Characterization of Porcine Epidemic Diarrhea Virus Isolate US/Iowa/18984/2013 Infection in 1-Day-Old Cesarean-Derived Colostrum-Deprived Piglets.

Porcine epidemic diarrhea virus (PEDV) was first recognized in North America in April 2013 and has since caused devastating disease. The objective of this study was to characterize disease and viral detection associated with an original North American PEDV isolate inoculated in neonatal piglets. Thirty-six 1-day-old cesarean-derived and colostrum-deprived piglets were randomly assigned to the control (n = 16) or challenged group (n = 20); the latter were orogastrically inoculated with 1 ml of US/Iowa/18984/2013 PEDV isolate titered at 1 × 10(3) plaque-forming units per milliliter. Rectal swabs were collected from all piglets prior to inoculation and every 12 hours postinoculation (hpi) thereafter, with 4 control and 5 challenged piglets euthanized at 12, 24, 48, and 72 hpi. One piglet had a positive real-time quantitative polymerase chain reaction test on rectal swab at 12 hpi, and all remaining piglets were positive thereafter, with highest viral quantities detected at 24 and 36 hpi. Diarrhea was evident in 30% and 100% of challenged piglets at 18 and 24 hpi, respectively. Viral antigen was detected in enterocytes by immunohistochemistry in the duodenum and ileum of piglets euthanized at 12 hpi and was apparent throughout the small intestine of all piglets thereafter, with villus height:crypt depth ratios consistently below 4:1. Viremia was confirmed in 18 of 20 pigs at euthanasia. Clinical disease was severe and developed rapidly following infection with an original North American PEDV isolate, with lesions, viremia, and antigen detection possible by 12 hpi.

Value of double-contrast barium enema performed immediately after incomplete colonoscopy.

OBJECTIVE: The purpose of this study was to evaluate the ease, completeness, and clinical utility of double-contrast barium enema (DCBE) performed immediately after incomplete colonoscopy. SUBJECTS AND METHODS: During a 30-month period, a prospective study was performed in 103 patients (79 women, 24 men) to determine the ease and completeness of DCBE immediately after failed colonoscopy and any additional useful information provided by the enema. The ease with which DCBE was performed was graded from 1 (easy) to 10 (difficult). RESULTS: DCBE revealed the entire colon in 97 patients (94%). Incomplete DCBE was a result of obstruction and incontinence in three patients each. The mean score for ease of performing DCBE was 5.0. In 14 patients (14%), significant additional diagnostic information was provided by the immediate DCBE. In eight patients, abnormalities were identified on DCBE that had not been seen at colonoscopy (five malignant neoplasms, one diverticular mass, two extrinsic masses, and multiple strictures). In four patients, a suspected colonoscopic abnormality was excluded with DCBE findings; and in two patients, a colonoscopic abnormality was further characterized with DCBE. CONCLUSION: Immediate DCBE after incomplete colonoscopy allows complete colonic evaluation in most cases, often adds vital diagnostic information, and eliminates repeated bowel preparation and unnecessary delay in diagnosis.

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.

A prospective blinded randomized trial comparing oral sodium phosphate and polyethylene glycol solutions for bowel preparation prior to barium enema.

PURPOSE: A prospective blinded randomized trial to compare oral sodium phosphate (NaP) solution with polyethylene glycol (PEG) preparations as bowel preparation prior to barium enema examination. PATIENTS AND METHODS: One hundred and ten patients consented to take part and each patient was randomly assigned to receive either NaP (Oral Fleet Prep) or PEG (Lyteprep). The barium enemas were reviewed by two radiologists blinded to the type of bowel preparation the patient had received. The colon was divided into six segments and each segment was assessed for the amount of stool and water present, the adequacy of coating, the ability to exclude inflammatory bowel disease and the presence of polyps. A score of 0-3 (failure to good) was assigned per segment on each of these criteria. RESULTS: The average individual score for the NaP group was 89.2. The average individual score for the PEG group was 88.81. No significant difference was found in the quality of bowel cleansing between the two agents. In particular there was no significant difference in the scores for water retention (two-tailed P = 0.748) and the difference for the quality of coating was considered not quite significant (two-tailed P = 0.0818). CONCLUSION: Oral sodium phosphate cleans the colon as well as polyethylene glycol solutions. The use of NaP will result in significant cost savings and improved patient compliance.

