G Viteri-Ramírez

Clínica Universidad de Navarra, Madrid, Madrid, Spain

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Publications (18)3.7 Total impact

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    ABSTRACT: To evaluate the safety and patency of self-expanding stents to treat hepatic venous outflow obstruction after orthotopic liver transplantation. To evaluate differences in the response between patients with early obstruction and patients with late obstruction. This is a retrospective analysis of 16 patients with hepatic venous outflow obstruction after liver transplantation treated with stents (1996-2011). Follow-up included venography/manometry, ultrasonography, CT, and laboratory tests. We did a descriptive statistical analysis of the survival of patients and stents, technical and clinical success of the procedure, recurrence of obstruction, and complications of the procedure. We also did an inferential statistical analysis of the differences between patients with early and late obstruction. The mean follow-up period was 3.34 years (21-5,331 days). The technical success rate was 93.7%, and the clinical success rate was 81.2%. The rate of complications was 25%. The survival rates were 87.5% for patients and 92.5% for stents. The rate of recurrence was 12.5%. The rate of primary patency was 0.96 (95% CI 0.91-1) at 3 months, 0.96 (95% CI 0.91-1) at 6 months, 0.87 (95% CI 0.73-1) at 12 months, and 0.87 (95% CI 0.73-1) at 60 months. There were no significant differences between patients with early and late obstruction, although there was a trend toward higher rates of primary patency in patients with early obstruction (P=.091). Treating hepatic venous outflow obstruction after orthotopic transplantation with self-expanding stents is effective, durable, and effective. There are no significant differences between patients with early obstruction and those with late obstruction.
    Radiología 04/2014;
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    ABSTRACT: Objectives To evaluate the safety and patency of self-expanding stents to treat hepatic venous outflow obstruction after orthotopic liver transplantation. To evaluate differences in the response between patients with early obstruction and patients with late obstruction. Material and methods This is a retrospective analysis of 16 patients with hepatic venous outflow obstruction after liver transplantation treated with stents (1996-2011). Follow-up included venography/manometry, ultrasonography, CT, and laboratory tests. We did a descriptive statistical analysis of the survival of patients and stents, technical and clinical success of the procedure, recurrence of obstruction, and complications of the procedure. We also did an inferential statistical analysis of the differences between patients with early and late obstruction. Results The mean follow-up period was 3.34 years (21-5,331 days). The technical success rate was 93.7%, and the clinical success rate was 81.2%. The rate of complications was 25%. The survival rates were 87.5% for patients and 92.5% for stents. The rate of recurrence was 12.5%. The rate of primary patency was 0.96 (95% CI 0.91-1) at 3 months, 0.96 (95% CI 0.91-1) at 6 months, 0.87 (95% CI 0.73-1) at 12 months, and 0.87 (95% CI 0.73-1) at 60 months. There were no significant differences between patients with early and late obstruction, although there was a trend toward higher rates of primary patency in patients with early obstruction (P = .091). Conclusions Treating hepatic venous outflow obstruction after orthotopic transplantation with self-expanding stents is effective, durable, and effective. There are no significant differences between patients with early obstruction and those with late obstruction.
    Radiología. 01/2014;
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    ABSTRACT: Cardiac comorbidity is one of the most important prognostic factors in lung disease, especially in chronic obstructive pulmonary disease (COPD). The imaging techniques available for the study of this systemic manifestation concomitant with COPD include heart catheterization, transthoracic echocardiography, and magnetic resonance imaging. Multidetector computed tomography (MDCT) represents a significant advance in this field because it enables the acquisition of simultaneous studies of the cardiopulmonary anatomy that go beyond anatomic and morphologic analysis to include a functional approach to this condition. In this article, we review the practical aspects necessary to evaluate cardiac comorbidity in patients with COPD, both from the point of view of pulmonary hypertension and of the analysis of ventricular dysfunction and coronary heart disease.
    Radiología 07/2012;
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    ABSTRACT: To determine the image quality and diagnostic performance of an optimized pulmonary computed tomography angiography (CTA) protocol in terms of radiation and contrast volume saving. Seventy consecutive patients weighting ≤80 kg with clinical suspicion of pulmonary embolism (PE) were prospectively enrolled. Two pulmonary CTA protocols (group A: n = 35, 80 kV/60 ml; group B: n = 35, 100 kV/80 ml) were compared. The presence of PE, image quality parameters [contrast attenuation, contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR)] and effective radiation dose (mSv) were assessed. PE was found in 11 patients (five of group A, six of group B). The total mean attenuation of the pulmonary arteries was significantly higher in group A (362.4 ± 100.2 HU) than in group B (262.4 ± 134.3 HU), whereas the CNR and SNR did not differ statistically (14.8 ± 7.4 and 16.3 ± 7.5 for group A and 12.5 ± 8.6 and 13.8 ± 9.1 for group B, respectively). The estimated effective radiation dose was significantly lower in group A (1.1 ± 0.7 mSv) than in group B (2.7 ± 1.2 mSv). In individuals weighting ≤80 kg, the evaluated pulmonary CTA protocol allows similar image quality to be achieved as compared with the conventional pulmonary CTA protocol while reducing radiation exposure by 60% and contrast media volume by 25%.
