Publicaciones Internacionales

año 2010

• Carrascosa P Capuñay C Carrascosa J Deviggiano A Goldsmit A Bettinotti M Garcia MJ. Tajer C
• 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.

• Carrascosa P Capuñay C Carrascosa J Deviggiano A Goldsmit A Garcia MJ. Tajer C Fallahi A Ivanc T
• 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. Copyright 2010 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

• Carrascosa P Capuñay C Baronio M Vallejos J Carrascosa J
• 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.

• Carrascosa P Baronio M López EM Vallejos J Carrascosa J
• 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.

año 2009

• Carrascosa P Capuñay C López EM Vallejos J Carrascosa J Deviggiano A

• Carrascosa P Capuñay C Vallejos J Deviggiano A Goldsmit A Garcia MJ. Tajer C

• Carrascosa P Capuñay C Baronio M López EM Vallejos J Borghi M Sueldo C Papier S.

• Carrascosa P Capuñay C Baronio M López EM Vallejos J Borghi M Sueldo C Papier S.

• Carrascosa P Capuñay C López EM Deviggiano A

• Carrascosa P Capuñay C López EM Carrascosa J Salis G Mazzadi S
• 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.

• Carrascosa P Capuñay C López EM Vallejos J Carrascosa J
• 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.

• Carrascosa P Capuñay C Baronio M López EM Vallejos J Borghi M Sueldo C Papier S.
• OBJECTIVE: To illustrate the large variety of pathologies found on 64-row computed tomographic (CT) virtual hysterosalpingography (CT-VHSG) in the evaluation of the female reproductive tract in infertile patients. MATERIAL AND METHODS: We prospectively evaluated CT datasets from 209 patients with diagnosis of infertility. CT-VHSG was performed with a 64-row CT scanner using 64 x 0.625 mm(2) collimation and 0.9 mm slice thickness. A total volume of 20 mL of an iodine contrast dilution was injected into the uterine cavity. The duration of the CT scan and the grade of patient discomfort of the procedure were documented. Images were analyzed on a workstation. The CT-VHSG exams were divided in studies with normal or pathological findings; pathologies were classified according to their locations (cervical, uterine, and fallopian tube pathology). RESULTS: No complications occurred during the procedure. The mean scan time was 3.4 +/- 0.4 s; the mean patient effective dose was 2.58 +/- 0.75 mSv. In relation to the patient's discomfort evaluation, 55.5% of the patients referred no discomfort during the procedure. Cervical pathology was found in 100/209 patients, uterine pathology in 93/209 patients, and fallopian tubes pathology in 37/209 patients. CONCLUSION: A 64-row CT-VHSG provides a reliable, non-invasive alternative diagnostic technique in the infertility workup algorithm.

año 2008

• Carrascosa P Capuñay C López EM Borghi M Sueldo C Papier S. Mariano B Jorge C

• Carrascosa P Capuñay C Baronio M López EM Sueldo C Papier S.

• Carrascosa P Capuñay C Deviggiano A Kantor P Goldsmit A Bettinotti M Palacios A

• Carrascosa P Capuñay C Vallejos J Bengolea L Nazar M

• Núñez Lina Blejman Oscar Fernández Alonso G

• Carrascosa P Capuñay C Deviggiano A
• Double right coronary artery (RCA) arising from two separated ostia in the right sinus of Valsalva is an extremely rare coronary artery variation. We report a case of double RCA detected by multidetector-row computed tomography (MDCT). MDCT allows three-dimensional comprehension of the coronary artery anatomy and it is extremely useful to identify coronary artery anomalies.

año 2007

• Carrascosa P Capuñay C Carrascosa J Goldsmit A Bettinotti M Merletti PG
• 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.

• Carrascosa P Capuñay C Carrascosa J Deviggiano A Goldsmit A Bettinotti M García MJ.
• 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.

• Carrascosa P Nazar M Sangster G González-Beicos A Carbo AI Heldmann MG Ibrahim H D'Agostino HB.

• Carrascosa P Capuñay C López EM Carrascosa J Castiglioni R
• 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.

