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1.
J Ultrasound Med ; 40(8): 1479-1483, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33098581

RESUMEN

The Sound Judgment Series consists of invited articles highlighting the clinical value of using ultrasound first in specific clinical diagnoses where ultrasound has shown comparative or superior value. The series is meant to serve as an educational tool for medical and sonography students and clinical practitioners and may help integrate ultrasound into clinical practice.


Asunto(s)
Anticonceptivos , Implantes de Medicamentos , Humanos , Ultrasonografía
2.
Clin Imaging ; 72: 31-36, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33202292

RESUMEN

BACKGROUND: To evaluate Interventional Radiology (IR) procedural volume changes at a large Midwest health system between March 17, 2020 and April 30, 2020 following a state-mandated shutdown of nonessential procedures during the initial phase of COVID-19. METHODS: IR procedural volumes were compiled, stratified by location and compared with Diagnostic Radiology (DR) volumes during the same timeframe. Procedure volume was categorized by type, including oncology, dialysis interventions, and drainage procedures with comparisons made using Z-score test for proportions. IR and system-wide surgical procedural volume was compared with baseline values. RESULTS: System-wide IR procedural volume decreased by 35%, with a 41% decrease in outpatient and a 25% decrease in inpatient volume during the state-mandated order. DR volume decreased by 45%, with a 57% decrease in outpatient and a 22% decrease in inpatient volume. Total IR procedural volume during the mandate was 1077 versus 1518 during the preceding six weeks. The proportion of Interventional Oncology and dialysis interventions showed no significant change (p > 0.05) while that of drainage procedures increased (p < 0.05). Compared to baseline values, system-wide procedural volumes for IR, Vascular Surgery, Urology, General Surgery, Gastroenterology and Gynecology decreased by 3%, 11%, 25%, 20%, 38% and 31% in March 2020 and 25%, 47%, 68%, 63%, 79% and 73% in April 2020 respectively. CONCLUSION: Outpatient IR volumes were less impacted compared to DR during the initial phase of COVID-19. Oncology, dialysis and drainage interventions may be considered essential procedures due to their stability. IR volumes were less affected compared to other procedural specialties.


Asunto(s)
COVID-19 , Radiología Intervencionista , Humanos , Pacientes Internos , Radiografía , SARS-CoV-2
3.
Gland Surg ; 9(5): 1708-1715, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33224848

RESUMEN

Rapid on-site evaluation/adequacy assessment (ROSE) is considered an essential component of thyroid fine needle aspiration (FNA) and many reported that it significantly decreases the nondiagnostic (ND) rate. The average reported ND rate without ROSE is about 20% and is improved by 12% when ROSE is implemented. However, the data also suggest that the improvement in ND rate after implementation of ROSE is directly related to the ND rate prior to ROSE and that it is mostly beneficial to aspirators with less experience. Several studies have also raised concerns regarding the impact of ROSE as it prolongs the procedure time, requires additional resources and increases the cost incurred by the additional fees. This resulted in a wide variation in the methodology applied to acquire the sample and implement ROSE across the globe with variation in the number of passes performed, stain utilized and the personnel reviewing the slides, e.g., cytotechnologists versus pathologist. This review summarized the literature reporting the impact of ROSE including its pros and cons, its accuracy and reproducibility, concordance between cytotechnologists and pathologists based on final diagnosis and highlights the different ways laboratories attempted to circumvent the challenges. In particular, the review highlights a unique approach practiced in Ito Hospital, Tokyo, Japan.

4.
J Ultrasound Med ; 38(10): 2541-2557, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30714653

RESUMEN

Since its introduction, contrast-enhanced ultrasound (CEUS) has gained an important role in the diagnosis and management of abdominal and pelvic diseases. Contrast-enhanced ultrasound can improve lesion detection rates as well as success rates of interventional procedures when compared to conventional ultrasound alone. Additionally, CEUS enables the interventionalist to assess the dynamic enhancement of different tissues and lesions, without the adverse effects of contrast-enhanced computed tomography, such as exposure to ionizing radiation and nephrotoxicity from iodinated contrast material. This review article describes the various applications and advantages of the use of CEUS to enhance performance of ultrasound-guided interventions in the abdomen and pelvis.


