The value of dynamic ultrasound scanning in Crohn's disease

Small intestinal contrast ultrasonography for the detection of small bowel complications in Crohn's disease: correlation with intraoperative findings and magnetic resonance enterography

BACKGROUND AND AIMS

In evaluating small bowel Crohn's disease (CD), small intestine contrast-enhanced ultrasonography (SICUS) is emerging as an alternative to magnetic resonance enterography (MRE). This retrospective study compared the diagnostic accuracy of SICUS and MRE with surgical findings, and their level of agreement.

METHODS

We identified a cohort of CD patients investigated by either SICUS and/or MRE that subsequently required resective bowel surgery within 6 months. The accuracy and agreement of SICUS and MRE to detect small bowel complications were compared with intraoperative findings using kappa coefficient (κ). Agreement between SICUS and MRE in those undergoing both modalities was also assessed.

RESULTS

A total of 67 patients were evaluated; 25 underwent SICUS and 17 underwent MRE prior to surgery. Another 25 patients underwent both SICUS and MRE. When compared with intraoperative findings, the sensitivity of SICUS and MRE was 87.5% and 100%, respectively, in detecting strictures, 87.7% and 66.7% for fistulae, 100% for both in identifying abscesses, 100% and 66.7% for bowel dilatation, and 94.7% and 81.8% in defining bowel wall thickening. When correlating SICUS and MRE with surgery, there was a high level of agreement in localizing strictures (κ = 0.75, 0.88, respectively), fistulae (κ = 0.82, 0.79) and abscesses (κ = 0.87, 0.77). Concordance between SICUS and MRE was substantial or almost complete in identifying stricturing disease (κ = 0.84), their number and location (κ = 0.85), fistulae (κ = 0.65), and mucosal thickening (κ = 0.61).

CONCLUSION

SICUS accurately identified small bowel complications and correlated well with MRE and intraoperative findings. SICUS offers an alternative in the preoperative assessment of CD.

Diagnostic accuracy of small intestine ultrasonography using an oral contrast agent in Crohn's disease: comparative study from the UK

AIM

To evaluate the usefulness of small intestine contrast-enhanced ultrasonography (SICUS) using an oral contrast agent in routine clinical practice by assessing the level of agreement with the established techniques, small bowel follow-through (SBFT) and computed tomography (CT), and diagnostic accuracy compared with the final diagnosis in the detection of small bowel Crohn's disease (CD) and luminal complications in a regional centre.

MATERIALS AND METHODS

All symptomatic known or suspected cases of CD who underwent SICUS were retrospectively reviewed. The level of agreement between SICUS and SBFT, CT, histological findings, and C-reactive protein (CRP) level was assessed using kappa (κ) coefficient. Sensitivity was demonstrated using the final diagnosis as the reference standard defined by the outcome of clinical assessment, follow-up, and results of investigations other than SICUS.

RESULTS

One hundred and forty-three patients underwent SICUS of these 79 (55%) were female. Eighty-six (60%) were known to have CD and 57 (40%) had symptoms suggestive of intestinal disease with no previous diagnosis. Forty-six (55%) of the known CD patients had had at least one previous surgical resection. The sensitivity of SICUS in detecting active small bowel CD in known CD and undiagnosed cases was 93%. The kappa coefficient was 0.88 and 0.91 with SBFT and CT, respectively. SICUS detected nine patients who had one or more small bowel strictures and six patients with a fistula all detected by SBFT or CT.

CONCLUSION

SICUS is not only comparable to SBFT and CT but avoids radiation exposure and should be more widely adopted in the UK as a primary diagnostic procedure and to monitor disease complications in patients with CD.

Noninvasive imaging of the small bowel in Crohn's disease: the final frontier

The substantial morbidity and mortality associated with Crohn's disease underlines the importance of accurate assessment at presentation, during follow-up, when investigating complications, and when evaluating the response to therapeutic interventions. Accurate methods are required to quantify the severity and extent of disease.

Ultrasound and inflammatory bowel disease

Transabdominal bowel sonography is a fast, efficient, and cheap way of examining the intestines. It is also virtually hazard-free and well accepted by patients. During the last 20 years, it has been established as a procedure for detecting bowel disease early in the diagnostic workup. Although rather unspecific, the method is sensitive for detection of bowel disease and can be applied to find the extent and location of inflammatory bowel disease. In patients with known ulcerative colitis and Crohn disease, it can also be used for follow-up because it is easily repeatable and radiation-free. Because it can be applied to find both intraluminal and peri-intestinal pathological features, it is a particularly valuable tool for the detection of complications of Crohn disease as stenosis, fistulas, and abscesses. Neither B-mode nor Doppler techniques have been proven obviously useful in categorizing disease activity, but new techniques using intravenous contrast might come closer to solving this question. Finally, recent longitudinal studies using transabdominal bowel sonography show that it can also give important prognostic information and be used for monitoring the effect of therapy.