• Carrascosa P Capuñay C Baronio M López EM Vallejos J Borghi M Sueldo C Papier S.
• OBJECTIVE: To compare the efficacy of multidetector CT virtual hysterosalpingography (MDCT-VH) with conventional X-ray hysterosalpingography (HSG) in the evaluation of patients with diagnosis of infertility. METHODS: Sixty patients with diagnosis of infertility scheduled to perform a HSG, were evaluated with 16-row (n=50) and 64-row (n=10) MDCT-VH. In 35 patients the examination was performed without a tenaculum. The HSGs were carried out using standard technique. The HSG and MDCT-VH findings were compared. The duration for both examinations and patient discomfort were documented. The sensitivity and specificity of MDCT-VH for the detection of uterine pathology and tubal obstruction were calculated using the exact binomial method. Agreement between the two methods was assessed by the Cohen's kappa method (k). RESULTS: The mean duration for MDCT-VH (16 and 64-rows) was 5+/-3 min, whereas for HSG was 28+/-3. The MDCT-VH without a tenaculum was the procedure with less patient discomfort. Sensitivity, specificity and inter-method agreement for the detection of uterine pathology were 100%, 92% and k=0.92 for 16-row MDCT-VH and 100%, 100% and k=1 for 64-row MDCT-VH, respectively. Sensitivity and specificity for detection of tubal obstruction were 80% and 80% for 16-row MDCT-VH and 100% and 100% for 64-row MDCT-VH, respectively; inter-method agreement for the visualization of the tubes was k=0.54 for 16-row MDCT-VH and k=1 for 64-row MDCT-VH. CONCLUSION: This study demonstrated the feasibility of evaluating the female reproductive system by MDCT-VH. 64-Row MDCT-VH could be an alternative diagnostic technique in the infertility workup algorithm. A larger study is in progress to validate these encouraging results.

año 2006

• Carrascosa P Capuñay C López EM Carrascosa J Ulla M Corti R
• With the development of multidetector computed tomography and the improvement in the capabilities of workstations, the use of high-quality three-dimensional reconstructions and virtual images can be applied to organs other than the colon such as the stomach. As a noninvasive technique, virtual gastroscopy represents an alternative to conventional endoscopy for the detection of elevated lesions. Findings of this technique are illustrated.

• Carrascosa P Capuñay C Carrascosa J Garcia-Merletti P Garcia MF.
• 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.

• Carrascosa P Sigurdsson G Yamani MH Greenberg NL Perrone S Lev G Desai MY Garcia MJ.
• OBJECTIVES: This study sought to determine whether multidetector computed tomography (MDCT) may be able to detect occlusive coronary disease in transplanted hearts. BACKGROUND: In heart transplant recipients, asymptomatic coronary disease requiring frequent surveillance commonly develops. Recent advancements in MDCT allow for noninvasive assessment of the coronary vessels. METHODS: Electrocardiogram-gated contrast-enhanced MDCT scans (16 x 0.75-mm detectors, 420 ms rotation, 100 ml contrast) with multisegment reconstruction were performed on 54 transplant recipients within 6 +/- 11 days of quantitative coronary angiography (QCA). Heart rate at the time of the scan was 90 +/- 11 beats/min. Coronary arterial segments >1.5 mm in diameter were analyzed by independent investigators. RESULTS: There was a good correlation between MDCT and QCA percent stenosis (r = 0.75, p < 0.01, SEE = 15%). Of the 791 segments identified by QCA, 754 (95%) were analyzable by MDCT. The sensitivity, specificity, and positive and negative predictive values of MDCT compared with QCA for the detection of segments with significant (>50%) stenosis were 86%, 99%, 81%, and 99%, respectively. The MDCT correctly identified 15 of the 16 (94%) transplant patients classified by QCA as having occlusive coronary artery disease and 29 of the 37 patients without significant stenosis (78%). In 1 patient who received intravenous beta-blockers, transient bradycardia requiring temporary pacing developed, but there were no other complications. CONCLUSIONS: Detection of occlusive coronary disease in heart transplant recipients with elevated resting heart rate by MDCT is feasible using multicycle reconstruction. The need for surveillance invasive coronary angiography in transplant recipients might be mitigated by use of MDCT.