Asunto(s)
Medios de Contraste , Enfermedades del Sistema Digestivo/diagnóstico por imagen , Enfermedades Urogenitales Femeninas/diagnóstico por imagen , Aumento de la Imagen/métodos , Enfermedades Urogenitales Masculinas/diagnóstico por imagen , Enfermedades del Bazo/diagnóstico por imagen , Ultrasonografía Intervencional/métodos , Abdomen/diagnóstico por imagen , Femenino , Humanos , Masculino , Pelvis/diagnóstico por imagen
5.
Cardiovasc Diagn Ther ; 8(Suppl 1): S118-S130, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29850424

RESUMEN

Ultrasound (US) represents the initial modality in the workup of abdominal aortic pathology based on the plethora of advantages including widespread availability, low cost, safety profile and repeatability. However, US has inherent limitations including limited spatial information of pathologic processes to neighboring structures, lower sensitivity to slow blood flow and aortic luminal irregularities. For evaluation of aortic pathology angiography has long been considered the gold standard. Non-invasive cross-sectional imaging techniques like computed tomography angiography (CTA) and magnetic resonance angiography (MRA) have gradually replaced interventional angiography for the evaluation of aorta, currently being regarded as the diagnostic imaging modalities of choice for diagnosis of virtually every aortic disease. Interventional angiography is currently primarily performed for treatment purposes of aortic pathology. The introduction of microbubbles as ultrasonographic contrast agents has rendered contrast-enhanced ultrasound (CEUS) an evolving valuable complementary technique with markedly increased diagnostic accuracy for certain aortic applications. CEUS is characterized by the potential to be performed in patients with impaired renal function. Due to its superior spatial and temporal resolution, ability for prolonged scanning and dynamic and real-time imaging, it provides clinically significant additional information compared to the standard Duplex US. The purpose of this paper is to discuss the currently available literature regarding abdominal aortic applications of CEUS, briefly elaborate on CEUS technique and safety and present cases in order to illustrate the added value in aortic pathologies. Conditions discussed include abdominal aortic aneurysm (AAA), aneurysm rupture, aneurysm surveillance after endovascular repair, dissection and aortitis.

6.
Diagn Cytopathol ; 45(6): 501-506, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28261999

RESUMEN

BACKGROUND: With the increased use of whole body fluorodeoxyglucose positron emission tomography (PET) scan for staging/restaging or primary diagnosis of neoplasia, thyroid incidentalomas have become more common. The limited reports of PET-positive thyroid incidentalomas showed incidence of malignancy ranging from 14 to 66%, and there is discrepancy in terms of the diagnostic significance of the standard uptake value (SUV) value. METHODS: This is a retrospective study of 20 PET incidentalomas which had cytological evaluation from October 2009 to February 2015 at a tertiary care university medical center, M:F = 8:12. RESULTS: Of the 20 cases, 14 (70%) had a cytological diagnosis of atypia or suspicious for neoplasia. Eleven of those (55%) underwent surgical resection with final diagnosis of PTC in 8 cases, follicular carcinoma in one case (5%), follicular adenoma in one case (5%), and Hurthle cell adenoma in one case (5%). There was good correlation between cytological and histological diagnosis. For two cases with cytological diagnosis of suspicious for follicular neoplasm, no further histological diagnosis was obtained. One patient had direct cytological diagnosis of PTC also did not undergo surgical resection/diagnosis due to the advanced primary pancreatic adenocarcinoma. The remaining 6 (30%) cases had a cytological diagnosis of benign follicular nodule. Furthermore, no significant difference between malignant SUV and benign SUV was observed. CONCLUSIONS: Malignancy was identified in 50% of the PET-positive incidentalomas in our series. PTC constitutes the major malignant diagnosis. No diagnostic value of SUV was observed to differentiate malignant from benign lesions. Diagn. Cytopathol. 2017;45:501-506. © 2017 Wiley Periodicals, Inc.


