RESUMEN
PURPOSE: This study aims to compare assessment of cystic duct patency between gadoxetate disodium MRI and hepatobiliary scintigraphy. MATERIALS AND METHODS: We performed a prospective study of patients who underwent gadoxetate disodium MRI within 16 h of scintigraphy. RESULTS: The gallbladder filled on MRI and scintigraphy in 8 patients, none with acute cholecystitis. The mean time to gallbladder filling was 14.6 and 18.9 min for MRI and scintigraphy, respectively. The gallbladder did not fill on both MRI and scintigraphy in 3 patients, all of whom had acute cholecystitis. CONCLUSION: Evaluation of cystic duct patency using gadoxetate disodium MRI is comparable to hepatobiliary scintigraphy.
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Colecistitis Aguda/diagnóstico por imagen , Conducto Cístico/diagnóstico por imagen , Adulto , Pancreatocolangiografía por Resonancia Magnética , Colecistitis Aguda/diagnóstico , Medios de Contraste , Conducto Cístico/patología , Femenino , Gadolinio DTPA , Humanos , Masculino , Valor Predictivo de las Pruebas , Estudios Prospectivos , CintigrafíaRESUMEN
PURPOSE: Thrombotic and embolic vascular occlusion represents a leading cause of morbidity and mortality. Currently available thrombectomy devices have limitations, including difficulty removing organized thrombus and clot fragmentation with distal embolization. A novel mechanical thrombectomy device (MTD), designed to remove both hard and soft thrombus without trauma to the blood vessel, was tested in preclinical porcine models evaluating efficacy, safety, and ease of use. MATERIALS AND METHODS: A total of 26 vessels in 14 pigs underwent mechanical thrombectomy with MTD. Thrombectomy was performed in nine superficial femoral arteries, eight subclavian arteries, five primary branches of the subclavian artery, lateral thoracic artery or the thyrocervical trunk, and four external carotids. Subacute organized fibrin-laden thrombus was injected into the arteries producing vascular occlusion. The MTD was then used for thrombectomy to restore patency and blood flow. RESULTS: Intact thrombus was retrieved from 24 of 26 of the vessels with a single pass of the MTD, resulting in complete restoration of patency in 21 vessels and partial patency in 4 vessels. In 8 cases that used an early design, the embolic material fragmented during withdrawal from the access sheath. In 4 procedures that used an early design, the MTD failed to deploy fully and the embolus was not completely captured. No intraprocedural complications or vascular damage occurred. CONCLUSIONS: The present pilot studies demonstrate basic safety and efficacy of a novel MTD with design attributes suitable for retrieval of intact acute and organized chronic thrombus. The device has potential intracranial and peripheral utility.
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Trombectomía/instrumentación , Trombosis/terapia , Animales , Arteria Carótida Externa/diagnóstico por imagen , Modelos Animales de Enfermedad , Diseño de Equipo , Falla de Equipo , Análisis de Falla de Equipo , Arteria Femoral/diagnóstico por imagen , Proyectos Piloto , Radiografía , Arteria Subclavia/diagnóstico por imagen , Porcinos , Arterias Torácicas/diagnóstico por imagen , Trombectomía/métodos , Resultado del Tratamiento , Grado de Desobstrucción VascularRESUMEN
PURPOSE: To compare an algorithm of gradually ramped-up power to a full-power-level technique to determine which technical parameters maximized tissue coagulation by using a saline-perfused electrode. MATERIALS AND METHODS: Institutional review board approval was not necessary and animal committee approval was unnecessary because an ex vivo bovine liver model was used and the animals were not specifically killed for this study. This four-part experiment utilized multiple ablations of ex vivo bovine liver with a standard radiofrequency (RF) generator and an internally cooled needle. First, 10 RF ablations were performed at 20-60 W for 12 minutes. Second, ablation volumes obtained from an algorithm of eight ablations performed at 50 W were compared with those obtained from an algorithm of eight ablations that were gradually ramped-up to 50 W, until full impedance. Third, volumes obtained from 10 ablations performed at impedance control power levels were compared with those obtained from 10 ablations performed with a gradual ramp-up of power that started at 50 W, terminating at full impedance. Last, the third part was repeated, but with 11 ablations continuing past full impedance for 12 minutes each. RESULTS: In the first part, maximum measurements of tissue coagulation seemed to plateau from 40 to 60 W. The second part produced significantly larger measurements of tissue coagulation than did the use of a constant power level of 50 W. The third and final parts produced larger measurements of tissue coagulation than did utilizing full power for 12 minutes. Larger measurements and volumes were obtained from repeat ablations after the generator reached impedance level than were obtained from ablations stopped at maximum impedance. CONCLUSION: A gradual ramp-up of power and repeating ablations after power impedance level is reached are the two methods that increased tissue ablation in this ex vivo experiment.
