Thoracic aorta cardiac-cycle related dynamic changes assessed with a 256-slice CT scanner.

OBJECTIVE: The aim of our study was to demonstrate whether the dynamic changes previously documented at the ascending and abdominal aorta are replicated at the thoracic aorta. METHODS AND RESULTS: A consecutive series of thirty patients referred to our institution to undergo CT angiography of the thoracic aorta (CTA) constituted the study population. Patients with diffuse aortic atherosclerosis were excluded from the analysis. All studies were acquired with a 256-MDCT scanner and ECG-gating was performed in all cases. Two orthogonal imaging planes (maximal and minimal diameters) were obtained at three different levels of the descending thoracic aorta, using the distance from the left subclavian artery as proximal landmark: 10, 40, and 80 mm distance. The mean age was 58.9±15.7 years and 16 (53%) patients were male. Descending aorta measurements at 10, 40, and 80 mm distance from the left subclavian artery were all significantly larger within the systolic window (P<0.01 for all comparisons). Measurements of the maximal diameter were systematically larger than the minimal diameters among all aortic positions including ungated, systolic, and diastolic measurements (P<0.05 for all comparisons). CONCLUSIONS: The main finding of our pilot investigation was that the thoracic descending aorta undergoes significant conformational changes during the cardiac cycle, irrespective from the distance from the left subclavian artery.

Virtual hysterosalpingography: experience with over 1000 consecutive patients.

With the advent of multidetector computed tomography (MDCT), a whole new spectrum of diagnostic imaging techniques and procedures appears. Virtual hysterosalpingography (VHSG) is a novel non-invasive modality for assessing the uterus and female reproductive system that combines hysterosalpingography technique with MDCT technologies. Nowadays, 64-row VHSG offers an excellent diagnostic performance, in concordance with the development of new reproductive interventions and the need of accurate diagnostic procedures. In this article, we review the VHSG technique and describe normal and pathologic findings.

Histerosalpingografía virtual por TC multidetector de 64 filas: hallazgos en 2.500 pacientes / 64-Row multidetector CT virtual hysterosalpingography: findings in 2500 patients

Objective. To depict typical features of virtual hysterosalpingography (VHSG) in infertile patients. Material and methods: 2500 VHSG performed using a 64-row MDCT were evaluated. Results: Cervical abnormalities visualized corresponded to parietal irregularities (21 percent); thickened folds (9 percent); polyps (11 percent); diverticula (5 percent); cervical strictures (8 percent), and synechiae (1.5 percent). At the level of uterine cavity, polyps (44 percent); submucous myomas (8 percent); intramural and subserosal fibroids (11 percent); synechiae (10 percent); malformations (10 percent); adenomyosis (4 percent), and cesarean section scar (3 percent). Unilateral hydrosalpinx (7 percent) and bilateral hydrosalpinx (2 percent). Tubal obstruction was reported in 6 percent of cases. The average radiation dose was 0.94 mSv. Eighty-four percent of the patients reported mild pain or no postoperative discomfort. Conclusions: The virtual hysterosalpingography allowed a proper assessment of the internal genital organs, providing useful diagnostic information on infertility and other gynecological disorders. It constitutes a virtually painless, low-dose radiation technique, besides being well tolerated by patients.

Objetivo. Ilustrar los hallazgos característicos de la histerosalpingografía virtual (HSG-V) en pacientes en estudio de infertilidad. Material y métodos: Se evaluaron 2500 HSG-V efectuadas con un equipo de TCMD de 64 filas. Resultados A nivel del cuello se visualizaron irregularidades parietales (21 por ciento); pliegues engrosados (9 por ciento); pólipos (11 por ciento); divertículos (5 por ciento); estrechez (8 por ciento; y sinequias (1,5 por ciento). A nivel de la cavidad: pólipos (44 por ciento); miomas submucosos (8 por ciento); intramurales y subserosos (11 por ciento); y sinequias (10 por ciento); malformaciones (10 por ciento); adenomiosis (4 por ciento); cicatriz de cesárea (3 por ciento). Hidrosalpinx unilateral (7 por ciento) y bilateral (2 por ciento); obstrucción tubaria en el 6 por ciento de los casos. La dosis de radiación promedio fue 0.94 mSv. El 84 por ciento de los pacientes refirieron disconfort leve o ausente. Conclusiones: La HSG-Virtual permitió una adecuada evaluación de los órganos genitales internos, brindando información diagnóstica útil en infertilidad y otros desórdenes ginecológicos. Es una técnica poco dolorosa, bien tolerada por las pacientes y con baja dosis de radiación.