Severity of postoperative recurrence in Crohn's disease: correlation between endoscopic and sonographic findings

BACKGROUND

Crohn's disease (CD) recurrence is currently assessed by ileocolonoscopy. Small intestine contrast ultrasonography (SICUS) visualizes the small bowel lesions in CD, although its role after curative resection is undefined. We aimed to investigate the accuracy of SICUS in assessing CD recurrence after ileocolonic resection when using ileocolonoscopy as a gold standard. The correlation between the bowel wall thickness (BWT) measured by SICUS and the endoscopic score of recurrence was also assessed.

METHODS

The analysis included 72 CD patients with ileocolonic resection requiring ileocolonoscopy, undergoing SICUS within 6 months. Recurrence was assessed by ileocolonoscopy using the Rutgeerts' score. SICUS was performed after PEG ingestion and findings compatible with recurrence included: increased BWT (>3 mm), bowel dilation (>25 mm) or stricture (<10 mm).

RESULTS

Ileocolonoscopy detected recurrence in 67/72 (93%) patients. SICUS detected findings compatible with recurrence in 62/72 (86%) patients (5 false negative (FN), 4 false positive (FP), 1 true negative (TN), 62 true positive (TP)), showing a 92.5% sensitivity, 20% specificity, and 87.5% accuracy for detecting CD recurrence. The BWT detected by SICUS was correlated with the Rutgeerts' score (P = 0.0001; r = 0.67). The median BWT, the extent of the ileal lesions, and the prestenotic dilation were higher in patients with an endoscopic degree of recurrence >or=3 versus <or=2 (P < 0.001) and the lumen diameter was lower in patients with a Rutgeerts' score >or=3 versus <or=2 (P < 0.0001).

CONCLUSIONS

: Although SICUS and ileocolonoscopy provide different views of the small bowel, SICUS shows a significant correlation with the endoscopic findings. SICUS may represent an alternative noninvasive technique for assessing CD recurrence after ileocolonic resection.

Contrast-enhanced ultrasonographic evaluation of inflammatory activity in Crohn's disease

BACKGROUND & AIMS

We sought to test the diagnostic accuracy of ultrasound (US), color Doppler US (CD-US), and contrast-enhanced US (CE-US) in the evaluation of inflammatory activity in patients with Crohn's disease (CD), and to correlate the findings of these sonographic studies with inflammatory activity, as scored by the CD activity index (CDAI).

METHODS

Patients with CD were enrolled in the study. Radiologists performing the scans were blinded to clinical status. Baseline US, CD-US, and CE-US examinations were conducted with high-frequency probes (8-14 and 5-7 MHz) before and after injection of sulfur hexafluoride-filled microbubbles. The diagnostic accuracy of baseline US, CD-US, and CE-US were calculated by using the endoscopic and histologic findings as reference standards and correlated with the CDAIs by using the Pearson linear correlation coefficient.

RESULTS

Forty-seven patients (20 men; 27 women; mean age +/- SD, 38 +/- 14 years) with a CDAI > 150 (n = 30) or < 150 (n = 17), were recruited. CE-US showed the highest performance, with 93.5% sensitivity, 93.7% specificity, and 93.6% overall accuracy. CE-US revealed 3 bowel wall perfusion patterns after microbubble injection: submucosal enhancement and inward and outward transparietal enhancement. The linear correlation coefficient for CE-US versus CDAI was 0.74 (P < .0001); for baseline US (assessing thickness, length, and multilayer appearance of the diseased bowel) versus the CDAI, the coefficients were 0.68 (P < .0001), 0.47 (P = .0009), and 0.60 (P < .0001), respectively; and for CD-US versus CDAI the coefficient was 0.73 (P < .0001).

CONCLUSIONS

CE-US has a high sensitivity and specificity in detecting inflammatory activity and a strong correlation with the CDAI.