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Ablación por Catéter/instrumentación , Electrodos , Hepatectomía/instrumentación , Hepatectomía/métodos , Hígado/fisiología , Hígado/cirugía , Cirugía Asistida por Computador/métodos , Animales , Temperatura Corporal , Ablación por Catéter/métodos , Bovinos , Frío , Técnicas In VitroRESUMEN
OBJECTIVE: The purpose of this study was to compare the detection rate of injury and characterize imaging findings of contrast-enhanced sonography and non-contrast-enhanced sonography in the setting of confirmed solid organ injury. SUBJECTS AND METHODS: This prospective study involved identifying hepatic, splenic, and renal injuries on contrast-enhanced CT. After injury identification, both non-contrast-enhanced sonography and contrast-enhanced sonography were performed to identify the possible injury and to analyze the appearance of the injury. The sonographic appearance of hepatic, splenic, and renal injuries was then analyzed, and the conspicuity of the injuries was graded on a scale from 0 (nonvisualization) to 3 (high visualization). RESULTS: Non-contrast-enhanced sonography revealed 11 (50%) of 22 injuries, whereas contrast-enhanced sonography depicted 20 (91%) of 22 injuries. The average grade for conspicuity of injuries was increased from 0.67 to 2.33 for spleen injuries and from 1.0 to 2.2 for liver injuries comparing non-contrast-enhanced with contrast-enhanced sonography, respectively, on a scale from 0, being nonvisualization, to 3, being high visualization. The splenic injuries appeared hypoechoic with occasional areas of normal enhancing splenic tissue within the laceration with contrast-enhanced sonography. Different patterns were observed in liver injuries including a central hypoechoic region. In some liver injuries there was a surrounding hyperechoic region. CONCLUSION: Contrast-enhanced sonography greatly enhances visualization of liver and spleen injuries compared with non-contrast-enhanced sonography. Solid organ injuries usually appeared hypoechoic on contrast-enhanced sonography, but often a hyperechoic region surrounding the injury also was identified with liver injuries.
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Traumatismos Abdominales/diagnóstico por imagen , Heridas no Penetrantes/diagnóstico por imagen , Traumatismos Abdominales/patología , Adulto , Medios de Contraste/administración & dosificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X , Ultrasonografía , Heridas no Penetrantes/patologíaRESUMEN
PURPOSE: The goal of this study was to evaluate the sonographic changes in the epididymis and testis after vasectomy using state-of-the-art high-resolution equipment. METHODS: We performed a retrospective study of 30 patients with a history of vasectomy and 30 patients without who were referred for scrotal sonography for various indications over a 1-year period. After excluding findings related to acute pathology, sonographic findings for the epididymis and testis in the 2 groups were tabulated and compared. RESULTS: The following findings had a statistically higher incidence in the vasectomy group than in the controls: thickened epididymides (53% versus 17%, p < 0.05); epididymal tubular ectasia (43% versus 7%, p < 0.001); and both of the previous 2 findings simultaneously (37% versus 7%, p < 0.01). Sperm granulomas were found in 3 patients in the vasectomy group, and none was seen in the control group. Other findings (eg, epididymal cysts) showed no statistical difference in incidence. CONCLUSIONS: We found a significantly higher incidence of thickened epididymides, epididymal tubular ectasia, a combination of both these findings, and sperm granuloma in the vasectomy group than in the controls. These findings are most likely attributable to postvasectomy obstructive changes and increased intraluminal pressure in the efferent ducts, epididymis, and vas deferens.
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Escroto/diagnóstico por imagen , Enfermedades Testiculares/diagnóstico por imagen , Vasectomía , Adulto , Anciano , Distribución de Chi-Cuadrado , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Escroto/patología , Enfermedades Testiculares/patología , UltrasonografíaRESUMEN
RATIONALE AND OBJECTIVES: This study was conducted to define and characterize magnetic resonance (MR) contrast medium enhancement of the renal cortex, medulla, and pelvocaliceal system in normal and hydronephrotic kidneys with and without furosemide administration. MATERIALS AND METHODS: In 30 subjects known or suspected to have unilateral hydronephrosis and normal serum creatinine levels, multiple timed sets of coronal fast spoiled gradient-echo images were acquired before and after contrast medium administration. MR renograms were derived from changes in the signal intensity (SI) of the cortex, medulla, and pelvocaliceal system. Ten subjects received 40 mg of intravenous furosemide approximately 10 minutes before contrast medium administration. RESULTS: The following values were significantly different between subjects who were given furosemide and those who were not: the peak cortical, medullary, and pelvocaliceal system SIs measured in the normal kidneys during the 4 1/2 minutes following contrast medium administration (163.2 +/- 17.7 [mean arbitrary units plus or minus standard error] vs 120.5 +/- 10.2 [P = .033], 155.5 +/- 18.8 vs 111.5 +/- 9.4 [P = .025], and 332.5 +/- 27.2 vs 229.3 +/- 31.9 [P = .026], respectively); the crossover time between the SI curves of the pelvocaliceal system and the medulla in the normal kidney (2.45 minutes +/- 0.2 vs 3.27 minutes +/- 0.25 [P = .02]); and the peak SIs of the cortex, medulla, and pelvocaliceal system in the unilateral obstructive hydronephrotic kidneys throughout the first 4 1/2 minutes after contrast medium administration (174.6 +/- 16.4 vs 90.6 +/- 13.7 [P = .003], 117.6 +/- 14.1 vs 86.7 +/- 11.8 [P = .015], and 337.2 +/- 41.4 vs 143.1 +/- 74.4 [P = .034], respectively). CONCLUSION: MR renography can be used to depict three separate components of renal enhancement: cortical, medullary, and pelvocaliceal. Furosemide-induced diuresis increases renal parenchymal and pelvocaliceal SI and urinary flow rates.