• Carrascosa P Capuñay C López EM Carrascosa J Castiglioni R Ulla M
• 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.

• Carrascosa P Capuñay C López EM Carrascosa J Sisco P Perrone N Ulla M Pagliarino G
• 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.

año 2005

• Carrascosa P Capuñay C Carrascosa J Vembar M Ciancibello L
• BACKGROUND: Computed tomographic (CT) angiography represents an important clinical tool in the evaluation of vascular disorders. Virtual angioscopy can be reconstructed with volumetric CT data sets. We evaluated the feasibility and clinical value of this application in the assessment of abdominal vessels. METHODS: Data sets of CT angiographic studies obtained with helical (n = 120) and multislice (n = 180) CT scanners were analyzed on a workstation for postprocessing. Vascular evaluation was done on conventional enhanced axial images, three-dimensional reconstructions, and virtual angioscopic images. RESULTS: We made 123 studies in patients without aortic disease. Of the patients evaluated for stent-graft treatment, 63 showed normal patency, seven had partial thrombosis of the stent-graft, five showed total occlusion of the stent-graft, and 10 had leaks. From the 92 remaining CT studies, 63 vascular aneurysms and nine dissections were diagnosed. CONCLUSION: The current technology produces high-quality virtual angioscopic images. Although axial and multiplanar views are usually adequate for detecting a vascular disorder, virtual angioscopic views better define anatomic details.

• Carrascosa P Capuñay C Carrascosa J Bou-Khair A Castagnino N Ninomiya I
• The purpose of this study was to determine the sensitivity (S) and specificity (sp) of virtual colonoscopy in the detection of elevated lesions in children, and to compare these results with conventional colonoscopy. Between April 2000 and January 2003, 100 patients (mean: 6 years old) were evaluated with virtual colonoscopy and conventional colonoscopy. All patients presented rectal bleeding and both methods were performed the same day. All patients had received a standard bowel cleansing the day before. Virtual colonoscopies were carried out with 2.5 mm thick slices, 1.3 mm reconstruction intervals, 15 mAs, and 90 kV. The acquisition time ranged from 5-10 s depending on the age of the patient. For each method, two scans were performed in both a supine and a prone position. After the acquisitions, images were reprocessed using two-dimensional, volume rendering, and virtual endoscopy reconstructions. Findings of the two methods were compared blinded. They were classified in two groups: (1) normal studies, and (2) elevated lesions studies. The second group was subdivided according to the diameter of the lesions: (2a) <5 mm, (2b) 5-9 mm, and (2c) >9 mm. All studies were performed without complications. Forty-eight patients were normal. In the other 52 patients, virtual colonoscopy detected 86 lesions, whereas conventional colonoscopy depicted only 80 lesions. There were 70 true-positive findings, 48 true-negative findings, 12 false-positive findings, and 8 false-negative findings. The global S was 89%, sp: 80%, positive predictive value: 85%, and negative predictive value: 85%. In group (2a), sensitivity, specificity, positive predictive value, and negative predictive value were 81, 90, 81, and 90% respectively; in group (2b), 90, 90, 85, and 94%, respectively; and in group (2c), 100, 96, 90, and 100%, respectively. We concluded that virtual colonoscopy is an alternative method for the evaluation of children with elevated lesions. It is fast, has no complications, and uses a low radiation dose.

