RESUMEN
To assess the effect of adenosine infusion by evaluating the relationship between heart rate (HR) response to adenosine and myocardial flow reserve (MFR) of remote regions supplied by normal coronary arteries in (13)N-ammonia PET. Thirty-one consecutive subjects (20 known coronary artery disease patients, 4 chronic heart failure patients, and 7 normal volunteers) except cases having 3-vessel disease underwent rest and adenosine stress (13)N-ammonia myocardial perfusion PET. Semi-quantitative, quantitative, and gated analyses were performed. Subjects were divided into two groups with regard to HR response to adenosine. Twenty-two subjects had normal HR response (peak/rest HR > 1.20), while reduced HR response (≤ 1.20) was observed in nine subjects. There were no differences in rest myocardial blood flow (MBF) of remote regions between the groups. Subjects with reduced HR response had significantly lower stress MBF and MFR of remote regions than those with normal HR response (stress MBF: 1.559 ± 0.517 vs. 2.279 ± 0.530, p = 0.004, MFR: 1.59 ± 0.36 vs. 2.35 ± 0.53, p = 0.001). There were no significant differences between the groups by means of semi-quantitative scoring. Rest and stress ejection fraction (EF) in the reduced HR response group was lower than that in the normal HR response group. In a multiple stepwise regression analysis, HR ratio, dyslipidemia, and Brinkman index were identified as predictors of the change in MFR of remote regions. Subjects with reduced HR response to adenosine had lower stress MBF and MFR of remote regions and lower EF. Moreover, HR response was one of the predictors of the change in MFR of remote regions.
Asunto(s)
Adenosina/administración & dosificación , Amoníaco , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Reserva del Flujo Fraccional Miocárdico/efectos de los fármacos , Insuficiencia Cardíaca/diagnóstico por imagen , Frecuencia Cardíaca/efectos de los fármacos , Imagen de Perfusión Miocárdica/métodos , Radioisótopos de Nitrógeno , Tomografía de Emisión de Positrones , Radiofármacos , Anciano , Estudios de Casos y Controles , Enfermedad Crónica , Enfermedad de la Arteria Coronaria/fisiopatología , Femenino , Insuficiencia Cardíaca/fisiopatología , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
BACKGROUND: The impact of time-of-flight (TOF) in myocardial perfusion (13)N-ammonia positron emission tomography (PET) is unclear. METHODS AND RESULTS: Twenty consecutive subjects underwent rest and adenosine stress (13)N-ammonia myocardial perfusion PET. Two sets of images were reconstructed using TOF-ordered subset expectation maximization (TOF-OSEM) and 3-dimensional row-action maximum likelihood algorithm (3D-RAMLA). Qualitative and quantitative analyses from the TOF-OSEM and 3D-RAMLA reconstructions were compared. Count profile curves revealed that TOF relatively increased the uptake of (13)N-ammonia at the lateral walls, and apical thinning was emphasized on the TOF images. Both segmental rest and stress myocardial blood flow (MBF) values were higher with TOF-OSEM use than with 3D-RAMLA use (rest MBF: 0.955 ± 0.201 vs 0.836 ± 0.185, P < .001; stress MBF: 2.149 ± 0.697 vs 2.058 ± 0.721, P < .001). The differentiation of MBF between reconstructions was more enhanced under rest conditions. Thus, segmental myocardial flow reserve (MFR) observed using TOF-OSEM reconstruction was lower than that observed using 3D-RAMLA (2.25 ± 0.57 vs 2.46 ± 0.75, P < .001). No remarkable differences were observed between segmental and territorial results. CONCLUSIONS: TOF increased lateral wall counts and emphasized apical thinning. Quantitatively, TOF reconstruction showed increased MBF, especially under relatively low perfusion conditions.
