[Colorectal cancer: role of imaging in screening]. / Kolorektales Karzinom: Rolle bildgebender Verfahren in der Vorsorge.

CLINICAL PROBLEM: Colorectal cancer (CRC) is a major cause of cancer-related morbidity and mortality. Most colorectal cancers derive from benign precursor lesions, so-called adenomatous polyps, over a long period of time. Colorectal cancer screening is based on the detection of precancerous polyps and early stage CRC in asymptomatic individuals to reduce CRC incidence and mortality. The protective effect of screening programs can be improved by increasing the screening rates. PRACTICAL RECOMMENDATIONS: Apart from the established examinations, CT colonography (CTC) has been proposed as an optional test for colorectal cancer screening. The detection rates of CTC for large polyps and cancer are similar to the ones of colonoscopy and superior to stool-based tests. CTC is therefore the radiological test of choice for the detection of colorectal neoplasia. It has replaced double contrast barium enema for almost all indications. As a minimally invasive procedure, CTC has a high safety profile and good patient acceptance. The evaluation of extracolonic organs in addition to the colon can increase examination efficacy. The option to choose CTC as a CRC screening test has the potential to increase the overall screening rates.

[Imaging of gastrointestinal inflammation : Characteristic patterns and signs]. / Bildgebung gastrointestinaler Entzündungen : Charakteristische Muster und Zeichen.

CLINICAL PROBLEM: Pathological conditions of the gastrointestinal tract can result from various disorders, including inflammatory, infectious, neoplastic, and ischemic diseases. RADIOLOGICAL STANDARD PROCEDURES: Cross-sectional imaging techniques have largely replaced many of the conventional fluoroscopic examinations, such as small bowel follow-through and double-contrast barium enema. The former allow for time-efficient, accurate, and minimally invasive diagnostics. Therefore, they have become important diagnostic tools for the evaluation of inflammatory diseases of the gastrointestinal tract. The distension of the intestinal lumen with orally administered neutral contrast media improves not only the evaluation of the intraluminal aspect, but also of the cross-sectional appearance. Furthermore, with cross-sectional imaging techniques, the additional assessment of the extraintestinal structures and organs is also possible. METHODICAL INNOVATIONS AND ASSESSMENT: With the ongoing development of scanner and software technology, pathologic conditions of the gastrointestinal wall can be characterized in more detail by both computed tomography and magnetic resonance imaging. A structured approach, based on the analysis of typical radiological signs and patterns, combined with the evaluation of extraintestinal findings may help to assign the observed imaging findings to specific disease groups. RECOMMENDATIONS: This article summarizes common signs and typical patterns frequently seen in inflammatory conditions of the gastrointestinal tract. A systematic approach for structured analysis of specific and nonspecific imaging features and common pitfalls may aid in the interpretation and help to narrow the spectrum of potential differential diagnoses.

Learning from clinical phenotypes: Low-dose biophotonics therapies in oral diseases.

This narrative review on the use of biophotonics therapies for management of oral diseases is written as a tribute to Prof. Crispian Scully. His seminal contributions to the field are highlighted by the detailed, comprehensive description of clinical presentations of oral diseases. This has enabled a more thorough, fundamental understanding of many of these pathologies by research from his group as well as inspired mechanistic investigations in many groups globally. In the same vein, a major emphasis of this narrative review is to focus on the evidence from human case reports rather than in vitro or in vivo animal studies that showcases the growing and broad impact of biophotonics therapies. The similarities and differences between two distinct forms of low-dose biophotonics treatments namely photodynamic therapy and photobiomodulation therapy are discussed. As evident in this review, a majority of these reports provide promising evidence for their clinical efficacy. However, a lack of adequate technical details, precise biological rationale, and limited outcome measures limits the current utility of these treatments. Future investigations should attempt to address these shortcomings and develop better designed, rigorous, controlled studies to fully harness the tremendous potential of low-dose biophotonics therapies.

Clinical indications for computed tomographic colonography: European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline

This is an official guideline of the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR). It addresses the clinical indications for the use of computed tomographic colonography (CTC). A targeted literature search was performed to evaluate the evidence supporting the use of CTC. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence. Main recommendations 1 ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia. ESGE/ESGAR do not recommend barium enema in this setting (strong recommendation, high quality evidence). 2 ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. Delay of CTC should be considered following endoscopic resection. In the case of obstructing colorectal cancer, preoperative contrast-enhanced CTC may also allow location or staging of malignant lesions (strong recommendation, moderate quality evidence). 3 When endoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with symptoms suggestive of colorectal cancer (strong recommendation, high quality evidence). 4 ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp  ≥  6  mm in diameter detected at CTC. CTC surveillance may be clinically considered if patients do not undergo polypectomy (strong recommendation, moderate quality evidence). 5 ESGE/ESGAR do not recommend CTC as a primary test for population screening or in individuals with a positive first-degree family history of colorectal cancer (CRC). However, it may be proposed as a CRC screening test on an individual basis providing the screenee is adequately informed about test characteristics, benefits, and risks (weak recommendation, moderate quality evidence).