año 2003

• Carrascosa P Capuñay C Carrascosa J Smith D Parodi JC Padilla LT Johnson P Chandra S Belardi J.
• OBJECTS: To show all cardiac evaluations multislice computed tomography (MSCT) can perform. METHODS: MSCTs were performed on an MSCT scanner (Mx8000; Philips Medical Systems) with enhanced contrast acquisition. The reconstructed images were sent to a workstation for multiplanar reconstruction, volume rendering, and 3-D reconstruction. A total of 140 patients were studied with MSCT and conventional angiography (CA) to assess coronary artery stenosis. 30 of these patients were also evaluated by intravascular ultrasound (IVUS) for plaque characterization. A group of 20 patients were studied with MSCT, gated single-photon emission computed tomography (SPECT), and echocardiography for myocardial perfusion test and volumetric analysis. RESULTS: The results of MSCT versus CA showed a sensitivity of 79.2% and a specificity of 93.7%, whereas for MSCT versus IVUS the sensitivity was 84.4% and the specificity 91.6%. A total of 156 plaques were detected by both methods. 105 (67%) were soft, 14 (24%) were fibrous and 37 (9%) were calcified. In the evaluation of myocardial perfusion, the cardiac software showed a sensitivity of 55% and a specificity of 80%. However, general evaluation disclosed a sensitivity of 88.5% and a specificity of 96.4%. The volumetric analysis showed a good correlation between MSCT and echocardiography for end-systolic volume (ESV), rS = 0.874, and end-diastolic volume (EDV), rS = 0.828. There was also a good correlation for the evaluation of the left ventricular anatomy: septal wall rS = 0.96, posterior wall rS = 0.81, and diameter of left ventricle rS = 0.69. CONCLUSION: Nowadays, MSCT allows different cardiologic evaluations with the same acquisition as that for the coronary arteries. These data show a general view of the patient providing information that is obtained by the hand of multiple cardiologic methods such as DA, IVUS, gated SPECT, and echocardiography.

• Carrascosa P Capuñay C Carrascosa J Castiglioni R Sangster G Corti R Smith D
• OBJECTIVE: To show our experience and results in Virtual Colonoscopy (VC). MATERIAL AND METHOD: Five hundred patients with personal or familial history of colorectal carcinoma and/or adenomas, or any kind of coloproctologic symptoms were studied. VCs were practiced using a helical CT scanner (300 patients) and a multislice CT scanner (200 patients) a few hours after Conventional Colonoscopy (CC), considered the gold standard. The patients were evaluated in a prospective blind study, to determine sensitivity and specificity of VC. Findings were classified as: 1) normal studies; 2) studies with pathological findings. This one was subdivided into: 2a) Lesions below 5 mm., 2b) Lesions between 5-9 mm., 2c) Lesions above 9 mm. RESULTS: VC detected 253 normal studies whereas CC only detected 233. The sensitivity and specificity for each subgroup were: 2a) 87.8% and 86.9%; 2b) 95.6% and 91.4%; 2c) 100.0% and 100.0% respectively. CONCLUSION: VC is a feasible and useful method for evaluating the entire colon. It is well tolerated, it has no complications and a high sensitivity and specificity for elevated lesions, especially the ones above or equal to 5 mm.

año 2002

• Carrascosa P Capuñay C Carrascosa J Sangster G Corti R Suinbourn G Schenone L Giordano A Doweck J Menéndez G Valero J Zerbo O
• OBJECTIVE: To define the role of virtual gastroscopy (VG) in the detection of elevated lesions comparing its results with conventional endoscopy (CE) as the gold standard method. MATERIALS AND METHODS: Between December 2000 and July 2001, 19 patients were evaluated. The age ranged between 41 and 72 (mean 58.8 years old). VG and CE were performed in all the patients during the same week. VG were carried out with a multislice CT scanner (Mx 8000, Marconi Medical Systems). The technical parameters used were 3 mm with slices and 1.5 mm reconstruction intervals. The acquisition time was 22 seconds. Images were sent to a workstation (MxView, Marconi Medical Systems) where they were reprocessed in three different ways: 1) Bidimensionally 2) Tridimensionally 3) Virtual Endoscopy Findings of VG were compared with CE. RESULTS: VG detected 39 lesions, whereas CE detected 40 lesions. There were 39 true-positive findings, 2 true-negative findings, 0 false-positive findings and 1 false-negative findings. The Sensitivity (Se) was 97.5%; Specificity (Sp) was 100%, positive predictive value 100% and Negative predictive value 66%. CONCLUSIONS: VG is a new non-invasive method with high Se and Sp in the detection of elevated lesions. The actual role of VG consist in identification of gastric lesions and possibility to diagnose gastric disease.