Accuracy of low-dose prospectively gated axial coronary CT angiography for the assessment of coronary artery stenosis in patients with stable heart rate.

BACKGROUND: Desirable methods for cardiac CT angiography would both reduce radiation exposure from cardiac CT angiography and preserve accuracy. OBJECTIVES: We assessed image quality, radiation dose, and diagnostic accuracy of a low-dose, prospectively gated axial cardiac CT angiography protocol for the evaluation of patients with suspected coronary artery disease (CAD). METHODS: Fifty consecutive patients referred for diagnostic invasive coronary angiography (ICA) and with a stable heart rate < 60 beats/min after beta-blocker administration were prospectively enrolled in a single center study. Subjects underwent CT angiography with a 64-row multidetector CT scanner with a prospectively gated axial imaging protocol. If the examination was determined to be nondiagnostic, then a retrospectively gated helical scan was performed. Two reviewers independently assessed image quality and the presence of significant coronary artery stenosis (>50%). RESULTS: Prospectively gated CT angiography was successfully performed in 46 of 50 patients. Of 794 coronary segments, 777 were determined to be of diagnostic image quality. The overall patient-based sensitivity (95% CI), specificity, positive predictive value, negative predictive value, and accuracy for the diagnosis of significant coronary stenosis were 100% (87%-100%), 75% (53%-90%), 81% (64%-93%), 100% (81%-100%), and 88% (81%-95%), respectively. The mean effective radiation dose for CT angiography and ICA were 3.4 +/- 0.4 mSv and 6.9 +/- 0.8 mSv, respectively. CONCLUSIONS: Cardiac CT angiography performed in a prospectively gated axial mode with 64-row multidetector CT provides an accurate, low-dose alternative for the detection of CAD.

Virtual hysterosalpingography: a new multidetector CT technique for evaluating the female reproductive system.

Recent advances in reproductive medicine have generated a demand for more accurate imaging methods for identifying the specific cause of female infertility and other gynecologic disorders. Virtual hysterosalpingography is an emerging modality in which aspects of the established technique of hysterosalpingography are combined with the cutting-edge technology of multidetector computed tomography (CT) to allow a comprehensive and highly accurate evaluation of both the female reproductive system and the pelvic anatomy generally. Unlike ultrasonography (US) and magnetic resonance (MR) imaging, multidetector CT is capable of depicting both the external and internal surfaces of the uterus, fallopian tubes, and other pelvic organs, providing high-resolution data that are suitable for two- and three-dimensional reconstructions and virtual endoscopic views. Thus, virtual hysterosalpingography may prove to be superior to other noninvasive modalities for evaluating tubal patency. Moreover, in comparison with conventional hysterosalpingography, which may involve cervical clamping, virtual hysterosalpingography is painless. Because of the health risks associated with ionizing radiation, the use of another modality (eg, MR imaging, US) may be preferred if the presence of a focal uterine lesion is strongly suspected. However, virtual hysterosalpingography with multidetector CT may provide a diagnostic advantage in complex cases.

Feasibility of 64-slice gadolinium-enhanced cardiac CT for the evaluation of obstructive coronary artery disease.

OBJECTIVE: To assess the feasibility of gadolinium-enhanced 64-slice cardiac CT (CCT) for the diagnosis of obstructive coronary artery disease. DESIGN: Comparative prospective study. SETTING: Outpatient Imaging Diagnostic Centre, Diagnóstico Maipú, Buenos Aires, Argentina. PATIENTS: Twenty patients with suspected coronary artery disease. INTERVENTIONS: Gadolinium-enhanced 64-slice CCT was performed before invasive coronary angiography (ICA). MAIN OUTCOME MEASURES: The feasibility of gadolinium-enhanced 64-slice CCT for detection of obstructive coronary artery disease (>50% diameter reduction) was evaluated, using ICA as the 'gold standard'. Mean lumen attenuation, non-calcified and calcified plaques densities were correlated between gadolinium-enhanced CCT studies and iodine-enhanced CCT studies of a control group. Renal function was strictly monitored. RESULTS: Gadolinium-enhanced CCT demonstrated adequate visualisation of 283/289 coronary segments that were evaluable by ICA, 31 of which had >50% luminal stenosis. In per-segment analysis, gadolinium-enhanced CCT showed a sensitivity of 90.3%, specificity of 96.8%, positive predictive value of 77.8% and negative predictive value of 98.8%. The agreement of coronary stenosis between multidetector CT (MDCT) and ICA was 94.1% (272/289). The mean lumen attenuation, non-calcified and calcified plaques densities in gadolinium-enhanced CCT studies were 140.1 Hounsfield units (HU), 51.1 HU and 523.6 HU, whereas in iodine-enhanced CCT studies the values were 354.1 HU, 101.0 HU and 778.5 HU, respectively (p < 0.001). CONCLUSION: Gadolinium-enhanced CCT is a feasible alternative for patients with severe contraindications to iodinated contrast agents referred for MDCT coronary angiography.

