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1.  Traumatic Ventricular Septal Defect: Characterization with ECG-Gated Cardiac Computed Tomography Angiography (CTA) 
Journal of thoracic imaging  2012;27(6):W174-W176.
Ventricular septal defects secondary to blunt trauma to the chest are infrequently reported in the literature. Additionally, the majority of these cases have been imaged with echocardiography alone. We report a case in which a ventricular septal defect caused by blunt chest trauma was characterized with ECG-gated CT angiography (CTA). A review of the current literature and theories of injury mechanism are also included.
PMCID: PMC3481198  PMID: 23090365
thoracic trauma; ventricular septal defect; blunt chest trauma; ECG-gated CTA; cardiac trauma
2.  Prospectively ECG-triggered high-pitch spiral acquisition for cardiac CT angiography in clinical routine: initial results 
Journal of Thoracic Imaging  2012;27(3):194-201.
The study was performed to evaluate the ways of application, image quality (IQ) and radiation exposure resulting from introduction of a prospectively ECG-triggered high-pitch cardiac CTA acquisition mode into routine clinical practice.
Materials and Methods
42 prospectively triggered cardiac CTAs were acquired in 34 patients (11 female, 23 male, mean age 56±15 years) using a high-pitch mode (pitch 3.4) on a dual source CT (DefinitionFLASH, Siemens, Germany). In 8 of these patients with higher heart rates or occasional premature ventricular contractions (PVCs) two immediately subsequent CTAs were performed (“double flash protocol”). Subjective IQ was assessed for coronary arteries using a four-point scale (1=unevaluable –4=excellent). Contrast-to-noise ratio (CNR) was measured in nine locations. CT-Dose-Index and Dose-length-product were obtained, patient’s effective dose was calculated.
Mean effective doses were 2.6±1.4 mSv (range 1.1–6.4) for the entire cardiac examination and 1.4±0.7 mSv (0.4–3.1) for individual high-pitch cardiac CTA. Z-coverage ranged from 9.9cm in a native coronary CTA to 31.4cm in a bypass graft case. Overall subjective IQ was good to excellent (mean score: 3.5) with 1.5 % unevaluable coronary segments. The “double flash protocol” resulted in a fully diagnostic CT study in all cases just after taking both scans into consideration. Mean CNR of all locations was 19.7±2.6.
Prospectively ECG-triggered high-pitch mode cardiac CTA is a feasible and promising technique in clinical routine, allowing for evaluation of the coronaries at good to excellent IQ providing high CNR and minimal radiation doses. The “double flash protocol” might become a more robust tool in patients with elevated heart rates or PVCs.
PMCID: PMC3251691  PMID: 21964497
cardiac CT; Flash; dose; pitch; image quality
3.  Using Keynote to Present Radiology Images 
Journal of Digital Imaging  2010;24(5):844-847.
Numerous articles have offered instructions for working with advanced radiology images in Microsoft PowerPoint (Redmond, WA); however, no articles have detailed instructions to do the same on alternative presentation software. Apple Macintosh (Cupertino, CA) computers are gaining popularity with many radiologists, due in part to the availability of a powerful, free, open-source Digital Imaging and Communications in Medicine (DICOM) viewing and manipulating software OsiriX ( Apple’s own presentation software, Keynote, is particularly effective in dealing with medical images and cine clips. This article demonstrates how to use Apple’s Keynote software to present radiology images and scrollable image stacks, without third-party add-on software. The article also illustrates how to compress media files and protect patient information in Keynote presentations. Lastly, it addresses the steps to converting between PowerPoint and Keynote file formats. Apple’s Keynote software enables quick and efficient addition of multiple static images or scrollable image stacks, compression of media files, and removal of patient information. These functions can be accomplished by inexperienced users with no software modifications.
PMCID: PMC3180549  PMID: 20978920
Computers in medicine; Radiology Information Systems (RIS); Radiology teaching file; Image processing; Image display; Productivity; Keynote
4.  CC8 MRSA Strains Harboring SCCmec Type IVc are Predominant in Colombian Hospitals 
PLoS ONE  2012;7(6):e38576.
Recent reports highlight the incursion of community-associated MRSA within healthcare settings. However, knowledge of this phenomenon remains limited in Latin America. The aim of this study was to evaluate the molecular epidemiology of MRSA in three tertiary-care hospitals in Medellín, Colombia.
An observational cross-sectional study was conducted from 2008–2010. MRSA infections were classified as either community-associated (CA-MRSA) or healthcare-associated (HA-MRSA), with HA-MRSA further classified as hospital-onset (HAHO-MRSA) or community-onset (HACO-MRSA) according to standard epidemiological definitions established by the U.S. Centers for Disease Control and Prevention (CDC). Genotypic analysis included SCCmec typing, spa typing, PFGE and MLST.