año 2001

• Fernández Alonso G Matturri L Cazzullo A Turconi P Lavezzi AM Vandone PL Gabrielli L Grana D Milei J.
• Alterations of chromosomes 7 and 11 have been involved in the progression of atherosclerosis. Twenty-three carotid endarterectomy specimens were studied for the presence of alterations in chromosomes 7 and 11, and fibroblastic growth factor-3 (FGF-3) gene amplification. Besides classic histological stainings, immunophenotyping of cellular and vascular components and fluorescence in situ hybridization (FISH) were performed. At the caps, unstable plaques (n=18) showed inflammatory infiltration of macrophages, smooth muscle cells, and T-lymphocytes. Specifically in these regions, the FISH showed varying percentages of trisomy (15/18) and tetrasomy (8/15) of chromosome 7. In four cases polisomy 7 was noted in some nuclei. Monosomy of chromosome 11 and gene amplification of FGF-3 gene was observed. The FISH of the five stable plaques and normal arterial walls showed no chromosome alterations; furthermore, chromosome 3, which is not involved in atherosclerotic progression, presented a normal ploidy of smooth muscle cells in stable and unstable plaques and normal arterial walls. In conclusion, chromosome 7 and 11 alterations and FGF-3 gene amplification are components of unstable plaques, and might contribute to the evolution of stable plaques into complicated plaques.

año 2000

• Fernández Alonso G Palermo M Alves Rosa F Rubel C Fernández GC Alberto F Rivas M Isturiz M.
• ARHaemolytic uraemic syndrome (HUS) has been closely associated with infection with a group of Shiga toxin-producing enterohaemorrhagic Eschericchia coli in young children. Shiga toxins (Stx) have been implicated as pathogenic agents of HUS by binding to the surface receptor of endothelial cells. LPS is a central product of the Gram-negative bacteria and several reports have documented that both LPS and Stx are important for disease development. In this study the reciprocal interactions between LPS and Stx2 are analysed in a mouse model. The results demonstrated that LPS was able to reduce or enhance Stx2 toxicity, depending on the dose and the timing of the injection. The involvement of the main early cytokines induced by LPS, tumour necrosis factor alpha (TNF-alpha) and IL-1beta, in those LPS opposite effects on Stx2 toxicity was evaluated. Stx2 toxicity was enhanced by in vivo injection of murine TNF-alpha and low doses of murine IL-1beta. However, at higher doses of IL-1beta which induced corticosteroid increase in serum, Stx2 lethality was decreased. Considering that dexamethasone and IL-1beta reproduce the LPS protective effects, it is suggested that endogenous corticosteroids secondary to the inflammatory response induced by LPS, mediate the protection against Stx2. It can be concluded that the fine equilibrium between proinflammatory and anti-inflammatory activities strongly influences Stx2 toxicity.

• Fernández Alonso G Matturri L Turconi P Lavezzi AM Grana D Colombo B Milei J
• Atherosclerosis is the most frequent cause of death in industrialized countries. Lesions are characterized by lipid deposits, focal thickening of the arterial wall with proliferation of smooth muscle cells (SMC), mononuclear infiltrates and neoformed vessels. In this paper, we studied the proliferative characteristics and cytogenetic alterations of SMC. These cells, expressing specific muscular actin, were diploid with an increased proliferative index for PCNA. A high percentage of SMC showed intense expression of p53. There were signs of chromosomal instability, being the most frequent findings chromosome 7 trisomy and chromosome 11 monosomy. Additionally, the gene for FGF-3 showed a marked amplification. These findings strongly suggest that SMC proliferation is active, and is related to the accumulation or mutation of the p53 oncoprotein. It also presents specific chromosomal alterations in close relation with growth factors. According to these findings SMC hyperplasia in the atherosclerosis plaque may be considered as a cellular clonal expansion.