Virtual colonoscopy in paediatric patients Usefulness of a colon dissection technique.

OBJECTIVE: To determine the usefulness of perspective-filet view for polypoid lesions in paediatric patients in comparison with conventional virtual colonoscopy (VC) analysis and optical colonoscopy. METHODS: Sixty-one patients (mean age 5 years old) with a previous episode of rectal bleeding were studied using a 16 slices CT scanner. All patients underwent a colonic preparation. Two acquisitions were done in supine and prone positions with slices of 2mm thickness; increment 1mm, 30-50mA; 90-120kV. In a workstation an experienced radiologist reviewed images twice. The first read was done using the conventional virtual colonoscopy technique with the evaluation of two-dimensional (2D), three-dimensional (3D) and endoscopical images. Later, in a second session, perspective-filet view was used. It shows a 360 degrees unrolled visualization of the inner colon. The presence, size and location of the lesions were determined. A record of the reading time was made. RESULTS: At per patient evaluation the conventional virtual colonoscopy analysis obtained a sensitivity of 86% and a specificity of 98%. The perspective-filet view obtained a sensitivity of 91% and a specificity of 99%. In the evaluation on a per lesion basis the conventional analysis had a sensitivity of 81% and a specificity of 88%. Perspective-filet view, had a sensitivity of 82% and specificity of 90%. The average total reading time using conventional colonoscopy technique was 18+/-3min, versus 4+/-1min using the perspective-filet view. CONCLUSION: Virtual colon dissection with perspective-filet view is more time-efficient than conventional virtual colonoscopy evaluation with correct correlation in results.

Prevalencia y características de los puentes miocárdicos en estudios de angiografía coronaria por tomografía computarizada multidetector / Prevalence and Characteristics of Myocardial Bridging in Multidetector-Row Computed Tomography Coronary Angiography

Introducción Los puentes miocárdicos (PM) representan una anomalía congénita de las arterias coronarias en la que un segmento de una arteria coronaria principal, de habitual trayecto epicárdico, transcurre dentro del miocardio describiendo un curso intramural. Aunque el método diagnóstico de referencia es la angiografía convencional, existen otras técnicas invasivas. Con el advenimiento de la angiografía coronaria por tomografía computarizada multidetector (ACTCM) ha surgido una alternativa no invasiva para su evaluación. Objetivos              Evaluar la prevalencia y las características de los puentes miocárdicos en pacientes examinados con angiografía coronaria por tomografía computarizada multidetector (ACTCM). Material y métodos Se evaluaron en forma consecutiva 452 pacientes con ACTCM de 16 y 64 filas. Los motivos de la solicitud médica incluyeron hallazgos patológicos en estudios de perfusión miocárdica, síntomas sugestivos de enfermedad coronaria y pacientes asintomáticos con antecedentes heredofamiliares de enfermedad coronaria. Se determinaron la presencia, la localización y las características de los PM, los cuales se clasificaron en completos e incompletos según el grado de tunelización de la arteria involucrada. Se evaluó también su comportamiento durante la sístole y la diástole. Resultados La prevalencia de PM fue del 35,18%; se identificaron 88 casos de PM completos y 71 incompletos. Dentro del grupo de los PM completos, 6 mostraron compresión sistólica-diastólica, 27 sólo compresión sistólica y 55 no mostraron compresión. En el grupo de los PM incompletos no se detectaron casos con compresión arterial. Conclusiones La ACTCM mostró una prevalencia de PM mayor que la esperada en la población en estudio y permitió su clasificación y la evaluación de su comportamiento durante las fases del ciclo cardíaco.