    Clinical Radiology 06/2012; 67(9):833-9. · 1.66 Impact Factor
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    ABSTRACT: Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Sixty consecutive asymptomatic smokers (47 men; mean age 64 ± 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 ± 58.3 mL) with respect to ECG-gated CT (142.7 ± 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 ± 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols.
    Acta Radiologica 05/2012; 53(5):536-40. · 1.33 Impact Factor
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    ABSTRACT: Anastomoses often leak after esophageal surgery; if they are not detected in time, leaks can give rise to complications like fluid collections, superinfections, and mediastinitis. Although these complications usually require surgical treatment, different series of patients successfully treated with conservative or minimally invasive approaches have been reported. We present the case of a patient who developed a mediastinal abscess after epiphrenic diverticulectomy. We treated the abscess with US-guided percutaneous transhepatic drainage to avoid surgical reintervention. Although other cases of a transhepatic approach to thoracic lesions have been reported, to our knowledge this is the first report of this technique in mediastinal abscesses. We recommend that transhepatic drainage be considered a therapeutic option in the management of these complications.
    Radiología 03/2012;
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    ABSTRACT: Anastomoses often leak after esophageal surgery; if they are not detected in time, leaks can give rise to complications like fluid collections, superinfections, and mediastinitis. Although these complications usually require surgical treatment, different series of patients successfully treated with conservative or minimally invasive approaches have been reported. We present the case of a patient who developed a mediastinal abscess after epiphrenic diverticulectomy. We treated the abscess with US-guided percutaneous transhepatic drainage to avoid surgical reintervention. Although other cases of a transhepatic approach to thoracic lesions have been reported, to our knowledge this is the first report of this technique in mediastinal abscesses. We recommend that transhepatic drainage be considered a therapeutic option in the management of these complications.
    Radiología. 01/2012;
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    ABSTRACT: The replacement of conventional films and view boxes with digital images and computer monitors managed by PACS has clearly improved the diagnostic imaging workplace. The new setup has many advantages, including increased productivity brought about by decreased overall time required for image interpretation. On the other hand, the implementation of the digital workplace has increased the importance of factors like background lighting and the position of the chair, work table, mouse, keyboard, and monitor to prevent lesions that can disable the radiologist. The influence of these factors is often undervalued in the design and implementation of the radiological workplace. This article provides recommendations for the design of the radiological workplace based on ergonomics, which is the science that studies interactions among humans and other elements of a system.
    Radiología 09/2011; 53(6):507-15.
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    ABSTRACT: The right aberrant subclavian artery or «arteria lusoria» is the most common anatomical variant of the embryonic development of the aorta and its branches, with a presence in 0.5-2% of the population. Less frequently, a right aortic arch with aberrant left subclavian artery may be present. These anatomical variations should be included in the differential diagnosis of superior mediastinal widening seen on chest radiographs. In this report, we present a right aortic arch with left aberrant subclavian artery dilated at its origin (Kommerell's diverticulum) as a cause of superior mediastinal widening detected incidentally on a chest radiograph.
    Anales del sistema sanitario de Navarra 08/2011; 34(2):295-300. · 0.35 Impact Factor
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    ABSTRACT: The replacement of conventional films and view boxes with digital images and computer monitors managed by PACS has clearly improved the diagnostic imaging workplace. The new setup has many advantages, including increased productivity brought about by decreased overall time required for image interpretation. On the other hand, the implementation of the digital workplace has increased the importance of factors like background lighting and the position of the chair, work table, mouse, keyboard, and monitor to prevent lesions that can disable the radiologist. The influence of these factors is often undervalued in the design and implementation of the radiological workplace. This article provides recommendations for the design of the radiological workplace based on ergonomics, which is the science that studies interactions among humans and other elements of a system.