Asunto(s)
Amoníaco/química , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Imagen de Perfusión Miocárdica , Radioisótopos de Nitrógeno/química , Tomografía de Emisión de Positrones , Radiofármacos/química , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Circulación Coronaria , Femenino , Reserva del Flujo Fraccional Miocárdico , Humanos , Procesamiento de Imagen Asistido por Computador , Imagenología Tridimensional , Funciones de Verosimilitud , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Análisis de RegresiónRESUMEN
PURPOSE: The purpose of this study was to assess the effect of anemia on the incidence of contrast-induced nephropathy (CIN) in patients with renal impairment undergoing MDCT. MATERIALS AND METHODS: Institutional review board approval was waived for this retrospective review of 843 patients with stable renal insufficiency (eGFR between 15 and 60 mL/min) who had undergone contrast-enhanced MDCT. Baseline hematocrit and hemoglobin values were measured. Serum creatinine (SCr) was assessed at the baseline and at 48-72 h after contrast administration. RESULTS: The overall incidence of CIN in the patient population with renal insufficiency was 6.9%. CIN developed in 7.8% (54 of 695) of anemic patients, and in 2.8% (4 of 148) of non-anemic patients (P=.027). After adjustment for confounders, low hemoglobin and low hematocrit values remained independent predictors of CIN (odds ratio 4.6, 95% CI 1.0-20.5, P=.046). CONCLUSIONS: Anemia is associated with a higher incidence of CIN in patients with renal insufficiency. Anemia is a potentially modifiable risk factor for CIN, and has an unfavorable impact on prognosis in patients with renal insufficiency undergoing contrast-enhanced MDCT.
Asunto(s)
Lesión Renal Aguda/epidemiología , Anemia/epidemiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Yohexol , Insuficiencia Renal/diagnóstico por imagen , Insuficiencia Renal/epidemiología , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Lesión Renal Aguda/diagnóstico por imagen , Anciano , Anemia/diagnóstico , Causalidad , Comorbilidad , Medios de Contraste , Femenino , Humanos , Incidencia , Japón/epidemiología , Enfermedades Renales , Masculino , Estudios Retrospectivos , Factores de RiesgoRESUMEN
A study was conducted to evaluate the sensitivity of computer-aided detection (CAD) with full-field digital mammography in detection of breast cancer, based on mammographic appearance and histopathology. Retrospectively, CAD sensitivity was assessed in total group of 152 cases for subgroups based on breast density, mammographic presentation, lesion size, and results of histopathological examination. The overall sensitivity of CAD was 91 % (139 of 152 cases). CAD detected 100 % (47/47) of cancers manifested as microcalcifications; 98 % (62/63) of those manifested as non-calcified masses; 100 % (15/15) of those manifested as mixed masses and microcalcifications; 75 % (12/16) of those manifested as architectural distortions, and 69 % (18/26) of those manifested as focal asymmetry. CAD sensitivity was 83 % (10/12) for cancers measuring 1-10 mm, 92 % (37/40) for those measuring 11-20 mm, and 92 % (92/100) for those measuring >20 mm. There was no significant difference in CAD detection efficiency between cancers in dense breasts (88 %; 69/78) and those in non-dense breasts (95 %; 70/74). CAD showed a high sensitivity of 91 % (139/152) for the mammographic appearance of cancer and 100 % sensitivity for identifying cancers manifested as microcalcifications. Sensitivity was not influenced by breast density or lesion size. CAD should be effective for helping radiologists detect breast cancer at an earlier stage.
Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Mamografía/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Adulto , Anciano , Anciano de 80 o más Años , Calcinosis/diagnóstico por imagen , Femenino , Humanos , Persona de Mediana Edad , Intensificación de Imagen Radiográfica/métodos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: An advantage of PET/CT has been demonstrated for diagnosis of several tumor entities. In patients with breast cancer, early diagnosis and accurate restaging of recurrence after surgery is important for selection of the most appropriate therapeutic strategy. Purpose To evaluate the accuracy of integrated positron emission tomography and computed tomography (PET/CT) using 18F-fluorodeoxyglucose (FDG), for follow-up of patients with suspected recurrent breast cancer. MATERIAL AND METHODS: Forty-seven patients with suspected recurrent breast cancer underwent PET/CT. The PET and PET/CT images were interpreted without knowledge of the results of other diagnostic modalities, and compared with each other with reference to the final diagnosis. RESULTS: Twenty-five (53%) patients suffered tumor recurrence. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT were 96%, 91%, 92%, 95%, and 94%, respectively. In comparison with PET, PET/CT had a higher sensitivity and accuracy (96% vs. 80% and 94% vs. 81%, respectively). The difference in diagnostic accuracy between PET/CT and PET was significant (P < 0.05). CONCLUSION: The present findings indicate that PET/CT is an accurate, sensitive and reliable modality for screening and detection of breast cancer recurrence. PET/CT appears to be an effective surveillance tool, as it is able to cover the whole body in a single procedure and shows good performance.
Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Imagen Multimodal/métodos , Recurrencia Local de Neoplasia/diagnóstico por imagen , Neoplasias Primarias Secundarias/diagnóstico por imagen , Tomografía de Emisión de Positrones , Radiofármacos , Tomografía Computarizada por Rayos X , Adulto , Anciano , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: Images using the fast row action maximum likelihood algorithm (fast-RAMLA), which employs half-interpolated sinograms of conventional 3DRAMLA, are immediately generated following positron emission tomography (PET) scanning and are invariably produced in the process of line-of-response RAMLA (LOR-RAMLA) reconstruction. We quantitatively and visually compared the clinical validity of dual time point [(18)F]-FDG imaging with fast-RAMLA and LOR-RAMLA. METHODS: An International Electrotechnical Commission (IEC) phantom was established in which the ratio of the activities in the hot sphere was set up and a background of 3.8:1 was scanned and reconstructed using both algorithms. The contrast recovery coefficient was then calculated. The clinical study retrospectively analyzed 35 patients (25 men and 10 women; age range 30-84 years; mean age 63.9 years) with confirmed specific pathological lesions or clinical follow-up; 21 of the patients had 51 malignant lesions and 15 had 23 benign lesions. The maximum standard uptake value (SUV(max)) was measured in all lesions using LOR-RAMLA. The maximal counts of all lesions determined manually were divided by the average count of bilateral ventricles and the aortic arch for standardization on fast-RAMLA, and the values were compared with the SUV(max) of LORRAMLA. Inter-observer variation in detection was determined among three radiologists who blindly reviewed and scored 70 maximum intensity projection images from 35 patients reconstructed using LORRAMLA and fast-RAMLA. RESULTS: We identified a quantitative correlation and determined the visual quality of lesion detection between fast-RAMLA and LOR-RAMLA and indicated usefulness and improvement point on fast-RAMLA. CONCLUSIONS: Fast-RAMLA can improve the strategy for using dual time point [(18)F] fluorodeoxyglucose positron emission tomography ([(18)F]-FDG-PET) and increase the efficiency of the [(18)F]-FDG-PET scanner.
Asunto(s)
Fluorodesoxiglucosa F18 , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Neoplasias/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Imagen de Cuerpo Entero/métodos , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Radiographic contrast media (CM) induce renal vasoconstriction and may initiate induced nephropathy. Endothelin (ET), a vasoconstrictor, and nitric oxide (NO), a vasodilator, which are synthesized in the kidney by the vascular endothelium as well as by tubular epithelial and glomerular mesangial cells, are key modulators of renal circulation after CM administration. Intravascular CM, in addition, induces pronounced diuresis and natriuresis. The aim of the present study was to evaluate and compare changes in endogenous vasoactive mediators and contrast-induced natriuresis after CM administration. METHODS: Diagnostic angiographic procedures were performed in 14 patients (9 males and 5 females) using the non-ionic CM Iopamidol. Before and immediately after angiography, venous blood and urine samples were obtained. The urinary excretion of ET-1 and nitrates/nitrites (NOx), and the fractional excretion of sodium (FENa) were measured and analyzed. RESULTS: The urinary excretion of both ET-1 and NOx increased significantly (p < 0.05) after angiography, and urinary ET-1 and NOx excretion was correlated with an increase in FENa (p < 0.05). CONCLUSION: Exposure to CM in humans is associated with an increase in urinary ET and NOx. The excretion of sodium following CM administration is associated with an increase in urinary ET and NOx. ET and NO might be important in the renal change in humans after CM administration.
Asunto(s)
Medios de Contraste/efectos adversos , Endotelina-1/orina , Natriuresis/efectos de los fármacos , Óxido Nítrico/orina , Anciano , Creatinina/sangre , Femenino , Humanos , Enfermedades Renales/inducido químicamente , Masculino , Persona de Mediana Edad , Vasoconstricción/efectos de los fármacosRESUMEN
We encountered a patient with Leriche syndrome and general atherosclerotic disease. His renal function had deteriorated, and diabetic nephropathy was suspected. Severe left renal artery stenosis was also found and considered, if untreated, to be an important factor in aggravation of his renal function. Because the infrarenal abdominal aorta was completely occluded, we treated the patient by insertion of a stent into the left renal artery from the brachial approach. The operation was successful, without residual stenosis or complications. Renal blood flow was remarkably improved after stent placement.