Background Myocardial bridging (MB) are congenital defects of the coronary arteries in which a segment of an epicardial artery lies in the myocardium for part of its course. The current gold standard for diagnosing MB is coronary angiography; however other invasive techniques are also useful. Myocardial bridging can also be visualized with the use of novel non-invasive imaging techniques such as multidetector-row computed tomography coronary angiography (MDCT-CA). Objectives To assess the prevalence and characteristics of myocardial bridging in patients undergoing multidetector-row computed tomography coronary angiography (MDCT-CA). Material and Methods A total of 452 consecutive patients were evaluated with 16-row and 64-row MDCT-CA due to the presence of abnormal findings in myocardial perfusion image tests, symptoms suggestive of coronary artery disease, and in asymptomatic patients with a family history of coronary artery disease. The presence of MB, their location and characteristics were analyzed. Myocardial bridging were classified as complete and incomplete bridges with respect to continuity of the myocardium over the tunneled segment of the artery involved. Quantitative measurements of vessel diameter during systole and diastole were evaluated. Results The prevalence of MB was 35.18%; 88 were complete and 71 incomplete. Among complete MB, 6 affected both systole and diastole, 27 presented only systolic compression and 55 showed no compression. Incomplete MB showed absence of arterial compression. Conclusions Multidetector-row computed tomography coronary angiography detected a higher prevalence of MB in the study population and allowed to classify them and to assess their functional aspects throughout the cardiac cycle.

Certeza diagnóstica de la tomografía computarizada multicorte para la detección de la vasculopatía del injerto cardiaco: comparación con angiografía coronaria invasiva y ecografía intravascular / Accuracy of multidetector row computed tomography for the detection of transplant vasculopathy: comparison with invasive coronary angiography and intravascular ultrasound

Objetivo: Evaluar la certeza diagnóstica de la tomografía computarizada multicorte (TCM) en pacientes trasplantados cardiacos para la detección de estenosis coronaria y vasculopatía del injerto cardiaco (VDI) en comparación con la angiografía coronaria (AC) y la ecografía intravascular (EIV), respectivamente. Material y métodos: Diecinueve pacientes trasplantados cardiacos fueron estudiados con angiografía coronaria por TCM entre 7 a 14 días después del cateterismo (AD y EIV). Los estudios se llevaron a cabo con un tomógrafo multicorte de 16 filas. Dos observadores evaluaron en forma ciega los estudios de TCM para la detección de estenosis coronaria >50% y VDI. Resultados: Para la detección de estenosis coronaria >50%, la sensibilidad fue: 80-88% y la especificidad: 98- 99%; para la detección de VDI, 91-96% y 88-98%, respectivamente. Conclusión: En esta serie preliminar, nuestros resultados mostraron que la TCM fue una técnica adecuada para evaluar pacientes trasplantados cardiacos y podría ser una alternativa a la AD y EIV para el seguimiento y control no invasivo de estos pacientes.

Objective: To evaluate the diagnostic accuracy of multidetector computed tomography (MDCT) for detection of luminal stenosis and cardiac allograft vasculopathy in comparison with coronary angiography (CA) and intravascular ultrasound (IVUS) respectively. Material and methods: Nineteen cardiac transplant patients scheduled for follow-up CA were included. MDCT coronary angiography was performed using a 16-row CT scanner within 7-14 days after CA and IVUS. Studies were analyzed by independent readers; two observers evaluated the CT datasets for the presence of coronary artery stenosis >50% and allograft vasculopathy. Results: The sensitivity for detecting >50% luminal stenosis was 80-88% and specificity, 98-99% and for detection of cardiac allograft vasculopathy, the sensitivity was 91-96% and specificity, 88-91%. Conclusion: In this preliminary series, our results indicate that MDCT coronary angiography was capable of detecting both significant coronary stenosis as well as diffuse intimal proliferation. This non-invasive procedure could be an alternative to CA and IVUS in the surveillance of heart transplant patients.

Esophageal stenosis: three-dimensional multidetector CT and virtual endoscopy.

The improvement in spatial, temporal, and contrast resolutions with the newest multidetector computed tomographic (MDCT) scanners opens the opportunity to explore other applications of the virtual endoscopy technique besides the colon and stomach evaluation. As a non-invasive technique, virtual esophagoscopy represents an alternative to conventional endoscopy for the assessment of esophageal stenosis. The procedure and diagnostic performance are reviewed. Findings of this modality are illustrated.

