[Colorectal cancer screening with virtual colonography]. / Screening des Kolonkarzinoms mit virtueller Kolographie.

BACKGROUND: Since 2003, a decline in the age-standardized incidence rates of colorectal cancer (CRC) has been observed in Germany. Nonetheless, one in eight cancer cases still affects the colon or rectum. The prognosis has improved, with the relative 5­year survival rate for CRC being approximately 65%. METHODS: This positive trend is probably a result of preventive measures introduced over the last 20 years. This could be further improved, however, as CRC can not only be detected early but in almost all cases also prevented through the identification of benign precursors. Less than half of all eligible individuals participate in screening via colonoscopy. This implies that further, possibly even imaging, screening test methods should be explored and offered. Studies have reported that virtual colonography techniques have a comparable accuracy to endoscopy of about 90% for polyp sizes larger than 5 mm. The data for computed tomography (CT) is more extensive than for magnetic resonance imaging (MRI). CONCLUSION: Significant challenges are posed however by the fact that in Germany CT colonography (CTC) is not considered a viable screening option due to radiation protection concerns, and MRI screening is not an established screening method. Radiologists should be familiar with classification using the CT Colonography Reporting and Data System (C-RADS), which uses criteria such as CT density, morphology, size, and location for classification. C­RADS classification follows the categories: C0 (inadequate study), C1 (normal), C2a (indeterminate), C2b (benign), C3 (suspicious), and C4 (malignant), as well as extracolonic categories E1/2 (no clinically significant findings), E3 (likely insignificant findings), and E4 (likely significant findings).

[Position paper on reporting of intestinal ultrasound findings in patients with inflammatory bowel disease]. / Positionspapier zur Befunderhebung von Darmultraschallbefunden bei chronisch entzündlichen Darmerkrankungen.

BACKGROUND: Intestinal ultrasound is increasingly used for primary diagnosis, detection of complications and monitoring of patients with Crohn's disease and ulcerative colitis. Standardization of reporting is relevant to ensure quality of the methodology and to improve communication between different specialties. The current manuscript describes the features required for optimized reporting of intestinal ultrasound findings in inflammatory bowel disease (IBD). METHODS: An expert consensus panel of gastroenterologists, radiologists, pathologists, paediatric gastroenterologists and surgeons conducted a systematic literature search. In a Delphi- process members of the Kompetenznetz Darmerkrankungen in collaboration with members of the German Society for Radiology (DRG) voted on relevant criteria for reporting of findings in intestinal ultrasound. Based on the voting results statements were agreed by expert consensus. RESULTS: Clinically relevant aspects of intestinal ultrasound (IUS) findings have been defined to optimize reporting and to standardize terminology. Minimal requirements for standardized reporting are suggested. The statements focus on description of disease activity as well as on complications of IBD. Attributes of intestinal inflammation are described and illustrated by exemplary images. CONCLUSION: The current manuscript provides practical recommendations on how to standardize documentation and reporting from intestinal ultrasound findings in patients with IBD.

Importance and Qualitative Requirements of Magnetic Resonance Imaging for Therapy Planning in Rectal Cancer - Interdisciplinary Recommendations of AIO, ARO, ACO and the German Radiological Society. / Stellenwert und qualitative Voraussetzungen der Magnetresonanztomografie (MRT) für die Therapieplanung beim Rektumkarzinom ­ Interdisziplinäre Empfehlungen der AIO, ARO, ACO und der Deutschen Röntgengesellschaft.

Due to its excellent intrinsic soft tissue contrast, magnetic resonance imaging allows excellent visualization and anatomical separation of therapy-relevant risk structures such as the mesorectal fascia, local lymph nodes, and vascular structures in patients with rectal carcinoma. This makes magnetic resonance imaging (MRI) a valuable evaluation method for further therapeutic stratification. In particular, MRI is indispensable for the decision to refrain from neoadjuvant therapy and to choose a primary surgical approach. In addition to the oncologically generally relevant T-, N-, and M-criteria, two further parameters are included: the extramural vascular infiltration and the circumferential resection margin. Due to the significant impact of MRI on further therapeutic decision-making, standardized MR image quality is considered essential. KEY POINTS:: · Magnetic resonance imaging is a valuable evaluation method for further therapeutic stratification.. · Critical anatomic landmarks for evaluation are circumferential resection margins.. CITATION FORMAT: · Attenberger UI, Clasen S, Ghadimi M et al. Importance and Qualitative Requirements of Magnetic Resonance Imaging for Therapy Planning in Rectal Cancer - Interdisciplinary Recommendations of AIO, ARO, ACO and the German Radiological Society. Fortschr Röntgenstr 2021; 193: 513 - 520.

