Volume navigation with contrast enhanced ultrasound and image fusion for percutaneous interventions: first results.

OBJECTIVE: Assessing the feasibility and efficiency of interventions using ultrasound (US) volume navigation (V Nav) with real time needle tracking and image fusion with contrast enhanced (ce) CT, MRI or US. METHODS: First an in vitro study on a liver phantom with CT data image fusion was performed, involving the puncture of a 10 mm lesion in a depth of 5 cm performed by 15 examiners with US guided freehand technique vs. V Nav for the purpose of time optimization. Then 23 patients underwent ultrasound-navigated biopsies or interventions using V Nav image fusion of live ultrasound with ceCT, ceMRI or CEUS, which were acquired before the intervention. A CEUS data set was acquired in all patients. Image fusion was established for CEUS and CT or CEUS and MRI using anatomical landmarks in the area of the targeted lesion. The definition of a virtual biopsy line with navigational axes targeting the lesion was achieved by the usage of sterile trocar with a magnetic sensor embedded in its distal tip employing a dedicated navigation software for real time needle tracking. RESULTS: The in vitro study showed significantly less time needed for the simulated interventions in all examiners when V Nav was used (p<0.05). In the study involving patients, in all 10 biopsies of suspect lesions of the liver a histological confirmation was achieved. We also used V Nav for a breast biopsy (intraductal carcinoma), for a biopsy of the abdominal wall (metastasis of ovarial carcinoma) and for radiofrequency ablations (4 ablations). In 8 cases of inflammatory abdominal lesions 9 percutaneous drainages were successfully inserted. CONCLUSION: Percutaneous biopsies and drainages, even of small lesions involving complex access pathways, can be accomplished with a high success rate by using 3D real time image fusion together with real time needle tracking.

Magnetic resonance enterography with and without biphasic contrast agent enema compared to conventional ileocolonoscopy in patients with Crohn's disease.

BACKGROUND: Magnetic resonance imaging (MRI) of the bowel is a valuable diagnostic tool for assessing disease activity in patients with inflammatory bowel disease (IBD). We compared magnetic resonance enterography (MRE) with and without water enema to conventional ileocolonoscopy to evaluate the advantage of a water enema for MRI diagnostics of Crohn's disease (CD). METHODS: We prospectively evaluated 50 patients with known CD. MRE with enema was performed in 23 cases, whereas 27 patients received an MRE without enema. All patients underwent conventional ileocolonoscopy. We assessed the degree of inflammation in both modalities, evaluating up to seven bowel segments in each patient. We compared MRE with and without rectal enema to each other and to conventional ileocolonoscopy. RESULTS: MRE achieved a sensitivity and specificity of 100% and 74%, respectively, for detection of inflammation in the terminal ileum with enema and a sensitivity and specificity of 72% and 87%, respectively, without enema. Considering the colon, MRE with enema had a sensitivity of 79% (specificity 96%), while the examination without enema showed a sensitivity of 38% (specificity 99%). MRE with enema proved statistically superior to MRE without enema in detecting inflammation in the terminal ileum, ascending colon, and rectum (P < 0.05). CONCLUSIONS: MRE with enema is a valuable diagnostic tool for assessing inflammation in CD patients. Water enema is well tolerated and significantly improves detection of inflammation in the terminal ileum. Water enema should therefore be included in MRE protocols for CD patients.

Comparison of high-resolution ultrasound and MR-enterography in patients with inflammatory bowel disease.

AIM: To compare the results of high-resolution ultrasound (HR-US) and magnetic resonance enterography (MRE) examinations in patients with inflammatory bowel disease (IBD). METHODS: The reports of 250 consecutive cases with known IBD, who had an MRE and HR-US examination, were retrospectively analyzed. Using a patient-based approach we evaluated morphological disease features such as affected bowel wall, stenosis, abscess and fistula. The comparison between the two modalities was based on the hypothesis, that any pathological change described in any imaging modality was a true finding, as no further standard of reference was available for complete assessment. RESULTS: Two hundred and fifty examinations representing 207 different patients were evaluated. Both modalities assessed similar bowel wall changes in 65% of the examinations, with more US findings in 11% and more MRE findings in 15%. When the reports were analyzed with regard to "bowel wall inflammation", US reported more findings in 2%, while MRE reported more findings in 53%. Stenoses were assessed to be identical in 8%, while US found more in 3% and MRE in 29% (P < 0.01). For abscess detection, US showed more findings in 2% (n = 4) while MRE detected more in 6% (n = 16). US detected more fistulas in 1% (n = 2), while MRE detected more in 13% (n = 32) (P < 0.001). The most common reason for no detected pathology by US was a difficult to assess anatomical region (lesser pelvis, n = 72). CONCLUSION: US can miss clinically relevant pathological changes in patients with IBD mostly due to difficulty in assessing certain anatomical regions.

Influence of percutaneous abscess drainage on severe postoperative septic complications in patients with Crohn's disease.