Multidetector CT angiography and virtual angioscopy of the abdomen.

Computed tomographic angiography (CTA) has gained wide clinical acceptance as a powerful diagnostic tool in the non-invasive evaluation of vascular disorders and has became the method of choice for the assessment of aortic pathology. In addition, recent advances in computed tomography (CT) technology improve the image quality and diagnostic performance of the procedure in the abdominal vascular system. In this paper, we briefly review the CTA technique and describe the main applications of abdominal CTA.

CT colonoscopy in inflammatory bowel disease.

Virtual colonoscopy is used worldwide for the detection of colon polyps, but this technique has not been used much for the evaluation of inflammatory bowel diseases. The advent of multidetector-computed tomography and the use of high quality 3D and virtual images opened up the opportunity to assess these patients with this non-invasive technique. Early and late colonic changes are illustrated.

New approach to noninvasive coronary angiography by multidetector computed tomography: initial experience using gadolinium.

OBJECTIVE: To investigate the gadolinium performance for 16-detector-row coronary computed tomography (CT) angiography. METHODS: Ethics committee approval and informed consent were obtained. Ten patients with coronary artery disease underwent digital coronary angiography and gadolinium-enhanced CT coronary angiography (Gd-CTCA) within the same week. For the Gd-CTCA, each patient received a dose of 0.3 mmol/kg of body weight of 0.5 mmol/mL gadoterate meglumine. Two readers interpreted the CT angiographies independently, and their results were matched with the digital angiography findings. The diagnostic accuracy of Gd-CTCA was calculated by the exact binomial method. RESULTS: Sensitivity, specificity, and positive and negative predictive values were for observer 1: 91.67%, 98.73%, 84.62%, and 99.36%, and for observer 2: 83.33%, 98.73%, 83.33%, and 98.73%, respectively. CONCLUSION: Preliminary results demonstrated that gadolinium chelates may be used as an alternative CT contrast media in coronary CT angiographies, without detriment to diagnosis results.

Multidetector CT colonoscopy: evaluation of the perspective-filet view virtual colon dissection technique for the detection of elevated lesions.

BACKGROUND: The purpose of our study was to determine the usefulness of a virtual computed tomography colon dissection visualization technique for the detection of polypoid lesions in comparison with conventional virtual colonoscopy analysis and optical colonoscopy. METHODS: Twenty-three patients were evaluated with optical colonoscopy and computed tomography colonoscopy using 16-row MDCT on the same day. CT images were analyzed by the colon dissection workup with unfolded haustra visualization and also using the conventional virtual colonoscopy technique (axial images and endoluminal views). The CT analysis was performed by an experienced radiologist using both viewing methods in a randomized order and blinded to optical colonoscopy results. RESULTS: Optical colonoscopy revealed 35 colonic lesions; 15 < 5 mm, 18 between 5-9 mm and 2 > 9 mm. For conventional virtual colonoscopy analysis the overall sensitivity was 86.67%; for the colon dissection visualization technique, the overall sensitivity was 82.86%. The average reading time for conventional virtual colonoscopy was 15 +/- 3 vs. 8 +/- 2 min for the colon dissection visualization technique. CONCLUSIONS: Our results showed that there is a significant reduction in the reading time using the colon dissection visualization technique without detriment to the detection rate, that is, competitive to conventional virtual colonoscopy interpretation results.

Feasibility of gadolinium-diethylene triamine pentaacetic acid enhanced multidetector computed tomography for the evaluation of coronary artery disease.