LI-RADS in the year 2020 - Are you already using it or still considering? / LI-RADS im Jahr 2020 ­ Nutzt du es schon oder überlegst du noch?

PURPOSE: The working group for gastrointestinal and abdominal imaging within the German Radiological Society performed a nationwide online survey in order to assess the current status regarding the awareness and application of LI-RADS, a classification for evaluation of liver lesions in patients at risk. MATERIALS AND METHODS: Using the website www.deutsches-krankenhausverzeichnis.de a list of hospitals was generated meeting the criteria internal medicine, gastroenterology, general and visceral surgery and radiology (n = 391). Randomly, 102 department directors were contacted, and asked to name one consultant and one resident from their department in order to participate in the survey. 177 potential participants were invited to fill out an approximately 10-minute online survey in the form of 17 questions regarding the awareness and application of LI-RADS. The results of the survey were analyzed by means of descriptive statistics. RESULTS: 77 participants were registered, which corresponds to a response rate of 43.5 %. 47 % of all participants were radiologists, 30 % surgeons and 23 % internal doctors/gastroenterologists, respectively, many with more than 13 years of professional experience (37.2 %). The majority of participants worked in a hospital with a focus (37.2 %) or a university hospital (29.1 %). Even though the majority of participants knows about or has heard of LI-RADS (73.2 %), only a minority uses the classification themselves (26 %) or within the context of tumor boards (19.2 %). CONCLUSION: The results of our survey demonstrate that LI-RADS is relatively known in Germany, the application however quite sparse. This is in contrast to the general desire and endeavor for more standardized reporting in radiology. KEY POINTS: · LI-RADS is not yet broadly implemented in clinical routine in Germany. · The sparse application is in contrast to the general desire for more standardized reporting in radiology. · Interdisciplinary education may support the propagation and use of the LI-RDAS classification. CITATION FORMAT: · Ringe KI, Gut A, Grenacher L et al. LI-RADS in the year 2020 - Are you already using it or still considering? Fortschr Röntgenstr 2021; 193: 186 - 193.

Structured Reporting of Solid and Cystic Pancreatic Lesions in CT and MRI: Consensus-Based Structured Report Templates of the German Society of Radiology (DRG). / Strukturierte Befundung von soliden und zystischen Pankreasläsionen im CT und MRT: Konsensus-basierte Befundvorlagen der Deutschen Röntgengesellschaft (DRG).

BACKGROUND: Radiological reports of pancreatic lesions are currently widely formulated as free texts. However, for optimal characterization, staging and operation planning, a wide range of information is required but is sometimes not captured comprehensively. Structured reporting offers the potential for improvement in terms of completeness, reproducibility and clarity of interdisciplinary communication. METHOD: Interdisciplinary consensus finding of structured report templates for solid and cystic pancreatic tumors in computed tomography (CT) and magnetic resonance imaging (MRI) with representatives of the German Society of Radiology (DRG), German Society for General and Visceral Surgery (DGAV), working group Oncological Imaging (ABO) of the German Cancer Society (DKG) and other radiologists, oncologists and surgeons. RESULTS: Among experts in the field of pancreatic imaging, oncology and pancreatic surgery, as well as in a public online survey, structured report templates were developed by consensus. These templates are available on the DRG homepage under www.befundung.drg.de and will be regularly revised to the current state of scientific knowledge by the participating specialist societies and responsible working groups. CONCLUSION: This article presents structured report templates for solid and cystic pancreatic tumors to improve clinical staging (cTNM, ycTNM) in everyday radiology. KEY POINTS: · Structured report templates offer the potential of optimized radiological reporting with regard to completeness, reproducibility and differential diagnosis.. · This article presents consensus-based, structured reports for solid and cystic pancreatic lesions in CT and MRI.. · These structured reports are available open source on the homepage of the German Society of Radiology (DRG) under www.befundung.drg.de.. CITATION FORMAT: · Persigehl T, Baumhauer M, Baeßler B et al. Structured Reporting of Solid and Cystic Pancreatic Lesions in CT and MRI: Consensus-Based Structured Report Templates of the German Society of Radiology (DRG). Fortschr Röntgenstr 2020; 192: 641 - 655.

