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

Color Doppler Ultrasound Assessment of Clinical Activity in Inflammatory Bowel Disease

BACKGROUND

Ulcerative colitis (UC) and Crohn's disease (CD) are two varieties of inflammatory bowel disease (IBD). Clinicians need a monitoring technique in the IBD. The disease activity can be assessed with endoscopy, activity indexes, and imaging techniques. Color Doppler US (CDUS) is also a non-invasive, radiation, and contrast material free examination which shows the intramural blood flow.

OBJECTIVE

To evaluate the usefulness of B-mode, CDUS, and a newly developed software Color Quantification (CQ) to determine the activity of the IBD.

METHODS

The disease activity was assessed by clinical activity indexes. Caecum, terminal ileum, ascending colon, transverse colon, and descending colon were evaluated by B-mode, CDUS, and the CQ. Bowel wall thickness (BWT), loss of bowel stratification, loss of haustration, and the presence of enlarged lymph nodes, mesenteric masses, abscesses, fistula, visual vascular signal patterns of the bowel as "hypo and hyper-flow" and the CQ values were investigated. BWT was compared with laboratory results and clinical activities. Vascular signal patterns and the CQ values were compared with BWT and clinical activity. The diagnostic performances of the CQ were investigated.

RESULTS

Fifty-two patients with IBD were evaluated. Patients with increased BWT at the transverse colon had an increased frequency of "hyper-flow" pattern. Clinically active patients had an increased incidence of "hyper-flow" pattern at the terminal ileum, ascending colon, and whole segments. They had increased CQ values at the terminal ileum, ascending colon, and descending colon, and whole segments. A cut-off value for the CQ (24.7%) was obtained at the terminal ileum. In the diagnostic performances of CQ, we observed utilities significantly at the ascending colon, descending colon, terminal ileum, and whole segments. There was a positive correlation between the CQ values and BWT at the caecum, ascending colon, transverse colon, and descending colon.

CONCLUSION

Increased visual vascular signal scores and CQ values might be useful for monitoring the disease activity in patients with IBD.

Bowel Ultrasonography in the Management of Crohn's Disease. A Review with Recommendations of an International Panel of Experts

BACKGROUND

Bowel ultrasonography (US) is considered a useful technique for assessing mural inflammation and complications in Crohn's disease (CD). The aim of this review is to appraise the evidence on the accuracy of bowel US for CD. In addition, we aim to provide recommendations for its optimal use.

METHODS

Publications were identified by literature search from 1992 to 2014 and selected based on predefined criteria: 15 or more patients; bowel US for diagnosing CD, complications, postoperative recurrence, activity; adequate reference standards; prospective study design; data reported to allow calculation of sensitivity, specificity, agreement, or correlation values; articles published in English.

RESULTS

The search yielded 655 articles, of which 63 were found to be eligible and retrieved as full-text articles for analysis. Bowel US showed 79.7% sensitivity and 96.7% specificity for the diagnosis of suspected CD, and 89% sensitivity and 94.3% specificity for initial assessment in established patients with CD. Bowel US identified ileal CD with 92.7% sensitivity, 88.2% specificity, and colon CD with 81.8% sensitivity, 95.3% specificity, with lower accuracy for detecting proximal lesions. The oral contrast agent improves the sensitivity and specificity in determining CD lesions and in assessing sites and extent.

CONCLUSIONS

Bowel US is a tool for evaluation of CD lesions in terms of complications, postoperative recurrence, and monitoring response to medical therapy; it reliably detects postoperative recurrence and complications, as well as offers the possibility of monitoring disease progression.

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.

Prediction of the need for surgical intervention in obstructive Crohn's disease by 18F-FDG PET/CT

We preoperatively determined the accuracy of (18)F-FDG PET/CT for differentiating fixed muscle hypertrophy and fibrotic stenoses from acute transmural inflammatory stenoses in patients with Crohn's disease (CD) scheduled to undergo surgical resection for obstructive symptoms.

METHODS

Seventeen patients with known CD prospectively underwent (18)F-FDG PET/CT before already-planned surgery for obstructive symptoms. Image interpretation was by consensus of 2 readers with knowledge of patient participation in the study but not of other clinical history. Lesions were qualitatively graded on a 5-point scale for the presence of increased (18)F-FDG uptake consistent with active inflammation. Maximum lean standardized uptake value (SUL(max)) was determined for lesions scored 1 or more. Imaging results were compared with the pathologic grading of inflammation and predominant histopathologic subtype for each patient's surgical specimen, whether mainly inflammation, fibrosis, or muscle hypertrophy.