Asunto(s)
Adenoma/diagnóstico por imagen , Carcinoma/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Tomografía de Emisión de Positrones/normas , Radiofármacos , Nódulo Tiroideo/diagnóstico por imagen , Adenoma/patología , Adulto , Anciano de 80 o más Años , Biopsia con Aguja Fina , Carcinoma/patología , Reacciones Falso Positivas , Femenino , Humanos , Hallazgos Incidentales , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Nódulo Tiroideo/patología
7.
Curr Probl Diagn Radiol ; 46(3): 177-180, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28162863

RESUMEN

Preprocedural evaluation of patients in an interventional radiology (IR) clinic is a complex synthesis of physical examination and imaging findings, and as IR transitions to an independent clinical specialty, such evaluations will become an increasingly critical component of a successful IR practice and quality patient care. Prior research suggests that preprocedural evaluations increased patient's perceived quality of care and may improve procedural technical success rates. Appropriate documentation of a preprocedural evaluation in the medical record is also paramount for an interventional radiologist to add value and function as an effective member of a larger IR service and multidisciplinary health care team. The purpose of this study is to examine the quality of radiology resident notes for patients seen in an outpatient IR clinic at a single academic medical center before and after the adoption of clinic note template with reminders to include platelet count, international normalized ratio, glomerular filtration rate, and plan for periprocedural coagulation status. Before adoption of the template, platelet count, international normalized ratio, glomerular filtration rate and an appropriate plan for periprocedural coagulation status were documented in 72%, 82%, 42%, and 33% of patients, respectively. After adoption of the template, appropriate documentation of platelet count, international normalized ratio, and glomerular filtration rate increased to 96%, and appropriate plan for periprocedural coagulation status was documented in 83% of patients. Patient evaluation and clinical documentation skills may not be adequately practiced during radiology residency, and tools such as templates may help increase documentation quality by radiology residents.


Asunto(s)
Atención Ambulatoria/normas , Documentación/normas , Radiología Intervencionista/educación , Radiología Intervencionista/normas , Competencia Clínica , Educación de Postgrado en Medicina , Humanos , Indicadores de Calidad de la Atención de Salud , Derivación y Consulta , Estudios Retrospectivos
8.
Int Urogynecol J ; 28(5): 763-768, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27844121

RESUMEN

INTRODUCTION AND HYPOTHESIS: Disorders of micturition result from a wide variety of conditions and evaluation often involves multiple diagnostic modalities. However, the sensitivity and specificity of these techniques are highly variable and may not always yield a diagnosis. Novel imaging techniques such as ultrasound shear wave elastography may help to improve diagnostic accuracy. METHODS: Continent women were recruited from outpatient gynecology offices from a tertiary medical system. Participants underwent ultrasound evaluation with measurement of the shear wave velocity (SWV) of the bladder neck (BN). SWV was used to determine the Young's modulus of the bladder neck. The median bladder neck stiffness was calculated and univariate and step-wise and backward multivariate logistic regression analyses were used to identify significant patient characteristics associated with bladder neck stiffness above or below the median. RESULTS: Fifty-seven women underwent SWE of the bladder; 12 were excluded, and 45 were included in the analysis. The median bladder neck stiffness of the study population was 22 (17.1-28.2) kPa. Age greater than 45 years was associated with a bladder neck stiffness above the median, OR 8.39, p < 0.001. Having no vaginal deliveries was also associated with a bladder neck stiffness greater than 22 kPa, unadjusted OR 4.76 (95 % CI 1.41-20.0, p = 0.012). Bladder volume and bladder neck thickness were not significantly associated with bladder neck stiffness above or below the median. CONCLUSION: Trans-abdominal shear wave elastography can be used to quantitatively assess bladder neck stiffness. This technique may potentially be useful for evaluating chronic urinary retention.


