Inflammatory fibroid polyp presenting with intestinal invagination: sonographic and correlative imaging findings

We report a case of a large inflammatory fibroid polyp of the small bowel presenting with intussusception in a 22-year-old man. Sonography demonstrated a solid, mobile, homogeneous, echogenic mass surrounded by the typical mural layers of an invaginated ileum. CT demonstrated a well-defined intraluminal solid mass with an attenuation of 17 HU. The pathologic diagnosis after segmental ileal resection was ileal inflammatory fibroid polyp.

Sonographic and color Doppler findings of gastrointestinal myogenic tumors with a marked extraluminal growth

We present five cases with gastro (four cases) and intestinal (one case) myogenic tumors with a marked extraluminal growth. In all cases, incidental discovery of an asymptomatic mass prompted further examination. One of three cases with a pedunculated growth mimicked a gallbladder cancer. The mass of a jejunal leiomyoma case changed markedly in location under probe compression. Color Doppler sonography confirmed not only the hypervascular nature of the mass but also feeding and draining vessels.

Utility of flexible sigmoidoscopy as an adjunct to double-contrast barium enema examination

BACKGROUND

There is controversy regarding the most appropriate investigation for suspected colorectal carcinoma. We offered these patients same-day flexible sigmoidoscopy (FS) and double-contrast barium enema (DCBE).

METHODS

We reviewed the results of 117 consecutive adult patients. All patients underwent FS followed by DCBE on the same day. The radiographs were reviewed by two of the authors who were blinded to the clinical information, flexible sigmoidoscopy reports, and the original DCBE report.

RESULTS

One hundred seventeen patients made up the study population. Thirty-four of the 117 patients had polyps and/or carcinoma. Three malignant tumours were detected by DCBE; one of these was also seen on FS, and the other two cancers were out of FS range. Fifty-three polyps were found by FS; nine were removed by biopsy prior to the enema examination. Of the 44 remaining polyps, DCBE failed to detect 87% of the 0-9-mm group and 67% of the >9-mm group. Ten polyps were seen only on DCBE; seven of these 10 were beyond the range of the sigmoidoscope, and the three remaining polyps were less than 5 mm.

CONCLUSION

DCBE is insensitive in the detection of rectosigmoid polyps. FS should continue to be used as a complementary examination to DCBE in the investigation of suspected colorectal carcinoma.

Visualization of colorectal polyps with spiral CT colography: evaluation of processing parameters with perspective volume rendering

PURPOSE

To evaluate two key processing steps for detection of colon polyps with spiral computed tomographic (CT) colography with perspective volume rendering (PVR): image reconstruction and opacity assignment of the attenuation data.

MATERIALS AND METHODS

Spiral CT was performed in 10 patients with known polyps confirmed at colonoscopy, and detailed quantitative analyses were performed of data obtained in four. First, anatomic fidelity of three-dimensional (3D) images generated from two-dimensional (2D) source images with equal voxel dimensions (87%-90% overlap) was compared with 3D images generated from 2D source images with unequal voxel dimensions (0%-80% overlap). Next, the relative dimensions of colorectal polyps to adjacent structures were evaluated for various opacity threshold settings. Then, step and sigmoidal opacity functions were compared with respect to image smoothness and edge sharpness.

RESULTS

PVR images generated after interpolation of image data reconstructed with at least 60% overlap were equivalent in image quality to PVR images generated from source images with equal voxel dimensions. Relative polyp-to-haustral fold dimensions demonstrated substantial distortions with opacity thresholds below -700 HU. The 3D PVR images generated with the sigmoidal opacity function were significantly smoother than those generated with the step opacity function (paired t test, P < .02), with small differences noted in edge sharpness.

CONCLUSION

Use of highly overlapping source images (87%-90%) was not necessary to generate 3D PVR images of colorectal polyps. Image artifacts were suppressed with use of an appropriate opacity threshold and a sigmoidal opacity function without substantial loss in edge sharpness.

Detection of colorectal polyps with CT colography: initial assessment of sensitivity and specificity

PURPOSE

To estimate the sensitivity and specificity of computed tomographic (CT) colography in detection of colorectal polyps and to compare these findings with those at axial CT.

