Johannes Wessling

Endoscopic Retrograde Cholangiopancreatography, Intraductal Ultrasonography, and Magnetic Resonance Cholangiopancreatography in Bile Duct Strictures: A Prospective Comparison of Imaging Diagnostics with Histopathological Correlation

OBJECTIVES:A variety of imaging techniques are available to diagnose bile duct strictures; the most effective imaging technique, however, has not been established yet. In the present study, we compared the impact of endoscopic retrograde cholangiopancreatography (ERCP), intraductal ultrasonography (IDUS), and magnetic resonance cholangiopancreatography (MRCP) with regard to diagnosing bile duct strictures.METHODS:We prospectively examined 33 patients with jaundice due to bile duct strictures by ERCP plus IDUS and MRCP. The objectives were to assess diagnostic quality of imaging, complete presentation of the bile duct, and differentiation of malignant from benign lesions. Surgical and histopathological correlations, which were used as the gold standard, were available in all cases since all included patients underwent laparotomy.RESULTS:Diagnostic image quality for ERCP was 88% and 76% for MRCP (p > 0.05). Comparing ERCP and MRCP, complete presentation of the biliary tract was achieved in 94% and 82%, respectively (p > 0.05). ERCP and MRCP allowed correct differentiation of malignant from benign lesions in 76% and 58% (p = 0.057), respectively. By supplementing ERCP with IDUS, the accuracy of correct differentiation of malignant from benign lesions increased significantly to 88% (p = 0.0047).CONCLUSIONS:Comparing ERCP with MRCP, we found adequate presentation of bile duct strictures in high imaging quality for both techniques. ERCP supplemented by IDUS gives more reliable and precise information about differentiation of malignant and benign lesions than MRCP alone without additional imaging sequences.

Detection and differentiation of inflammatory versus fibromatous Crohn's disease strictures: prospective comparison of 18F-FDG-PET/CT, MR-enteroclysis, and transabdominal ultrasound versus endoscopic/histologic evaluation.

Background: Differentiation between inflammatory and fibromatous strictures in Crohns disease (CD) is difficult but crucial for therapeutic decisions. The aim of this study was to assess the best noninvasive imaging method for the detection and differentiation of inflammatory and fibromatous stenoses in CD in comparison to endoscopic and histologic evaluation. Methods: Patients with suspected CD strictures were included. According to a formalized endoscopic and histologic protocol, strictures were classified as inflammatory, mixed, and fibrostenotic. Strictures were further analyzed using fluorine 18‐labeled fluoro‐2‐deoxy‐D‐glucose (18FDG) / positron emission tomography (PET) low‐dose computed tomography (CT), magnetic resonance (MR) enteroclysis and transabdominal ultrasound using standardized scoring systems. Results: Thirty patients with 37 strictures were evaluated (inflamed n = 22; mixed n = 12, fibromatous n = 3). 18FDG‐PET/CT detected 81%, MR‐enteroclysis 81%, and ultrasound 68% of the strictures. Correct differentiation rates of strictures were 57% for MRE, 53% for 18FDG‐PET/CT, and 40% for ultrasound. Differences of detection rates and differentiation rates were not statistically significant. When combining transabdominal ultrasound with 18FDG‐PET/CT or MR‐enteroclysis all strictures that required invasive treatment were detected. Conclusions: Detection rates of the strictures were not significantly different between 18FDG‐PET/CT, MR‐enteroclysis, and ultrasound. Despite good stricture detection rates relating to our gold standard, 18FDG‐PET/CT nor MR‐enteroclysis nor ultrasound can accurately differentiate inflamed from fibrotic strictures. A combination of MR‐enteroclysis and ultrasound as well as a combination of 18FDG‐PET/CT and ultrasound resulted in a 100% detection rate of strictures requiring surgery or endoscopic dilation therapy, suggesting the combination of these methods as an alternative to endoscopy at least in the group of patients not able to perform an adequate bowel preparation. (Inflamm Bowel Dis 2012;)

Mycobacterium avium subsp. paratuberculosis Infection in a Patient with HIV, Germany

Mycobacterium avium subsp. paratuberculosis (MAP), the causative agent of Johne disease in ruminants, has been incriminated as the cause of Crohn disease in humans. We report the first case of human infection with MAP in a patient with HIV; infection was confirmed by obtaining isolates from several different specimen types.

