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1.
J Digit Imaging ; 35(4): 817-833, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35962150

RESUMEN

Despite technological advances in the analysis of digital images for medical consultations, many health information systems lack the ability to correlate textual descriptions of image findings linked to the actual images. Images and reports often reside in separate silos in the medical record throughout the process of image viewing, report authoring, and report consumption. Forward-thinking centers and early adopters have created interactive reports with multimedia elements and embedded hyperlinks in reports that connect the narrative text with the related source images and measurements. Most of these solutions rely on proprietary single-vendor systems for viewing and reporting in the absence of any encompassing industry standards to facilitate interoperability with the electronic health record (EHR) and other systems. International standards have enabled the digitization of image acquisition, storage, viewing, and structured reporting. These provide the foundation to discuss enhanced reporting. Lessons learned in the digital transformation of radiology and pathology can serve as a basis for interactive multimedia reporting (IMR) across image-centric medical specialties. This paper describes the standard-based infrastructure and communications to fulfill recently defined clinical requirements through a consensus from an international workgroup of multidisciplinary medical specialists, informaticists, and industry participants. These efforts have led toward the development of an Integrating the Healthcare Enterprise (IHE) profile that will serve as a foundation for interoperable interactive multimedia reporting.


Asunto(s)
Medicina , Sistemas de Información Radiológica , Comunicación , Diagnóstico por Imagen , Registros Electrónicos de Salud , Humanos , Multimedia
3.
Gastroenterology ; 147(3): 646-654.e2, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24906040

RESUMEN

BACKGROUND & AIMS: Administration of secretin improves noninvasive imaging of the pancreatic duct with magnetic resonance cholangiopancreatography (MRCP). We performed a large prospective study to investigate whether synthetic human secretin (RG1068)-stimulated MRCP detects pancreatic duct abnormalities with higher levels of sensitivity than MRCP. METHODS: We performed a phase 3, multicenter, baseline-controlled study of patients with acute or acute recurrent pancreatitis who were scheduled to undergo endoscopic retrograde cholangiopancreatography (ERCP) between March 26, 2008, and October 28, 2009. Patients underwent a baseline MRCP that was immediately followed by administration of RG1068 and repeat MRCP and then underwent ERCP within 30 days; they were followed up for 30 days. MRCP and ERCP images were read centrally by 3 radiologists and 2 endoscopists, respectively, who were all independent and blinded; pancreatic duct abnormalities were evaluated. The accuracy of MRCP was evaluated using ERCP as the standard. RESULTS: In total, 258 patients were enrolled in the study; 251 MRCP image sets were assessed, and 236 patients had evaluable ERCPs. Pancreatic duct abnormalities were observed in 60.2% of ERCP images. All radiologists identified duct abnormalities in RG1068-ciné MRCP image sets with significantly higher levels of sensitivity (P < .0001) than in images from MRCP, with minimal loss of specificity. Adverse events were reported in 38.0% of patients after MRCP and 68.1% after ERCP. Of the 55 patients who experienced a serious adverse event, 3 (1.2%) and 52 (20.5%) of the events were reported to be temporally associated with MRCP and ERCP, respectively. The adverse events most frequently considered related to RG1068 were nausea, abdominal pain, and flushing; most were mild. CONCLUSIONS: Compared with images from MRCP, those from RG1068-stimulated MRCP are improved in many aspects and could aid in diagnosis and clinical decision making for patients with acute, acute recurrent, or chronic pancreatitis. RG1068-enhanced MRCP might also better identify patients in need of therapeutic ERCP (ClinicalTrials.gov, Number: NCT00660335).


Asunto(s)
Pancreatocolangiografía por Resonancia Magnética , Conductos Pancreáticos/patología , Pancreatitis/diagnóstico , Secretina , Enfermedad Aguda , Adulto , Canadá , Colangiopancreatografia Retrógrada Endoscópica , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Pancreatitis/patología , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Recurrencia , Secretina/administración & dosificación , Estados Unidos
4.
J Comput Assist Tomogr ; 39(4): 479-82, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25783800