BACKGROUND: Multidetector computed tomography (MDCT) has been proposed as a noninvasive method for the diagnosis of obstructive coronary artery disease (CAD). In patients with high risk of iodinated contrast adverse effects such as acute allergic-type reactions, the use of gadolinium could be an alternative. OBJECTIVE: We sought to evaluate the feasibility of gadolinium-enhanced MDCT for the diagnosis of obstructive CAD. METHODS: Twenty patients (mean age, 61 years; range, 50-73 years) referred for X-ray coronary angiography were studied by both gadolinium and iodine-enhanced 16-row MDCT coronary angiography. The degree of enhancement and the accuracy for detection of obstructive CAD (>50% diameter reduction) were evaluated with X-ray coronary angiography as the standard. Renal nephrotoxicity was strictly monitored. RESULTS: Gadolinium- and iodine-enhanced MDCT showed adequate visualization of the coronary arteries in 310 of the 312 coronary artery segments that were available by X-ray angiography, respectively. The average density of the coronary arteries in both iodine and gadolinium CT scans was 253.65 Hounsfield unit (HU) and 135.20 HU, respectively. In a per-coronary segment analysis, gadolinium- and iodine-enhanced MDCT showed sensitivities of 89% vs 84%, specificities of 96% vs 95%, and negative predictive values of 97% vs 96%, respectively. In a per-patient analysis, both gadolinium- and iodine-enhanced MDCT showed sensitivities of 92.85% vs specificities of 83.33%. Intermethod agreement between gadolinium- and iodine-enhanced MDCT (kappa) was 0.95 (P < 0.0001). CONCLUSION: Our preliminary results indicate lower attenuation with gadolinium but similar diagnostic accuracy for the detection of obstructive CAD when compared with iodine-enhanced MDCT. Therefore, gadolinium is a feasible alternative contrast agent for patients with iodine contrast allergy referred for MDCT coronary angiography.

Colonoscopía virtual con apertura de haustras / Virtual colonoscopy with unfolded haustra software

Objetivo: Evaluar la utilidad del programa informático de apertura de haustras denominado Filet View en la evaluación de las lesiones colónicas elevadas, mediante colonoscopia virtual. Pacientes y métodos: Veintitrés pacientes fueron evaluados mediante videocolonoscopía y colonoscopía virtual, en su forma convencional y utilizando el programa Filet View. Fue registrado el tiempo de análisis de cada procedimiento. Los estudios fueron clasificados: 1) normal, 2) patológico, 2a) lesiones de menos de 5 mm 2b) lesiones entre 5 y 9 mm y 2c) lesiones de más de 9 mm. Las proporciones fueron calculadas por el método exacto binomial, con intervalos de confianza del 95 por ciento. Resultados: Colonoscopía virtual contra videocolonoscopía: sensibilidad 85,3 por ciento, especificidad 96 por ciento. El tiempo del procesamiento de la información fue de 15 ± 3 minutos. Colonoscopía virtual con apertura de haustras contra videocolonoscopía: sensibilidad 82,9 por ciento, especificidad 97,4 por ciento; con un tiempo de 8 ± minutos. Conclusiones: Utilizando a la videocolonoscopía como testigo, el programa de apertura de haustras no tiene diferencias significativas en el diagnóstico de lesiones elevadas colónicas comparado con el sistema de colonoscopía virtual convencional, pero reduce significativamente el tiempo de análisis.

Colonoscopía virtual con apertura de haustras / Virtual colonoscopy with unfolded haustra software

Objetivo: Evaluar la utilidad del programa informático de apertura de haustras denominado Filet View en la evaluación de las lesiones colónicas elevadas, mediante colonoscopia virtual. Pacientes y métodos: Veintitrés pacientes fueron evaluados mediante videocolonoscopía y colonoscopía virtual, en su forma convencional y utilizando el programa Filet View. Fue registrado el tiempo de análisis de cada procedimiento. Los estudios fueron clasificados: 1) normal, 2) patológico, 2a) lesiones de menos de 5 mm 2b) lesiones entre 5 y 9 mm y 2c) lesiones de más de 9 mm. Las proporciones fueron calculadas por el método exacto binomial, con intervalos de confianza del 95 por ciento. Resultados: Colonoscopía virtual contra videocolonoscopía: sensibilidad 85,3 por ciento, especificidad 96 por ciento. El tiempo del procesamiento de la información fue de 15 ± 3 minutos. Colonoscopía virtual con apertura de haustras contra videocolonoscopía: sensibilidad 82,9 por ciento, especificidad 97,4 por ciento; con un tiempo de 8 ± minutos. Conclusiones: Utilizando a la videocolonoscopía como testigo, el programa de apertura de haustras no tiene diferencias significativas en el diagnóstico de lesiones elevadas colónicas comparado con el sistema de colonoscopía virtual convencional, pero reduce significativamente el tiempo de análisis. (AU)

Colonoscopía virtual con apertura de haustras / Virtual colonoscopy with unfolded haustra software

