Value of the BI-RADS classification in MR-Mammography for diagnosis of benign and malignant breast tumors.

AIM: To assess whether the BI-RADS classification in MR-Mammography (MRM) can distinguish between benign and malignant lesions. MATERIAL AND METHOD: 207 MRM investigations were categorised according to BI-RADS. The results were compared to histology. All MRM studies were interpreted by two examiners. Statistical significance for the accuracy of MRM was calculated. RESULTS: A significant correlation between specific histology and MRM-tumour-morphology could not be reported. Mass (68%) was significant for malignancy. Significance raised with irregular shape (88%), spiculated margin (97%), rim enhancement (98%), fast initial increase (90%), post initial plateau (65%), and intermediate T2 result (82%). Highly significant for benignity was an oval mass (79%), slow initial increase (94%) and a hyperintense T2 result (77%), also an inconspicuous MRM result (77%) was often seen in benign histology. Symmetry (90%) and further post initial increase (90%) were significant, whereas a regional distribution (74%) was lowly significant for benignity. CONCLUSION: On basis of the BI-RADS classification an objective comparability and statement of diagnosis could be made highly significant. Due to the fact of false-negative and false-positive MRM-results, histology is necessary.

Computer-assisted diagnosis in full-field digital mammography--results in dependence of readers experiences.

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.

Measurement of response of pulmonal tumors in 64-slice MDCT.

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.

Cyclopamine treatment of full-blown Hh/Ptch-associated RMS partially inhibits Hh/Ptch signaling, but not tumor growth.

Mutations in the Hedgehog (Hh) receptor Patched (Ptch) are responsible for a variety of tumors, which show ligand-independent stimulation of the Hh/Ptch signaling cascade. Cyclopamine is an alkaloid of the corn lily Veratrum californicum, which blocks activity of the pathway by inhibition of Smoothened (Smo), the signal transduction partner of Ptch. This results in growth inhibition of Hh/Ptch-dependent tumor cells in vitro, of subcutaneous xenografts as well as of precancerous lesions in Ptch(+/-) mice. However, the evidence that treatment with cyclopamine is an effective anti-cancer therapy against full-blown tumors is sparse. Here, we have investigated the responsiveness of full-blown Hh/Ptch-associated rhabdomyosarcoma (RMS) to this drug. Hh pathway activity and proliferation of cultured primary RMS cells was inhibited by cyclopamine. Hh signaling was also partially suppressed by the drug in RMS in vivo, but cyclopamine treatment did not result in stable disease or tumor regression. It also did not affect proliferation, apoptosis or the differentiation status of RMS. This was in contrast to anti-proliferative effects on tumor growth caused by doxorubicin, an anthracycline routinely used in therapy of human RMS. In summary, our data indicate that there must be additional factors that render full-blown Hh/Ptch-associated RMS insensitive against anti-proliferative effects of cyclopamine in vivo.

The significance of a uniform definition of pathological lymph nodes in Hodgkin lymphoma: impact of different thresholds for positive lymph nodes in CT imaging on staging and therapy.

BACKGROUND AND PURPOSE: The most commonly used approach for the assessment for differentiating malignant versus reactive lymph nodes is the measurement of the cross-section diameter of the lymph nodes in the transversal CT-planes. The intention of this article is to assess the impact of varying definitions of pathological lymph node size in CT-imaging in patients with Hodgkin lymphoma and to evaluate its effect on staging, chemotherapy regimes and radiation field size. MATERIALS AND METHODS: Pretherapeutic CT-scans of 10 consecutive patients with Hodgkin lymphoma have been evaluated based on two different definitions for malignant lymph node size; the classification of the German study group for Hodgkin lymphoma (1.0 cm) and the classification according to the results of the Cotswold consensus meeting 1989 (1.5 cm). RESULTS: Applying the definitions of the DHSG and the Cotswold meeting we found more affected lymph node regions compared to the evaluation of the referring institutions in 9/10 and 6/10 patients, higher stages in 2/10 and 1/10 patients, more intense chemotherapy regimes in 3/10 and 1/10 and larger radiation fields in 10/10 and 6/10 patients, respectively. CONCLUSIONS: Varying definitions of pathologic lymph node size and inconsequent application of definitions reduce the comparability between different studies and within each study.

Fetal MRI of lung hypoplasia: imaging findings.