[CT colonography as routine method]. / CT-Kolonographie in der täglichen Praxis.

CLINICAL/METHODICAL ISSUE: Colorectal cancer is a major public health challenge in Austria and Germany. As the participation in dedicated colonoscopy screening programs is rather low, the question of alternative methods is raised again and computed tomography (CT) colonography seems to be a gentle alternative with a very high patient acceptance. STANDARD RADIOLOGICAL METHODS: In recent years CT colonography (CTC) has been established besides conventional colonoscopy as a radiological method for the investigation of the entire colon. From axial two-dimensional images three-dimensional images can be generated, allowing a virtual flight through the colon which is why this technique is also known as virtual colonoscopy. METHODICAL INNOVATIONS: The technique of CTC has been improved continuously during recent years. On the one hand the steady decrease in the layer thickness (currently ≤ 1 mm) has improved the resolution of volume data sets and on the other hand there has been significant progress in postprocessing. PERFORMANCE: Numerous studies have recently shown that the significance of CTC in the detection of advanced adenomas is similar to conventional colonoscopy. ACHIEVEMENTS: Meanwhile CT colonography is now a routine investigation method established in both symptomatic and asymptomatic patients (screening). PRACTICAL RECOMMENDATIONS: Study data now clearly show that CTC, as an alternative to conventional colonoscopy, is a powerful method for investigation of colorectal cancer. To achieve good results adequate preparation including fecal tagging, standardized technical procedures during the investigation and expertise in both 2D and 3D reading are essential.

Photodynamic inactivation of normal and antifungal resistant Candida species.

BACKGROUND: Susceptibility of bacterial and fungal species to the photodynamic killing effects of various photosensitizing dyes has received increasing attention. In the oral cavity oral candidiasis is primarily caused by Candida albicans. Evidence suggests that Oropharyngeal Candidiasis, found frequently in patients with immunodeficiency, present with mixed Candida organisms and are more difficult to treat than those solely due to C. albicans. In the present study we demonstrate the ability to efficiently kill antifungal resistant isolates of Candida using Photofrin induced PDT. METHODS: Candida strains from the ATCC as well as fluconazole and amphotericin B resistant and sensitive isolates from adults with AIDS were grown cultures and grown under standard conditions. Photofrin was added to appropriate cultures as dictated by experimental design. Light was delivered to assigned cultures using a 630 nm laser source at a power density of 150 mW/cm(2), for appropriate time to deliver 45-135 J/cm(2). Colony forming assays were used to determine survival. RESULTS: After illumination cultures treated with Photofrin had significant reduction in colony forming ability at all light doses examined. Isolates from AIDS patients which had demonstrated antifungal resistance showed equivalent sensitivity to photodynamic killing as did control ATCC cultures of the same strain. CONCLUSION: This study demonstrates Photofrin induced PDT can eliminate Candida species with significant efficiency as revealed by colony forming ability. Further Candida isolates from AIDS patients that had demonstrated fluconazole and amphotericin B resistance were equally susceptible to photodynamic killing.

Gadoxate-enhanced T 1-weighted MR cholangiography: comparison of 1.5 T and 3.0 T.

PURPOSE: To qualitatively and quantitatively compare gadoxate-enhanced T 1-weighted MR cholangiography at magnetic field strengths of 1.5 T and 3.0 T. MATERIALS AND METHODS: A total of 40 patients with a non-dilated biliary system were retrospectively included in the study. T 1-weighted MR cholangiography 20 min after IV administration of 0.025 mmol/kg gadoxate (Primovist) was performed in 20 patients at 1.5 T and in another 20 patients at 3.0 T. Contrast-to-noise ratios (CNR) of the biliary system (common bile duct - CBD, right hepatic duct - RHD, left hepatic duct - LHD) compared to the periductal tissue were measured. Two radiologists also qualitatively assessed the visibility of the intrahepatic and extrahepatic biliary system using a six-point rating scale. The Mann-Whitney U-test and Pearson's correlation coefficient were used for statistical analysis. RESULTS: The CNRs of the intrahepatic and extrahepatic hepatic bile ducts were significantly higher at 3.0 T. Qualitative analysis showed a significant superiority for 3.0 T in the delineation of the intrahepatic biliary system (RHD, LHD, segmental ducts). CONCLUSION: Gadoxate-enhanced T 1-w MR cholangiography at 3.0 T offers better delineation of the intrahepatic biliary system in comparison to imaging at 1.5 T.

[Indications for and results of CT colonography: from screening to the symptomatic patient]. / Indikationen und Ergebnisse der CT-Kolonographie: von der Vorsorge bis zum symptomatischen Patienten.

CT colonography (CTC) is also referred to as virtual colonoscopy and is being used with increasing frequency in radiological practice. While there are still no generally accepted, clear-cut indications for its use in mass colorectal cancer screening, there is evidence that this investigation is useful in patients in whom colonoscopy has not been successful or who have known stenotic lesions in the colon. Recent results of significant comparative studies of CTC and conventional colonoscopy will have some influence on the future place of CTC in screening for cancer of the bowel; they show the great potential of CT-aided bowel examination.