MATERIALS AND METHODS

In 70 consecutive patients, CT colography and colonoscopy were performed. Helical axial CT images and CT colographic images (multiplanar two- and three-dimensional endoluminal images) were evaluated separately by two radiologists blinded to results from colonoscopy and other imaging studies. Findings were compared with those at colonoscopy, which was the standard.

RESULTS

The sensitivity and specificity for the two observers with CT colography averaged 75% and 90% in patients with adenomas 10 mm in diameter or larger, 66% and 63% in patients with adenomas 5 mm in diameter or greater, and 45% and 80% for patients with adenomas less than 5 mm in diameter, respectively. Sensitivity and specificity with axial CT were lower than those with CT colography (58% and 74%, respectively) in patients with adenomas 10 mm in diameter or larger.

CONCLUSION

Compared with axial CT, CT colography appears to have superior sensitivity and specificity in detection of clinically important colorectal adenomas. Early performance of CT colography seems promising for detection of colorectal polyps 5 mm and larger.

Colorectal lesions: evaluation with CT colography

Computed tomographic (CT) colography is a promising technique for differentiating malignant or premalignant colorectal disease from benign lesions. In this technique, helical CT data are used to produce reformated two-dimensional (2D) CT images and simulated endoscopic images of the colon. Adenomatous polyps 0.7 cm in diameter or larger are easily detected on CT colographic images: A pedunculated polyp is identified by means of its stalk, whereas a sessile polyp appears as a polypoid soft-tissue mass projecting into the air-filled lumen of the colon. However, flat adenomas (lesions raised less than 2 mm from the surface of the colon) are difficult to detect with CT colography. In cases of colorectal cancer, both intraluminal and extraluminal disease can be evaluated with CT colography. Although CT colography does not allow differentiation between hyperplastic and adenomatous polyps, lipomas can be confidently diagnosed because of their fatty attenuation on reformatted 2D images. Pseudolesions that can produce false-positive findings at CT colography include the ileocecal valve, retained stool, retained barium, respiratory artifacts, and a stool-filled diverticulum.

A case of systemic malignant lymphoma with intestinal involvement of lymphomatous polyposis type

Multiple lymphomatous polyposis is a rare type of intestinal lymphoma characterized by non-Hodgkin's lymphoma of follicular mantle cell origin and extremely poor prognosis. We report a case of systemic lymphoma with the intestinal involvement of multiple lymphomatous polyposis. Although radiographic and endoscopic features of the case were compatible with multiple lymphomatous polyposis, histologic evidence suggested the diagnosis of diffuse large cell lymphoma rather than mantle cell lymphoma. Our case seems to be unique in its histologic findings and also in its prognosis, because the patient has been alive for more than 50 months after diagnosis.

Colorectal cancer. Radiologic diagnosis

Barium enema examination of the colon has proved to be safe and accurate in the detection of colorectal polyps and cancers. The study must be performed by dedicated fluoroscopists and interpreted with the highest standards so that it remains comparable in accuracy to colonoscopy. This article summarizes the key points necessary for accomplishing this goal.

The investigation of symptomatic inguinal hernia: a complication of barium enema

The controversy surrounding the value of performing screening barium enema in patients with inguinal hernia persists. It was Myers & Zollinger who, in 1942, reviewed 200 consecutive cases of inguinal hernia and noted that 18%; of patients complained of gastrointestinal symptoms. Of these, two cases of adenocarcinoma were discovered on further evaluation. Subsequently, many authors have reported a low diagnostic yield of barium enema in patients with inguinal hernia unless specific colonic symptoms were present. We present a case in which this investigation was indicated, but led to irreducibility.

Pseudolipoma of inverted Meckel's diverticulum: clinical, radiological and pathological correlation

Three cases of isolated inverted Meckel's diverticulum are described. In two cases an initial pathological diagnosis of small bowel lipoma was suggested. In a third case central fat was demonstrated on CT and peristalsis of the intraluminal polypoid mass was observed during US examination. In all three cases small bowel enema examination demonstrated the lesion. Correlation of the clinical, radiological and pathological features is emphasised, as this will allow the correct diagnosis.