Asunto(s)
Módulo de Elasticidad/fisiología , Diagnóstico por Imagen de Elasticidad/métodos , Vejiga Urinaria/diagnóstico por imagen , Adulto , Factores de Edad , Femenino , Humanos , Persona de Mediana Edad , Análisis de Regresión , Sensibilidad y Especificidad , Vejiga Urinaria/patología
9.
J Gastrointest Oncol ; 8(6): 1056-1064, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29299367

RESUMEN

BACKGROUND: To assess the technical success of contrast enhanced ultrasound (CEUS) guided biopsies of liver lesions poorly visualized on B-mode ultrasound. METHODS: Patients were selected during the procedure based on the real-time clinical scenario of unsatisfactory B-mode ultrasound lesion visualization and all patients would have otherwise undergone CT guided liver lesion biopsy. A total of 26 patients underwent CEUS guided biopsy and were included in this retrospective analysis. The review of the patients' files included demographic information, lesion characteristics on imaging, procedural details and pathology outcome. Technical success was defined as concordance between the radiological findings, pathology report and clinical follow-up-demonstrating lack of need for re-biopsy or re-biopsy with identical pathological results. Patients with less than 2 months follow-up were excluded from the study. RESULTS: CEUS guided liver biopsy was successful in 23 out of 26 patients (88.5%). The average procedure time was 30.7±12.3 minutes and the average lesion size was 2.2±1.7 cm. The majority of lesions (80.8%) were hypoenhancing on the delayed phase of CEUS. The mean number of samples taken from each lesion per procedure was 3.2 (±1.7). CONCLUSIONS: CEUS guidance biopsies of focal liver lesions (FLL) that were difficult to visualize on B-mode ultrasound demonstrated high success rate and may be an evolving image guidance modality in selected patients to avoid CT guided procedures.

10.
Diagn Cytopathol ; 44(12): 1010-1023, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27753244

RESUMEN

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pulmonary cytology including indications for bronchial brushings, washings and endobronchial ultrasound-guided fine needle aspiration, technical recommendations for cytologic sampling, recommended terminology and classification scheme, recommendations for ancillary testing and recommendations for postcytologic diagnosis management and follow-up. All recommendation documents are based on the expertise of the authors, extensive literature review and feedback from presentations at national and international conferences. This document selectively presents the results of these discussions. The present document summarizes the recommendations for clinical and imaging evaluation of pulmonary lesions along with the indications for cytologic studies regarding these abnormalities. Preprocedural requirements regarding brushing, washing and needle aspiration procedures are discussed also. Diagn. Cytopathol. 2016;44:1010-1023. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Broncoscopía/métodos , Biopsia por Aspiración con Aguja Fina Guiada por Ultrasonido Endoscópico/métodos , Neoplasias Pulmonares/patología , Guías de Práctica Clínica como Asunto , Broncoscopía/efectos adversos , Broncoscopía/normas , Diagnóstico Diferencial , Biopsia por Aspiración con Aguja Fina Guiada por Ultrasonido Endoscópico/efectos adversos , Biopsia por Aspiración con Aguja Fina Guiada por Ultrasonido Endoscópico/normas , Humanos , Neoplasias Pulmonares/clasificación , Neoplasias Pulmonares/diagnóstico por imagen , Patología Clínica/organización & administración , Sociedades Médicas , Terminología como Asunto
11.
J Ultrasound Med ; 35(6): 1131-41, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27091917

RESUMEN

OBJECTIVES: To compare the diagnostic yield, complication rate, and procedure length of ultrasound fusion-guided liver biopsy to the diagnostic yield, complication rate, and procedure length of computed tomography (CT)-guided liver biopsy; to measure the average ionizing radiation dose that patients are exposed to during a typical CT-guided liver biopsy procedure; and to present relevant and interesting cases of ultrasound fusion-guided abdominal interventions to describe the efficacious use of the technology. METHODS: A retrospective analysis of 63 patients who had image-guided liver biopsies performed at our institution was completed. Patient records were divided into 2 groups according to the type of image guidance used during the procedure (ultrasound fusion versus CT), and data were compared by the χ(2) test, Student t test, and Mann-Whitney U test. RESULTS: The diagnostic yields and complication rates were not statistically significantly different between the modalities. The average procedure durations were significantly different: ultrasound fusion-guided biopsy, 31.63 minutes; compared to CT-guided biopsy, 61.67 minutes (P = .003). CONCLUSIONS: Diagnostic yields and complication rates were comparable for ultrasound fusion and CT. However, the average procedure duration for an ultrasound fusion-guided liver biopsy was approximately half that of CT-guided liver biopsy, likely increasing both cost-effectiveness and patient satisfaction.