RESULTS

Thirteen of the 17 patients underwent surgery (median, 28 d after PET/CT; range, 2-148 d), and 12 of these 13 had histopathologic correlation. Despite the predominant histopathologic subtype (inflammation, 5; fibrosis, 4; and muscle hypertrophy, 3), acute and chronic inflammation, fibrosis (median, 50%; range, 40%-90%), and muscle hypertrophy (median, 20-fold thickening; range, 9- to 40-fold thickening) were found in all patients. SUL(max) was significantly higher in severe than in mild-to-moderate chronic inflammation (8.2 +/- 2.8 vs. 4.7 +/- 2.5, P = 0.04). No patient with predominantly fibrosis or muscle hypertrophy (n = 7) had an SUL(max) greater than 8. Visually, 10 of 12 patients on PET/CT were considered to have active inflammation of the bowel.

CONCLUSION

Patients with CD who undergo surgery for obstructive symptoms have histopathologically mixed findings of inflammation, fibrosis, and muscle hypertrophy. Qualitative PET interpretations were quite sensitive, but additional semiquantitative analyses using SUL(max) helped identify patients with active inflammation. This information may be beneficial for referring gastroenterologists considering medical therapy versus surgery for patients with CD who present with obstructive symptoms.

Reproducibility of bowel ultrasonography in the evaluation of Crohn's disease

BACKGROUND

Bowel ultrasonography is increasingly used in the detection and follow-up of patients with Crohn's disease, but a limitation to its further diffusion is the lack of standardisation of ultrasonography parameters.

AIMS

This study aimed to standardise the most common bowel ultrasonography parameters in order to develop an unequivocal imaging interpretation and to assess bowel ultrasonography reproducibility.

PATIENTS

Twenty patients with Crohn's disease were examined.

METHODS

Six ultrasonographers (mean bowel ultrasonography experience=16 years) performed the study. They chose and discussed a common assessment methodology concerning eight ultrasonography parameters: bowel wall thickness, bowel wall pattern, bowel wall blood flow, enlarged mesenteric lymph nodes, mesenteric hypertrophy, abdominal free fluid, and stenosis or fistulae at four preliminary meetings. The day of the study operators were randomised to two rooms where they independently and in turn performed ultrasonography scans. Interobserver agreement was scored by kappa statistics.

RESULTS

Excellent k values were observed for bowel wall thickness (0.72-1). k Values were poor for bowel wall pattern (-0.22-0.85) and good for bowel wall blood flow (0.53-0.89). The presence of lymph nodes was reproducible (0.56-0.90) except in one case (0.25). Concordance on free fluid was excellent (0.85-1), whereas that on mesenteric hypertrophy was generally poor (0.14-0.69). Agreement was excellent for stenosis (0.81-1) whereas that for fistula was fair in room abscesses (0.31-0.48) and very good in room B (0.87-1).

CONCLUSION

Bowel ultrasonography signs used in Crohn's disease can be standardised as most of them showed a fair to good reproducibility. In particular, bowel wall thickness, the most relevant parameter for Crohn's disease detection, showed an excellent reproducibility.

Imaging of the small bowel in Crohn's disease: A review of old and new techniques

The investigation of small bowel morphology is often mandatory in many patients with Crohn’s disease. Traditional radiological techniques (small bowel enteroclysis and small bowel follow-through) have long been the only suitable methods for this purpose. In recent years, several alternative imaging techniques have been proposed. To review the most recent advances in imaging studies of the small bowel, with particular reference to their possible application in Crohn’s disease, we conducted a complete review of the most important studies in which traditional and newer imaging methods were performed and compared in patients with Crohn’s disease. Several radiological and endoscopic techniques are now available for the study of the small bowel; each of them is characterized by a distinct profile of favourable and unfavourable features. In some cases, they may also be used as complementary rather than alternative techniques. In everyday practice, the choice of the technique to be used stands upon its availability and a careful evaluation of diagnostic accuracy, clinical usefulness, safety and cost. The recent development of innovative imaging techniques has opened a new and exciting area in the exploration of the small bowel in Crohn’s disease patients.