Colorectal polyp detection with CT colography: two- versus three-dimensional techniques. Work in progress

PURPOSE

To compare detection of colorectal polyps with two-dimensional (2D) computed tomographic (CT) colography only, three-dimensional (3D) CT colography only, and a combination of 2D and 3D CT colography.

MATERIALS AND METHODS

A total of 11 computer-simulated polyps (1-10 mm) were placed randomly in five identical CT data sets for images of a 72-year-old man's polyp-free, rectosigmoid colon. Fifteen CT colographic data sets were produced: five with 2D CT images only, five with 3D CT images only, and five with 2D and 3D CT images. Two radiologists randomly, blindly, and independently evaluated all 15 data sets to detect the simulated polyps.

RESULTS

No polyps 2 mm or smaller were detected. No statistically significant differences in the detection of colorectal polyps were found between the three techniques. However, the combination of 2D and 3D CT colography resulted in polyp detection rates that were greater than or equal to those of 2D or 3D CT colography alone. Flat polyps were more difficult to detect than sessile polyps. Five false-positive findings occurred with 2D CT colography.

CONCLUSION

A combined display of 2D and 3D CT images likely provides the greatest rate of detection of colorectal polyps.

Comparison of two techniques of transrectal ultrasonography for the assessment of local extent of polypoid tumours of the rectum

The capability of transrectal ultrasonography (TRUS) to differentiate between benign and malignant rectal polyps was evaluated. Digital palpation and sigmoidoscopy were followed by TRUS with a 7.5-MHz linear-array transducer, in a blinded design. In the second part of the study the procedure was extended with an acoustic window system (AWS), preventing compression of the polyp. Pathological examination after surgical resection was used for definitive diagnosis in 110 polyps. Digital examination detected 10 of 22 carcinomas with adenomas, compared with 19 by TRUS (P < 0.01). However, TRUS falsely indicated 20 of 49 adenomas to be carcinomas, compared with 4 out of 49 by digital examination (P < 0.001). TRUS combined with AWS detected 23 of 24 carcinomas, and gave a false positive result in only 3 of 26 benign polyps. The results suggest that the best way to discriminate between benign and malignant rectal polyps is to combine TRUS with AWS.

Intussusception: ability of fluoroscopic images obtained during air enemas to depict lead points and other abnormalities

PURPOSE

To evaluate the ability of fluoroscopic images obtained during air enemas to depict or exclude lead points of intussusceptions and other abnormalities that require surgical treatment in the absence of intussusception.

MATERIALS AND METHODS

The clinical, radiologic, surgical, and pathologic findings were reviewed in 14 patients with lead points or other lesions.

RESULTS

Fluoroscopic images failed to depict a lead point in 10 patients. The air enema easily reduced intussusceptions with benign lead points in seven patients. Fluoroscopic images depicted pathologic lead points in two patients and were normal in two patients with intussusception. Fluoroscopic images failed to depict an abnormality that required surgery in the absence of intussusception in two patients.

CONCLUSION

Successful reduction of an intussusception does not always rule out a lead point. Other imaging studies, the patient's condition, and laparotomy may also be necessary to diagnose and treat lead points and other lesions.

Dilemma of an inverted cecal diverticulum simulating a pedunculated polyp: CT appearance

The computed tomographic (CT) appearance of an intussuscepting cecal diverticulum is described. Some features on CT suggest that the term "inverted" may not be accurate.

Hydrosonography in the evaluation of colorectal polyps

Prewarmed saline enemas and transabdominal ultrasound (hydrosonography) were used to evaluate 17 consecutive children with rectal bleeding before colonoscopy. Twelve patients with polyps were identified (10 by ultrasound, 10 by endoscopy): these included multiple hyperplastic polyps (1), multiple polyps (1), solitary polyps (9), and pseudopolyps (1). Ultrasound identified 11 polyps in 10 patients, missing two patients with small polyps less than 0.5 cm in diameter. The polyps were hyperechoic ovoid masses fixed to the colonic wall, with a stalk (7), submucosal infolding (5), and intraluminal floating (5). There was one false positive. Colonoscopy was refused by one patient and failed to reach beyond the distal sigmoid in another following previous surgery for malrotation. Colonoscopy was superior in identifying finer mucosal detail (colitis, ulcers, proctitis, anal fissure) and in detecting smaller polyps (sessile polyps, hyperplastic polyps). Hydrosonography of the colon is a simple, relatively non-invasive procedure that provides an alternative, radiation-free examination of the whole colon before colonoscopy. It is complementary to colonoscopy in the management of rectal bleeding in children.