año 1998

• Fernández Alonso G Matturri L Grana D Milei J
• As more effective therapies have produced longer survival times for human immunodeficiency virus (HIV)-infected patients, new complications of late-stage HIV infection including HIV-related heart disease have emerged. Almost any agent that can cause disseminated infection in patients with acquired immunodeficiency syndrome (AIDS) may involve myocardium, but clinical evidence of cardiac disease is usually overshadowed by manifestations in other organs, primarily the brain and lungs. Cardiac abnormalities are found at autopsy in two-thirds of patients with AIDS, and more than 150 reports of cardiac complications have been published. Cardiac involvement in HIV disease includes pericardial effusion, myocarditis, dilated cardiomyopathy, and/or endocardial involvement at any stage of the disease. This review deals with all the cardiac manifestations of AIDS and serves to highlight two problems and one indication. First of all, there are very few clinical studies. Current knowledge is based almost exclusively on echocardiography and autopsy studies. Observational or clinical trials would be useful. Second, there exists very poor information on the impact of treatment; and epidemiologic and clinicopathologic studies are mandatory for obtaining detailed data concerning the mechanisms of myocardial damage in AIDS. Finally, because cardiac complications are often clinically inapparent or subtle in the initial stages, periodic screening of HIV-positive patients by electrocardiogram and echocardiogram is probably indicated. In addition, AIDS may also provide the opportunity to gain insights into the pathogenesis of little understood cardiac diseases such as lymphocytic myocarditis and dilated cardiomyopathy.

• Fernández Alonso G Milei J Mosca SM Gelpi RJ Cingolani HE.
• In a model of global ischemia in the isolated perfused rat heart, a 20 min ischemic period followed by 30 min of reperfusion induces a decrease in isovolumic developed pressure (LVDP) and +dP/dtmax to 61+/-6% and 61+/-7% of baseline, respectively. Left ventricular end-diastolic pressure (LVEDP) increases to 36+/-4 mmHg at the end of the reperfusion period. No significant necrotic area as assessed by triphenyltetrazolium chloride (TTC) was detected at the end of the reperfusion period. By an immunohistochemical method using antiactin monoclonal antibodies 10.8+/-1.9% of unstained cells were detected in the stunned hearts and 10.3+/-1.2% in control hearts. Preceding the ischemic episode with a cycle of 5 min of ischemia followed by 10 min of reperfusion (ischemic preconditioning) protected contractile function. LVDP and +dP/dtmax now stabilized at 89+/-5% and 94+/-5% of baseline respectively. LVEDP was 20+/-2 mmHg at the end of the reperfusion period. The protection of contractile dysfunction after 20 min of ischemia was achieved also by early reperfusion of low Ca2+-low pH perfusate. With this intervention LVDP stabilized at 87+/-5% of baseline. LVEDP was 12+/-2 mmHg at the end of the reperfusion period. A positive inotropic intervention induced by a modified postextrasystolic potentiation protocol at the end of the reperfusion period increases LVDP to levels higher than baseline in the stunned hearts. However, these values were less than those obtained in control hearts. Ischemic preconditioning significantly increased the maximal inotropic response. Therefore, ischemic preconditioning diminishes the contractile dysfunction of early stunning.

año 1997

• Fernández Alonso G Palermo M Alves Rosa F Isturiz M.
• Lipopolysaccharides (LPS) occupy centre stage in the pathogenesis of gram-negative sepsis. Although LPS are potent stimulators of the mononuclear phagocyte system (MPS), their effects on immune complex (IC)-specific clearance have not yet been reported. In order to evaluate this issue, we examined the MPS function after LPS treatment by measuring intravascular removal rate of syngeneic erythrocytes sensitized with specific immunoglobulin G (IgG) (EA). Our findings showed that LPS, directly or through the release of endogenous cytokines, enhance Fc gamma receptor (Fc gamma R)-dependent clearance. The EA uptake by liver, spleen and bone marrow was significantly increased leading to an effective clearance of immune complexes. Splenic antibody-dependent cellular cytotoxicity (ADCC), an in vitro indicator of Fc gamma R functionality, was also increased after in vivo LPS treatment. However, cytometric studies showed that endotoxin did not modify Fc gamma R expression on splenocytes, but markedly enhanced the expression of CD11b/CD18 (Mac-1), an adhesion molecule closely related to Fc gamma R activity. We conclude that LPS enhance Fc gamma R-dependent effector functions and suggest that this effect is mediated through alterations in adhesion molecules.