Fetal magnetic resonance imaging has become a useful noninvasive modality to examine the human fetus in case of suspicious sonography. Normally, central nervous system structures of the fetus in utero indicate the need for further evaluation. Fast T(2)-weighted sequences are used, which minimize artifacts and allow high contrast between different structures. Cases in which a diaphragmatic hernia was diagnosed via ultrasound will be shown in the magnetic resonance images of the fetuses in this study.

Detection of gastrointestinal bleeding by using multislice computed tomography--acute and chronic hemorrhages.

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.

Flat panel detector-based volumetric computed tomography (fpVCT): performance evaluation of volumetric methods by using different phantoms in comparison to 64-multislice computed tomography.

OBJECTIVES: Evaluation of a silicon-based flat panel volumetric computed tomography (fpVCT) and multislice CT in terms of volumetry of phantoms with different algorithms. Furthermore, to compare the different volumetric analysis methods themselves. MATERIALS AND METHODS: Four phantoms of different materials have been scanned with fpVCT (GE prototype with circular gantry with 2 aSi/CsI flat panel detector) and a 64-slice spiral CT (MSCT: LightSpeed VCT). Three spherical phantoms of different materials and 1 phantom with an irregular shape were evaluated. True volumes were calculated in dependence from the diameter or by water displacement method. Imaging parameters (80 kVp, 100 mA) and the position of the phantoms were identical in both techniques. After reconstruction of the images different algorithms have been used 4 times for each phantom. These analysis methods have been performed: Region growing, threshold method, planimetry, 3-dimensional volumetry measurement by using the equation of an ellipsoid (ellipse) and an advanced lung analysis modus [single advanced lung analysis (ALA)]. The mean values and the standard deviations have been evaluated and compared with the true volumes. RESULTS: In all phantoms fpVCT showed better results with lower deviations from the true values than in MSCT, especially for small volumes of the phantoms. However, the results of the ALA single method demonstrated no significant difference between the fpVCT and MSCT. The comparison of the different analysis methods revealed that 3-dimensional measurement with the ellipse method was the worst method for volume estimation, especially for the irregularly formed phantom. CONCLUSION: fpVCT was superior to MSCT in the volumetry of small objects. The ellipse method has been shown to be the worst for volumetry with the highest relative deviations from the true volume value. The single ALA method shows the lowest standard deviation thereby revealing a reproducible volumetric method for small nodules. However, further future developments of volumetric analysis methods are necessary to use them accurately in daily routine. Due to the truly isotropic volume data set with high spatial resolution fpVCT is a powerful tool for the volumetry of small nodules.

Palpable masses in breast during lactation.

OBJECTIVES: Diagnosis of breast cancer is more difficult in pregnant and lactating women. In the present study, the value of different radiological methods has been evaluated. MATERIAL AND METHODS: Twenty-seven patients with palpable breast masses during the lactation period were evaluated. All masses were investigated in the clinical course as well as in ultrasound. If ultrasound demonstrated a suspicious lesion a mammogram was done. If clinical course, ultrasound, and mammography could not rule out breast cancer, MR mammography was done. RESULTS: Eighteen ultrasound-guided biopsies were done, revealing three cysts, seven hyperplasias/mastopathia, three cases of papilloma, and two carcinomas. The 18 mammograms were classified as BI-RADS 1 and 2 in nine cases, as BI-RADS 3 in seven case, as BI-RADS 4 in one cases, and as BI-RADS 5 in also one case. MR mammography was done in 9 cases revealing three BI-RADS 4 categories and one BI-RADS 5 category, all of them showed a malignant histology. CONCLUSIONS: The density of the lactating breast compromises breast cancer diagnosis. Ultrasound should be the method of choice. If possible mammography and MR mammography should be done after lactating period.

Flat-panel-detector-based volumetric CT: performance evaluation of imaging for skeletal structures of small animals in comparison to multislice CT.