Contribution of PET/CT to Prediction of Outcome in Children and Young Adults with Rhabdomyosarcoma

The purpose of this retrospective study was to evaluate the role of 18F-FDG PET or PET/CT in the prediction of patient outcome in children and young adults affected by rhabdomyosarcoma. Methods: Forty-one patients with histology-proven rhabdomyosarcoma who underwent PET or PET/CT were identified (age range, 1–20 y; mean age ± SD, 9.9 ± 5.8 y). Tumor maximum standardized uptake value (SUVmax) and visually rated metabolic activity, as well as the presence of metabolically active lymph nodes and distant metastases, were compared with event-free and overall survival. Multivariate Cox regression analyses were performed to compare the prediction of outcome according to metabolic tumor intensity in relation to established prognostic factors. Results: Kaplan–Meier analyses revealed a significantly shorter overall survival in primary tumors visually rated as highly metabolically active or with a ratio of SUVmax to SUV of the liver above 4.6. In addition, metabolically active lymph node and distant site involvement was indicative of significantly lower survival rates. On multivariate Cox regression analysis, the impact of intensity or SUVmax of the primary tumor on outcome failed to attain significance, although PET performed better than some of the prognostic factors established in larger patient groups (P = 0.081). Conclusion: 18F-FDG PET/CT is a valuable tool for initial staging in children affected by rhabdomyosarcoma. 18F-FDG PET/CT may be an additional predictor of outcome and may be used to refine risk-adapted therapy. PET performed better than some established risk factors. The borderline significance level of primary tumor metabolism in multivariate testing may be an effect of the limited sample size. Further prospective evaluations are warranted.

Multislice CT angiography of the iliac arteries in the presence of various stents: In vitro evaluation of artifacts and lumen visibility

RATIONALE AND OBJECTIVES To evaluate the imaging characteristics of various iliac artery stents and stent-grafts in a multislice, computed tomography angiography (MSCTA) phantom study. METHODS Twelve types of stents and three stent-grafts made of different materials (steel, nitinol, tantalum, cobalt-based alloy) were implanted in plastic tubes with an 8-mm inner diameter filled with iodinated contrast medium diluted to 200 HU. To evaluate the influence of scan parameters on artifacts, the Palmaz stent (as one example) was scanned with a four-slice scanner (Siemens VolumeZoom) with different detector collimations and pitches. All other stents were examined with a collimation of 4 x 1 mm and a table feed of 4 mm/rotation. Axial images and multiplanar reformations were evaluated regarding artifact size, lumen visibility, and intraluminal attenuation values. RESULTS Higher pitch values caused more pronounced artifacts. Image quality and delineation of the stent struts improved with thinner detector collimation. The size of the stent-related artifacts and the visibility of the stent lumen depended on the underlying stent material and design. Pronounced artifacts, resulting in an insufficient delineation of the stent lumen, were caused by the Strecker tantalum stent and the Zenith stent. Moderate artifacts were caused by the Wallgraft, Passager, Palmaz P 395 and P 424, Bridge, Perflex, and ZA stents. Some artificial lumen narrowing but good lumen delineation was seen with the Strecker nitinol, Symphony, Memotherm, SMART, Corinthian, and Wallstent stents. CONCLUSIONS Scanning parameters, stent material, and stent design influence lumen assessability and image quality in MSCTA. Detailed lumen assessment is impossible in the Strecker tantalum and Zenith stents and limited in the Wallgraft, Passager, Palmaz P 395 and PS 424, Bridge, Perflex, and ZA-stent stent-grafts but feasible in all other examined products.

Diagnostic and radiological management of cystic pancreatic lesions: Important features for radiologists

Cystic pancreatic neoplasms are often an incidental finding, the frequency of which is increasing. The understanding of such lesions has increased in recent years, but the numerous types of lesions involved can hinder differential diagnosis. They include, in particular, intraductal papillary mucinous neoplasms (IPMN), serous cystic neoplasms (SCN), and mucinous cystic neoplasms (MCN). Knowledge of their histological and radiological structure, as well as distribution in terms of localization, age, and sex, helps to differentiate such tumours from common pancreatic pseudocysts. Several types of cystic pancreatic neoplasms can undergo malignant transformation and, therefore, require differentiated radiological management. This review aims to develop a broader understanding of the pathological and radiological characteristics of cystic pancreatic neoplasms, and provide a guideline for everyday practice based on current concepts in the radiological management of the given lesions.