Improving visualization of distal and terminal ileum during the small bowel meal: an evaluation of fluoroscopic manoeuvres.

This study evaluated a variety of fluoroscopic manoeuvres used during small bowel meals for assessment of the terminal ileum and pelvic loops of small bowel. The purpose was to identify those manoeuvres which provide maximum diagnostic yield. Fifty-six consecutive patients undergoing small bowel meal and pneumocolon entered the study. The individual manoeuvres were graded and their contribution to diagnostic quality determined. An analysis of variance was used to determine the diagnostic value of the manoeuvres. There was a significant difference in the diagnostic quality provided by the different manoeuvres. Compression of the terminal ileum with the 'F spoon' and of the pelvic bowel loops with the compression paddle in the supine position provided the best diagnostic information in single contrast. The double contrast images obtained with the pneumocolon contributed most to the diagnostic quality of the examination. The results enable us to recommend a sequence of manoeuvres which are most likely to provide diagnostic views of the terminal ileum and pelvic ileal loops yielding maximum information and optimizing use of fluoroscopic time.

Digital subtraction in defecography.

BACKGROUND: Defecography is commonly used in investigation of pelvic floor and anorectal dysfunction, and incorporates measurement of pelvic floor movement during various maneuvers. These measurements are usually referenced to bony landmarks, particularly the ischial tuberosities. These bony landmarks may be difficult to visualize; theoretically, the use of digital subtraction in filming defecography studies should eliminate the need to pinpoint bony position. METHODS: We filmed 25 defecogram studies in both non-subtracted and subtracted formats, and interpreted each study blindly, subsequently comparing diagnoses and measurements. RESULTS: Subtraction was of limited benefit in only one case, was impossible in one case, added no useful information in 18 cases, and hindered visualization of abnormalities in five cases. CONCLUSIONS: Because of the multiple overlapping densities and the inability to restrict patient movement, digital subtraction is unhelpful in defecography.

Colorectal cancer overlooked at barium enema examination and colonoscopy: a continuing perceptual problem.

PURPOSE: To evaluate reasons for missed diagnosis of colorectal carcinoma at barium enema (BE) examination and colonoscopy and determine if standards have improved since a similar study in 1981. MATERIALS AND METHODS: Relevant studies obtained within 3 years of diagnosis in 161 patients with colorectal carcinoma treated in 1990 were reviewed. RESULTS: Twenty-seven carcinomas were overlooked at BE examination and seven at colonoscopy. Fifteen percent of BE examination errors were purely perceptive (ie, the tumor was visible in retrospect). Another 15% were purely technical. Combined perceptive and technical errors occurred in 45% of cases. Interpretive errors (ie, the lesion was misinterpreted as benign) occurred in 25% of cases. CONCLUSION: Similar reasons for missing diagnoses of colorectal cancer at BE examination were seen in 1990 and 1981, with a high rate of perceptive errors. Double reading BE studies may reduce this rate, and readiness to perform BE examination after an incomplete colonoscopy may reduce colonoscopic "misses."

Colon cancer detection: an algorithm using endoscopy and barium enema.

A review of findings on flexible sigmoidoscopy (FS), colonoscopy and selected double-contrast barium enema (DCBE) radiographs from a group of 66 patients with rectal bleeding was performed to test the value of an algorithm in the detection of colonic cancers and polyps. In this algorithm the FS findings would direct patients either to colonoscopy or to a modified DCBE which focused attention on the colon proximal to the sigmoid. Only patients with neoplasms diagnosed by FS, or by MDCBE after negative FS, would proceed to colonoscopy. The study population contained four cancers, 11 polyps > 5 mm and 11 polyps < or = 5 mm; FS+MDCBE missed four polyps, all < 5 mm. For polyps > 5 mm and cancer, FS+MDCBE had a sensitivity of 100%, a specificity of 82%, a negative predictive value of 1.0 and a positive predictive value of 0.62. Using the algorithm, 24 patients (36%) would have required colonoscopy. The results suggest that FS+MDCBE is a potentially valuable method for screening patients for colonic neoplasia.