OBJECTIVES: The aim of this study was to compare the image performance of silicon-based flat-panel-detector-based volumetric computed tomography (fpVCT) to multislice spiral computed tomography (MSCT) for the visualization and detail detectability of skeletal structures in rodents of different development stages. MATERIALS AND METHODS: Rodents of different development stages were imaged with fpVCT (GE prototype with circular gantry with two 1024 x 1024, 200-microm pixel size, amorphous silicon/Cesium lodid (Csl) flat-panel detector) and eight-slice MSCT (LightSpeed Ultra). Imaging parameters (80 kVp, 100 mA) and the position of the rodents were identical in both techniques. Image quality, detail detectability, and contour of skeletal structures were judged by two observers in consensus using a 4-point scale (1 = unsatisfactory...4 = good). Findings were displayed and evaluated in axial slices, multiplanar reconstructions (MPR), maximum intensity projections (MIP) and volume rendering technique (VRT) in both modalities. Mean and standard of error of mean were calculated. RESULTS: In axial slices, visualization and detail detectability of very subtle skeletal structures, e.g., the basis of the skull was better in fpVCT than in MSCT (4 vs. 2 points). The MPRs of fpVCT showed less artifacts and more details than those of the MSCT. The MIPs and VRTs of the fpVCT demonstrated best image quality in all rodents of different development stages, whereas MSCT showed significant artifacts. CONCLUSION: fpVCT outperformed MSCT in imaging of small rodents. Due to the truly isotropic volume data set with high spatial resolution, fpVCT is a powerful tool in evaluating detailed skeletal structures.

Diagnostic accuracy of abnormal galactographic and sonographic findings in the diagnosis of intraductal pathology in patients with abnormal nipple discharge.

The purpose of the study was to compare the diagnostic accuracy of the combination of galactography and ultrasound in patients with pathologic nipple discharge. Fifty-six patients with pathologic nipple discharge were included in the study. Sensitivity, specificity, and positive (PPV) and negative predictive value (NPV) for each method and the combination of both were calculated. Both methods together had a sensitivity, specificity, PPV, and NPV of 91%, 17%, 61%, and 57%. The combined sensitivity of galactography and ultrasound for intraductal pathologies is higher than either modality alone, with a low specificity. No specific signs exist to predict benign or malignant lesions.

Contrast-enhanced high in-plane resolution dynamic MRI of the breast. Are there advantages in comparison to standard dynamic MRI?

OBJECTIVE: To evaluate the diagnostic advantages of high in-plane resolution contrast-enhanced (CE) magnetic resonance imaging (MRI) of the breast in comparison to standard CE-MRI. METHODS: Forty-one patients with 51 hypervascularized lesions were selected prospectively after undergoing bilateral standard CE MRI (slice thickness 4 mm, in-plane resolution 1.52 x 1.25 mm2, temporal resolution 81 s). Patients underwent high in-plane resolution CE MRI, either (n=21) a two-dimensional fast-low-angle-shot sequence (slice thickness 4 mm, in-plane resolution 0.76 x 0.63 mm2, temporal resolution 96 s) or (n=20) a SE sequence being used (slice thickness 4 mm, in-plane resolution 0.8 x 0.63 mm2, temporal resolution 115 s). RESULTS: Histopathology revealed 33 malignant and 18 benign lesions (0.2-2.2 cm). Morphologic characteristics were much better visualized with high in-plane resolution. Additional diagnostic information, however, resulted only in one patient with fibroadenoma due to a better visualization of smooth contours. CONCLUSIONS: High in-plane resolution provides better visualization of morphologic patterns in comparison to standard dynamic MRI. However, a diagnostic advantage is only rare.

Detection of intracardiac masses in patients with coronary artery disease using cardiac magnetic resonance imaging: a comparison with transthoracic echocardiography.

We sought to evaluate the diagnostic accuracy of contrast-enhanced cardiac magnetic resonance (CMR) imaging for the detection of intracardiac masses and thrombus formation in patients with history of coronary artery disease (CAD) in comparison to transthoracic echocardiography (TTE) under clinical routine conditions. 171 patients with history of CAD (89 male, aged 34-89 years, median 63 ± 11) underwent TTE and CMR during routine clinical examinations. TTE and CMR were independently analysed regarding the presence of intracardiac thrombus formation, masses and related size, dimensions, shape and signal characteristics. TTE depicted intracavitary thrombus formation in 40/171 patients (23.4 %) and intracardiac mass in 12/171 patients (7.0 %). All masses revealed in TTE were correctly detected on CMR and confirmed by histology. However, CMR showed 15 additional thrombi and 3 additional intracardiac masses (p = 0.001) that were not seen in TTE. Patients with poor systolic function (LVEF <30 %) had misleading results when referred to TTE (19 vs. 27 thrombi detected, p < 0.01). The detection of intracardiac masses or thrombi was not significantly different in patient with LVEF >30 %, whereas CMR was superior when the LVEF was <30 %. Routine TTE in patients with CAD leads to lower detection rates of intracardiac masses and thrombus formation in patients with severely impaired EF. Consequently we are missing a significant amount of clinically relevant diagnosis when only assessing patients with TTE. In patients with CAD and severely impaired LVEF, CMR should be considered as first line imaging tool to detect or rule out intracardiac masses and thrombi.