Asunto(s)
Hígado/diagnóstico por imagen , Hígado/patología , Imagen por Resonancia Magnética/métodos , Imagen Multimodal/métodos , Tomografía Computarizada por Rayos X/métodos , Ultrasonografía Intervencional/métodos , Abdomen/diagnóstico por imagen , Abdomen/patología , Adulto , Anciano , Anciano de 80 o más Años , Biopsia con Aguja , Femenino , Humanos , Biopsia Guiada por Imagen/métodos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Reproducibilidad de los Resultados , Estudios Retrospectivos
12.
Curr Probl Diagn Radiol ; 45(2): 137-8, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26596560

RESUMEN

Patient satisfaction is becoming an increasingly important part of America's healthcare system. Patient satisfaction is now a metric assessed for value-based incentive payments by the Center for Medicare and Medicaid Services, and the healthcare market is becoming increasingly consumer-driven as patients are provided with more options regarding where they receive care as well as improved access to medical information. Radiologists, while less involved with direct patient care than other medical specialties, are not immune to the changing medical landscape and need to adapt to a progressively value- and patient-oriented healthcare system. At our institution, first-year radiology residents take an active role in our outpatient interventional radiology clinic by performing clinical histories and physical exams in a dedicated radiology clinic examination rooms. Stressing the various opportunities for patient interaction and the potential benefits of patient- centered radiology in the evolving healthcare system may increase its perceived value among both radiology residents as well as practicing radiologists. ​Directly engaging patients may be unfamiliar territory for the practicing radiologist and an unexpected prospect for current residents, but available data suggests that patients do value direct interaction with radiologists during the course of their care.


Asunto(s)
Instituciones de Atención Ambulatoria , Satisfacción del Paciente , Radiología Intervencionista , Humanos , Estados Unidos , Compra Basada en Calidad
13.
Am J Surg ; 209(6): 999-1006, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25442512

RESUMEN

BACKGROUND: Several postoperative gastrointestinal complications are attributed to ischemia. We herein evaluate the gastric wall perfusion using computed tomography (CT) scan perfusion index on trial to address the etiology of ischemic complication after sleeve gastrectomy. METHODS: A retrospective study of 205 patients undergoing CT scan of the abdomen to evaluate the pattern of gastric vascular perfusion was performed. The perfusion index of the gastric mucosa was measured at 5 gastric points using CT perfusion scanning. RESULTS: Gastric perfusion at the angle of His (AOH) (53.51 ± 14.38) was statistically significantly lower (P < .001) than that at the other gastric points studied: fundus, greater curvature, lesser curvature, incisura angularis, and mid gastric points (76.16 ± 15.21, 73.27 ± 16.55, 76.12 ± 16.12, and 75.24 ± 14.9, respectively). Gastric perfusion was significantly lower at all the gastric points (and especially so at the AOH) among obese patients (33 cases) compared with nonobese patients (18 cases). Gastric perfusion at all the points studied showed a decrease as the body mass index increases. Hypertensive patients had a better gastric perfusion compared with nonhypertensive patients. CONCLUSIONS: Gastric wall perfusion is statistically significantly decreased at the AOH and gastric fundus compared with perfusion at other gastric points. Gastric perfusion at all the gastric points studied decreased with the increase in body mass index. Gastric leakage in obese patients following sleeve gastrectomy could be attributed to a decrease in the blood supply at AOH.


Asunto(s)
Gastrectomía , Mucosa Gástrica/irrigación sanguínea , Isquemia/etiología , Obesidad/cirugía , Complicaciones Posoperatorias/etiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Gastrectomía/métodos , Mucosa Gástrica/diagnóstico por imagen , Humanos , Isquemia/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico por imagen , Estudios Retrospectivos , Factores de Riesgo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Adulto Joven
14.
Diagn Cytopathol ; 41(12): 1107-14, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24254202

RESUMEN

Asymptomatic incidental thyroid nodules (thyroid incidentalomas) are found in up to a third of the adult population. There is notable overlap in the sonographic appearance of benign and malignant thyroid nodules. This paper provides a brief review of the ultrasound findings of thyroid nodules that are suspicious for malignancy with pathologic correlates. We then discuss the standard approach to a fine needle aspiration biopsy of a thyroid nodule at our institution. Finally, we review specific diagnostic challenges in image guided fine needle aspiration biopsies.


Asunto(s)
Calcinosis/diagnóstico por imagen , Calcinosis/patología , Carcinoma Papilar/patología , Biopsia Guiada por Imagen/métodos , Neoplasias de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/patología , Biopsia con Aguja Fina , Carcinoma Papilar/diagnóstico por imagen , Diagnóstico por Imagen de Elasticidad , Humanos , Nódulo Tiroideo/diagnóstico por imagen , Nódulo Tiroideo/patología
16.
J Radiol Case Rep ; 5(9): 16-22, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22470813

RESUMEN

We describe a 91-year-old woman with a clinical history of invasive ductal carcinoma of the breast diagnosed in 1991 who was admitted because of dizziness, poor appetite, and some swelling and tenderness over her cheeks. The patient's initial work up revealed a 5-cm well-demarcated hypodense solid lesion in her spleen with abnormally intense uptake on PET/CT scan raising suspicion for malignancy i.e. breast metastasis versus lymphoma. Further review demonstrated the presence of this splenic lesion, though slightly smaller, on a CT scan from ten years earlier (2000). An ultrasonographic guided core needle splenic biopsy was performed and the pathology result revealed histological findings compatible with inflammatory pseudotumor of the spleen. As a result, unnecessary splenectomy was avoided.


Asunto(s)
Granuloma de Células Plasmáticas/diagnóstico por imagen , Granuloma de Células Plasmáticas/patología , Bazo/diagnóstico por imagen , Bazo/patología , Enfermedades del Bazo/diagnóstico , Anciano de 80 o más Años , Biopsia con Aguja , Femenino , Humanos , Imagen Multimodal , Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X
17.
J Cancer Res Ther ; 7(4): 481-3, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22269414

RESUMEN

Computed Tomography (CT)-guided percutaneous cryoablation was performed in a 43-year-old patient with intractable epigastric abdominal pain caused by advanced adenocarcinoma of the pancreas and extensive celiac trunk involvement. Initial treatment with celiac plexus nerve neurolysis using local ethanol injection was unsuccessful. A 17-gauge 17-cm cryoablation probe (Galil Medical Inc. Plymouth Meeting, PA) was placed into the expected location of the celiac plexus through a left paraspinal approach under CT guidance and two cycles of freeze-thaw were performed. Patient's pain decreased from 10 of 10 (subjective pain scoring using a visual analog scale; VAS; 0-10) to 3. No post-procedure complication was observed. His pain has remained stable after 6 months of follow up. Percutaneous cryoablation appears to be an effective alternative to neurolytic celiac plexus block for palliative treatment of celiac plexus involvement. Further study with larger number of patients is needed to evaluate the safety and efficacy.


Asunto(s)
Plexo Celíaco/cirugía , Criocirugía/métodos , Dolor Intratable/cirugía , Neoplasias Pancreáticas/fisiopatología , Adulto , Humanos , Masculino , Tomografía Computarizada por Rayos X
18.
J Control Release ; 143(2): 183-90, 2010 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-20060859

RESUMEN

In situ forming drug delivery systems provide a means by which a controlled release depot can be physically inserted into a target site without the use of surgery. The release rate of drugs from these systems is often related to the rate of implant formation. Currently, only a limited number of techniques are available to monitor phase inversion, and none of these methods can be used to visualize the process directly and noninvasively. In this study, diagnostic ultrasound was used to visualize and quantify the process of implant formation in a phase inversion based system both in vitro and in vivo. Concurrently, sodium fluorescein was used as a mock drug to evaluate the drug release profiles and correlate drug release and implant formation processes. Implants comprised of three different molecular weight poly(lactic-co-glycolic acid) (PLGA) polymers dissolved in 1-methyl-2-pyrrolidinone (NMP) were studied in vitro and a 29 kDa PLGA solution was evaluated in vivo. The implants were encapsulated in a 1% agarose tissue phantom for five days, or injected into a rat subcutaneously and evaluated for 48 h. Quantitative measurements of the gray-scale value (corresponding to the rate of implant formation), swelling, and precipitation were evaluated using image analysis techniques, showing that polymer molecular weight has a considerable effect on the swelling and formation of the in situ drug delivery depots. A linear correlation was also seen between the in vivo release and depot formation (R(2)=0.93). This study demonstrates, for the first time, that ultrasound can be used to noninvasively and nondestructively monitor and evaluate the phase inversion process of in situ forming drug delivery implants, and that the formation process can be directly related to the initial phase of drug release dependent on this formation.


Asunto(s)
Implantes de Medicamentos/química , Fluoresceína/administración & dosificación , Ultrasonografía/métodos , Animales , Ácido Láctico/química , Masculino , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Pirrolidinonas/química , Ratas , Sefarosa/química
19.
J Radiol Case Rep ; 4(2): 5-8, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-22470705

RESUMEN

Vicarious renal excretion of iodinated contrast introduced into the bowel is a known phenomenon that has rarely been reported. In clinical settings like Crohn's disease in which evaluation for recto-vesical fistula is frequently requested, vicarious excretion can cause misapprehension and error in diagnosis. We present a case of Crohn's disease in which gastrografin enema was performed to evaluate for fistula and initial interpretation was mistakenly positive, however, simple methods of elucidation were utilized to prevent error in diagnosis.

20.
Mol Pharm ; 7(1): 49-59, 2010 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-19957968

RESUMEN

The advent of microbubble contrast agents has enhanced the capabilities of ultrasound as a medical imaging modality and stimulated innovative strategies for ultrasound-mediated drug and gene delivery. While the utilization of microbubbles as carrier vehicles has shown encouraging results in cancer therapy, their applicability has been limited by a large size which typically confines them to the vasculature. To enhance their multifunctional contrast and delivery capacity, it is critical to reduce bubble size to the nanometer range without reducing echogenicity. In this work, we present a novel strategy for formulation of nanosized, echogenic lipid bubbles by incorporating the surfactant Pluronic, a triblock copolymer of ethylene oxide copropylene oxide coethylene oxide into the formulation. Five Pluronics (L31, L61, L81, L64 and P85) with a range of molecular weights (M(w): 1100 to 4600 Da) were incorporated into the lipid shell either before or after lipid film hydration and before addition of perfluorocarbon gas. Results demonstrate that Pluronic-lipid interactions lead to a significantly reduced bubble size. Among the tested formulations, bubbles made with Pluronic L61 were the smallest with a mean hydrodynamic diameter of 207.9 +/- 74.7 nm compared to the 880.9 +/- 127.6 nm control bubbles. Pluronic L81 also significantly reduced bubble size to 406.8 +/- 21.0 nm. We conclude that Pluronic is effective in lipid bubble size control, and Pluronic M(w), hydrophilic-lipophilic balance (HLB), and Pluronic/lipid ratio are critical determinants of the bubble size. Most importantly, our results have shown that although the bubbles are nanosized, their stability and in vitro and in vivo echogenicity are not compromised. The resulting nanobubbles may be better suited for contrast enhanced tumor imaging and subsequent therapeutic delivery.


Asunto(s)
Medios de Contraste , Lípidos , Microburbujas , Poloxámero , Ultrasonografía/métodos , Animales , Neoplasias Colorrectales/diagnóstico por imagen , Medios de Contraste/química , Portadores de Fármacos , Estabilidad de Medicamentos , Femenino , Interacciones Hidrofóbicas e Hidrofílicas , Lípidos/química , Tamaño de la Partícula , Poloxámero/química , Ratas , Ensayos Antitumor por Modelo de Xenoinjerto
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