año 1996

• Parodi JC Matturri L Milei J fernández Alonso G Barone A Beigelman R Ferreira LM Arrigoni G
• Papers dealing with rupture of carotid plaque surface are few in spite of the growing importance of the subject. The aim of this study was to analyze the cellular and vascular components of surgically excised carotid endarterectomies in order to obtain information about their role in the pathogenesis of the plaque rupture and intraplaque hemorrhage. Seventy-six surgical specimens of carotid endarterectomies were used for this study. The findings of immunophenotyping of the cellular constituents of the plaques were: 1) endothelial lining: the fibrous cap at the site of the rupture showed an eroded surface with loss of the endothelial lining. Conversely, in the remaining surface a continuous, not damaged row of endothelial cells stained with anti-CD31 and anti-CD34 was observed; 2) fibrous cap: the collagenous fibrous cap at the site of erosion was attenuated and the phenotypic characterization of the cells showed inflammatory components consisting mainly of macrophages (CD68 positive), 2/3 of the total infiltration. The remaining 1/3 was composed of T-lymphocytes and scarce B-lymphocytes. A close interaction between macrophages and capillaries and macrophages and T-lymphocytes was observed; 3) lipid cores: two different types of lipid cores could be depicted. Avascular or mildly vascularized lipid cores and highly vascularized, with neoformed vessels stained with CD34 and CD31. CD34 stained endothelia of all kind of vessels; conversely, neoformed vessels showed a weak stain with CD31. T-lymphocytes were found to be in close contact with neoformed vessels, and in some cases, migrating through the endothelial cells; 4) deeper layers of the plaque: the base and the shoulder of the plaques showed in 28/76 cases neoformed vessels, thin or thick walled, CD34 positive, generally surrounded by mild to extensive mononuclear infiltrates. Atherosclerotic plaques were found to belong to six different lesions: plaque rupture plus thrombosis (18/76, 23.6%), plaque rupture plus intraplaque hemorrhage plus thrombosis (18/76, 23.6%), intraplaque hemorrhage without plaque rupture (16/76, 21.0%), plaque rupture plus intraplaque hemorrhage (5/76, 6.5%), stable calcified non complicated plaque (14/76, 18.4%) and unstable, soft, non complicated plaque (5/76, 6.5%). The first four lesions were considered as "complicated lesions". Complicated plaques presented neoformed vessels in the periphery, shoulder and base of the plaque in 22/57 (38.5%) cases. Conversely only 1/14 (7.1%) of non complicated, stable calcified plaques presented neoformed vessels, (p < 0.05). Of note, the 5 causes of unstable, soft non complicated plaque presented neoformed vessels surrounding the plaque. In 10/57 (17.5%) complicated plaques unequivocal histological signs of old hemorrhages were found surrounding those vessels. Irrespective of presenting no rupture, 11/35 plaques showed a mononuclear infiltrate in the fibrous cap. In conclusion, rupture of carotid plaques (50% of the cases), is characterized by the presence of a macrophagic infiltration of the caps and by the direct apposition of T-lymphocytes to macrophages and a close relation of these cells to endothelial cells. This highly suggests a cell-to-cell interaction, which results in an inflammatory process. Intraplaque hemorrhage without rupture represented 21% of the endarterectomies. These lesions are not related to cap erosion, but to plaque vascularization. Most lipid cores were highly vascularized with neoformed vessels with macrophages and T-cells in close contact and in some cases disrupting the endothelium. The abrupt growing of the lipid core and/or an overproduction of oxygen free radicals could lead to the breakdown of core vessels and intraplaque hemorrhage.

año 1995

• Fernández Alonso G Meiss R. De Kaminsky AR Kaminsky C Fernández Blanco G Lago R Sánchez G Basso D

