Patricia Mergo
Mayo Clinic Graduate School, Department of Radiology, Faculty Member
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Poster: "ESCR 2015 / P-0026 / Spectrum of Findings of Sinus Venosus Atrial Septal Defect: CT and MR Findings " by: "J. M. Madrid1, P. J. Mergo 2, P. Bartolome1, J. Phelan2, P. Parikh2, A. Bowman2, B. Shapiro2; 1Pamplona/ES,... more
Poster: "ESCR 2015 / P-0026 / Spectrum of Findings of Sinus Venosus Atrial Septal Defect: CT and MR Findings " by: "J. M. Madrid1, P. J. Mergo 2, P. Bartolome1, J. Phelan2, P. Parikh2, A. Bowman2, B. Shapiro2; 1Pamplona/ES, 2Jacksonville, FL/US"
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Received April 23, 2014; accepted without revision May 26, 2014. a fraction of cryptogenic strokes may actually arise from a cardiac source that is undetectable with current methods [3]. In addition to appropriate cardiac monitoring for... more
Received April 23, 2014; accepted without revision May 26, 2014. a fraction of cryptogenic strokes may actually arise from a cardiac source that is undetectable with current methods [3]. In addition to appropriate cardiac monitoring for electrical abnormalities, echocardiography, particularly transthoracic echocardiography (TTE), is often the initial screening test for cardiac abnormalities in stroke patients [1]. Clear advantages of TTE are that the equipment is portable and that the procedure is noninvasive, widely available, and relatively inexpensive. However, in patients with suspected cardioembolism, TTE has a number of pitfalls. Although a few of the potential causes of cardiac emboli (e.g., LV thrombi) may be identified with TTE, it is rarely adequate for assessing aortic plaque and small valvular abnormalities and is not adequate for assessing LAA thrombi. Furthermore, technical challenges from poor acoustic windows are common, particularly in patients with obesity, chronic...
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Research Interests: Medicine and Chest Pain
PURPOSE/AIM An understanding of the anatomy of the left atrial appendage (LAA) is becoming increasingly important as it is recognized as a significant site for thrombus. Advanced techniques for LAA closure (including the Larait and... more
PURPOSE/AIM An understanding of the anatomy of the left atrial appendage (LAA) is becoming increasingly important as it is recognized as a significant site for thrombus. Advanced techniques for LAA closure (including the Larait and Watchman procedures, as well as surgical closure) require precise anatomic localization and description of the LAA and its anatomic relationships prior to intervention. To date, this is not well described in the literature. CONTENT ORGANIZATION This scientific exhibit describes the anatomy of the LAA, as imaged with CTA, including parameters for normal size and positioning of the LAA relative to the heart. Additionally, the anatomic relationships are discussed in context of their impact on pre-procedural planning for LAA closure, including a detailed discussion of the Lariat, Watchman and surgical techniques. Specific teaching points are made emphasizing the relevant findings on CTA as they relate to pre-procedural planning. Finally, imaging techniques ar...
PURPOSE/AIM 1. Briefly review the physiology of pulmonary arterial hemodynamics 2. Review imaging manifestations of pulmonary hypertension and abnormal flow dynamics affecting the pulmonary artery CONTENT ORGANIZATION Review of pulmonary... more
PURPOSE/AIM 1. Briefly review the physiology of pulmonary arterial hemodynamics 2. Review imaging manifestations of pulmonary hypertension and abnormal flow dynamics affecting the pulmonary artery CONTENT ORGANIZATION Review of pulmonary artery physiology. - Hemodynamics of pulmonary arterial circulation - Effects of abnormal pressure or flow on the central pulmonary arteries - Effects of the activation of pulmonary vascular endothelium and the inflammatory response Imaging manifestations of pulmonary hypertension - Findings in primary peripheral pulmonary hypertension, chronic pulmonary thromboembolic disease, portopulmonary hypertension - Quantification of PA pulsatility as a surrogate for compliance - PA and RV size - Signs of RV strain Imaging manifestations of abnormal flow phenomena affecting the pulmonary artery - Left to right shunt: ASD, VSD, PDA, anomalous pulmonary venous return - Pulmonary stenosis or regurgitation - Quantification of shunt or regurgitant fraction SUMMAR...