Out of 538 total MRSA isolates, 68 (12.6%) were defined as CA-MRSA, 243 (45.2%) as HACO-MRSA and 227 (42.2%) as HAHO-MRSA. The majority harbored SCCmec type IVc (306, 58.7%), followed by SCCmec type I (174, 33.4%). The prevalence of type IVc among CA-, HACO- and HAHO-MRSA isolates was 92.4%, 65.1% and 43.6%, respectively. From 2008 to 2010, the prevalence of type IVc-bearing strains increased significantly, from 50.0% to 68.2% (p = 0.004). Strains harboring SCCmec IVc were mainly associated with spa types t1610, t008 and t024 (MLST clonal complex 8), while PFGE confirmed that the t008 and t1610 strains were closely related to the USA300-0114 CA-MRSA clone. Notably, strains belonging to these three spa types exhibited high levels of tetracycline resistance (45.9%).
CC8 MRSA strains harboring SCCmec type IVc are becoming predominant in Medellín hospitals, displacing previously reported CC5 HA-MRSA clones. Based on shared characteristics including SCCmec IVc, absence of the ACME element and tetracycline resistance, the USA300-related isolates in this study are most likely related to USA300-LV, the recently-described ‘Latin American variant’ of USA300.
PMCID: PMC3380008  PMID: 22745670
5.  Efficacy of Miltefosine for the Treatment of American Cutaneous Leishmaniasis 
Miltefosine is an oral agent used for cutaneous leishmaniasis treatment. An open-label, randomized, phase III clinical trial was carried out in the Colombian army population. Miltefosine, 50 mg capsule was taken orally three times per day for 28 days (N = 145) or meglumine antimoniate, 20 mg/kg body weight per day for 20 days by intramuscular injection (N = 143). The efficacy of miltefosine by protocol was 69.8% (85/122 patients) and 58.6% (85/145 patients) by intention to treat. For meglumine antimoniate, the efficacy by protocol was 85.1% (103/121 patients) and 72% (103/143 patients) by intention to treat. No association was found between drug efficacy and L. (V.) braziliensis or L. (V.) panamensis species of Leishmania responsible for infection. Adverse gastrointestinal events were associated with the use of miltefosine, the meglumine antimoniate treatment was associated with adverse effects on the skeletal musculature, fever, cephalea, and higher toxicity in kidney, liver, pancreas, and hematological system.
PMCID: PMC2911184  PMID: 20682881
6.  IFNγ Response to Mycobacterium tuberculosis, Risk of Infection and Disease in Household Contacts of Tuberculosis Patients in Colombia 
PLoS ONE  2009;4(12):e8257.
Household contacts (HHCs) of pulmonary tuberculosis patients are at high risk of Mycobacterium tuberculosis infection and early disease development. Identification of individuals at risk of tuberculosis disease is a desirable goal for tuberculosis control. Interferon-gamma release assays (IGRAs) using specific M. tuberculosis antigens provide an alternative to tuberculin skin testing (TST) for infection detection. Additionally, the levels of IFNγ produced in response to these antigens may have prognostic value. We estimated the prevalence of M. tuberculosis infection by IGRA and TST in HHCs and their source population (SP), and assessed whether IFNγ levels in HHCs correlate with tuberculosis development.
A cohort of 2060 HHCs was followed for 2–3 years after exposure to a tuberculosis case. Besides TST, IFNγ responses to mycobacterial antigens: CFP, CFP-10, HspX and Ag85A were assessed in 7-days whole blood cultures and compared to 766 individuals from the SP in Medellín, Colombia. Isoniazid prophylaxis was not offered to child contacts because Colombian tuberculosis regulations consider it only in children under 5 years, TST positive without BCG vaccination.
Using TST 65.9% of HHCs and 42.7% subjects from the SP were positive (OR 2.60, p<0.0001). IFNγ response to CFP-10, a biomarker of M. tuberculosis infection, tested positive in 66.3% HHCs and 24.3% from the SP (OR = 6.07, p<0.0001). Tuberculosis incidence rate was 7.0/1000 person years. Children <5 years accounted for 21.6% of incident cases. No significant difference was found between positive and negative IFNγ responders to CFP-10 (HR 1.82 95% CI 0.79–4.20 p = 0.16). However, a significant trend for tuberculosis development amongst high HHC IFNγ producers was observed (trend Log rank p = 0.007).
CFP-10-induced IFNγ production is useful to establish tuberculosis infection prevalence amongst HHC and identify those at highest risk of disease. The high tuberculosis incidence amongst children supports administration of chemoprohylaxis to child contacts regardless of BCG vaccination.
PMCID: PMC2788133  PMID: 20011589

Results 1-6 (6)