Same-day computed tomography during arterial portography and delayed high-dose iodine computed tomography: an efficient approach to imaging potentially resectable liver tumours.

Preoperative imaging in patients with potentially resectable liver tumours has traditionally been performed in specialized hepatobiliary centres. To assess the feasibility and value of establishing a same-day, pre-resectional hepatic imaging service, computed tomography during arterial portography (CTAP) and delayed high-dose iodine computed tomography (DICT) were used to examine patients considered suitable for curative hepatic resection. The study group comprised 27 patients (14 from hospitals not affiliated with a university and 13 from two university-affiliated hospitals) for whom pre-referral imaging showed tumour distribution amenable to resection. Among the patients from centres not affiliated with a university, seven had undergone ultrasonography (US) and equilibrium-phase CT, four had undergone US and unenhanced CT, two had undergone equilibrium-phase CT only and one had undergone bolus dynamic incremented CT (BDCT) only. For 12 of the patients coming from the university-affiliated centres, the pre-referral imaging had consisted of US and BDCT; the other had undergone US only. After CTAP and DICT, 20 (74%) of the 27 patients were reclassified as having unresectable disease: 7 (54%) of the 13 patients who had undergone BDCT before CTAP and DICT and 12 (92%) of the 13 patients who had undergone unenhanced or equilibrium-phase CT, as well as the patient who had undergone US only. By averting laparotomy in 20 of the patients, CTAP and DICT resulted in short-term health care savings of about $160,000. These findings suggest that BDCT was underused in the hospitals not affiliated with university centres.(ABSTRACT TRUNCATED AT 250 WORDS)

Single-visit screening and treatment of first-degree relatives. Colon cancer pilot study.

A pilot study has been carried out to evaluate three aspects of screening of first-degree relatives of patients with colon cancer in four Hamilton hospitals; yield of adenomas, feasibility of a one-visit approach to screening and treatment, and compliance. Protocol included flexible sigmoidoscopy after full bowel preparation, followed immediately by either therapeutic colonoscopy or diagnostic barium enema, depending on the flexible sigmoidoscopy findings. We found adenomas in 19 percent of 88 first-degree relatives, with a mean age of 52, compared with an expectation of 8 percent. The protocol was found to be acceptable to the relatives and workable for the various groups of physicians in three of four hospitals, despite many initial logistic difficulties. Numerous problems were encountered with compliance of referring physicians, index patients, relatives, and investigating physicians.

Double-contrast barium enema studies: effect of multiple reading on perception error.

The images from 60 double-contrast barium enema (DCBE) examinations of patients who had also undergone colonoscopy were reviewed independently by three radiologists. The average radiologist detected 70.2% of the 46 radiologically visible lesions. The reports of the individual observers were combined to generate double and triple reading reports. The corresponding average double and triple reading combinations resulted in detection of 83.3% and 89.0%, respectively, of the visible lesions. These increases in sensitivity over those of the readings of the single observers were clinically and statistically significant. They were, however, accompanied by some decreases in specificity. The results confirm the concept that false-negative perception error is a major problem in the interpretation of DCBE examinations and indicate that multiple reading is an effective way to reduce this error.

Prospective comparison of double contrast barium enema plus flexible sigmoidoscopy v colonoscopy in rectal bleeding: barium enema v colonoscopy in rectal bleeding.

Rectal bleeding often heralds serious colonic disease. The literature suggests that colonoscopy is superior to barium enema plus sigmoidoscopy, although no good comparative studies exist. Seventy one patients with overt rectal bleeding had prospectively flexible sigmoidoscopy, double contrast barium enema and colonoscopy completed independently. Against the gold standard, the sensitivity and specificity of colonoscopy were 0.69 and 0.78 respectively for a spectrum of colonic lesions, while for combined flexible sigmoidoscopy and double contrast barium enema these values were 0.80 and 0.56, respectively. When assessing adenoma or carcinoma, colonoscopy was more sensitive at 0.82 v 0.73, while flexible sigmoidoscopy plus double contrast barium enema was superior for detecting diverticular disease. The positive predictive value for colonoscopy was 0.87 against 0.81 for flexible sigmoidoscopy and double contrast barium enema. This study confirms that colonoscopy should be a first line investigation in subjects likely to require biopsy or therapeutic intervention.