Comparative analysis of ERCP, IDUS, EUS and CT in predicting malignant bile duct strictures.

AIM: To compare endoscopic retrograde cholangio-pancreatography (ERCP), intraductal ultrasound (IDUS), endosonography (EUS), endoscopic transpapillary forceps biopsies (ETP) and computed tomography (CT) with respect to diagnosing malignant bile duct strictures. METHODS: A patient cohort with bile duct strictures of unknown etiology was examined by ERCP and IDUS, ETP, EUS, and CT. The sensitivity, specificity, and accuracy rates of the diagnostic procedures were calculated based on the definite diagnoses proved by histopathology or long-term follow-up in those patients who did not undergo surgery. For each of the diagnostic measures, the sensitivity, specificity, and accuracy rates were calculated. In all cases, the gold standard was the histopathologic staging of specimens or long-term follow-up of at least 12 mo. A comparison of the accuracy rates between the localization of strictures was performed by using the Mann-Whitney U-test and the χ(2) test as appropriate. A comparison of the accuracy rates between the diagnostic procedures was performed by using the McNemar's test. Differences were considered statistically significant if P < 0.05. RESULTS: A total of 234 patients (127 males, 107 females, median age 64, range 20-90 years) with indeterminate bile duct strictures were included. A total of 161 patients underwent operative exploration; thus, a surgical histopathological correlation was available for those patients. A total of 113 patients had malignant disease proven by surgery; in 48 patients, benign disease was surgically found. In these patients, the decision for surgical exploration was made due to the suspicion of malignant disease in multimodal diagnostics (ERCP, CT, or EUS). Fifty patients had a benign diagnosis and were followed by a surveillance protocol with a follow-up of at least 12 mo; the median follow-up was 34 mo. Twenty-three patients had extended malignant disease, and thus were considered palliative. A comparison of the different diagnostic tools for detecting bile duct malignancy resulted in accuracy rates of 91% (ERCP/IDUS), 59% (ETP), 92% (IDUS + ETP), 74% (EUS), and 73% (CT), respectively. In the subgroup analysis, the accuracy rates (%, ERCP + IDUS/ETP/IDUS + ETP; EUS; CT) for each tumor entity were as follows: cholangiocellular carcinoma: 92%/74%/92%/70%/79%; pancreatic carcinoma: 90%/68%/90%/81%/76%; and ampullary carcinoma: 88%/90%/90%/76%/76%. The detection rate of malignancy by ERCP/IDUS was superior to ETP (91% vs 59%, P < 0.0001), EUS (91% vs 74%, P < 0.0001) and CT (91% vs 73%, P < 0.0001); EUS was comparable to CT (74% vs 73%, P = 0.649). When analyzing accuracy rates with regard to localization of the bile duct stenosis, the accuracy rate of EUS for proximal vs distal stenosis was significantly higher for distal stenosis (79% vs 57%, P < 0.0001). CONCLUSION: ERCP/IDUS is superior to EUS and CT in providing accurate diagnoses of bile duct strictures of uncertain etiology. Multimodal diagnostics is recommended.

Crohn's disease complicated by intestinal infection with methicillin-resistant Staphylococcus aureus.

We report on a 24-year-old male patient with history of bloody diarrhea, abdominal pain and vomiting. Endoscopy revealed massive ulcerative discontinuous proctosigmoiditis with deep, sharply demarcated epithelial denudations and enterotoxigenic methicillin-resistant Staphylococcus aureus (MRSA) was detected in mucosal biopsies. After treatment with linezolide and steroids, a significant amelioration of colitis was detected and testing for MRSA became negative. In face of the case presented here, we suggest that in patients with refractory inflammatory bowel disease (IBD), microbiological assessment should be performed to detect a possible Staphylococcus aureus infection in order to initiate an antimicrobial treatment in addition to IBD-specific treatment.