Non-invasive techniques for assessing postoperative recurrence in Crohn's disease

Postoperative recurrence after ileo-colonic resection is a feature of Crohn's Disease (CD), almost 73% of patients show endoscopic recurrence at 1 year and 90% at 3 years. After surgical resection for CD, symptoms may be related to the surgical resection itself. Moreover, the development of an early severe endoscopic recurrence within 1 year represents a risk factor for early clinical recurrence. On the basis of these observations, the early detection and assessment of asymptomatic endoscopic recurrence may allow a timely and appropriate treatment of CD patients after ileo-colonic resection. At this purpose, conventional colonoscopy with ileoscopy currently represents the gold standard for assessing CD recurrence, graded according to the Rutgeerts' score. Lesions compatible with CD recurrence can be also detected by conventional radiology, including small bowel follow through and enema, both associated with a high radiation exposure. Due to the ineluctable course of CD after resection, and to the need of a proper follow up for assessing CD recurrence, several alternative, non invasive techniques have been searched in order to assess the post-operative recurrence, including: faecal alpha 1-antitrypsin clearance, faecal calprotectin, 99Tc-HMPAO scintigraphy, virtual colonoscopy, ultrasonography and, more recently, wireless capsule endoscopy (WCE) and Small Intestine Contrast Ultrasonography (SICUS). Among these, current evidences suggest that in experienced hands, ultrasound examination by SICUS represents a non-invasive technique useful for assessing recurrence in CD patients under regular follow up after surgery. The same findings are suggested for WCE, although the impact risk related to the recurrence or to the surgical anastomosis itself limits the use of this non-invasive technique for assessing CD recurrence after surgery.

Wireless capsule endoscopy and small intestine contrast ultrasonography in recurrence of Crohn's disease

BACKGROUND

The best available tool to assess recurrence of Crohn's disease (CD) is ileocolonoscopy (CC). Small intestine contrast ultrasonography (SICUS) and wireless capsule endoscopy (WCE) are noninvasive techniques able to detect small bowel lesions. In a prospective longitudinal study, we aimed to investigate the usefulness of SICUS and WCE for assessing postoperative recurrence of CD 1 year after surgery, using CC as the gold standard.

METHODS

Twenty-two patients (11 men, median age 33 years, range 22-67 years) undergoing ileocolonic resection for CD were prospectively followed from July 2003 to May 2006, with the Crohn's Disease Activity Index (CDAI) used for clinical assessment every 3 months for 1 year. At 1 year, recurrence was assessed by SICUS and CC, followed by WCE. CD recurrence was assessed by CC (Rutgeerts score). SICUS was performed after ingestion of polyethylene glycol, and WCE was performed with Given M2A equipment.

RESULTS

At 1 year, all 22 patients had inactive CD (CDAI < 150). In 5 patients, WCE was not performed because of luminal narrowing or stenosis. Seventeen of the 22 patients had all 3 techniques performed. CC detected recurrence in 21 of 22 patients. Lesions compatible with recurrence were detected by SICUS in all 22 patients (1 false positive). When considering only the 17 patients studied by all 3 techniques, recurrence was detected by CC in 16 of 17 patients, whereas lesions compatible with recurrence were detected by SICUS in all 17 patients (16 true positives [TPs], 1 FP) and by WCE in 16 of 17 patients (16 TPs, 1 true negative).

CONCLUSIONS

The present findings suggest that SICUS and WCE may be used as noninvasive techniques for the assessment of recurrence of CD in patients being regularly followed up after ileocolonic resection.

Role of US in detection of Crohn disease: meta-analysis

PURPOSE

To evaluate the accuracy of ultrasonography (US) in the detection of Crohn disease in adults by systematically reviewing both cohort studies (those including patients whose clinical characteristics were consistent with those caused by an inflammatory bowel disease) and case-control studies (those in which patients with Crohn disease were compared with patients with other bowel diseases or healthy control subjects).

MATERIALS AND METHODS

The MEDLINE, EMBASE, and Cochrane Library databases were used to retrieve all the cross-sectional studies that assessed the diagnostic accuracy of US against that of one of several predefined reference standards (ie, radiologic, endoscopic, or histologic findings). The studies that fulfilled the inclusion criteria were identified, and their methodological quality was evaluated. Of the 2860 primary studies identified, two case-control and five cohort series fulfilled the inclusion criteria. Statistical analysis was performed by using the summary receiver operating characteristic (SROC) model.

RESULTS

The ranges of US sensitivity and specificity for the diagnosis of Crohn disease reported for the included series were 75%-94% and 67%-100%, respectively; the heterogeneity of these values prevented the calculation of a cumulative value. The SROC curve revealed a clear cutoff effect that depended on the chosen bowel wall thickness threshold. Sensitivity and specificity of 88% and 93%, respectively, were achieved when a bowel wall thickness threshold greater than 3 mm was used, and sensitivity and specificity of 75% and 97%, respectively, were achieved when a threshold greater than 4 mm was used.

CONCLUSION

US examination seems appropriate for confirming or excluding Crohn disease as a diagnosis in a clinical context characterized by a pretest probability of Crohn disease that ranges from 12% to about 60%. In particular, for Crohn disease limited to the ileum, US may represent a valid alternative to the small-bowel series, while for colonic involvement US may be useful in ruling out the diagnosis.