Pulmonary vein variants predispose to atrial fibrillation: a case-control study using multislice contrast-enhanced computed tomography

AIMS Pulmonary veins (PV) play a pivotal role in atrial fibrillation (AF). Anatomical variants of PV have been described and related to a higher arrhythmogenic potential. The aim of this study was to compare the prevalence of PV variants and diameters of PV ostia in AF patients and controls. METHODS AND RESULTS Variants of PV were defined as right or left common ostia (RCO, LCO), a right middle or right top PV . A long common trunk (LCT) was defined as an LCO with a distance to the first branching ≥ 10 mm. Multislice contrast-enhanced thoracic computed tomography was performed prior to AF ablation in 166 consecutive patients, 47.6% with paroxysmal, 52.4% with persistent AF, as well as in a sex- and age-matched control group without AF, for non-cardiological indications. Images were evaluated by two independent observers. The mean age was 59 ± 10 years, 108 were men (65.1%). A higher prevalence of LCO was found in the AF group: 33.7 vs. 19.9% (P= 0.004), odds ratio (OR) 2.1; 15.4% in patients vs. 10.2% in controls had an LCT (P= 0.14). No differences in other PV variants were found. The ostial diameters were greater in AF-patients (P< 0.001). CONCLUSIONS To the best of our knowledge, the present study shows for the first time a higher prevalence of an LCO in patients with AF as compared with controls, with an OR of 2.1. This suggests a pre-disposing role of LCO in the development of AF.

Measurement Accuracy and Reproducibility of Semiautomated Metric and Volumetric Lymph Node Analysis in MDCT

OBJECTIVE The purpose of this study was to assess the measurement accuracy and reproducibility of semiautomated metric and volumetric lymph node analysis in MDCT. MATERIALS AND METHODS Whole-body CT with IV contrast administration was performed on 112 patients. Peripheral (cervical, axillary, and inguinal), abdominal, and thoracic lymph nodes were evaluated independently by two radiologists both manually and with semiautomated segmentation software. Long-axis diameter, short-axis diameter, and volume were measured. Agreement between the semiautomated and manual measurements (measurement error), need for manual correction, and relative interobserver differences were determined. Statistical analysis encompassed the variance inhomogeneity test, intraclass correlation coefficients, and Bland-Altman plots. RESULTS In total, 742 peripheral (cervical, axillary, and inguinal), abdominal, and thoracic lymph nodes (mean diameter, 13.2 ± 4.3 mm; range, 4-37 mm) were evaluated. Semiautomatic segmentation without need for further correction was possible for 480 of 742 lymph nodes (64.7%). Calculation of intraclass correlation coefficients revealed high correlation between manual and semiautomatic measurements (r = 0.70-0.81) with a slight trend toward size overestimation for semiautomatic short-axis diameter (14.3%; limits of agreement, -34.3%, 62.9%) and long-axis diameter (11.7%; limits of agreement, -25.2%, 48.5%). Bland-Altman plots showed significantly (p < 0.0001) lower interobserver differences for semiautomated short-axis diameter (1.2%; 95% CI, -39.9% to 42.3%) compared with the manual measurement (7.6%; 95% CI, -38.7% to 53.9%). Among all locations, the relative interobserver difference for semiautomatic volume (2.9%; 95% CI, -31.4% to 37.3%) was significantly lower than that for manual short-axis diameter (p < 0.0001), manual long-axis diameter (0.0178), and semiautomatic short-axis diameter (p < 0.0001). CONCLUSION Semiautomatic short-axis diameter, particularly volume measurements, of lymph nodes are, irrespective of location, precise in terms of reproducibility and appear to be considerably more reliable than manual lymph node assessment.

Prediction of lymph node manifestations in malignant lymphoma: significant role of volumetric compared with established metric lymph node analysis in multislice computed tomography.

