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The object of this study was to assess the clinical usefulness of computer-assisted diagnosis (CAD) in the interpretation of early-research, benign and malignant mammograms in dependence on readers' experience with CAD. CAD was applied on digital mammograms of 303 patients who were divided into three groups: early-research (n=103), benign (n=102) and malignant group (n=98). Mammograms were analyzed by three readers with different experience in evaluating mammograms (medical student, an assistant and an attending physician specifically trained in mammography). All images were presented accidentally with and without the influence of CAD and from different patient groups. The mammograms were classified according to BI-RADS classification. To evaluate readers' sensitivity and specificity with and without the application of the CAD system, ROC analysis and the corresponding area under the curve (AUC) were evaluated for each reader. Afterwards significant differences of the accuracy according to readers experience and according to the assistance of the CAD system were calculated. All readers have an account of accuracy by using CAD in both patient groups. The highest benefit has the student (10% increase of the AUC) followed by the resident (4%) and at least followed by the mammography fellow (3%). There are significant varieties of the accuracy in addiction to the readers' experience and to the examination method with and without CAD system. Patient group has not a significant influence to the elevation of accuracy by using the CAD. All three readers have nearly the same increase of AUC in the examinations of malignant and early-research group summarized and of the malignant group only. Finally, the increase of accuracy depends on the readers' experience. For all patient groups CAD-application causes a steeply increase of the ROC curve and consequently a gain of sensitivity., (© 2010 Wiley Periodicals, Inc.)

Objective: Hypertrophic obstructive cardiomyopathy (HOCM) is treated by surgical myectomy or transcoronary ablation of septal hypertrophy (TASH). The aim of this study was to visualize the feasibility, success and short-term results of TASH on the basis of cardiac MRI (CMR) in comparison with cardiac catheterization and echocardiography., Methods: In this in vivo study, nine patients with HOCM were treated with TASH. Patients were evaluated by transthoracic echocardiography, invasive cardiac angiography and CMR. Follow-up examinations were carried out after 1, 3 and 12 months. MR imaging was performed on a 1.5-T scanner. All images were processed using the semiautomatic Argus software and were evaluated by an attending thoracic radiologist and cardiologist., Results: The echocardiographic pressure gradient (at rest) was 69.3 +/- 15.3 mmHg before and 22.1 +/- 5.7 mmHg after TASH (P < 0.01, n = 9). The flux acceleration over the aortic valve examined (V (max)) was 5.1 +/- 0.6 m/s before and 3.4 +/- 0.3 m/s after the TASH procedure (P < 0.05). Also, there was a decrease of septum thickness from 22.0 +/- 1.2 to 20.2 +/- 1.0 mm (P < 0.05) after 6 +/- 3 weeks. The invasively assessed pressure gradient at rest was reduced from 63.7 +/- 15.2 to 21.2 +/- 11.1 mmHg (P < 0.01) and the post-extrasystolic gradient was reduced from 138.9 +/- 12.7 to 45.6 +/- 16.5 mmHg (P < 0.01). All differences as well as the quantity of injected ethanol were plotted against the size or amount of scar tissue as assessed in the MRI. There was a statistically significant correlation between the post-extrasystolic gradient decrease and the amount of scar tissue (P = 0.03, r (2) = 0.5). In addition, the correlation between the quantity of ethanol and scar tissue area was highly significant (P < 0.01, r (2) = 0.6), whereas the values for the gradient deviation (P = 0.10, r (2) = 0.34), DeltaV (max) (P = 0.12, r (2) = 0.31), as well as the gradient at rest (P = 0.27, r (2) = 0.17) were not significant., Conclusion: TASH was consistently effective in reducing the gradient in all patients with HOCM. In contrast to the variables investigated by echocardiography, the invasively measured post-extrasystolic gradient correlated much better with the amount of scar tissue as assessed by CMR. We conclude that the optimal modality to visualize the TASH effect seems to be a combination of CMR and the invasive identification of the post-extrasystolic gradient.