Small intestine contrast ultrasonography: an alternative to radiology in the assessment of small bowel disease

BACKGROUND

Radiology and transabdominal ultrasonography (TUS) are used in the evaluation of the small bowel; however, the former technique is limited by radiation exposure, and the latter by its inability to visualize the entire small bowel.

AIM

To evaluate the diagnostic accuracy of small intestine contrast ultrasonography (SICUS) to assess the presence, number, site, and extension of small bowel lesions.

SUBJECTS AND METHODS

TUS, SICUS, and small bowel follow-through (SBFT) were performed in 148 consecutive patients (78 women; age range, 12 to 89 yr), 91 with undiagnosed conditions, and 57 with previously diagnosed Crohn's disease (CD).

RESULTS

In the undiagnosed patients, the sensitivity and specificity of TUS and SICUS were 57% and 100%, and 94.3% and 98%, respectively. In the CD patients, the sensitivity of TUS and SICUS was 87.3% and 98%, respectively. In comparison with SBFT, the extension of lesions was correctly assessed with SICUS and greatly underestimated with TUS. The concordance index between SBFT and SICUS for the number and site of lesions was 1 and 1 (P < 0.001), respectively, in undiagnosed patients, and 0.81 and 0.83 (P < 0.001), respectively, in CD patients. Between SBFT and TUS, the concordance index was 0.28 and 0.27 (not significant), respectively, in undiagnosed patients, and 0.28 and 0.31 (not significant), respectively, in CD patients.

CONCLUSIONS

The diagnostic accuracy of SICUS is comparable to that of a radiologic examination, and is superior to that of TUS in detecting the presence, number, extension, and sites of small bowel lesions. These findings support the use of noninvasive SICUS for an initial investigation when small bowel disease is suspected and in the follow-up of CD patients.

Crohn's disease: a comparative prospective study of transabdominal ultrasonography, small intestine contrast ultrasonography, and small bowel enema

BACKGROUND

Small intestine contrast ultrasonography (SICUS), when performed after distention of the small bowel lumen with an iso-osmolar polyethylene glycol electrolyte-balanced solution, shows high sensitivity (100%) and specificity (97%) in detecting small bowel abnormalities in patients who have not received a diagnosis but in whom there is a suspicion of intestinal diseases. The diagnostic yield of SICUS remains to be established in detecting small bowel lesions in patients with proven Crohn's disease (CD) in comparison with transabdominal ultrasonography (TUS), and in relationship to the experience of the operator, using small bowel enema (SBE) as the "gold standard."

AIM

The aim of this study was to evaluate the diagnostic value of SICUS, when performed by a sonologist with 1 year of experience, and TUS, when performed by a sonologist with 10 years of experience, compared to SBE in the assessment of the site, extension, and stenosis of small intestinal lesions in CD patients.

PATIENTS AND METHODS

A total of 28 consecutive patients (men, 16; women, 12; age range, 21 to 60 yr) with a diagnosis of CD underwent TUS and SICUS, which were performed by 2 sonologists who were unaware of the radiologic findings, on the same day. SICUS was performed after the ingestion of 375 mL of a polyethylene glycol contrast solution. A standard SBE was performed on a different day by an expert radiologist who was unaware of the sonographic findings.

RESULTS

Sensitivities in the detection of small bowel lesions were 96% for TUS and 100% for SICUS. Compared with SBE, SICUS detected the presence of 4 lesions in the jejunum that had been missed by TUS. The mean (+/-SD) extent of the ileal disease was 22 +/- 12.5 cm when measured during SBE, 14.5 +/- 8.6 cm when measured during TUS, and 19.5 +/- 12.5 cm when measured during SICUS [P = 0.05 (SICUS versus SBE)]. The correlation of the extension of the lesions between SICUS and SBE (r = 0.88) was better than that between TUS and SBE (r = 0.64). The sensitivities of TUS and SICUS in the detection of at least 1 stricture were 76% and 94%, respectively. Sensitivity and specificity in assessing prestenotic dilatation were 50% and 100%, respectively, at TUS, and 100% and 90%, respectively, at SICUS.

CONCLUSION

In inexperienced hands, SICUS is a more accurate technique for assessing CD lesions, and the accuracy is better than that of TUS performed by an expert sonologist. The use of SICUS, instead of SBE, could be indicated for the follow-up of patients with CD.