Use of contrast-enhanced spectral mammography for intramammary cancer staging: preliminary results.

RATIONALE AND OBJECTIVES: To prospectively evaluate and compare the accuracy of contrast-enhanced spectral mammography (CESM) and ultrasound (US) in size measurement of breast cancer with histologic tumor sizes as gold standard. MATERIALS AND METHODS: Twenty women aged between 40-73 years (mean age, 57 ± 10 years) with histologically proven invasive ductal/lobular carcinomas were included in the study. Agreement between imaging tumor size (CESM and US) and histopathologic tumor size was evaluated with Bland-Altman analysis. Stereotactically guided vacuum biopsy was performed in four patients after CESM. Two independent reviewers described artifacts of CESM. RESULTS: Motion artifacts did not occur in the study. CESM-specific artifacts caused by scattered radiation mostly occurred in oblique view of CESM. Background enhancement of breast tissue was seen in four patients. Mean difference of tumor sizes was 0.3 mm (6.34%) between CESM and histology and -2.2 mm (-7.59%) between US and histology. Limits of agreement ranged from -18.9 to 19.48 mm for CESM and from -17.1 to 12.7 mm with US. Especially smaller tumors with a size <23 mm were measured more precisely with CESM. Enhancement of breast tissue around microcalcifications correlated with abnormalities. CONCLUSIONS: CESM is accurate in size measurements of small breast tumors. On average CESM leads to a slight overestimation of tumor size, whereas US tends to underestimate tumor size. Assessment of the breast tissue can be limited by the scattered radiation artifact and background enhancement of breast tissue. CESM seems to be helpful in the characterization of breast tissue around microcalcifications.

Accuracy of 64-multidetector computed tomography coronary angiography in patients with symptomatic atrial fibrillation prior to pulmonary vein isolation.

AIMS: Aim of our study was to investigate the value of multidetector computed tomography (MDCT) for detecting significant stenoses of coronary arteries in patients with symptomatic atrial fibrillation (AF) prior to pulmonary vein (PV) ablation (PVA). BACKGROUND: Many patients undergoing PVA for AF receive three-dimensional computed tomography or magnetic resonance tomography imaging for improving anatomical orientation. METHODS: One-hundred and eighty-one patients with AF refractory to antiarrhythmic treatment underwent ECG-gated 64-MDCT for identification of PV anatomy and simultaneous assessment of coronary vessels before PVA. No additional radiation was incurred for MDCT coronary angiography during MDCT scan. Pretest probability for obstructive coronary artery disease (CAD) was estimated. Invasive coronary angiography (ICA) was performed in all patients with at least intermediate risk of CAD. RESULTS: Eighty-six out of 181 patients (48%) had ICA and MDCT, 95 patients (52%) underwent MDCT alone. ICA revealed significant stenoses in 9% of the catheterized patients (8/86). MDCT investigation lead to a sensitivity of 90% (9/10), specificity of 98% (829/844 lesions), positive predictive value (PPV) of 39% (9/24), and negative predictive value (NPV) of 100% (829/830 lesions) for the detection of >50% stenoses seen on ICA. All patients with a significant stenosis were classified as patients with CAD. Overall prevalence of significant CAD detected by MDCT was found to be low with 10% of patients and 2% of all segments. CONCLUSION: MDCT coronary angiography is sensitive and highly specific in patients presenting for PVA. In this group a negative scan reliably excludes significant CAD. These data suggest that MDCT coronary angiography can replace ICA prior to PVA.

Extra cardiac findings by 64-multidetector computed tomography in patients with symptomatic atrial fibrillation prior to pulmonal vein isolation.