Background: Advances in CT technology from single to multi-detector row CT (MDCT) permit a high resolution and volumetric presentation of pulmonary lesions. This implicates emerging measurement techniques that need to be contrasted with established methods., Purpose: To compare bidimensional, unidimensional, and volumetric methods for evaluation of treatment response in patients with lung lesions., Material and Methods: This study comprised 68 patients with pulmonary lesions who underwent a total of 276 64-MDCTs of chest at baseline and follow-up. RECIST and WHO criteria were used for unidimensional and bidimensional methods and region growing (RG) for volumetry. Patients were classified into four response categories. Respectively, two measurement techniques were contrasted and the kappa index was calculated. For intra-observer reproducibility the relative measurement error (RME) and kappa index with regard to agreement of response categories were evaluated., Results: Comparison of WHO und RECIST criteria achieves high correlation with kappa indices of 0.76 and 0.82. In particular, lesions with moderate increase of size in the range of 25-44% for bidimensional and 12-29% for unidimensional measurement result in different response categories when applying WHO and RECIST criteria. WHO criteria delivered PD more often than RECIST. kappa indices of 0.79 and 0.87 were attained in comparison of RECIST and RG, and 0.83 and 0.84 for WHO and RG. RME was 2.82% for RECIST, 7.53% for WHO, and 8.97% for RG. Intra-observer reproducibility was 95% for RECIST, 95% for WHO, and 96% for RG., Conclusion: The comparison of all methods resulted in no statistically significant differences. WHO criteria seemed to diverge the most, they declared several lesions prematurely as progression, and showed no benefit in comparison to RECIST. RG showed the best reproducibility, considered irregular lesions, was slightly superior to RECIST, and could be applied uniformly. Unidimensional measurement represents an adequate alternative with the advantage of better clinical work flow.

We report a case of a male patient who received an implantation of a Starr-Edwards-caged-ball-valve-prosthesis in 1967. The surgery and postoperative course were without complications and the patient recovered well after the operation. For the next four decades, the patient remained asymptomatic--no restrictions on his lifestyle and without any complications. In 2006, 39 years after the initial operation, we performed a Bentall-Procedure to treat an aortic ascendens aneurysm with diameters of 6.0 x 6.5 cm: we explanted the old Starr-Edwards-aortic-caged-ball-valve-prosthesis and replaced the ascending aorta with a 29 mm St.Jude Medical aortic-valve-composite-graft and re-implanted the coronary arteries.This case represents the longest time period between Starr-Edwards-caged-ball-valve-prosthesis-implantation and Bentall-reoperation, thereby confirming the excellent durability of this valve.

Aim: In this retrospective study, we assess the current role and future potential of computed tomography (CT) in the diagnostic algorithm of acute pulmonary embolism (PE)., Materials and Methods: Two hundred patients underwent 64-multidetector-row spiral CT of the chest, pelvis, and thigh for suspected PE. CT scans were reviewed, and the degree of contrast enhancement and the presence of PE and/or (deep) venous thrombosis were recorded. In the case of PE, the level of thrombus was noted as central, main, or lobar. If the scan yielded a positive result for thrombosis, intravenous localization was also determined. Patient age, length of admission, clinical course, clinical indication, and incidental findings were registered as well., Results: PE was detected in 60 of the 200 patients with a high clinical probability of having PE (30%). Thirty-four patients had a positive CT scan result for venous thrombosis (17%). Twenty-four of the 60 patients had proximal deep venous thrombosis (40%), and 2 patients had arm venous thrombosis (3%). Thirty-four of the 60 patients had PE without venous thrombosis (57%). Eight of the 200 patients had deep venous thrombosis without suspicion of PE (4%). The distribution of the proximal thrombi showed 15 in a central artery (25%), 13 in a main pulmonary artery (22%), and 32 in a lobar segmental artery (53%). There was diffuse allocation of the thrombus in all lobes. Furthermore, CT scan noted a total of 120 incidental findings., Conclusion: Our study indicates the potential clinical use of a diagnostic strategy for ruling out PE based on D-dimer testing and multidetector-row CT. A larger outcome study is needed before this approach can be adopted.