Colorectal polyps: a correlation of radiological and pathological findings.

Ninety colorectal polyps seen on double contrast barium enema were reviewed and note was made of surface and base characteristics, size, site and the presence of associated disease. Results were then correlated with the histology. The radiological characteristics of each histological type of polyp encountered are described. Because of the variation in radiological appearance of each histological type and similarities in appearance between these types, we conclude that radiology cannot accurately predict the histology of a colorectal polyp.

A comparison of Golytely and standard preparation for barium enema.

A randomized prospective trial was performed comparing Golytely (with bisacodyl) with our standard two-day catharsis and bowel washout regimen as colon preparation for double-contrast barium enema examinations. Of the 107 patients who participated, 50 received the standard preparation and 57 Golytely. Two radiologists reviewed the enema films without knowledge of which preparation had been used. No significant difference was detected either in the number of failed preparations or in the quality. We conclude that routine use of Golytely is preferable to methods involving catharsis and standard tap water enemas for barium enema examination, on the grounds that it is equally effective, yet more convenient for patients and for the radiology department, and reduces total costs.

Pain after barium enema: effect of CO2 and air on double-contrast study.

One hundred fifty-one consecutive patients scheduled for double-contrast barium enema studies were assigned randomly to insufflation with either air or carbon dioxide (CO2) in a double-blind, prospective trial. Within 24 hours after the enema study, the patients were contacted by telephone by an interviewer, who completed a standard questionnaire. Radiographs from the enema studies were assessed for quality by two radiologists. Pain experienced after the procedure was graded from 0 (none) to 4 (severe). Clinically relevant (grades 2-4) pain was experienced by 30% of patients after insufflation with room air, compared with 11% of patients in whom CO2 was used for insufflation (P = .005). The mean pain score for CO2 was 0.4, and for room air, 1.2 (P less than .005). Although five patients experienced grade 4 pain after insufflation with air, no patient reported severe pain after CO2 insufflation. Post-evacuation films confirmed there was significantly less residual gas in the CO2 group. The quality of radiographs was equal in the two groups. CO2 has advantages for use in the double-contrast barium enema examination.

Rectal biopsy as a cause of rectal ulceration.

We report three patients in whom the performance of a rectal biopsy produced an ulcer that was found during a subsequent examination (two at double-contrast barium enema examinations and one at colonoscopy). In each case, the iatrogenic ulcers presented an unusual appearance and resulted in the performance of inappropriate follow-up studies.

The colitides.

Diverse signs may be seen on barium enema in the various forms of colitis. Barium enema is only reasonably specific in the diagnosis of Crohn's disease and ulcerative colitis once the other possible diseases have been excluded from consideration by biopsy, microscopy, culture, or therapeutic trial. In particular, campylobacter colitis has proved to be such a common entity that many patients originally thought to have had one attack of ulcerative colitis, ischemic colitis, or Crohn's colitis may never have had these diseases. Many of the relatively specific signs can be seen in a variety of conditions. For example, aphthae in the colon may be seen in Crohn's disease, yersinia enterocolitis, Behçet's syndrome, amebiasis, ischemia, tuberculosis, and campylobacter colitis. Continuity of disease is characteristic in ulcerative colitis. Nevertheless, patches of healing may occur, so that a rare patient may be seen during a resolving attack of ulcerative colitis in whom only scattered patches of active disease can be seen on barium enema. In general, few radiologic signs on barium enema are truly specific for one disease, with penumatosis cystoides coli being an exception to this rule. However, the sensitivity of barium enema with currently available materials for double-contrast techniques is such that radiology continues to be useful at present in diagnosing the colitides and in managing patients.

Evaluation of double contrast barium enemas performed by radiographic technologists.

This study was undertaken to see if radiographic technologists could be trained to perform double contrast barium enemas of a quality comparable to that produced by gastrointestinal radiologists and radiology residents. One technologist was from a remote rural hospital and the other from a university gastrointestinal radiology department. After initial training the two technologists continued to produce work of high quality. Analysis of the films showed that there was no significant difference between those films produced in the rural hospital and in the university centre. We recommend more widespread training of radiographic technologists in this work.