PURPOSE: Severe postoperative intra-abdominal septic complications (IASC) such as an anastomotic leak, intra-abdominal abscess, and fistula are significantly associated with the presence of spontaneous intra-abdominal abscess at the time of laparotomy in patients with Crohn's disease (CD). The purpose of this study was to compare the incidence of severe postoperative IASC in patients undergoing intestinal resections with and without preoperative percutaneous abscess drainage (PAD) before definitive surgery. METHODS: Using a prospective surgical database, we searched for patients with CD and spontaneous intra-abdominal abscesses who underwent intestinal resection at our hospital from May 2005 to February 2009. Postoperative IASC were defined as anastomotic leaks, abscess, and fistula within 1 month after surgery. We compared the incidence of postoperative IASC in patients with (group I) and without (group II) preoperative PAD (Fisher's exact test). RESULTS: We identified 25 patients (15 men, 10 women; mean age, 31 years) with spontaneous intra-abdominal abscesses. PAD was performed in 12 of 25 patients (48%), with an average of 37 days before surgery (range, 6-83 days). The overall rate of postoperative IASC was 48% (12 of 25 patients). In group I, postoperative IASC occurred in 3 of 12 patients (25%). In group II, postoperative IASC were assessed in 9 of 13 patients (69%). The differences between these two groups were considered to be statistically significant (p = 0.04). CONCLUSION: PAD of intra-abdominal abscesses before surgery could significantly reduce the occurrence of severe postoperative IASC in patients with CD.

Comparison of conventional abdominal CT with MR-enterography in patients with active Crohn's disease and acute abdominal pain.

RATIONALE AND OBJECTIVES: Patients with known Crohn's disease (CD) and an acute onset of severe abdominal pain attending an emergency room frequently undergo contrast-enhanced emergency computed tomography (CT) for complication assessment. To assess small bowel changes, an additional dedicated imaging procedure such as magnetic resonance enterography (MRE) is regularly performed. Therefore, these patients undergo two imaging procedures, although the clinical and diagnostic value of such an approach is not known. In a retrospective study, we compared the diagnostic value of a conventional abdominal CT with a dedicated small bowel MRE to assess bowel wall changes as well as typical complications in patients with advanced CD. MATERIALS AND METHODS: We retrospectively evaluated 53 patients with CD having a conventional abdominal multidetector-CT (MD-CT) and MRE within 2 days. Image quality and bowel inflammation was analyzed for each bowel segment. Lymph nodes, abscesses, and fistulas were evaluated. RESULTS: For small bowel and colon assessment, there was no significant difference for image quality between CT and MRE. Inflammation diagnosis was not significantly different between CT (69.4%) and MRE (71.4%). Colonic inflammation was diagnosed in 30.2% based on CT and 14.3% based on MRE. The difference for the detection of lymph nodes was significant (CT 49; MRE 27), whereas the differences between fistula (CT 25, MRE 27) or abscesses (CT and MRE 32) detection were not significant. CONCLUSIONS: In patients with known advanced CD with acute abdominal pain conventional abdominal MD-CT, which is frequently performed as an emergency imaging procedure, is sufficient for bowel wall assessment. Based on our data, additional dedicated small bowel imaging such as MRE seems not to be necessary.

Meta-analysis: effect of monotherapy and combination therapy with inhibitors of the renin angiotensin system on proteinuria in renal disease.

BACKGROUND: Reduction of proteinuria is associated with delayed progression of chronic kidney disease. Reports suggest that angiotensin-receptor blockers (ARBs) reduce proteinuria, but results are variable. The relative effect of ARBs and angiotensin-converting enzyme (ACE) inhibitors, and their combined administration, remains uncertain. PURPOSE: To establish the effect of ARBs versus placebo and alternative treatments, and the effect of combined treatment with ARBs and ACE inhibitors, on proteinuria. DATA SOURCES: English-language studies in MEDLINE and the Cochrane Library Central Register of Controlled Trials (January 1990 to September 2006), reference lists, and expert contacts. STUDY SELECTION: Randomized trials of ARBs versus placebo, ACE inhibitors, calcium-channel blockers, or the combination of ARBs and ACE inhibitors in patients with or without diabetes and with microalbuminuria or proteinuria for whom data were available on urinary protein excretion at baseline and at 1 to 12 months. DATA EXTRACTION: Two investigators independently searched and abstracted studies. DATA SYNTHESIS: Forty-nine studies involving 6181 participants reported results of 72 comparisons with 1 to 4 months of follow-up and 38 comparisons with 5 to 12 months of follow-up. The ARBs reduced proteinuria compared with placebo or calcium-channel blockers over 1 to 4 months (ratio of means, 0.57 [95% CI, 0.47 to 0.68] and 0.69 [CI, 0.62 to 0.77], respectively) and 5 to 12 months (ratio of means, 0.66 [CI, 0.63 to 0.69] and 0.62 [CI, 0.55 to 0.70], respectively). The ARBs and ACE inhibitors reduced proteinuria to a similar degree. The combination of ARBs and ACE inhibitors further reduced proteinuria more than either agent alone: The ratio of means for combination therapy versus ARBs was 0.76 (CI, 0.68 to 0.85) over 1 to 4 months and 0.75 (CI, 0.61 to 0.92) over 5 to 12 months; for combination therapy versus ACE inhibitors, the ratio of means was 0.78 (CI, 0.72 to 0.84) over 1 to 4 months and 0.82 (CI, 0.67 to 1.01) over 5 to 12 months. The antiproteinuric effect was consistent across subgroups. LIMITATIONS: Most studies were small, varied in quality, and did not provide reliable data on adverse drug reactions. Proteinuria reduction is only a surrogate for important progression of renal failure. CONCLUSION: The ARBs reduce proteinuria, independent of the degree of proteinuria and of underlying disease. The magnitude of effect is similar regardless of whether the comparator is placebo or calcium-channel blocker. Reduction in proteinuria from ARBs and ACE inhibitors is similar, but their combination is more effective than either drug alone. Uncertainty concerning adverse effects and outcomes that are important to patients limits applicability of findings to clinical practice.