Aim: In this retrospective study, we assess the current role and future potential of computed tomographic (CT) colonography as a viable alternative imaging tool for colorectal polyp detection and colon cancer screening., Materials and Methods: Twenty patients have undergone virtual colonographic examinations with 64-multidetector-row spiral CT (MDCT), and three-dimensional images were created on a separate workstation that had the appropriate software for image processing. Images were reviewed by a radiologist, and anatomic division of the entire colon was used to locate the suspected lesions. Characteristics of bowel preparation, intracolonic, extracolonic, and incidental findings were noted, too., Results: Ten of the 20 patients (50%) had a positive CT colonography for polypoid lesions. Those lesions were distributed into the cecum (4 cases), colon ascendens (2 cases), colon descendens (2 cases), and sigma (2 cases). In 80%, bowel preparation was good, in 15% moderate, and in 5% inadequate. Furthermore, CT scan noted in total 20 incidental findings., Conclusion: CT colonography is currently a viable alternative imaging tool for colorectal polyp detection. There are several clinical situations where CT colonography may play an important role in patient care. These include for example evaluation of the colon after an incomplete conventional colonoscopic examination or evaluation in patients who are clinically unfit to undergo conventional colonoscopy. At centers where there is expertise in data acquisition and interpretation, CT colonography is being offered as a routine imaging examination. With continued improvements in bowel preparation, colonic distention, and CT colonography interpretation by sufficient numbers of radiologists this technology might have a substantial influence on colon cancer screening.

Nowadays, computed tomography (CT) is established for diagnosing gastrointestinal bleeding. In this retrospective study, the use of CT in diagnosing gastrointestinal bleeding was evaluated. Fifty-three patients received a contrast-medium-enhanced helical multislice CT (MSCT) to locate the bleeding site. Seventy-nine percent of the hemorrhage were acute gastrointestinal bleedings. Fifty-five percent of the acute hemorrhages were located via helical MSCT, 45% of the chronic bleeding sites were detected. Notably, bleeding of diverticula, tumors, and angiodysplasias were well demonstrated. In conclusion, contrast-medium-enhanced MSCT may be used effectively as a noninvasive diagnostic tool for detecting gastrointestinal bleedings.

The goal of this study was to evaluate the performance of a computer-aided detection (CAD) system in full-field digital mammography (Senographe 2000D, General Electric, Buc, France) in finding out carcinomas depending on the parenchymal density. A total of 226 mediolateral oblique (MLO) and 186 craniocaudal (CC) mammographic views of histologically proven cancers were retrospectively evaluated with a digital CAD system (ImageChecker V2.3 R2 Technology, Los Altos, CA, USA). Malignant tumors were detected correctly by CAD in MLO view in 84.85% in breasts with parenchymal tissue density of the American College of Radiology (ACR) type 1, in 70.33% of the ACR type 2, in 68.12% of the ACR type 3, and in 69.70% of the ACR type 4. For the CC view, similar results were found according to the ACR types. Using the chi-square and McNemar tests, there was no statistical significance. However, a trend of better detection could be seen with decreasing ACR type. In conclusion, there seems to be a tendency for breast tissue density to affect the detection rate of breast cancer when using the CAD system.

The object of this study was to determine the performance of a computer-aided detection system in full-field digital mammography (Senographe 2000D, General Electric, Buc, France) in detecting carcinomas in breasts in dependence of the initial Breast Imaging Reporting and Data System (BI-RADS) categories. A total of 226 mediolateral oblique (MLO) and 186 craniocaudal (CC) view mammograms of histologically proven cancers were retrospectively evaluated with a primary digital computer-aided detection system (Image Checker V2.3; R2 Technology, Los Altos, CA). According to BI-RADS of the American College of Radiology (ACR), the lesions were classified in MLO view as BI-RADS 1 in 2 cases, BI-RADS 2 in 11 cases, BI-RADS 3 in 37 cases, BI-RADS 4 in 56 cases, and BI-RADS 5 in 120 cases, and in CC view as BI-RADS 1 in 2 cases, BI-RADS 2 in 8 cases, BI-RADS 3 in 26 cases, BI-RADS 4 in 46 cases, and BI-RADS 5 in 104 cases. The computer-aided detection system shows markers also in mammograms classified as BI-RADS categories 1-3 by the radiologist. Furthermore, BI-RADS categories 4 and 5 in most cases demonstrate masses in mammography. With increasing BI-RADS category, the computer-aided detection system shows decreasing numbers of overlooked carcinomas. In MLO view, no markers were found in 100% (2/2), 81.8% (9/11), 59.5% (22/37), 46.4% (26/56), and 15% (18/120) for BI-RADS categories 1-5, respectively. False-positive markers, however, were seen in 0.5 per image (205/412). In conclusion, the high rate of false-positive markers shows that the specificity of the computer-aided detection system is limited and that improvements are necessary.