrayed coil is a useful preoperative diagnostic tool for the local staging of rectosigmoid carcinoma.

Staging of Colorectal Carcinoma by Spiral CT with Water Enema: Correlation with Pathologic Staging Using New AJCC Classification

PURPOSE: In cases of colorectal cancer, to correlate the spiral CT staging with water enema with thepathologic staging according to the new AJCC classification. MATERIALS AND METHODS: Ninety four patients withpathologically proven carcinoma of the colon who had un-dergone spiral CT with water enema were evaluated. CTscans were obtained after enema involving about 600-1,200mL of water. Scanning was performed from thediaphragmatic dome to the symphysis pubis using 10mm collimation thickness, 12mm table feed, and 10mmreconstruction interval. The TNM stage, as seen on spiral CT, was determined without reference to the pathologicresults. Staging was performed according to the new AJCC cancer staging manual(1997). The pathologic T-stage wasT1 in four cases(4.3%), T2 in 11(11.7%), T3 in 72(76.6%), and T4 in seven(7.4%). The pathologic N-stage was N0 in57 cases(60.6%), N1 in 25 cas-es(26.6%), and N2 in 12(12.8%). The pathologic M-stage was M0 in 90 cases(95.7%) andM1 in four(4.3%). RESULTS: The detection rate of colon cancer using spiral CT with water enema was 97.9%. At theT-stage, pathologic correlation was good in 68.1% of cases(64/94). Nine patients(9.6%) were overstaged and21(22.3%) were understaged. At the N-stage, pathologic correlation was good in 54.3% of cases(51/94), with 27pa-tients(28.7%) overstaged and sixteen(17.0%) understaged. At the M-stage, pathologic correlation was good in95.7% of cases(90/94). Four patients(4.3%) were overstaged. CONCLUSION: The accuracy of staging of colorectalcarcinoma by spiral hydro-CT was 68.1% at the T-stage, 54.3% at the N-stage, and 95.7% at the M-stage. As seen onspiral CT with water enema, the T-stage tended to-wards understaging and the N-stage towards overstaging.

Virtual Colonoscopy with Electron Beam CT: Correlation with Barium Enema, Colonoscopy and Pathology

PURPOSE: To perform virtual colonoscopy using electron beam tomography(EBT) in potients in whom a colonicmass was present, and to compare the results with those obtained using barium enema, colonoscopy and grosspathologic specimens. MATERIALS AND METHODS: Ten patients in whom colonic masses were diagnosed by either bariumenema or colonoscopy were involved in this study. There were nine cases of adenocarcinoma and one of tubulovillousadenoma. Using EBT preoperative abdominopelvic CT scans were performed. Axial scans were then three-dimensionallyreconstructed to produce virtual colonoscopic images and were compared with barium enema, colonoscopy and grosspathologic specimens. Virtual colonoscopic images of the masses were classified as either 1)polypoid, 2)sessile,3)fungating, or 4)annular constrictive. We also determined whether ulcers were present within the lesions andwhether there was obstruction. RESULT: After virtval colonoscopy, two lesions were classified as polypoid, oneas sessile, five as fungating and two as annular constrictive. Virtual colonoscopic images showed good correlationwith the findings of barium enema, colonoscopy and gross pathologic specimens. Three of six ulcerative lesionswere observed on colonoscopy; in seven adenocarcinomas with partial or total luminal obstruction, virtualcolonoscopy visualized the colon beyond the obstructed sites. In one case, barium contrast failed to pass throughthe obstructed portion and in six cases, the colonoscope similarly failed. CONCLUSION: Virtual colonoscopiescorrelated well with barium enema, colonoscopy and gross patholoic specimens. They provide three dimensionalimages of colonic masses and are helpful for the evaluation of obstructive lesions.

CT Findings of Early Right Colonic Diverticulitis

PURPOSE: To investigate the CT findings of acute right colonic diverticulitis, and to determine the differencebetween these and published reports deseribing left colonic, especially sigmoid, diverticulitis. MATERIAL AND METHODS: In 13 patients with acute right lower quadrant pain who underwent ultrasonography a normal appendix wasdemonstrated and acute right colonic diverticulitis was suspected. CT was performed within 24 hours and thefindings were analysed by two radiologists. For further confirmation of diverticulitis, follow-up barium enemaswere performed in ten patients. RESULTS: Inflamed diverticula were visible in all cases, and were solitary. Ninecases occured in the ascending colon and four in the cecum; in particular, eleven occurred around the ileocecalvalve. In three cases, the inflamed diverticulum was less than 1cm in diameter;in five cases, 1-2cm;in three,2-3cm, and in two, 3-4cm. These were able to be classified into two major forms. In three cases it was nodularwith hyperattenuation and some inhomogeneity, and ten shows the target form with thick walls and a central cavity.In five of these target lesions, the wall pattern was partially or completely inhomogenous, or multilayered. Thematerials filling the central cavity were gas in five cases, fecalith in two, and fluid in three. Abnormalpericoloic fat infiltrations were seen in twelve cases(92%), segmental colonic wall thickening in eleven(85%),other not-inflamed diverticula in five(38%), mesenteric lymph node enlargement in three(23%), free pericecal fluidcollection in three(23%), and perirenal fascial thickenings in two(15%). The complications such as remote abscesscavity, colonic obstruction, fistula or perforation were not found. On barium colon study, diverticulitis was inall cases confirmed by the presence of barium in the deformed diverticulum. CONCLUSION: Among CT findings foracute right colonic diverticulitis, the most important and pathognomonic is inflamed diverticula; the forms ofthese vary, and include gangrenous diverticulitis. The CT findings of early right colonic diverticulitis inKoreans might not, however, reveal the complications which sigmoid diverticulitis frequently involves; in patientswith right lower quadrant pain imaging studies are performed promptly, and for the mesentery, the anatomical basebetween right and left colons is different.