DexaBEAM versus ICE salvage regimen prior to autologous transplantation for relapsed or refractory aggressive peripheral T cell lymphoma: a retrospective evaluation of parallel patient cohorts of one center.

High-dose chemotherapy (HDT) followed by autologous stem cell transplantation (ASCT) is considered standard in the treatment of patients with relapsed or refractory aggressive peripheral T cell lymphoma (PTCL). However, the optimal salvage regimen before ASCT has not yet been established. We retrospectively analyzed 31 patients with relapsed or refractory aggressive PTCL after anthracycline-based first-line chemotherapy who received either DexaBEAM (dexamethasone, carmustine, etoposide, cytarabine, and melphalan; n = 16) or ICE (ifosfamide, carboplatin, and etoposide; n = 15) regimen as first salvage chemotherapy followed by HDT/ASCT. The overall response rate (OR) was significantly higher for patients treated with DexaBEAM (69 %; 95 % confidence interval 46.0-91.5 %) as compared to the ICE group (20 %; 95 % confidence interval -0.2-40.2 %; P = 0.01), with higher complete response (CR; 38 %; 95 % confidence interval 13.8-61.2 %; vs. 7 %; 95 % confidence interval -6.0-19.6 %) as well as partial response (PR; 31 vs. 13 %) rate. Changing regimen due to failure of first salvage therapy, 12 patients initially receiving ICE still achieved an OR of 58 % (33 % CR, 25 % PR) with DexaBEAM as second salvage therapy, whereas in three patients receiving ICE after DexaBEAM failure, only one achieved an OR (1 PR). Median progression-free survival was significantly higher in the DexaBEAM group (6.4 vs. 2 months; P = 0.01). Major adverse event in both groups was myelosuppression with higher but tolerable treatment-related toxicity for patients in the DexaBEAM group. For all patients proceeding to HDT/ASCT, a 3-year overall survival was 50 %. Together, considering the limitations of the retrospective design of the evaluation and the small sample size, our data suggest that DexaBEAM salvage chemotherapy is superior to ICE for patients with relapsed or refractory aggressive PTCL for remission induction prior to autologous transplantation, with higher but manageable treatment-related toxicity.

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 Crohn's 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 ((18) FDG) / 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). (18) FDG-PET/CT detected 81%, MR-enteroclysis 81%, and ultrasound 68% of the strictures. Correct differentiation rates of strictures were 57% for MRE, 53% for (18) FDG-PET/CT, and 40% for ultrasound. Differences of detection rates and differentiation rates were not statistically significant. When combining transabdominal ultrasound with (18) FDG-PET/CT or MR-enteroclysis all strictures that required invasive treatment were detected. CONCLUSIONS: Detection rates of the strictures were not significantly different between (18) FDG-PET/CT, MR-enteroclysis, and ultrasound. Despite good stricture detection rates relating to our gold standard, (18) FDG-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 (18) FDG-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.

Contribution of PET/CT to prediction of outcome in children and young adults with rhabdomyosarcoma.

UNLABELLED: The purpose of this retrospective study was to evaluate the role of (18)F-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 (SUV(max)) 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 SUV(max) 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 SUV(max) 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: (18)F-FDG PET/CT is a valuable tool for initial staging in children affected by rhabdomyosarcoma. (18)F-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.

Usefulness of semi-automatic volumetry compared to established linear measurements in predicting lymph node metastases in MSCT.