Objetivo: Evaluar la utilidad del programa informático de apertura de haustras denominado Filet View en la evaluación de las lesiones colónicas elevadas, mediante colonoscopia virtual. Pacientes y métodos: Veintitrés pacientes fueron evaluados mediante videocolonoscopía y colonoscopía virtual, en su forma convencional y utilizando el programa Filet View. Fue registrado el tiempo de análisis de cada procedimiento. Los estudios fueron clasificados: 1) normal, 2) patológico, 2a) lesiones de menos de 5 mm 2b) lesiones entre 5 y 9 mm y 2c) lesiones de más de 9 mm. Las proporciones fueron calculadas por el método exacto binomial, con intervalos de confianza del 95 por ciento. Resultados: Colonoscopía virtual contra videocolonoscopía: sensibilidad 85,3 por ciento, especificidad 96 por ciento. El tiempo del procesamiento de la información fue de 15 ± 3 minutos. Colonoscopía virtual con apertura de haustras contra videocolonoscopía: sensibilidad 82,9 por ciento, especificidad 97,4 por ciento; con un tiempo de 8 ± minutos. Conclusiones: Utilizando a la videocolonoscopía como testigo, el programa de apertura de haustras no tiene diferencias significativas en el diagnóstico de lesiones elevadas colónicas comparado con el sistema de colonoscopía virtual convencional, pero reduce significativamente el tiempo de análisis. (AU)

Characterization of coronary atherosclerotic plaques by multidetector computed tomography.

Multidetector computed tomography (MDCT) provides 3-dimensional noninvasive visualization of the coronary arterial tree. We compared MDCT with intravascular ultrasound (IVUS) for assessment of severity of coronary artery stenosis and composition of atherosclerotic plaques in 40 patients (32 men; mean age 52 years, range 33 to 86) with documented coronary artery disease. Cross-sectional images obtained at 10-mm increments were assessed for percent decrease in luminal area. Atherosclerotic plaques were classified by IVUS as soft, fibrous, or calcified. On the matched multidetector computed tomograms, regions of interest of 1 to 3 mm in diameter were placed inside each plaque, and tissue contrast was measured in Hounsfield units. Obstructive coronary artery disease was found in 50 segments by IVUS and 57 segments by MDCT. Sensitivity for detecting obstruction >50% was 86.0% (95% confidence interval 72.6 to 93.7) and specificity was 90.2% (95% confidence interval 83.9 to 94.4). In total, 276 plaques were examined by IVUS and MDCT. There were 188 soft plaques (68.2%), 45 fibrous plaques (16.2%), and 43 calcified plaques (15.5%). Multidetector computed tomographic tissue contrast of soft, fibrous, and calcified plaques were 71.5 +/- 32.1, 116.3 +/- 35.7, and 383.3 +/- 186.1, respectively (p <0.001). Using a cut-off value of 185 HU, 273 of 276 plaques (99%) were correctly classified as calcified or noncalcified plaques. Using a cut-off value of 88 HU, 192 of 233 noncalcified plaques (82%) were correctly classified as fibrous or soft plaques. In conclusion, our data indicate that MDCT can provide important information concerning the composition of atherosclerotic plaques in addition to detecting luminal obstruction.

[Liver evaluation with multidetector CT. Angiotomography, volume determination and virtual hepatectomy]. / Evaluación hepática con TC multidetector. Angiotomografía, determinación volumétrica y hepatectomia virtual.

AIM: to show a new technique of presurgical liver tumor evaluation using multidetector computed tomography (MDCT), determining the usefulness of an-giographic reconstructions, presurgical virtual hepatectomy and 3D liver volume determination, in correlation with surgery findings. METHODS: twenty patients with primary or secondary liver tumors were evaluated with MDCT and then operated on. Dual-phase CT was performed in all patients on a 4-row multidetector CT scanner (Mx8000; Philips Medical Systems) after mechanical injection of 120 ml of iodinated contrast medium. Scanning was performed using a detector configuration of 4 x 2.5 mm. Images were sent to a workstation and they were analysed with the surgeons. The 3D volumes of each lesion, of the total liver and of the segments to be resected were calculated. Vascular reconstructions and virtual hepatectomy were also performed. Correlation of the liver volume between MDCT and surgery was calculated using the Bland and Altman method. RESULTS: virtual liver segmentation allowed to perform the surgery in 100% of the patients in one time and there were no complications. The correlation coefficient was 0.83 (CI 95%: -132.08, 159.78). CONCLUSIONS: presurgical liver hepatectomy is a new application tool of MDCT The angiographic findings and the volume determination are useful to determine the surgical techniquefor each patient and this information allows the surgeons to know if the remnant liver will be enough for the patients to avoid a post-surgical liver insufficiency.