Research Interests: Medicine and Fatty Liver
To determine the radiation effective dose to adult and pediatric patients undergoing abdominal computed tomographic (CT) examinations. Technique factors were obtained for three groups of randomly selected patients undergoing abdominal CT... more
To determine the radiation effective dose to adult and pediatric patients undergoing abdominal computed tomographic (CT) examinations. Technique factors were obtained for three groups of randomly selected patients undergoing abdominal CT examinations: 31 children aged 10 years or younger; 32 young adults aged 11-18 years; and 36 adults older than 18 years. The radiographic techniques, together with the measured cross sections of patients, were used to estimate the total energy imparted to each patient. Each value of energy imparted was subsequently converted into the corresponding effective dose to the patient, taking into account the mass of the patient. All abdominal CT examinations were performed at 120 kVp with a section thickness of approximately 7 mm for all sizes of patients. The mean number of CT sections increased from 22.0 for children to 31.5 for adults, and the mean quantity of x radiation in milliampere-seconds increased from 220 mAs for children to 290 mAs for adults. The mean values (+/- SD) of energy imparted were 72.1 mJ +/- 24.4 for children, 183.5 mJ +/- 44.8 for young adults, and 234.7 mJ +/- 89.4 for adults. The corresponding mean values of patient effective dose were 6.1 mSv +/- 1.4 for children, 4.4 mSv +/- 1.0 for young adults, and 3.9 mSv +/- 1.1 for adults. Values of energy imparted to patients undergoing abdominal CT examinations were a factor of three higher in adults than in children, but the corresponding patient effective doses were 50% higher in children than in adults.
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... Rieber, Andrea; Tomczak, Reinhard J.; Mergo, Patricia J.; Wenzel, Volker; Zeitler, Holger; Brambs, Hans-Juergen. ... Mammography (Mammomat; Siemens, Erlangen, Germany) was performed with craniocaudal and mediolateral projections using... more
... Rieber, Andrea; Tomczak, Reinhard J.; Mergo, Patricia J.; Wenzel, Volker; Zeitler, Holger; Brambs, Hans-Juergen. ... Mammography (Mammomat; Siemens, Erlangen, Germany) was performed with craniocaudal and mediolateral projections using a technique of 28-30 kV. ...
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Research Interests: Cardiology, Medicine, Heart Failure, Humans, Internal Medicine, and 15 moreHemodynamics, Blood Pressure, Female, Male, Clinical Sciences, Middle Aged, Radiography, Adult, Retrospective Studies, Prognosis, Ejection Fraction, Heart Transplantation, Postoperative Complications, Cardiomegaly, and Diastole
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Although MR imaging has achieved a clear role in the assessment of focal benign and malignant hepatic lesions, its role in the evaluation of inflammatory processes in the liver is less well defined and studied. Many inflammatory diseases... more
Although MR imaging has achieved a clear role in the assessment of focal benign and malignant hepatic lesions, its role in the evaluation of inflammatory processes in the liver is less well defined and studied. Many inflammatory diseases in the liver have no characteristic or specific imaging findings with MR imaging. Familiarization with these entities and their respective imaging findings is important, however, to aid in their identification and distinction from the more commonly studied neoplastic disease.
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Esophageal perforation can be a catastrophic event for a patient regardless of the etiology of the perforation. Contrast esophagrams can typically diagnose an esophageal perforation if the clinical symptoms or history suggest the... more
Esophageal perforation can be a catastrophic event for a patient regardless of the etiology of the perforation. Contrast esophagrams can typically diagnose an esophageal perforation if the clinical symptoms or history suggest the diagnosis. Often, however, the clinical features are atypical and a CT scan is performed early in the patient's workup. It is, therefore, essential to recognize the CT features seen in esophageal perforation. The various etiologies and CT findings of esophageal perforation are reviewed in this article. The CT abnormalities include extraluminal air, periesophageal fluid, esophageal thickening, and extraluminal contrast. These CT findings may be the first clue to the correct diagnosis of esophageal perforation.
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While magnetic resonance imaging (MRI) is utilized primarily in the liver for evaluation and characterization of focal lesions, it also has utility in the assessment of diffuse disease of the liver. It can offer a noninvasive means of... more
While magnetic resonance imaging (MRI) is utilized primarily in the liver for evaluation and characterization of focal lesions, it also has utility in the assessment of diffuse disease of the liver. It can offer a noninvasive means of establishing the presence of diffuse liver disease, characterizing the extent of disease, and, in certain instances, identifying the underlying cause of the disease.
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Magnetic resonance (MR) imaging can aid in the detection and characterization of many pancreatic neoplasms. The MR imaging appearances of common pancreatic neoplasms such as ductal adenocarcinoma are well-known. However, MR imaging... more
Magnetic resonance (MR) imaging can aid in the detection and characterization of many pancreatic neoplasms. The MR imaging appearances of common pancreatic neoplasms such as ductal adenocarcinoma are well-known. However, MR imaging features of more unusual pancreatic neoplasms are not well understood. Such tumors include mucin-hyper-secreting carcinoma, serous microcystic neoplasm, mucinous macrocystic neoplasm, solid and papillary epithelial neoplasm, multiple cysts associated with von Hippel-Lindau disease, acinar cell carcinoma, pancreaticoblastoma, and endocrine neoplasms (eg, nonfunctioning islet cell tumors, insulinoma, and gastrinoma). In general, pancreatic neoplasms demonstrate high signal intensity on T2-weighted images; the signal intensity on T1-weighted images is more variable but is often intermediate or low. Gadolinium enhancement is often helpful in further characterizing pancreatic neoplasms. The gross and histologic features of pancreatic neoplasms are also not well-known. Correlation with the underlying pathologic features enhances understanding of the MR imaging characteristics of both common and unusual pancreatic neoplasms.