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Diuréticos , Furosemida , Hidronefrosis/patología , Riñón/patología , Imagen por Resonancia Magnética , Adulto , Estudios de Casos y Controles , Medios de Contraste , Estudios de Factibilidad , Femenino , Gadolinio , Gadolinio DTPA , Humanos , Inyecciones Intravenosas , Imagen por Resonancia Magnética/métodos , Masculino , Compuestos OrganometálicosRESUMEN
RATIONALE AND OBJECTIVES: The authors performed this study to assess the effects of furosemide-induced diuresis on paramagnetic contrast material enhancement at magnetic resonance (MR) imaging of the kidney, liver, spleen, and psoas muscle. MATERIALS AND METHODS: Twenty-five patients (average age, 44.9 years; age range, 23-74 years; 13 men, 12 women) who were suspected of having unilateral renal hydronephrosis received 0.1 mmol/kg contrast material with a standardized injection and imaging protocol to assess organ signal intensity at 0-5 minutes after injection. All patients had a normal serum creatinine level. Imaging was performed with a 1.5-T magnet by using a fat-suppressed fast spoiled gradient-echo pulse sequence and a 70 degrees flip angle. Eight patients received 40 mg of furosemide 10 minutes before contrast material injection. RESULTS: The areas of the renal cortical and medullary signal intensity curves minus baseline in the unilateral normal kidneys were significantly greater in the group who received furosemide (P = .026 and P = .037, respectively). The areas of the renal cortical and medullary signal intensity minus baseline in the unilateral hydronephrotic kidneys were also significantly greater in the group that received furosemide (P = .036 and P = .026, respectively). There was a statistically significant increase in splenic enhancement (P = .02) and a tendency for increased liver (P = .09) and psoas muscle (P = .08) enhancement. CONCLUSION: Furosemide-induced diuresis appears to potentiate the cortical and medullary MR renogram, as well as the MR splenogram. A rapid shift in water compartmentalization from the intracellular to the extracellular space and increased renal water content with diuresis are possible explanations.
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Abdomen/patología , Medios de Contraste , Diuresis , Gadolinio DTPA , Aumento de la Imagen/métodos , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Diuresis/efectos de los fármacos , Diuréticos/farmacología , Femenino , Furosemida/farmacología , Humanos , Hidronefrosis/diagnóstico , Hidronefrosis/fisiopatología , Riñón/patología , Hígado/patología , Masculino , Persona de Mediana Edad , Músculos Psoas/patología , Bazo/patologíaRESUMEN
RATIONALE AND OBJECTIVES: This study was conducted to compare the magnetic resonance (MR) contrast medium enhancement of abdominal organs in vivo with the signal intensity (SI) values of known in vitro gadolinium solutions. MATERIALS AND METHODS: A phantom was imaged with the MR contrast medium gadodiamide (Omniscan; Nycomed, Princeton, NJ) of solutions at full-strength (0.5 mmol/mL), one-third, 1/10, and 1/100 concentrations. A fat-suppressed fast spoiled gradient-echo pulse sequence with flip angles ranging from 10 degrees to 170 degrees (at 20 degrees increments) was performed with a 1.5-T magnet. In 12 subjects, the SIs of abdominal organs were determined with identical imaging parameters, before and after administration of gadodiamide injection at 0.1 mmol/kg. RESULTS: As anticipated, the plot of SI in relation to gadodiamide concentration is nonlinear, with a decrease in SI due to T2 effects at concentrations above 0.05 mmol/mL. The kidney showed the highest SI after gadodiamide enhancement (125.2 +/- 11.6 [standard error] at 2.5 minutes), followed by the liver (76.5 +/- 11.5 at 1 minute) and spleen (57.26 +/- 9.35 at 30 seconds). The SI of the renal medulla (114.2 +/- 9.8 at 4.5 minutes) was approximately one-third that in phantom observations. CONCLUSION: The authors observed a marked discrepancy between empirical contrast medium performance in abdominal organs and SI values for comparable gadodiamide concentrations in vitro. One possible reason is the intracellular compartmentalization of water molecules in vivo. These results suggest a need for a better understanding of MR contrast medium performance in vivo.