Modern imaging of Crohn's disease using bowel ultrasound

Technological advancement of ultrasound (US) equipments and understanding of bowel appearances with high resolution US during the last decade has led to consideration of this imaging procedure as an important tool for inflammatory bowel diseases assessment. In particular, Crohn's disease (CD) for its pathologic characteristics (that is, inflammatory infiltration of the entire bowel wall with possible extension to the surrounding mesentery) is the disease entity which has mainly taken advantage from this non-invasive, radiation-free technique. Beside correctly defining anatomic location and extension of CD lesions within the bowel in the majority of cases, US also shows perigut abnormalities and may demonstrate complications such as fistulas and abscesses. With the help of Power Doppler function, some additional information may be obtained about the local activity of the disease which is particularly useful in the presence of strictures. New US technologies (such as those using intravenous bolus contrast agents or oral nonabsorbable anechoic solutions) may further improve diagnostic capability of US in this context, thus probably revolutioning the diagnostic approach to this disease in the near future, particularly during follow-up in CD of the small bowel.

Doppler enhancement after intravenous levovist injection in Crohn's disease

Although transabdominal bowel sonography (TABS) has been proposed as a reliable tool to assess increased bowel wall thickness (BWT), the most common sonographic pattern in patients with Crohn's disease (CD), its accuracy is limited in the diagnosis of CD. We therefore tried to assess whether color Doppler enhancement with Levovist, a galactose-based intravenous sonographic contrast agent able to enhance the arterial Doppler signal, increases TABS accuracy. Thirty-one patients with ileal CD, diagnosed by endoscopy and enteroclysis, and 20 healthy volunteers were examined with conventional TABS. Color Doppler of the intramural enteric vessels was then performed before and after intravenous injection of Levovist. Twenty-two CD patients had a BWT >4 mm, and 16 of them presented with active disease. Two of the remaining nine CD patients, all with BWT <4 mm, presented with active disease. By means of color Doppler we identified six patients with inactive disease, normal BWT, and normal basal Doppler signal intensity, who showed an enhanced Doppler signal in intramural vessels after contrast agent bolus. Four of these patients, identified only by color Doppler after Levovist injection, relapsed within 6 months. In our experience, sensitivity and specificity of TABS, integrated with additional stimulated acoustic emission mode, were 96.7% and 100%, respectively. The use of Levovist in color Doppler increases the accuracy of TABS in CD diagnosis and follow-up.

Ultrasonography of the right lower quadrant

Whereas acute appendicitis is the most common cause of right lower quadrant (RLQ) pain, numerous other conditions may cause signs and symptoms that mimic acute appendicitis. These include other appendiceal diseases, inflammatory bowel diseases, nonbowel gastrointestinal conditions, urinary diseases, and, in females, gynecologic diseases and conditions associated with pregnancy. The important role of ultrasonography in the diagnosis of not only acute appendicitis but also each of the other conditions that cause RLQ pain is described. The ultrasound criteria for the positive, negative, and indeterminate appendix ultrasound examination and the sensitivity, specificity, and positive and negative predictive values of this modality are discussed. The limitations of ultrasound in such diagnoses are also discussed, and an algorithm for the management of patients with RLQ pain is suggested.

Hydrocolonic sonography for evaluating inflammatory bowel disease

OBJECTIVE

The purpose of our study was to compare the usefulness of hydrocolonic sonography and (99m)Tc-hexamethylpropyleneamine oxime (HMPAO)--labeled leukocyte scintigraphy in the examination of patients with inflammatory bowel disease, using precise sonographic criteria of bowel involvement.

SUBJECTS AND METHODS

Sixty-eight consecutive patients with active inflammatory bowel disease (34 ulcerative colitis and 34 Crohn's disease), 12 with inactive inflammatory bowel disease, and 10 control subjects were prospectively studied. Patients with active disease underwent clinical assessment, hydrocolonic sonography, scintigraphy, and colonoscopy within 72 hr, whereas patients with inactive disease and control subjects underwent clinical examination and hydrocolonic sonography.

RESULTS

Involvement of a colonic segment by active inflammatory bowel disease was best defined by mucosal thickness greater than 1.5 mm, bowel wall thickness greater than 4 mm, mucosal irregularity, or the absence of haustra; and involvement of the terminal ileum by bowel wall thickness greater than 4 mm. Using these criteria, hydrocolonic sonography had 100% sensitivity for identifying patients with active inflammatory bowel disease and a greater overall accuracy (87%) than scintigraphy (77%) in the assessment of disease extension. In addition, strong correlation was shown between a hydrocolonic sonography activity index and clinical and endoscopic activity indexes.

CONCLUSION

This prospective study provides precise sonographic criteria for the definition of bowel involvement by active inflammatory bowel disease. Hydrocolonic sonography has a greater accuracy than scintigraphy for assessing disease extension and activity. Therefore, hydrocolonic sonography should be considered a first-choice technique to complete the study of inflammatory bowel disease after confirmation of the diagnosis by histology.