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Our goal was to determine the efficacy of MRI with rectal administration of perflubron in the evaluation of perirectal and pelvic fistulae, with an emphasis on development of an improved method for fistula visualization. Fourteen pelvic... more
Our goal was to determine the efficacy of MRI with rectal administration of perflubron in the evaluation of perirectal and pelvic fistulae, with an emphasis on development of an improved method for fistula visualization. Fourteen pelvic and/or perirectal fistulae were evaluated in nine patients with MRI after the rectal administration of 200 ml of perflubron. Images were reviewed by two independent readers and evaluated for the presence or absence of fistulae. Qualitative assessment was also performed, rating the examinations for the ability to visualize the fistulae. Comparison was made with the clinical examination and/or operative findings, as well as available preperflubron imaging studies (CT = 10; fluoroscopy = 1; preperflubron MRI = 4). MRI with rectal perflubron demonstrated all 14 fistulae (100%), while preperflubron imaging demonstrated only 7 of 14 (50%) fistulae (p < or = 0.008, Wilcoxon signed rank test). In addition, MRI with perflubron resulted in significantly improved qualitative visualization of fistulae (overall very good rating versus poor rating for preperflubron imaging, p < or = 0.006, Wilcoxon signed rank test). MRI with rectal perflubron is a superior modality for imaging of fistulae, compared with conventional methods, since it allows a noninvasive means of demonstrating the presence of a fistula as well as offers improved qualitative assessment of fistulous disease.
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We review exceptional properties of the photonic crystal fibres enabling sensing applications of this new class of fibres. First, the sensing capabilities of highly birefringent index guided fibres are discussed. This includes dispersion... more
We review exceptional properties of the photonic crystal fibres enabling sensing applications of this new class of fibres. First, the sensing capabilities of highly birefringent index guided fibres are discussed. This includes dispersion characteristics of phase and group modal birefringence in different fibre structures, and sensitivity of these parameters to hydrostatic pressures and temperature. We demonstrate that index guided and photonic bandgap holey fibres of specific construction can be used as wide-band fibre-optic polarizer. We also show that combining of geometrical and stress effects makes it possible to design the holey fibres with either zero phase or group modal birefringence at virtually any given wavelength. Finally, different designs and performance of PCFs suitable for gas sensing are overviewed.
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We have experimentally characterized three polarizing photonic crystal fibers manufactured by the Laboratory of Optical Fiber Technology, Maria Curie-Sklodowska University, Lublin, Poland. In the investigated structures the dissimilarity... more
We have experimentally characterized three polarizing photonic crystal fibers manufactured by the Laboratory of Optical Fiber Technology, Maria Curie-Sklodowska University, Lublin, Poland. In the investigated structures the dissimilarity in the cut-off wavelengths is induced by a pair of large air holes adjacent to the fiber core. Because of different geometry, the investigated fibers have different polarization ranges. In the first structure, the polarization dependent loss (PDL) of 3 dB/m is observed at 1300 nm and further increases against wavelength. In the two other fibers, the polarization bandwidth is shifted towards longer wavelengths. We have also investigated the effect of bending on polarization characteristics. It was experimentally demonstrated that for bent fiber the attenuation of the LPy 01 increases for shorter wavelengths, which results in wider polarization bandwidth. Moreover, we have numerically analyzed and optimized for maximum operation bandwidth two constructions of the index guided PCFs, whose polarization properties are induced by unequal diameters of the cladding holes.
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ABSTRACT Microstructured optical fibers (MOFs) have been widely studied owing to their potential for obtaining novel transmission, nonlinear and sensing characteristics. Sensing applications of MOFs cover various types of devices for... more
ABSTRACT Microstructured optical fibers (MOFs) have been widely studied owing to their potential for obtaining novel transmission, nonlinear and sensing characteristics. Sensing applications of MOFs cover various types of devices for measurements of different physical and specific chemical compounds in gases and liquids employing evanescent field techniques. Such fibers can also be used as active and passive elements in fiber-optic polarimetric and interferometric sensors. We present an in-line fiber modal interferometer fabricated in boron-doped highly birefringent microstructured fiber. The boron-doped region located in the middle of the core decreases the effective index of the fundamental mode and facilitates coupling between the fundamental and the first order mode. The coupling regions have the form of fiber narrowings fabricated using CO2 laser and are distant by a few millimeters. The spectral intensity at the sensor output is modulated only by intermodal interference produced by a short piece of fiber between the two coupling points. Moreover, as the fiber is highly birefringence, each pair of polarization modes produces its own intermodal fringes, which results in the contrast modulation of the overall interference signal observed at the fiber output, and provides an additional degree of freedom to measure simultaneously a pair of measurands.