    Journal of Invertebrate Pathology - J INVERTEBR PATHOL. 01/2011;
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    ABSTRACT: PURPOSE Pulmonary CT Angiography (CTA) is being increasingly used for the diagnosis and follow-up of pulmonary embolism (PE). However, it implies a non-negligible amount of intravenous contrast and radiation dose. The aim of this prospective study was to determine image quality and diagnostic performance of an optimized CTA protocol in terms of radiation exposure and volume of contrast, with respect to a standard CTA protocol. METHOD AND MATERIALS After written informed consent, 86 consecutive patients (49 male, 37 female, mean age 62.8±17.1 years, mean body weight 71.9±12.9 kg) with clinical suspicion of PE were prospectively enrolled. Individuals weighting ≤ 80 kg (group A) were evaluated with a low-contrast, low-radiation pulmonary CTA protocol (80kV/60 ml at 4ml/s) whereas a conventional CTA protocol (100 kV/80 ml at 4ml/s) was used for patients >80 kg (group B). In all exams, the presence of PE and image quality parameters (contrast attenuation in central and peripheral pulmonary arteries, the contrast to noise ratio-CNR and the signal to noise ratio-SNR) were assessed. Effective radiation dose (mSv) was estimated. An independent sample student t-test was employed to compare quantitative image quality parameters and estimated effective radiation doses in both groups. A p value <0.05 was considered statistically significant. RESULTS PE was found in 14 patients (5 of group A, 9 of group B). The mean attenuation of the pulmonary arteries was significantly higher in group A (365.5±98.6 HU) than in group B (255. 9±120.4) whereas CNR and SNR did not statistically differ (14.8±7.4 and 16.2±7.4 for group A and 12.1±7.9 and 13.3±8.2 for group B, respectively). The estimated effective radiation dose was significantly lower with 80 kV protocol (1.1±0.7 mSv) as compared with 100 kV acquisition mode (2.8±1.1 mSv). CONCLUSION In individuals weighting ≤ 80 kg the evaluated low-radiation-dose, low-contrast pulmonary CTA protocol allows accurate depiction of PE with a similar image quality as conventional pulmonary CTA while reducing patient exposure to radiation by more than 50% and the contrast media volume by 20%. CLINICAL RELEVANCE/APPLICATION A low radiation and low-contrast dose CTA protocol enables accurate depiction of PE with unimpaired image quality and significant reduction of the contrast and radiation dose in non-obese patients.
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting; 11/2010
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    ABSTRACT: PURPOSE/AIM Kidney transplantation is the treatment of choice in patients with end-stage renal disease. Despite the continuing surgical improvement there is a wide variety of complications that may occur. The aim of this exhibit is to be aware of these complications and to show the typical ultrasonography features. CONTENT ORGANIZATION Acute complications: 1.- Vascular: Renal vein and artery thrombosis, arteriovenous fistula and renal artery pseudoaneurysm. 2.- Nonvascular: Collections (hematoma, urinoma) and decreased kidney function (acute tubular necrosis, acute-subacute rejection). Long-term complications: 1.- Vascular: Renal artery and vein stenosis. 2.- Nonvascular: Collections (abscess, lymphocele), decreased kidney function (chronic rejection, drug nephrotoxicity) and pyelocalyceal obstruction. SUMMARY We present cases of the most common complications in patients who underwent renal transplantation. 2D and Doppler ultrasonography images are shown. The knowledge of these complications and the typical 2D and Doppler ultrasonography appearance is crucial to achieve the correct diagnosis and avoid graft damage.
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting;
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    ABSTRACT: PURPOSE/AIM - To review usefulness of CMR in the diagnosis of patients presenting to the Emergency Department (ED) with acute chest pain - To emphasize the role of CMR in the diagnostic work-up of these patients - To describe specific CMR findings of most frequent cardiovascular entities causing acute chest pain CONTENT ORGANIZATION Acute chest pain is one of the most common referrals in the ED. It may be caused by potentially life threatening conditions that require rapid triage. Even if CT is increasingly being used for this purpose, the role of CMR is gaining importance due to the advantages inherent to this technique. In the field of acute chest pain of cardiac origin CMR allows to easily establish an ischemic or non-ischemic cause of the myocardial damage. Moreover, CMR is a suitable tool to depict acute aortic syndrome and pulmonary embolism, as well. In this exhibit, imaging features and usefulness of CMR in the differential diagnosis of patients with acute chest pain will be reviewed according to its cardiac (ischemic: acute myocardial infarction, instable angina, coronary anomaly; non- ischemic: Tako–Tsubo cardiomyopathy, accute myocarditis, acute pericarditis) or non-cardiac (acute aortic syndrome and acute pulmonary embolism) origin. SUMMARY CMR may play a significant role in the accurate triage of patients with acute chest pain admitted to the ED.