Technetium-99m HMPAO-labeled leukocyte imaging compared with endoscopy, ultrasonography, and contrast radiology in children with inflammatory bowel disease

BACKGROUND

The purpose of this study was to evaluate retrospectively the value of leukocyte-labeled scintigraphy, ultrasonography, and contrast radiography compared with endoscopy in children suspected of having inflammatory bowel disease (IBD).

METHODS

Twenty-eight children (17 boys; mean age, 10.2 years) with IBD based on standard colonoscopic, histologic, and radiologic criteria (16 with Crohn's disease, 5 with ulcerative colitis, 5 with nonspecific colitis, I with granulomatous disease, and I with Beh,cet's disease) were included. Endoscopic, ultrasonographic, and contrast radiologic examinations were realized for 28, 23, and 19 children respectively.

RESULTS

Sensitivity and specificity were 75% and 92% for leukocyte-labeled scintigraphy, 39% and 90% for ultrasonography, and 58% and 83% for contrast radiography. The authors noted discontinuous uptake for 14 of 15 true-positive results for patients with Crohn's disease and continuous uptake for 4 of 4 true-positive results for patients with ulcerative colitis. A negative correlation between scan activity index and Lloyd-Still clinical score was found for 11 patients with Crohn's disease (r = -0.77).

CONCLUSIONS

Leukocyte-labeled scintigraphy, a noninvasive and reproducible technique, is a useful tool in the diagnosis and therapeutic strategy of IBD, and provides information on the presence, the intensity, and the extent of the disease, particularly in the terminal ileum. Leukocyte-labeled scintigraphy may not replace colonoscopy with biopsies for diagnosis confirmation. Its reliability seems higher than that of ultrasonography.

Ultrasound in Crohn's disease of the small bowel

OBJECTIVE

The purpose of this work is to prospectively evaluate high resolution ultrasonography with graded compression in the ability to detect Crohn's disease of the small bowel (CDSB) together with its complications and activity signs, compared with enteroclysis, CT and immunoscintigraphy in the mirror of the final diagnosis.

METHODS AND MATERIAL

In a series of 73 consecutive patients, who were referred for enteroclysis with suspected Crohn's disease of the small bowel computed tomography (CT), ultrasound (US), immunoscintigraphy with 99mTc labeled monoclonal antigranulocyte antibody (AGAb) examinations were performed within 10 days from each other. For the final evaluation the diagnosis of CDSB was based on combination of clinical and enteroclysis findings (73 cases) and in 17 cases additional surgical and pathological data were available. The results of other modalities were blinded to the radiologists performing and reading out the exams. The diagnostic values of each modality was assessed also in those 18 patients, who had early Crohn's disease. In the group of 43 patients with proven CDSB who had all the four imaging modalities, the modalities were compared in their ability to demonstrate various pathological conditions related to CD. Increased (>500 ml/min) flow measured by Doppler US in the superior mesenteric artery and increased color signs in the gut wall seen by power Doppler sonography were compared to CDAI.

RESULTS

Of the 73 patients the combination of enteroclysis and clinical tests demonstrated CDSB in 47. The sensitivity, specificity and accuracy of ultrasound were 88.4, 93.3 and 90.4%, respectively. Enteroclysis was the most accurate method. CT was more sensitive than US, but less specific. The accuracy of US, CT and scintigraphy were similar. In the group of 18 patients, who had early CDSB, the sensitivity of US decreased to only 67%, CT and scintigraphy had higher values. Intra- and perimural abscesses, and sinus tracts were also more frequently visualized by US, especially if they were small. US was superior than CT in detecting stenoses and skip lesions, but inferior to enteroclysis. US and CT detected more fistulas, than enteroclysis. Compared to CT, US detected more cases with mesenteric lymphadenopathy, equal cases with abscesses and free peritoneal fluids. In detecting mesenteric inflammatory proliferation CT, and in detecting colonic involvement CT and immunoscintigraphy were slightly superior than graded compression US. Patterns of mural stratification detected by ultrasound correlated well with the enteroclysis severity stages. There was only 59% agreement between increased superior mesenteric artery flow detected by Doppler sonography and CDAI, and 60.5% agreement between increased number of Color pixels in the gut wall measured by power Doppler and increased CDAI.

CONCLUSION

High resolution graded compression sonography is a valuable tool for detecting small intestinal Crohn's disease. It has similar diagnostic values as CT. However in early disease the sensitivity substantially decreases. In known Crohn's disease for following disease course, evaluating relapses and extramural manifestations US is an excellent tool. Doppler and Power Doppler activity measurements do not correlate well with the more widespread clinical activity index.

The accuracy of abdominal ultrasound in the assessment of bowel disorders

BACKGROUND

Little is known about the sensitivity, specificity, and predictive values of transabdominal ultrasonographic (US) findings in a teaching hospital setting.

METHODS

We carried out a prospective study including 227 patients with symptoms suggestive of inflammatory bowel disorder. The Picker 9200 CS equipment (5-mHz curved-array probe) was used to obtain bowel images. Gastrointestinal endoscopy, enteroclysis, bowel enema, computed tomography scan, or bowel surgery was used as reference.

RESULTS

Of 227 patients, 168 had pathologic findings of the bowel as final diagnosis. The overall sensitivity of US was 76%, whereas the positive predictive value was 98%. Overall specificity was 95%. The negative predictive value for bowel disorders was only 58%, since US missed pathologic findings in 48 patients. Subgroup analysis showed a sensitivity of 84% for Crohn's disease, 66% for ulcerative colitis, 46% for bowel tumors, and 60% for diverticulitis. Topographic comparisons showed that US detected inflammatory bowel-wall alterations preferentially in the terminal ileum and colon, whereas abnormalities in the duodenum, jejunum, and rectum were frequently missed (sensitivity, 10%-20%).

CONCLUSIONS

Positive US findings are useful for the diagnosis of bowel processes. US is highly predictive albeit not disease-specific. Negative US examinations, however, do not exclude pathologic bowel processes. A topographic location of pathologic US findings is mostly confined to the colon.

Role of ultrasonography in the diagnosis of postsurgical recurrence of Crohn's disease

OBJECTIVE

Ultrasonography is a valid tool in the diagnosis of Crohn's disease, but its sensitivity, specificity, and overall accuracy in the diagnosis of postoperative recurrence are still not well established. The aim of this study was to evaluate the accuracy of ultrasonography compared with endoscopy in the diagnosis of postoperative recurrence of Crohn's disease.

METHODS

Forty-seven patients resected for Crohn's ileitis were studied by ultrasonography and colonoscopy to detect possible recurrence of the disease; 10 patients operated on for cancer of the right colon were used as controls. Six patients with Crohn's disease were excluded from the study because of failure to endoscopically reach the anastomosis; the remaining 41 patients had both ultrasonography and colonoscopy over a period of 14 days. Sonographic recurrence was defined as the presence of >5 mm thickness of the ileal wall.

RESULTS

Sensitivity, specificity, and overall accuracy of ultrasonography in diagnosis of postoperative recurrence were 81%, 86%, and 83% respectively. Positive predictive value was 96% and negative predictive value was 57%.

CONCLUSION

This study is the first to assess the role of ultrasonography in comparison with endoscopy in detecting Crohn's disease recurrence after surgery. Our data suggest that ultrasonography should be used first in the case of clinical suspicion of Crohn's disease recurrence, reserving ileocolonoscopy for negative or uncertain cases.

Ultrasonographic detection of intestinal complications in Crohn's disease

The aim of this study was to evaluate the sensitivity and specificity of ultrasound (US) in assessing the main abdominal complications of Crohn's disease (CD), such as strictures, fistulas and abscesses. A series of 98 consecutive inpatients with complicated and uncomplicated Crohn's disease, having undergone a complete endoscopic and radiographic evaluation of the intestinal tract, entered the study. In particular, in these patients the presence of strictures, fistulas, and abscesses, detected by means of colonoscopy, small bowel x-ray, double-contrast barium enema, and computed tomography, was also assessed by means of transabdominal US. US sensitivity and specificity in the assessment of stenosis of Crohn's disease were 74.4% and 93.1%, respectively. When ileal and colonic stenosis were considered separately, transabdominal US correctly assessed 84.6% of ileal stenosis and 58.8% of colonic stenosis. Eight of 12 fistulas were detected, but only 50% of enteroenteric fistulas were diagnosed. The presence of abscesses was correctly detected in 83.3% of cases by means of US. Our data suggest that US is a suitable complementary method for the detection of abdominal complications of Crohn's disease, such as strictures and abscesses; however, its usefulness in assessing enteroenteric fistulas seems to be fairly limited.

Sonographic features of colon carcinoma seen with high-frequency transabdominal ultrasound

To assess the value of high-frequency ultrasonography as a diagnostic imaging procedure in patients with colon carcinoma, we first evaluated the sonograms of 37 patients who had been already diagnosed with contrast enema and/or colonoscopy as having colon carcinoma. As a result, the sonographic criteria for diagnosis of a possible colon carcinoma were (1) a localized and irregular thickening of the colonic wall with heterogenous low echogenicity, (2) an irregular contour, (3) a lack of demonstrable movement or change of configuration of the bowel on real-time scanning, and (4) absence of wall stratification. During the last 4 years, 41 consecutive patients had findings meeting our sonographic criteria. In 37 patients (90%), the presence of colon carcinoma was confirmed by contrast enema and/or colonoscopy. Our study suggests that high-frequency real-time ultrasonography may be a useful imaging technique in diagnosis of colon carcinoma.

Ultrasonography as a primary diagnostic tool in patients with inflammatory disease and tumors of the small intestine and large bowel

In 240 patients with predefined indications, the validity of ultrasound imaging as a primary diagnostic procedure was examined prospectively. Ultrasonography revealed normal intestinal findings in 150 patients and pathological lesions in 90 subjects. All patients underwent subsequent endoscopic, radiological, or surgical examination. In 7 patients with Crohn's disease and in 2 patients with radiation colitis, the ultrasound findings were false-negative. In the other 9 cases, ultrasonography suggested false-positive results. Ultrasonographic examination of the small intestine and large bowel had a very high overall validity, with a sensitivity of 90% and specificity of 94%.

Comparison of scintigraphy with indium-111 leukocyte scan and ultrasonography in assessment of X-ray-demonstrated lesions of Crohn's disease

The aim of this study was to compare the results obtained with an indium-111 scan with those obtained with less expensive and harmless ultrasonography to evaluate the location and inflammatory activity of Crohn's disease. Thirty-one patients previously studied with x-ray underwent abdominal 111In scans and ultrasonography (US). Sensitivity and specificity of US in detecting lesions seen with 111In scan were 77% and 92.8%, respectively. Sensitivity and specificity of 111In scan in detecting x-ray-defined lesions were 69.2% and 92.7%; the figures for US were 73% and 93.3%, respectively. Considering the evaluation of disease activity, ultrasonographic bowel wall thickness was significantly related to scintigraphic intensity of emission (r = 0.75 P < 0.01). Our experience suggests that US provided information about the location and inflammatory activity of lesions similar to that obtained from 111In scan.

Sonography in acute colonic diverticulitis. A prospective study

The clinical value of high-resolution real-time sonography for the diagnosis of acute and complicated colonic diverticulitis was prospectively studied in 130 consecutive patients with abdominal complaints, because of which the disease entered into differential consideration. The results of ultrasound investigation were compared with those of clinical examination on admission. Regarding history and initial clinical evaluation, diverticulitis was graded as "highly suspected" in 19 (36.5 percent) out of a total of 52 patients with later proven colonic diverticulitis (prevalence 40 percent), as "possible but equivocal" in 24 (46.2 percent), and as "very unlikely" in the remaining nine (17.3 percent) patients. Ultrasonography enabled the diagnosis of diverticulitis with an overall accuracy of 97.7 percent, a sensitivity of 98.1 percent, and a specificity of 97.5 percent. The predictive values of positive and negative ultrasound examinations were 96.2 percent and 98.5 percent, respectively. The echomorphologic features of acute diverticulitis include visualization of a colon segment presenting with local tenderness on gradual compression, which showed hypoechogenic thickening of the wall and a targetlike appearance in transverse view due to inflammatory changes and muscular thickening. Sonographic signs of peridiverticulitis (hyperechoic halo) were found in 96 percent of patients, echogenic diverticula in 86 percent. Twelve (92 percent) of 13 abdominal abscesses were detected on initial ultrasound examination and could be treated by percutaneous drainage in seven cases, while six required surgical intervention. These results indicate that high-resolution sonography with graded compression is highly sensitive and specific for the imaging diagnoses of acute colonic diverticulitis and complicating abscess.

Detection of liver involvement in inflammatory bowel disease by abdominal ultrasound scan

Fifty patients with ulcerative colitis, 24 with Crohn's disease, and 50 controls were studied by liver function tests and abdominal ultrasound scan. Twenty-two percent of ulcerative colitis patients, 29% of Crohn's disease patients, and none of the controls showed abnormal liver function tests. All subjects with abnormal liver function tests also had changes in ultrasound liver scan, consisting of hepatomegaly and/or a dysechoic liver echo pattern. Furthermore, the same ultrasound changes were observed, in the absence of any liver function test abnormalities, in 58% of ulcerative colitis patients, 50% of Crohn's disease patients and 6% of controls (P less than 0.0005, inflammatory bowel disease versus controls). Overall, some evidence of liver involvement, as judged by abnormal liver tests and/or abnormal ultrasound liver scan, was detected in about 80% of inflammatory bowel disease patients. Six patients with minor abnormalities of liver function tests underwent liver biopsy and 5 of them had pericholangitis. Ultrasound liver scan may provide a useful tool to evaluate the occurrence of liver involvement in inflammatory bowel disease patients.