RESUMEN

OBJECTIVE: To determine the differences in enhancement of hepatocellular carcinoma during the first 5 minutes of postcontrast phases with gadoxetic acid (Gd-EOB-DTPA) vs gadobenate dimeglumine. METHODS: Ninety-five cirrhotic patients with hepatocellular carcinoma were examined on a 1.5-T scanner: 74 patients with Gd-BOPTA and 21 patients with Gd-EOB-DTPA. Same magnetic resonance imaging parameters were used for both groups. Gadoxetate isodium was administered at a dose of 0.025 mmol/kg; and Gd-BOPTA, at a dose of 0.1 mmol/kg. RESULTS: Mean contrast-to-noise ratios (CNR) were similar in arterial (P = 0.3), portal venous (P = 0.1), and 5-minute delayed phases (P = 0.73). The CNRs of lesions in the Gd-EOB-DTPA group were lower in arterial phase, although this did not reach statistical significance. The CNRs of Gd-EOB-DTPA during the equilibrium phase was higher (P = 0.006). CONCLUSIONS: Gadoxetate isodium resulted in lower CNR during the arterial phase and higher CNR during the portal venous, equilibrium, and 5-minute delayed phases compared with gadobenate dimeglumine using the Food and Drug Administration-approved doses; however, overall, there was no statistical significance (P = 0.077).


Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Medios de Contraste , Gadolinio DTPA , Aumento de la Imagen/métodos , Neoplasias Hepáticas/diagnóstico , Imagen por Resonancia Magnética , Meglumina/análogos & derivados , Compuestos Organometálicos , Femenino , Humanos , Hígado/patología , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
5.
Abdom Imaging ; 39(5): 1088-101, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24718661

RESUMEN

Pancreatic cysts are increasingly being identified by cross-sectional imaging studies. Pancreatic cystic lesions comprise a spectrum of underlying pathologies ranging from benign and pre-malignant lesions to frank malignancies. Magnetic resonance imaging with cholangiopancreatography is a non-invasive imaging modality used for the characterization of cystic pancreatic lesions. This article will review the most common pancreatic cystic neoplasms and the utility of MR imaging in the characterization of these cysts.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Quiste Pancreático/patología , Quiste Pancreático/cirugía , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/cirugía , Humanos , Páncreas/patología , Páncreas/cirugía
6.
AJR Am J Roentgenol ; 201(3): 573-7, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23971448

RESUMEN

OBJECTIVE: MRCP is increasingly used to evaluate pancreaticobiliary disease, yet its effect on patient care is unknown. The purpose of this study was to measure the effect of MRCP on referring physicians' initial diagnoses, the physicians' confidence in their diagnoses, and the influence of MRCP results on clinical management. SUBJECTS AND METHODS: We prospectively surveyed gastroenterologists who referred patients for nonurgent MRCP for pancreaticobiliary evaluation. Before MRCP, gastroenterologists reported the working diagnosis, confidence level (high, moderate, low), and next step in clinical management if MRCP was unavailable. MRCP was performed with standard protocols, including secretin enhancement. After reviewing MRCP findings and without referring to their previous assessment, gastroenterologists reported a revised diagnosis, confidence level, and next step in clinical management. They then compared pre- and post-MRCP management plans and rated the influence of MRCP on changing management from 1 (none) to 5 (major). Diagnostic confidence and frequency of common diagnoses and recommendation for an invasive next-step procedure (e.g., ERCP) or endoscopic ultrasound were compared between pre- and post-MRCP assessments. RESULTS: Survey data were analyzed on 171 patients (123 women, 48 men; mean age, 50 [SD, 17] years; range, 19-88 years) undergoing MRCP for unexplained abdominal pain (42.9%), suspected pancreaticobiliary neoplasm (20%), recent acute (17.1%) or suspected chronic (14.9%) pancreatitis, and other indications (5.1%). Recommendations of ERCP and endoscopic ultrasound decreased after MRCP (from 49.1% to 35.1%, p=0.03, and from 26.9% to 13.5%, p≤0.01). After MRCP, high confidence in diagnosis increased (from 72/171 to 100/171, p<0.01), as did recommendations for noninvasive therapy (from 18/171 to 56/171, p<0.01). A major or substantial change in clinical management was made in the care of 67 of 171 patients (39.2%). CONCLUSION: Use of MRCP significantly changes gastroenterologists' treatment of patients with suspected pancreaticobiliary disease by increasing diagnostic confidence and reducing the frequency of invasive follow-up procedures.


Asunto(s)
Enfermedades de las Vías Biliares/diagnóstico , Pancreatocolangiografía por Resonancia Magnética/estadística & datos numéricos , Enfermedades Pancreáticas/diagnóstico , Pautas de la Práctica en Medicina/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades de las Vías Biliares/terapia , Colangiopancreatografia Retrógrada Endoscópica , Medios de Contraste , Endosonografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Pancreáticas/terapia , Estudios Prospectivos , Derivación y Consulta
8.
AJR Am J Roentgenol ; 194(2): 438-45, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20093607

RESUMEN

OBJECTIVE: The objective of our study was to assess the value of diffusion-weighted imaging in differentiating among the various subgroups of renal masses. MATERIALS AND METHODS: This retrospective study measured the apparent diffusion coefficients (ADCs) of renal masses. Malignant lesions were confirmed with surgical pathology results. Benign cystic lesions were stable without treatment for a minimum follow-up of 24 months. RESULTS: There were 20 and 22 patients, respectively, with benign lesions (three abscess, 31 cysts) and malignant lesions (17 clear cell, five papillary, one chromophobe, and two transitional cell cancers). The malignant lesions were larger than the benign lesions (mean diameter, 4.2 vs 2.6 cm, respectively; p = 0.01, Student's t test). The ADC values of the benign lesions were significantly higher than those of the malignant lesions (mean, 2.72 vs 1.88 x 10(-3) mm(2)/s; p < 0.0001). The ADCs of the 31 benign cysts were significantly higher than those of the seven cystic renal cancers (2.77 vs 2.02 x 10(-3) mm(2)/s; p < 0.001). There was no significant difference between the ADCs of clear cell cancers and non-clear cell cancers (1.85 vs 1.97 x 10(-3) mm(2)/s; p = 0.18), but an ADC of less than 1.79 x 10(-3) mm(2)/s was seen only with clear cell cancer. The ADCs of high-grade clear cell cancers (Fuhrman grades III and IV) tended to be lower than those of low-grade clear cell cancers (1.77 vs 1.95 x 10(-3) mm(2)/s; p = 0.12). Among the clear cell cancers, an ADC value of greater than 2.12 x 10(-3) mm(2)/s was seen only with low-grade histology. For differentiating benign from malignant lesions, receiver operating characteristic (ROC) analysis showed an area under the ROC curve of 0.989 (95% CI, 0.919-0.996; p < 0.0001). CONCLUSION: ADC measurements may aid in differentiating among the various subgroups of renal masses, particularly benign cystic lesions from cystic renal cell cancers.


Asunto(s)
Carcinoma de Células Renales/diagnóstico , Imagen de Difusión por Resonancia Magnética/métodos , Neoplasias Renales/diagnóstico , Adulto , Anciano , Carcinoma de Células Renales/patología , Medios de Contraste , Diagnóstico Diferencial , Femenino , Humanos , Neoplasias Renales/patología , Masculino , Meglumina/análogos & derivados , Persona de Mediana Edad , Compuestos Organometálicos , Curva ROC , Estudios Retrospectivos , Estadísticas no Paramétricas
9.
Radiology ; 250(1): 103-9, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19001148

RESUMEN

PURPOSE: To retrospectively measure and compare changes in pancreatic apparent diffusion coefficient (ADC) following secretin administration in patients with and those without chronic pancreatitis (CP) who underwent magnetic resonance (MR) cholangiopancreatography with diffusion-weighted (DW) imaging. MATERIALS AND METHODS: This retrospective HIPAA-compliant study was approved by the authors' institutional review board, with waiver of informed consent. Eighty-nine patients were categorized by the referring gastroenterologist as having no CP (n = 37), mild CP (n = 33), or severe CP (n = 19) on the basis of Cambridge criteria and/or clinical course. Mean age was 52.2 years (range, 21-82 years) in women and 54.3 years (range, 32-81 years) in men. Patients underwent 1.5-T MR cholangiopancreatography, including DW sequences (b = 0, 100, and 400 sec/mm(2)) performed serially for 10 minutes after secretin injection. Severity level of CP was analyzed for sex (Fisher exact test) and age (analysis of variance) differences. Pairwise comparisons of mean ADCs for each parameter (no CP vs mild CP, no CP vs severe CP, mild CP vs severe CP) were performed (Mann-Whitney test). Threshold values of non-secretin-enhanced ADC for pancreatitis discrimination were calculated with receiver operating characteristic analysis. P < .05 was considered to show a significant difference. RESULTS: Patients with severe CP were more likely to be men than were those without pancreatitis; there were no significant age differences between groups. Mean nonenhanced and maximum secretin-enhanced ADCs were higher in patients without CP than in those with mild or severe CP but did not vary between those with mild and severe CP. Percentage increase in ADC after secretin injection and time to peak ADC did not vary among groups. An ADC of less than 179 x 10(-5) mm(2)/sec was optimal for delineating normal pancreas from CP groups. CONCLUSION: In symptomatic patients, baseline pancreatic ADC obtained with DW imaging prior to secretin administration may aid in diagnosis of CP and assessment of its severity; ADC response to secretin administration may be less useful.


Asunto(s)
Pancreatocolangiografía por Resonancia Magnética , Imagen de Difusión por Resonancia Magnética , Imagen Eco-Planar , Aumento de la Imagen , Pancreatitis Crónica/diagnóstico , Secretina , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Análisis de Fourier , Humanos , Masculino , Persona de Mediana Edad , Páncreas/patología , Conductos Pancreáticos/patología , Estudios Retrospectivos , Secretina/administración & dosificación , Sensibilidad y Especificidad , Factores Sexuales
10.
Radiology ; 252(2): 418-25, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19508986

RESUMEN

PURPOSE: To prospectively measure pancreatic apparent diffusion coefficient (ADC) before and after secretin administration in subjects with and without chronic pancreatitis (CP) who underwent magnetic resonance (MR) cholangiopancreatography with diffusion-weighted (DW) imaging at 3.0 T. MATERIALS AND METHODS: Institutional review board approval of this HIPAA-compliant study was obtained. Healthy volunteers, and patients with suspected and/or known CP who were scheduled for MR cholangiopancreatography, were recruited and gave written informed consent. All subjects underwent 3.0-T MR cholangiopancreatography, including serial DW imaging sequences (b = 0, 200, and 400 sec/mm(2)) acquired for 15 minutes after secretin administration. The referring gastroenterologist then classified subjects as healthy or with mild or severe CP, given endoscopic retrograde cholangiopancreatographic and/or clinical findings. CP severity was analyzed for sex and age. Mean presecretin and maximum postsecretin ADCs were compared between groups. Pairwise mean ADCs for healthy versus mild CP patient groups, healthy versus severe CP patient groups, and mild versus severe CP patient groups were compared. Presecretin ADC threshold levels for CP discrimination were calculated (P < .05). RESULTS: Thirty-two subjects were imaged; four CP patients were excluded owing to severe artifact, and the remaining 28 (15 healthy patients, five with mild CP, and eight with severe CP) comprised the study population. All CP patients had endoscopic retrograde cholangiopancreatographic confirmation of CP. Mild or severe CP patients were older than healthy patients; sex distribution did not vary among groups. Mean presecretin and maximum postsecretin ADCs were higher in healthy patients than in either mild or severe CP groups (P < .01), but did not vary between mild and severe CP groups (P = .25-0.28). An ADC of less than 220 x 10(-5) mm(2)/sec was optimal for delineating between healthy and CP patients. CONCLUSION: Pancreatic ADC obtained with DW imaging at 3.0 T prior to secretin administration may help diagnose CP; postsecretin ADC response does not distinguish CP severity.


Asunto(s)
Pancreatocolangiografía por Resonancia Magnética/métodos , Imagen de Difusión por Resonancia Magnética/métodos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Pancreatitis Crónica/diagnóstico , Secretina , Adulto , Medios de Contraste , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Secretina/administración & dosificación , Sensibilidad y Especificidad
11.
AJR Am J Roentgenol ; 193(6): 1556-60, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19933647

RESUMEN

OBJECTIVE: The objective of our study was to determine the usefulness of the apparent diffusion coefficient (ADC) of liver parenchyma for determining the severity of liver fibrosis. MATERIALS AND METHODS: This study investigated 78 patients who underwent diffusion-weighted imaging (DWI) with 1.5-T MRI and pathologic staging of liver fibrosis based on biopsy. DWI was performed with b values of 50 and 400 s/mm(2). ADCs of liver were measured using 2.0- to 3.0-cm(2) regions of interest in the right and left lobes of the liver; the mean ADC value was used for analysis. Pathologic METAVIR scores for liver fibrosis stage were used as a reference standard. RESULTS: The mean ADC values for fibrosis pathologically staged using the METAVIR classification system as F0 (n = 11), F1 (n = 16), F2 (n = 10), F3 (n = 14), and F4 (n = 27) were 125.9, 105.0, 104.5, 103.2, and 99.1 x 10(-5) s/mm(2), respectively. The correlation between the ADC values and the degree of liver fibrosis was moderate (Spearman's test, rho = -0.36). There was a significant difference in ADC values between patients with nonfibrotic liver (F0) and those with cirrhotic liver (F4) (p = 0.008). The best cutoff ADC value to distinguish between these groups was 118 x 10(-5) s/mm(2). However, ADC values were not useful for differentiating viral hepatitis patients with F2 fibrosis or higher from those with a lower degree of fibrosis (area under the receiver operating characteristic curve [AUC] = 0.66) or for differentiating low-stage fibrosis in all patients from high-stage fibrosis in all patients (AUC = 0.54). CONCLUSION: The ADCs in cirrhotic livers are significantly lower than those in nonfibrotic livers. However, ADC values measured using the current generation of scanners are not reliable enough to replace liver biopsy for staging hepatic fibrosis.


Asunto(s)
Cirrosis Hepática/patología , Adulto , Anciano , Biopsia , Imagen de Difusión por Resonancia Magnética/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Estudios Retrospectivos , Factores de Riesgo , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Estadísticas no Paramétricas
12.
AJR Am J Roentgenol ; 190(4): 993-1002, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18356447

RESUMEN

OBJECTIVE: The inflammatory subtype of nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, is becoming one of the most important causes of chronic liver disease. In this article, we discuss the epidemiology, pathogenesis, and clinical and radiologic diagnosis of the subtypes of nonalcoholic fatty liver disease. CONCLUSION: We discuss the current and evolving imaging tests in the evaluation of hepatic fatty content, inflammation, and fibrosis.


Asunto(s)
Diagnóstico por Imagen , Hígado Graso/diagnóstico , Diagnóstico Diferencial , Progresión de la Enfermedad , Humanos , Pruebas de Función Hepática , Factores de Riesgo
13.
Acad Radiol ; 15(5): 601-9, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18423317

RESUMEN

RATIONALE AND OBJECTIVES: To measure main pancreatic duct diameter (PDD) with magnetic resonance pancreatography (MRP) before and after secretin injection in patients with suspected sphincter of Oddi dysfunction (SOD) and to determine if the diameter change is predictive of sphincter of Oddi manometry (SOM) results. MATERIALS AND METHODS: We identified all patients during the study period referred for SOM for clinically suspected SOD; patients with an intact sphincter and without contraindication to MRP examination were considered for study entry. Consenting patients underwent MRP, including dynamic imaging of the pancreatic duct after intravenous administration of porcine secretin followed by SOM during endoscopic retrograde cholangiopancreatography. MRP was defined as abnormal when PDD remained increased by > or = 1.0 mm from baseline 15 minutes after secretin injection. SOM was abnormal when basal sphincter pressure (SP) was > or = 40 mm Hg. Mean PDD before and after secretin administration was compared within normal and abnormal SP groups with two-tailed unpaired t-test; the mean difference between baseline and peak PDD and duration of > or = 0.5 mm increase in PDD was compared between groups with two-tailed t-test. P < .05 was considered significant. RESULTS: Of 70 patients referred for SOM, 30 met all entry criteria, gave consent to participate, and underwent both MRP and SOM. Ten of 30 patients (33%) had normal SP; 20 (67%) were abnormal. PDD increased significantly after secretin injection (normal SP, 1.62 +/- 0.73 to 2.78 +/- 0.77 mm, P < .01; abnormal SP, 1.45 +/- 0.26 to 2.32 +/- 0.75 mm, P < .01). There was no difference between normal and abnormal SP groups in amount of PDD increase (1.15 +/- 0.75 vs. 0.88 +/- 0.72 mm; P = .33) or duration of > or = 0.5 mm increase in PDD (5.28 +/- 8.76 vs. 13.60 +/- 13.00 minutes; P = 0.07). CONCLUSIONS: In patients with suspected sphincter of Oddi dysfunction, magnetic resonance pancreatography demonstrated PDD increase following secretin injection but did not predict the results of manometry.


Asunto(s)
Pancreatocolangiografía por Resonancia Magnética , Fármacos Gastrointestinales , Secretina , Disfunción del Esfínter de la Ampolla Hepatopancreática/diagnóstico , Análisis de Varianza , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Masculino , Manometría , Persona de Mediana Edad , Estadísticas no Paramétricas
14.
AJR Am J Roentgenol ; 189(5): 1044-50, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17954638

RESUMEN

OBJECTIVE: The objective of this article is to discuss the CT findings that guide surgeons in deciding the feasibility of tumor excision in patients with locally advanced pancreatic head cancers. CONCLUSION: Vascular resection as an adjunct to pancreaticoduodenectomy is increasingly used in pancreatic head cancer. As a result, the imaging criteria to determine which patients are candidates for potentially curative resection are evolving.


Asunto(s)
Estadificación de Neoplasias/métodos , Pancreatectomía/métodos , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/terapia , Tomografía Computarizada por Rayos X/métodos , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en Medicina , Pronóstico
15.
Radiographics ; 27(5): 1433-44; discussion 1462-4, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17848701

RESUMEN

Magnetic resonance (MR) imaging at 3.0 T offers an improved signal-to-noise ratio compared with that at 1.5 T. However, the physics of high field strength also brings disadvantages, such as increases in the specific absorption rate, in magnetic field inhomogeneity effects, and in susceptibility artifacts. The use of 3.0-T MR imaging for abdominal evaluations, in particular, has lagged behind that for other applications because of the difficulty of imaging a large volume while compensating for respiratory motion. At a minimum, abdominal MR imaging at 3.0 T requires modifications in the pulse sequences used at 1.5 T. Such modifications may include a decrease in the flip angle used for refocusing pulses and an increase in the repetition time for T1-weighted acquisitions. In addition, parallel imaging and other techniques (hyper-echo sequences, transition between pseudo steady states) may be used to maintain a high signal-to-noise ratio while decreasing acquisition time and minimizing the occurrence of artifacts on abdominal MR images.


Asunto(s)
Abdomen Agudo/diagnóstico , Abdomen/patología , Neoplasias Abdominales/diagnóstico , Imagen por Resonancia Magnética/métodos , Imagen de Cuerpo Entero/métodos , Humanos , Imagen por Resonancia Magnética/efectos adversos , Imagen de Cuerpo Entero/efectos adversos
17.
Radiographics ; 26(3): 665-77, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16702446

RESUMEN

Secretin causes temporary dilatation of pancreatic ducts, principally by increasing pancreatic exocrine secretions, and thus allows better visualization of the ducts at magnetic resonance (MR) cholangiopancreatography. Secretin-enhanced MR cholangiopancreatography is useful for detection and diagnosis of a variety of congenital, inflammatory, and neoplastic conditions of the pancreas. Although MR cholangiopancreatography without secretin is a reliable method for evaluating the pancreatobiliary ductal system, the authors believe that secretin-enhanced MR cholangiopancreatography gives additional valuable functional and anatomic information about the pancreatic duct and pancreatic excretory capacity.


Asunto(s)
Colangiografía/métodos , Aumento de la Imagen/métodos , Imagen por Resonancia Magnética/métodos , Páncreas/efectos de los fármacos , Páncreas/patología , Enfermedades Pancreáticas/diagnóstico , Secretina , Humanos , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en Medicina
19.
Ann Intern Med ; 141(10): 753-63, 2004 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-15545675

RESUMEN

BACKGROUND: Accurate preoperative detection and staging of pancreatic cancer may identify patients with locoregional disease that is amenable to surgical resection. OBJECTIVE: To compare endoscopic ultrasonography and multidetector computed tomography (CT) for the detection, staging, and resectability of known or suspected locoregional pancreatic cancer. DESIGN: Prospective, observational, cohort study. SETTING: Single, tertiary referral hospital in Indianapolis, Indiana. PATIENTS: 120 participants with known or suspected locoregional pancreatic cancer. INTERVENTIONS: Endoscopic ultrasonography followed by multidetector CT was performed in all patients. Patients with known or suspected pancreatic cancer deemed potentially resectable by 1 or both tests were considered for surgery. MEASUREMENTS: Detection, staging, and resectability of pancreatic cancer. Surgically resected pancreatic cancer with negative microscopic histologic margins was considered resectable. RESULTS: Of 120 patients enrolled, 104 (87%) underwent endoscopic ultrasonography and CT. Of the 80 patients with pancreatic cancer, 27 (34%) were managed nonoperatively, and 53 (66%) treated surgically had resectable (n = 25) or unresectable (n = 28) cancer. For the 80 patients with cancer, the sensitivity of endoscopic ultrasonography (98% [95% CI, 91% to 100%]) for detecting a pancreatic mass was greater than that of CT (86% [CI, 77% to 93%]; P = 0.012). For the 53 surgical patients, endoscopic ultrasonography was superior to CT for tumor staging accuracy (67% vs. 41%; P < 0.001) but equivalent for nodal staging accuracy (44% vs. 47%; P > 0.2). Of the 25 resectable pancreatic tumors in patients recommended for surgery, endoscopic ultrasonography and CT correctly identified 88% and 92%, respectively, as resectable. Of the 28 unresectable pancreatic tumors in patients recommended for surgery, endoscopic ultrasonography and CT correctly identified 68% and 64%, respectively, as unresectable. LIMITATIONS: Radiologists who read the scans and endosonographers were not blinded to previous radiographic information. Because of the modest sample size, CIs of the sensitivity estimates were sometimes wide. CONCLUSION: Compared with multidetector CT, endoscopic ultrasonography is superior for tumor detection and staging but similar for nodal staging and resectability of preoperatively suspected nonmetastatic pancreatic cancer.


Asunto(s)
Endosonografía , Estadificación de Neoplasias/métodos , Neoplasias Pancreáticas/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Neuroendocrino/diagnóstico por imagen , Carcinoma Neuroendocrino/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/cirugía , Estudios Prospectivos , Sensibilidad y Especificidad
20.
Acad Radiol ; 16(10): 1208-14, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19608435

RESUMEN

RATIONALE AND OBJECTIVES: To determine if focal liver masses could be differentiated as benign or malignant on the basis of diffusion-weighted imaging (DWI). METHODS AND MATERIALS: A total of 104 patients with focal liver masses were scanned using 1.5 T magnetic resonance imaging (MRI). DWI was performed with b values of 0, 50, and 400 s/mm(2). Of these, 76 patients had lesions larger than 2 cm diameter, radiologic or pathologic characterization of the lesion, and diagnostic quality DWI. The apparent diffusion coefficient (ADC) of the largest liver lesion was measured. The liver masses were diagnosed on histology or had characteristic computed tomography/MRI findings and follow up of more than 6 months. The analyzed lesions were hemangioma (n = 17), cysts (n = 5), hepatocellular cancer (HCC) (n = 41), adenoma (n = 3), focal nodular hyperplasia (FNH) (n = 6), and metastases (n = 4). RESULTS: The mean (standard deviation) ADC values (10(-5) mm(2)/second) of hemangiomas, cysts, FNH, and HCC were 156.8 (54.1), 190.2 (43.0), 130.1 (81.9), and 107.6 (32.7). The ADC of cysts and hemangiomas were significantly higher than that of other lesions (P = .0003, t-test). There was no significant difference between ADC values of solid, benign liver lesions (FNH, adenoma) and malignant lesions (HCC, metastases) (P = .62). CONCLUSION: Solid liver lesions have a lower ADC than cysts and hemangiomas. However, there is no significant difference in ADC between solid benign and malignant lesions. DWI appears to have only minimal additional value over currently used MRI sequences in characterizing liver masses.


Asunto(s)
Imagen de Difusión por Resonancia Magnética/métodos , Neoplasias Hepáticas/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
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