Inverted Meckel's diverticulum simulating a pedunculated small bowel polyp

We report a rare case of an isolated inverted Meckel's diverticulum presenting with acute gastrointestinal hemorrhage. The radiographic appearances simulated a pedunculated small bowel polyp. The radiographic and pathologic features are described and a brief review of the reported cases is provided.

[Hydrocolonic sonography in the study of colonic diseases. Comparison with double-contrast enema]

This study was aimed at assessing the diagnostic value of hydrocolonic sonography (HS), a new technique of US examination of the colon during water enema, in colonic diseases. HS was performed on 120 clinically selected patients and was followed by double contrast barium enema (DCBE) in all patients, by endoscopy in 85, by pathology in 50 and by surgery in 36 patients. We obtained good quality images in 86% of cases, middle quality findings in 10% and poor results in 4% of cases. HS allowed the 5 layers of the colonic wall to be visualized. Forty of 50 polyps bigger than 1 cm, 9/10 cases of granulomatous colitis and diverticulitis were recognized and distinguished from cancer and 31/32 carcinomas were found--3 of them were locally invasive tumors, even though endoscopic biopsy had diagnosed them as adenomas. Compared with DCBE, HS exhibited lower sensitivity in recognizing small polyps (80% vs. 92%) but higher specificity (100% vs. 92.8%); in the diagnosis of carcinoma, HS exhibited higher sensitivity (96.8% vs. 90.6%) and the same specificity (about 100%); the depiction of parietal layers allowed also tumor staging. At present, HS cannot be proposed as the examination of choice to study polyps because of its limitations in recognizing them; nevertheless, HS appears to exhibit some advantages over DCBE in tumor detection and staging. HS is a simple, fast and safe technique which is well tolerated and easily repeatable, which calls for further investigation of its potentials, also because improved operator's experience is sure to increase HS reliability.

Double-contrast barium enema study with computed radiography: assessment in detection of colorectal polyps

Feasibility and diagnostic performance of digital radiography in gastrointestinal imaging have not been fully investigated. We performed double-contrast barium enema study with computed radiography (CR-DCBE) on a routine basis, and the efficacy of this system for detection of colorectal polyps was investigated. The files of 76 patients, who had undergone both CR-DCBE and colonoscopy, were reviewed by two observers who were blinded to the colonoscopic findings. The radiation dose of CR-DCBE was reduced to 50% of conventional film-screen system. By using colonoscopic findings as a reference, the sensitivity and positive predictive value for colorectal polyps were 66% to 71% and 32% to 41%, respectively. There was no significant interobserver difference. The use of postprocessing with gray-scale reversal and edge enhancement did not significantly improve the results. The sensitivity for polyps smaller than 1 cm was comparable with published data of conventional film-screen systems. Our preliminary results show that CR-DCBE has an acceptable sensitivity for detection of colorectal polyps. It is suggested that the use of CR is a promising approach to digital gastrointestinal radiography.

Detection of small mucosal and submucosal polyps with helical CT scanning in a patient with intestinal neurofibromatosis

The detection of small (diameter 5-12 mm) mucosal jejunal polyps and small (diameter 14-26 mm) submucosal rectal polyps with helical C.T.-scanning in a patient with neurofibromatosis is described. Because a volume is scanned with helical CT, overlapping image reconstructions can be made allowing to produce a contiguous image set for cine mode display. The combination of 'volume scanning' with cine mode display helps in the dynamic visualization of the course of the intestinal loops. This might result in a better depiction of small lesions within the bowels and in a better differentiation between mucosal folds and the lesions.