Bowel ultrasound in Crohn's disease

Most published studies have found bowel ultrasound to be a useful tool in the management of Crohn's disease. Indeed, it has been successfully used as the imaging technique of choice in screening patients with clinically suspected Crohn's disease. In these patients, bowel ultrasound, which is well accepted by patients, non-invasive and of low cost, may be the first diagnostic tool employed for young patients and can be used in the preliminary diagnostic work-up prior to further invasive tests. The most important application of bowel ultrasound is, however, in the follow-up of patients already diagnosed with Crohn's disease, in whom it may be useful to assess the site and extent of the lesions and to ensure the early detection of intra-abdominal complications, particularly abscesses and strictures. In this regard, improving the ultrasound assessment of intramural blood flow by means of colour power-Doppler ultrasonography and intravenous contrast agents may help to differentiate fibrotic and inflammatory strictures, and to discriminate inflammatory masses from intra-abdominal abscesses. Despite several attempts to correlate ultrasound findings with clinical and biochemical activity, there are as yet no convincing data on the usefulness of ultrasound in assessing the activity of Crohn's disease. In contrast, preliminary results are in agreement regarding the usefulness of ultrasound in the assessment of postoperative recurrence and in monitoring the outcome of the disease following surgery. In fact, the persistence of a thickened bowel wall or increased high bowel wall thickening at ultrasound following surgery has been identified as an index of early surgical recurrence. How these data may be usefully employed in the management of individuals with Crohn's disease needs to be investigated in further studies.

Nuclear medicine imaging of inflammatory/infective disorders of the abdomen

Different nuclear medicine modalities are currently used to study inflammatory and infective disorders of the abdomen. They are usually complementary to radiology and endoscopy, but they play a pivotal role in particular clinical situations. Several radiopharmaceuticals (e.g., 111In or 99mTc labelled white blood cells, monoclonal antibodies, human polyclonal immunoglobulins, 75Ga citrate) are commercially available, but they can not be used indifferently to study abdominal inflammatory disorders. The lack of comparative studies showing the accuracy of each radiopharmaceutical for the study of inflammatory/infective abdominal diseases does not allow the best nuclear medicine technique(s) to be chosen in an evidence-based manner. To this end we performed a meta-analysis of peer reviewed articles published between 1984 and 2004 describing the use of nuclear medicine imaging for the study of inflammatory bowel disorders, appendicitis and vascular graft infections. A guideline for the optimal radiopharmaceutical(s) to be used in each clinical condition and for different aims is provided.

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.

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.

Contrast radiology, computed tomography and ultrasonography in detecting internal fistulas and intra-abdominal abscesses in Crohn's disease: a prospective comparative study

OBJECTIVE

Accurate assessment of intestinal complications of Crohn's disease (CD) is extremely important, both in clinical practice and in trials. The accuracy of radiographic and ultrasonographic diagnosis of internal fistulae and abscesses complicating CD is still debated and requires further investigation. We compared ultrasonography (US) and contrast radiography in detecting intestinal fistulae and abscesses complicating CD.

METHODS

A prospective study was carried out on 625 consecutive CD patients who underwent complete evaluation of the intestinal tract by means of colonoscopy and double contrast barium enema, small bowel enteroclysis, and abdominal ultrasound (US). Computed tomography (CT) was also carried out in cases of severe CD with clinical suspicion of septic complications. The accuracy of US, barium radiology, and CT in detecting internal fistulae and abscesses was assessed by comparing results with intraoperative findings in 128 consecutive patients who underwent operation immediately after diagnostic workup.

RESULTS

Internal fistulae and intra-abdominal abscesses were identified intraoperatively in 56 (43.7%) and 26 (20.3%) patients, respectively. Diagnostic accuracy of US and x-ray studies in detecting internal fistulae was comparable (85.2% vs 84.8%), with sensitivity of 71.4% for US and 69.6% for x-ray studies, and specificity of 95.8% for both. Combination of radiographic techniques and US significantly improved diagnostic accuracy in detection of internal fistulae. In severe cases of CD with clinical suspicion of septic complications such as abdominal mass or fever, the accuracy of US, barium studies, and CT was 88.5%, 80.3%, and 77%, respectively (p = ns). The presence of abscesses was correctly detected in 90.9% of cases by means of US and in 86.4% by CT (p = ns), although accuracy was higher for CT (91.8%) than for US (86.9%) because of false positive results in US studies.

CONCLUSIONS

Despite the fact that barium radiology is widely considered the method of choice in detection of internal fistulae, accuracy is not entirely satisfactory. Comparable accuracy was found for US and CT. The combination of barium and US studies, or the sole use of US in more CD patients with more severe disease, can reliably detect most internal fistulae and abscesses.

Ultrasonographic findings correspond to clinical, endoscopic, and histologic findings in inflammatory bowel disease and other enterocolitides

OBJECTIVE

To compare results obtained by abdominal ultrasonography with clinical findings, including endoscopic and histologic findings, to evaluate the location and activity of inflammatory bowel disease, including disease controls in children.