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To facilitate and speed up the deployment of fiber-to-the-home networks, high-efficiency, low-cost, field installable fiber connectors are one of the key components. We present a novel type of small-form-factor 180°-bend single mode fiber... more
To facilitate and speed up the deployment of fiber-to-the-home networks, high-efficiency, low-cost, field installable fiber connectors are one of the key components. We present a novel type of small-form-factor 180°-bend single mode fiber socket, allowing for 0.5-dB coupling loss between two side-by-side positioned fibers, making use of specially designed low bending loss hole-assisted fiber. The components are prototyped in a polymer using Deep Proton Writing and show all the potentialities for low-cost fabrication in different types of plastics.
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ABSTRACT Paper presents technology manufacturing and basics parameters of photosensitive high birefringent photonic crystal fiber made from high silica glasses. It was especially elaborated for Bragg gratings inscriptions. Common photonic... more
ABSTRACT Paper presents technology manufacturing and basics parameters of photosensitive high birefringent photonic crystal fiber made from high silica glasses. It was especially elaborated for Bragg gratings inscriptions. Common photonic optical fibers have cores made from nondoped silica glasses. Therefore Bragg gratings inscriptions are difficult or impossible. In photosensitive photonic optical fibers cores are made from germanium doped silica glasses. In presented fiber core glass was made with MCVD method. Technology of manufacturing of high birefringent photonic crystal fibers are analogous to technology of manufacturing of common low birefringent holey fibers.
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Paper presents the state of advance of the silica glass microstructured optical fibers technology n Poland especially in Department of Optical Fibers Technology Maria Curie Sklodowska University. Only in this Department there are the... more
Paper presents the state of advance of the silica glass microstructured optical fibers technology n Poland especially in Department of Optical Fibers Technology Maria Curie Sklodowska University. Only in this Department there are the technological apparatus for advanced investigations on the technology of the silica glass optical fibers. In paper was describe the technology of optical fiber photonic structure manufacturing,
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This paper presents technology and characteristic of classic eleven cores single mode optical fibers with linear and circular shape. Manufactured optical fibers can be used in constructions of new class of optical fibers sensors, in witch... more
This paper presents technology and characteristic of classic eleven cores single mode optical fibers with linear and circular shape. Manufactured optical fibers can be used in constructions of new class of optical fibers sensors, in witch change of coupling length is used. Those optical fibers are the base for elaboration of the active multicore optical fiber for fiber laser worked
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Series of ten cores photonic optical fibers with different filing factors and different distances between cores was elaborated and manufactured. The measurements of energy transfer and coupling length between cores were done. Obtained... more
Series of ten cores photonic optical fibers with different filing factors and different distances between cores was elaborated and manufactured. The measurements of energy transfer and coupling length between cores were done. Obtained results are only in part compatible with known from literature theoretical descriptions of energy transfer in those structures.
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Research Interests: Medicine and Demographics
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Cardiac myxomas are common and account for 50% of primary intracardiac tumors. Atypical locations of cardiac myxoma increase the risk of intraoperative iatrogenic injuries. Herein, we report a case of using three‐dimensional printing (3D)... more
Cardiac myxomas are common and account for 50% of primary intracardiac tumors. Atypical locations of cardiac myxoma increase the risk of intraoperative iatrogenic injuries. Herein, we report a case of using three‐dimensional printing (3D) to facilitate the removal of an atypical cardiac myxoma in a 63‐year‐old woman.
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ABSTRACT: Pulmonary hypertension is characterized by alterations in the viscoelastic properties of the pulmonary arteries, leading to increased pulmonary arterial stiffness and elevated pressures. Early detection and accurate... more
ABSTRACT: Pulmonary hypertension is characterized by alterations in the viscoelastic properties of the pulmonary arteries, leading to increased pulmonary arterial stiffness and elevated pressures. Early detection and accurate quantification of pulmonary hypertension are limitations to conventional noninvasive imaging and may have therapeutic implications. Cardiac MRI provides important information that can aid the clinician, particularly relating to morphologic right ventricular alterations and quantification of stiffness, as well as providing a novel prognostic framework.