The aim of this study was to investigate the prevalence of extracardiac findings diagnosed by 64-multidetector computed tomography (MDCT) examinations prior to circumferential pulmonary vein (PV) ablation of atrial fibrillation (AF). A total of 158 patients (median age, 60.5 years; male 68%) underwent 64-MDCT of the chest and upper abdomen to characterize left atrial and PV anatomy prior to AF ablation. MDCT images were evaluated by a thoracic radiologist and a cardiologist. For additional scan interpretation, bone, lung, and soft tissue window settings were used. CT scans with extra-cardiac abnormalities categorized for the anatomic distribution and divided into two groups: Group 1-exhibiting clinically significant or potentially significant findings, and Group 2-patients with clinically non-significant findings. Extracardiac findings (n = 198) were observed in 113/158 (72%) patients. At least one significant finding was noted in 49/158 patients (31%). Group 1 abnormalities, such as malignancies or pneumonias, were found in 85/198 findings (43%). Group 2 findings, for example mild degenerative spine disease or pleural thickening, were observed in 113/198 findings (72%). 74/198 Extracardiac findings were located in the lung (37%), 35/198 in the mediastinum (18%), 8/198 into the liver (4%) and 81/198 were in other organs (41). There is an appreciable prevalence of prior undiagnosed extracardiac findings detected in patients with AF prior to PV-Isolation by MDCT. Clinically significant or potentially significant findings can be expected in ~40% of patients who undergo cardiac MDCT. Interdisciplinary trained personnel is required to identify and interpret both cardiac and extra cardiac findings.

MDCT in the diagnostic algorithm in patients with symptomatic atrial fibrillation.

Atrial fibrillation (AF) is the most common supraventricular arrhythmia and a major cause of morbidity. Arrhythmogenic foci originating within the pulmonary veins (PVs) are an important cause of both paroxysmal and persistent AF. A variety of endovascular and surgical techniques have been used to electrically isolate the PV from the left atrium. Pulmonary venography for localization of the PV ostium can be difficult to perform during the ablation procedure. While the anatomy of the PV is patient-specific, non-invasive imaging techniques may provide useful diagnostic information prior to the intended intervention. In this context, multidetector computed tomography (MDCT) visualization of the left atrial and PV anatomy prior to left atrial ablation and PV isolation is becoming increasingly important. MDCT imaging provides pre-procedural information on the left atrial anatomy, including atrial size and venous attachments, and it may identify potential post-procedural complications, such as pulmonary vein stenosis or cardiac perforations. Here, we review the relevant literature and present the current "state-of-the-art" of left atrial anatomy, PV ostia as well as the clinical aspects of refractory AF, MDCT imaging protocols and procedural aspects of PV ablation.

CAD in full-field digital mammography-influence of reader experience and application of CAD on interpretation of time.

AIM: To assess time expenditure using the influence of computer-assisted detection (CAD) system in the interpretation of the dependence of early research and benign and malignant mammograms on readers' experience. MATERIALS AND METHODS: CAD (Image Checker V2.3; R2 Technology, Los Altos, CA, USA) was prospectively applied on digital mammograms of 303 patients [early research (n=103), benign (n=102), and malignant group (n=98)]. Mammograms were analyzed by three readers with varying experience in evaluating mammograms (medical student, resident and attending) according to the BI-RADS classification. Time was stopped and recorded. All images were presented randomly with and without the influence of CAD and from the different patient groups. To evaluate the statistical significance, the corresponding P value for time to read the mammograms in addition to different patient groups, application of CAD, readers' experience, and interaction of reader was calculated. RESULTS: The attending needs, independent of CAD application, the least time, followed by the medical assistant and the student. In all three patient groups, CAD adoption elongates reading time of the student and the resident. The medical specialist needs with and without CAD median the same time. In the early research group, no significant differences were registered (P=.1343). Concerning readers' experience, there is an explicit significant difference (P<.0001). The application of CAD correlates with the corresponding readers' experience and also provides a not significant result. In comparison, the P value for the malignant and benign groups shows significant interactions between the readers' experiences as well as CAD application. CONCLUSION: The future role of CAD application depends on whether sensitivity can be increased and time expenditure caused by false-positive marks can be decreased. In the future, second reading could be substituted by a CAD system if the reader has a wide professional experience.

Visualization of transcoronary ablation of septal hypertrophy in patients with hypertrophic obstructive cardiomyopathy: a comparison between cardiac MRI, invasive measurements and echocardiography.

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.

Current role and future potential of computed tomographic colonography for colorectal polyp detection and colon cancer screening-incidental findings.

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.