Objective: Comparison of 2-dimensional and semiautomated 3-dimensional (3D) measurements to distinguish between benign and malignant lymph nodes in patients with malignant lymphoma. Methods: Whole-body positron emission tomography-computed tomography (PET-CT) was performed in 33 patients before therapy for malignant lymphoma. Two hundred fifty-seven peripheral lymph nodes (mean size, 13.4 ± 5.4 mm) were evaluated independently by 2 radiologists, both manually and with the use of semiautomated segmentation software. Long-axis diameter (LAD), short-axis diameter (SAD), maximal 3D diameter, volume, and elongation were measured. Positron emission tomography-CT and PET-CT follow-up and/or histology served as the reference standard. Statistical analysis encompassed intraclass correlation coefficients and receiver operating characteristic curves. Results: The standard of reference revealed involvement in 116 (45%) of 257 lymph nodes. Manual and semiautomated LAD and SAD showed good correlation with intraclass coefficients of 0.85 and 0.72, respectively. Semiautomated prediction of malignant lymph nodes revealed the highest areas under the receiver operating characteristic curves for volume (0.760; 95% confidence interval [CI], 0.639-0.887) followed by SAD (0.740; 95% CI, 0.616-0.862). The findings for LAD (0.722; 95% CI, 0.588-0.855), maximal 3D diameter (0.697; 95% CI, 0.565-0.830), and lymph node elongation (0.605; 95% CI, 0.466-0.745) were significantly lower (P < 0.05). Conclusions: Volumetric lymph node analysis is significantly superior compared with established LAD in the prediction of lymph node involvement and therefore can add to the definition of peripheral lymphoma target lesions.

Real-time ultrasonography-computed tomography fusion imaging for staging of hepatic metastatic involvement in patients with colorectal cancer: initial results from comparison to US seeing separate CT images and to multidetector-row CT alone.

Objectives:To prospectively evaluate the role of real-time ultrasonography (US)-computed tomography (CT) fusion imaging (US-CT) in comparison with US seeing separate CT images (US + CT) and multidetector-row CT (MDCT) for the correct staging of hepatic metastatic involvement in patients with colorectal cancer. Methods:Sixty-four patients with newly diagnosed colorectal cancer and who were referred for abdominopelvic staging before primary tumor resection underwent same-day MDCT, US + CT, and US-CT. Examinations were evaluated on-site by 2 investigators in consensus. Investigators recorded the size and location of detected lesions on segmental liver maps, classified them as being benign, malignant, or indeterminate, and finally assessed the M stage of the liver as being M0, M1, or Mx (indeterminate). All patients underwent surgical exploration including intraoperative US. Reference standard diagnosis was based on findings at surgery, intraoperative US, histopathology, and MDCT follow-up imaging. Differences among investigated modalities were analyzed using McNemar′s test. Results:The reference standard verified 109 (45 ≤ 1 cm) hepatic lesions in 25 patients, including 65 (25 ≤ 1 cm) metastases in 16 patients (M1). Regarding the 45 ≤ 1 cm liver lesions, rates for detection were significantly higher (P < 0.05) for MDCT (80%, 36/45) and US-CT (77.8%, 35/45) than for US + CT (64.4%, 29/45); the rate for correct classification by US-CT (71.1%, 32/45) was significantly higher than for US + CT (48.9%, 22/45) and MDCT (31.1%, 14/45) (all P < 0.05). On patient-based analysis, specificity of MDCT (85.4%, 41/48) was significantly lower (P < 0.05) than for US-CT (97.9%, 47/48) and US + CT (93.7%, 45/48); the positive predictive value of MDCT (63.1%, 12/19) was not significantly different (P = 0.27) compared with US + CT (82.3%, 14/17) but significantly lower (P < 0.05) than for US-CT (93.7%, 15/16). In 13 patients (59 lesions) with only benign (stage M0) or coexistent benign and malignant lesions (stage M1), indeterminate lesion ratings and indeterminate liver stagings (Mx) occurred both significantly lower (P < 0.05) with US-CT (3.4%, 2/59; and 0%, 0/13) than with US + CT (11.9%, 7/59; and 23.1%, 3/13) or with MDCT (30.5%, 18/59; and 53.8%, 7/13). Conclusions:Based on these initial diagnostic experiences, complementary US-CT fusion imaging of small CT-indeterminate liver lesions may have value in staging patients with colorectal cancer, focusing on patients who were likely to harbor only benign or coexisting benign and malignant liver lesions and in whom change of M staging would change the clinical management.