BACKGROUND: Volumetry of lymph nodes potentially better reflect asymmetric size alterations independently of lymph node orientation in comparison to metric parameters (e.g. long-axis diameter). PURPOSE: To distinguish between benign and malignant lymph nodes by comparing 2D and semi-automatic 3D measurements in MSCT. MATERIAL AND METHODS: FDG-18 PET-CT was performed in 33 patients prior to therapy for malignant melanoma at stage III/IV. One hundred and eighty-six cervico-axillary, abdominal and inguinal lymph nodes were evaluated independently by two radiologists, both manually and with the use of semi-automatic segmentation software. Long axis (LAD), short axis (SAD), maximal 3D diameter, volume and elongation were obtained. PET-CT, PET-CT follow-up and/or histology served as a combined reference standard. Statistics encompassed intra-class correlation coefficients and ROC curves. RESULTS: Compared to manual assessment, semi-automatic inter-observer variability was found to be lower, e.g. at 2.4% (95% CI 0.05-4.8) for LAD. The standard of reference revealed metastases in 90 (48%) of 186 lymph nodes. Semi-automatic prediction of lymph node metastases revealed highest areas under the ROC curves for volume (reader 1 0.77, 95%CI 0.64-0.90; reader 2 0.76, 95%CI 0.59-0.86) and SAD (reader 1 0.76, 95%CI 0.64-0.88; reader 2 0.75, 95%CI 0.62-0.89). The findings for LAD (reader 1 0.73, 95%CI 0.60-0.86; reader 2 0.71, 95%CI 0.71, 95%CI 0.57-0.85) and maximal 3D diameter (reader 1 0.70, 95%CI 0.53-0.86; reader 2 0.76, 95%CI 0.50-0.80) were found substantially lower and for elongation (reader 1 0.65, 95%CI 0.50-0.79; reader 2 0.66, 95%CI 0.52-0.81) significantly lower (p < 0.05). CONCLUSION: Semi-automatic analysis of lymph nodes in malignant melanoma is supported by high segmentation quality and reproducibility. As compared to established SAD, semi-automatic lymph node volumetry does not have an additive role for categorizing lymph nodes as normal or metastatic in malignant melanoma.

A typical presentation of a rare cause of obscure gastrointestinal bleeding.

A 52-year-old white woman had suffered from intermittent gastrointestinal (GI) bleeding for one year. Upper GI endoscopy, colonoscopy and peroral double-balloon enteroscopy (DBE) did not detect any bleeding source, suggesting obscure GI bleeding. However, in videocapsule endoscopy a jejunal ulceration without bleeding signs was suspected and this was endoscopically confirmed by another peroral DBE. After transfusion of packed red blood cells, the patient was discharged from our hospital in good general condition. Two weeks later she was readmitted because of another episode of acute bleeding. Multi-detector row computed tomography with 3D reconstruction was performed revealing a jejunal tumor causing lower gastrointestinal bleeding. The patient underwent exploratory laparotomy with partial jejunal resection and end-to-end jejunostomy for reconstruction. Histological examination of the specimen confirmed the diagnosis of a low risk gastrointestinal stromal tumor (GIST). Nine days after surgery the patient was discharged in good health. No signs of gastrointestinal rebleeding occurred in a follow-up of eight months. We herein describe the complex presentation and course of this patient with GIST and also review the current approach to treatment.

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 < or = 1 cm) hepatic lesions in 25 patients, including 65 (25 < or = 1 cm) metastases in 16 patients (M1). Regarding the 45 < or = 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.

Semiautomatic lymph node segmentation in multislice computed tomography: impact of slice thickness on segmentation quality, measurement precision, and interobserver variability.

OBJECTIVES: To determine the impact of slice thickness on semiautomatic lymph node analysis. MATERIALS AND METHODS: Thoracic multislice computed tomography (MSCT) of 46 patients with NSCLC were reconstructed at 1.0-, 3.0-, and 5.0-mm slice thickness. Two radiologists independently determined long and short axis diameter and volume of 299 thoracic lymph nodes by semiautomatic segmentation software. Necessity of manual correction (= relative difference between uncorrected and corrected segmented lymph node volume) and relative interobserver differences were determined. The precision of segmentation was expressed by relative measurement deviations (RMD) from the reference standard (mean of 1.0 mm datasets). Statistical analysis encompassed t test and Bland-Altman plots. RESULTS: Necessity of manual correction was significantly higher for 5.0 mm than for 3.0 (P = 0.042) or 1.0 mm (P = 0.0012). The RMD for long and short axis diameter were found to be independent of slice thickness, whereas the RMD for lymph node volume significantly (P = 0.021) increased from 4.0% at 1.0 mm (95% CI: 1.0%-3.5%) to 35% at 5.0 mm (95% CI: 10.5%-60.5%). The relative interobserver differences was consistently low for metric and volumetric parameters (eg, volume 2.3%, 95% CI: -7.4%-10.8% at 5.0 mm) with no difference in any of the slice thicknesses (P > 0.064). CONCLUSIONS: Significant deviations in lymph node volume together with excessive manual corrections suggest reconstruction of the data for semiautomatic lymph node assessment at a slice thickness of 1.0 mm but not exceeding 3.0 mm.