METHODS

Ninety-two ultrasonographic scans and 41 colonoscopic examinations with biopsies were performed in 78 patients (1 month to 17.8 years of age) with Crohn's disease (n = 26), ulcerative colitis (n = 21), inflammatory bowel disease of indeterminate type (n = 2), and disease controls (other intestinal disorders, including infectious and ischemic lesions; n = 29). Laboratory parameters for inflammatory bowel disease were determined, and disease activity was assessed by a combination of clinical and laboratory data. Bowel wall thickness and echo texture were recorded in a standardized way by ultrasonography and compared with endoscopic and histologic findings in a segment-by-segment comparison.

RESULTS

Sensitivity and specificity of ultrasonography in detecting patients with severe macroscopic lesions depicted on endoscopy were 77% and 83%, respectively. Sensitivity and specificity of ultrasonography in detecting patients with severe histologic inflammation were 75% and 82%. There was a statistically significant correlation between maximal bowel wall thickness and disease activity score (P < .01).

CONCLUSIONS

Abdominal ultrasonography may be helpful in evaluating the location, severity, and inflammatory activity of inflammatory bowel disease in children and young adults.

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.

Preoperative characteristics and postoperative behavior of bowel wall on risk of recurrence after conservative surgery in Crohn's disease: a prospective study

OBJECTIVE

To evaluate in patients with Crohn's disease, using transabdominal ultrasound, the morphologic characteristics of the diseased bowel wall before and after conservative surgery and to assess whether these characteristics and their behavior in the postoperative follow-up are useful and reliable prognostic factors of clinical and surgical recurrence.

SUMMARY BACKGROUND DATA

Ultrasound is effective for evaluating the thickness of bowel wall, the most typical and constant finding of Crohn's disease. No data are currently available concerning the behavior of the diseased intestinal wall after conservative surgery and whether the preoperative characteristics of bowel wall or its behavior after conservative surgery may predict recurrence.

METHODS

In 85 consecutive patients treated with strictureplasty and miniresections for Crohn's disease, clinical and ultrasonographic evaluations were performed before and 6 months after surgery. Assessed before surgery were the maximum bowel wall thickness, the length of bowel wall thickening, the bowel wall echo pattern (homogeneous, stratified, and mixed), and the postoperative bowel wall behavior, classified as normalized, improved, unchanged, or worsened.

RESULTS

A significant correlation was found between a long preoperative bowel wall thickening and surgical recurrence. Bowel wall thickness after surgery was unchanged or worsened in 43.3% of patients; in these patients, there was a high frequency of previous surgery. Patients with unchanged or worsened bowel wall thickness had a higher risk of clinical and surgical recurrence compared with those with normalized or improved bowel wall thickness.

CONCLUSION

With the use of abdominal ultrasound, the authors found that the thickening of diseased bowel wall may unexpectedly improve after conservative surgery, and this is associated with a favorable outcome in terms of clinical and surgical recurrence. In addition to its diagnostic usefulness, ultrasound also provides reliable prognostic information concerning clinical and surgical recurrence in patients with Crohn's disease in the postoperative follow-up.

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.

Doppler ultrasound measurement of intestinal blood flow in inflammatory bowel disease

BACKGROUND

Our aim was to assess the role of Doppler ultrasound (US) in detecting changes in the splanchnic hemodynamic variables measured in patients with active or quiescent inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS) and healthy subjects.

METHODS

Sixty-five patients, 31 with Crohn's disease (CD), 24 with ulcerative colitis (UC), 10 with IBS, and 10 matched normal subjects were evaluated by means of Doppler US. The mean velocity of portal and mesenteric venous flow, the blood flow volume of portal and mesenteric veins, and the resistance index (RI) of the superior mesenteric artery (SMA) were studied in all patients.

RESULTS

Patients with active IBD had a splanchnic venous flow that was significantly higher, and an RI of the SMA significantly lower, than the IBS patients and healthy controls; however, a higher portal and mesenteric blood flow and lower RI of the SMA was documented in patients with active UC but not in those in whom the disease was quiescent. Patients with quiescent CD had significantly higher portal and mesenteric blood flow and lower RI of the SMA than IBS and healthy controls. No significant differences were found between IBS patients, quiescent UC patients, and healthy controls.

CONCLUSION

This study shows that Doppler US can demonstrate splanchnic hemodynamic changes in active IBD patients and, in particular, can be used to differentiate between active and quiescent UC. However, the assessment of CD activity by means of Doppler US requires further investigation.