año 1992

• Milei J fernández Alonso G Beigelman R Storino R Vanzulli S Ferrans VJ.
• Mononuclear cellular infiltrates and extensive fibrosis, with or without apical ventricular aneurysms, are the usual morphological findings in chronic chagasic cardiomyopathy. These lesions are thought to be mediated by immune phenomena rather than by continuing parasitic invasion of the heart. In the present report, we correlated clinical, immunohistochemical and ultrastructural findings in 30 endomyocardial biopsies from patients with chronic chagasic cardiomyopathy. In 12 of these biopsies, immunocytochemical techniques were used to identify and count leukocytes (common leukocyte antigen, CLA), T lymphocytes (UCHL-1 antibody) and B lymphocytes (L-26 antibody). The biopsy specimens showed variable degrees of myocardial hypertrophy and mononuclear infiltrates. No tissue forms of trypanosomes were found. The endocardium averaged 24 +/- 12.6 microns (mean +/- SD) in thickness. The mean myocyte diameter was 20 +/- 7.33 microns. The hearts were severely fibrotic containing a mean of 24.1 +/- 12.8% of fibrous tissue (range 8.2-49%), mast cells were scarce. Mononuclear cell infiltrates were found in 25 of the 30 biopsies. In 12 biopsies, immunohistochemical studies showed that the majority of the lymphocytes were T lymphocytes and associated with necrotic or degenerating myocytes. 10 of the 12 biopsy samples showed 5 or more CLA-positive mononuclear cells/high power field. In these 10 patients, T and B lymphocytes represented 32 and 13% of the total mononuclear infiltrating cells, respectively. The remaining cells were monocytes and macrophages.

año 1991

• Matturri L Milei J fernández Alonso G Beigelman R Storino R Rossi L.
• Chagas disease, in the chronic phase, is known to be characterized by cardiac failure, and/or arrhythmias. To assess the involvement of the conduction system and of the working myocardium, morphometric and immunohistochemistry studies have been carried out on 4 autoptic hearts of chronic chagasic myocardiopathy. The characterization of interstitial infiltrates was performed by lymphocyte immunophenotyping with immunocytochemical techniques. These infiltrates were more prominent in the working myocardium and in the left branch of the His bundle. The infiltrates consisted of about 50% of macrophages and 50% of T-lymphocytes. Mast cells would not play a role in the chronic stages of the disease. Eosinophils were present in no more than the 5% of the inflammation. The fibrosis, especially of the conducting system seems to be facilitated by an impaired lymphatic outflow, whereas the evidence of neuroganglionic involvement was variable.

año 1990

• Fernández Alonso G Milei J Beigelman R Bortman G Grancelli H
• Interobserver variability in the interpretation of pathologic endomyocardial biopsies for detecting myocarditis has been widely reported. Thus, conflicting reports about the therapeutic benefit of immunosuppressive treatment in myocarditis may be due to differences in the interpretation of the biopsy findings. In doubtful cases, scattered interstitial cells may be present between myocytes and can be misinterpreted as true lymphocytes. In our study, a further characterization of interstitial cells in endomyocardial biopsies previously diagnosed as showing ´myocarditis´ was performed by lymphocyte immunophenotyping with immunocytochemical techniques for membrane and cytoplasmic antigens. Common leukocyte antigen (CLA), kappa and lambda light immunoglobulin chains and T lymphocyte antigens were made visible by an indirect immunoperoxidase technique. A previous diagnosis of ´myocarditis´ had been established histologically in 27 patients by the presence of an inflammatory cell infiltrate associated with focal acute cellular damage. These specimens were selected for further study using an immunoperoxidase technique. The number of negative and positive mononuclear cells for each marker was counted on all fields at a magnification of X 400. These numbers were correlated with the extent of interstitial fibrosis and/or myocyte damage on each sample. According to previous studies, 5.0 lymphocytes/high-power field were considered as the lower limit of myocarditis if they were associated with myocyte injury. From the 27 samples previously diagnosed histologically as ´myocarditis´ only 14 showed 5 or more CLA-positive mononuclear cells/X 400 field. In 6 out of 8 selected cases having less than 5 CLA-positive cells, no T-antigen-positive cells could be detected. The remaining samples showed T lymphocytes localized in acute infiltrated areas.

año 1988

• Fernández Alonso G Meiss R. Ragone S

año 1987

• Carrascosa J Fernández Alonso G Pissinis RC Gamboni M Meiss R. Magnanini F.
• 43 fine needle aspiration biopsies of abdominal masses were performed under echographic guide. Cytologic diagnosis was done with routine techniques. Tumor, lineage and origin biologic markers were detected by immunocytochemical methods. Sensibility, specificity and accuracy of this procedure were evaluated. Advantages of the method are discussed.