[CT colonography: patient preparation and examination technique]. / CT-Kolonographie: Patientenvorbereitung und Untersuchungstechnik.

An examination technique adapted to comply with the demands of CT colonography is not only a basic requirement for a high-quality examination and correct ascertainment of the findings; it is also essential for far-reaching applications of this method of examination. The technique of CT colonography is based on good patient preparation with the aid of fecal tagging, adequate distension of the colon with CO(2) and acquisition of data with the patient both prone and supine in a thin-slice technique using a low-dose protocol. The different technical aspects of CT colonography are explained in this paper.

[CT colonography: pathologic findings and pitfalls]. / CT-Kolonographie: Pathologische Befunde und Pitfalls.

Thin-section multidetector-row computed tomographic (MDCT) colonography is a powerful tool for detection and classification of colonic lesions. It is based on a helical thin-section (0.75-2 mm) CT dataset of the cleansed and air-distended colon. 2D and 3D projections are prepared and used for image interpretation. Evaluation of CT colonography datasets requires correct perception and interpretation of colonic lesions and filling defects. Various criteria are needed for correct interpretation of filling defects and differentiation between genuine lesions and artifacts. Such defects are characterized by their morphology, their structure, the absorption of contrast medium and their mobility. Knowledge of the morphologic and attenuation characteristics of common colonic lesions and of artifacts is essential for the correct interpretation of a filling defect. This review article summarizes the main imaging features of polyps, diverticula, lipomas, and carcinomas and also of common pseudolesions of the colon.

Computer-aided detection in CT colonography: initial clinical experience using a prototype system.

Computer-aided detection (CAD) algorithms help to detect colonic polyps at CT colonography (CTC). The purpose of this study was to evaluate the accuracy of CAD versus an expert reader in CTC. One hundred forty individuals (67 men, 73 women; mean age, 59 years) underwent screening 64-MDCT colonography after full cathartic bowel cleansing without fecal tagging. One expert reader interpreted supine and prone scans using a 3D workstation with integrated CAD used as "second reader." The system's sensitivity for the detection of polyps, the number of false-positive findings, and its running time were evaluated. Polyps were classified as small (< or =5 mm), medium (6-9 mm), and large (> or =10 mm). A total of 118 polyps (small, 85; medium, 19; large, 14) were found in 56 patients. CAD detected 72 polyps (61%) with an average of 2.2 false-positives. Sensitivity was 51% (43/85) for small, 90% (17/19) for medium, and 86% (12/14) for large polyps. For all polyps, per-patient sensitivity was 89% (50/56) for the radiologist and 73% (41/56) for CAD. For large and medium polyps, per-patient sensitivity was 100% for the radiologist, and 96% for CAD. In conclusion, CAD shows high sensitivity in the detection of clinically significant polyps with acceptable false-positive rates.

Imaging characteristics of toxoplasmosis encephalitis after bone marrow transplantation: report of two cases and review of the literature.

Toxoplasmosis encephalitis is a severe, but often misdiagnosed complication in patients after bone marrow transplantation (BMT). We describe the unique computed tomography (CT) and magnetic resonance (MR) imaging features of cerebral toxoplasmosis in two bone marrow recipients and compare them to the cases in the literature. To our knowledge, this is the first report analyzing the appearance of cerebral toxoplasmosis on diffusion-weighted MR imaging (DWI).

The use of photodynamic therapy using 630nm laser light and porfimer sodium for the treatment of oral squamous cell carcinoma.

PDT has been demonstrated in clinical studies to be an efficacious method for the treatment of dysplastic, microinvasive and early forms of cancer. The advantage of PDT for early carcinomas of the oral cavity is the ability to preserve normal tissues while effectively treating cancers up to 1cm in depth. The case presented here successfully demonstrates the ability to use PDT to treat maxillary gingival squamous cell carcinoma thereby sparing the use of surgery or radiation therapy at this point in the management of the disease.

[Virtual multislice computed tomography cystoscopy for evaluation of urinary bladder lesions]. / Virtuelle MDCT-Zystoskopie bei der Detektion von Blasenläsionen.

The introduction of multislice computed tomography (MDCT) with the possibility of acquiring isotropic datasets has been an ideal prerequisite for development of virtual MDCT cystoscopy. Remarkable technical progress regarding post-processing of high-resolution 3D datasets as well as a considerable reduction of the time required for post-processing made it possible to introduce virtual MDCT cystoscopy into the clinical routine. 3D post-processing that often required 7-8 h when virtual endoscopy techniques were first developed can now be performed in less than 5 min after transfer of data to the 3D workstation. With the limitations and contraindications of conventional cystoscopy in mind, virtual MDCT cystoscopy may be seen as a valuable alternative to conventional cystoscopy for evaluation of hematuria.