    Radiological Society of North America 2012 Scientific Assembly and Annual Meeting;
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    ABSTRACT: PURPOSE/AIM 1.-To familiarize radiologists with the imaging findings of Congenital Diaphragmatic Duplication (CDD) in the adult. 2.- To show something new about imaging findings of CDD in the adult. 3.- To explain why is important to know how to recognize a CDD. CONTENT ORGANIZATION 1- In conventional radiography, CDD was identified as an oblique line in the lateral view and blurring of the right dome in the PA view. 2.- CT findings. All CDD were identified by CT, and four of them with MDCT. All CDD occurred in the right hemithorax and all of them had a hole. We show some new aspects about the hole and the shape of the CDD. We show many cases with "normal appearance" on conventional radiography. SUMMARY Knowledge of CDD is important because, as we show in this exhibit, it is not uncommon to detect it in adults, an age group in which CDD is not usually suspected. Most of reported adult patients with CDD underwent surgery. We have seen nine patients, all of whom were diagnosed with CT without surgery. This exhibit shows the series with the largest number of adult patients with an accessory diaphragm, studied by helicoidal and MDCT and the first case of CDD demonstrated with low dose MDCT.
    Radiological Society of North America 2011 Scientific Assembly and Annual Meeting;
  • Conference Paper: Ergonomics in Radiology
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    ABSTRACT: PURPOSE/AIM Computer use is increasing in all fields of medicine, specially in radiology. The study of ergonomics allows the radiologist to ensure adequate adaptation to the workplace. The purpose of this educational exhibit is to review the role of ergonomics in radiology to maximize productivity and comfort, reducing fatigue and discomfort. CONTENT ORGANIZATION PACS system has helped improve the productivity of radiologists by reducing the overall time needed for image interpretation. Other aspects such as the number of monitors, screen type, the position of the table and chair, the proper use of the mouse and keyboard, the type of lighting, temperature and ventilation of the room, noise and in the case of sonographers to get a proper position are important things to prevent injuries that can reduce and even disable productivity of the radiologist. SUMMARY 1.- The successful implementation of ergonomics is based on adequate training of users. 2.- Attention to the basics of workplace ergonomics can contribute greatly to productivity and reducing fatigue of the radiologist. 3.- The lack of attention to ergonomics can cause repetitive stress injuries, eyestrain and muscle aches.
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting;
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    ABSTRACT: The right aberrant subclavian artery or "arteria lusoria" is the most common anatomical variant of the embryonic development of the aorta and its branches, with a presence in 0.5-2% of the population. Less frequently, a right aortic arch with aberrant left subclavian artery may be present. These anatomical variations should be included in the differential diagnosis of superior mediastinal widening seen on chest radiographs. In this report, we present a right aortic arch with left aberrant subclavian artery dilated at its origin (Kommerell's diverticulum) as a cause of superior mediastinal widening detected incidentally on a chest radiograph.
    Anales del sistema sanitario de Navarra 34(2):295-300. · 0.35 Impact Factor
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    ABSTRACT: PURPOSE/AIM The radiation dose from CT examinations has been a growing concern over the past several years. Reducing radiation dose has always been a challenge for radiologists. LDCT is the imaging diagnostic tool in some prevalent thoracic diseases like lung cancer, lung emphysema, pulmonary embolism or coronay artherisclerosis. However, LDCT is not actually a widespread technique. We have used LDCT (120 KV, 20mAs, DLP 50-60mGy-cm) for over three years in some scenarios different from those were pointed out before. We would like to persuade radiologists and clinics about how useful is LDCT in the daily practice. We propose the use of LDCT as a way to avoid unnecessary radiation. CONTENT ORGANIZATION 1. Follow-up in oncologic patients. 2. Characterization and follow-up of lung infectious diseases (i.e. reversed halo sign in TB). 3. Suspicion of chest congenital malformations in adults. 4. Emergency patients (i.e. epipericardial fat necrosis, pneumothorax, diaphragmatic hernia). 5. Planning of interventional procedures (i.e. acquisition in prone position when loculated pleural effusion is suspected). 6. Follow-up of incidentally detected lung nodules. 7. Miscellany (i.e. incidentally detected dense skin lesions) SUMMARY LDCT is useful in some specific thoracic diseases. It should be used in the daily radiological practice .
    Radiological Society of North America 2012 Scientific Assembly and Annual Meeting;
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    ABSTRACT: PURPOSE/AIM The purpose of this educational exhibit is to give a physical explanation with clinical examples of the most frequent artifacts found in clinical practice. Tips and tricks will be given to recognize and avoid artifacts, and how in some cases, they can help us to achieve a correct diagnosis. CONTENT ORGANIZATION Physical concepts of the main ultrasound artifacts such as the shadowing and increased through transmission artifacts, beam width and side lobe artifacts, reverberation, comet tail, ring-down, mirror image and anisotropy artifacts, among others are explained with US images and schematic drawings. US artifacts are secondary to: • Ultrasound beam characteristics • Presence of multiple echo paths • Errors in the beam velocity • Errors in the beam attenuation • Tissue characteristics SUMMARY Ultrasound artifacts are found every day in clinical practice, from a single gallbladder stone with its typical acoustic shadowing to a mirror image artifact which can simulate a lung or pleural nodule. Artifacts must be always recognized because they have the potential to interfere with or delay the correct diagnosis.
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting;