RESUMEN
BACKGROUND: The aim of this proof-of-concept study was to show that the liver segmental volume and attenuation ratio (LSVAR) improves the detection of significant liver fibrosis on portal venous CT scans by adding the liver vein to cava attenuation (LVCA) to the liver segmental volume ratio (LSVR). MATERIAL AND METHODS: Patients who underwent portal venous phase abdominal CT scans and MR elastography (reference standard) within 3 months between 02/2016 and 05/2017 were included. The LSVAR was calculated on portal venous CT scans as LSVR*LVCA, while the LSVR represented the volume ratio between Couinaud segments I-III and IV-VIII, and the LVCA represented the density of the liver veins compared to the density in the vena cava. The LSVAR and LSVR were compared between patients with and without significantly elevated liver stiffness (based on a cutoff value of 3.5 kPa) using the Mann-Whitney U test and ROC curve analysis. RESULTS: The LSVR and LSVAR allowed significant differentiation between patients with (n = 19) and without (n = 122) significantly elevated liver stiffness (p < 0.001). However, the LSVAR showed a higher area under the curve (AUC = 0.96) than the LSVR (AUC = 0.74). The optimal cutoff value was 0.34 for the LSVR, which detected clinically increased liver stiffness with a sensitivity of 53% and a specificity of 88%. With a cutoff value of 0.67 for the LSVAR, the sensitivity increased to 95% while maintaining a specificity of 89%. CONCLUSION: The LSVAR improves the detection of significant liver fibrosis on portal venous CT scans compared to the LSVR.
Asunto(s)
Diagnóstico por Imagen de Elasticidad , Cirrosis Hepática , Humanos , Hígado/diagnóstico por imagen , Hígado/patología , Cirrosis Hepática/diagnóstico por imagen , Cirrosis Hepática/patología , Vena Porta/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
Magnetic resonance (MR) T1 and T2* mapping allows quantification of liver relaxation times for non-invasive characterization of diffuse liver disease. We hypothesized that liver relaxation times are not only influenced by liver fibrosis, inflammation and fat, but also by air in liver segments adjacent to the lung - especially in MR imaging at 3T. A total of 161 study participants were recruited, while 6 patients had to be excluded due to claustrophobia or technically uninterpretable MR elastography. Resulting study population consisted of 12 healthy volunteers and 143 patients who prospectively underwent multiparametric MR imaging at 3T. Of those 143 patients, 79 had normal liver stiffness in MR elastography (shear modulus <2.8 kPa, indicating absence of fibrosis) and normal proton density fat fraction (PDFF < 10%, indicating absence of steatosis), defined as reference population. T1 relaxation times in these patients were significantly shorter in liver segments adjacent to the lung than in those not adjacent to the lung (p < 0.001, mean of differences 33 ms). In liver segments not adjacent to the lung, T1 allowed to differentiate significantly between the reference population and patients with steatosis and/or fibrosis (p ≤ 0.011), while there was no significant difference of T1 between the reference population and healthy volunteers. In conclusion, we propose to measure T1 relaxation times in liver segments not adjacent to the lung. Otherwise, we recommend taking into account slightly shorter T1 values in liver segments adjacent to the lung.
Asunto(s)
Hígado Graso/patología , Hepatopatías/patología , Hígado/patología , Imagen por Resonancia Magnética , Anciano , Hígado Graso/diagnóstico por imagen , Hígado Graso/metabolismo , Femenino , Humanos , Hígado/diagnóstico por imagen , Hepatopatías/diagnóstico por imagen , Hepatopatías/metabolismo , Pulmón/diagnóstico por imagen , Pulmón/metabolismo , Pulmón/patología , Espectroscopía de Resonancia Magnética , Masculino , Persona de Mediana Edad , Protones , Relajación/fisiología , Factores de RiesgoAsunto(s)
Aneurisma/diagnóstico por imagen , Arteria Pulmonar/diagnóstico por imagen , Tuberculosis Pulmonar/complicaciones , Tuberculosis Pulmonar/diagnóstico por imagen , Adulto , Angiografía , Broncoscopía , Diagnóstico Diferencial , Embolización Terapéutica , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Tomografía Computarizada por Rayos X , Tuberculosis Pulmonar/terapiaRESUMEN
AIM: To compare image quality and diagnostic confidence of 100 kVp CT pulmonary angiography (CTPA) in patients with body weights (BWs) below and above 100kg. MATERIALS AND METHODS: The present retrospective study comprised 216 patients (BWs of 75-99kg, 114 patients; 100-125kg, 88 patients; >125kg, 14 patients), who received 100 kVp CTPA to exclude pulmonary embolism. The attenuation was measured and the contrast-to-noise ratio (CNR) was calculated in the pulmonary trunk. Size-specific dose estimates (SSDEs) were evaluated. Three blinded radiologists rated subjective image quality and diagnostic confidence. Results between the BW groups and between three body mass index (BMI) groups (BMI <25kg/m(2), BMI = 25-29.9kg/m(2), and BMI ≥30kg/m(2), i.e., normal weight, overweight, and obese patients) were compared using the Kruskal-Wallis test. RESULTS: Vessel attenuation was higher and SDDE was lower in the 75-99kg group than at higher BWs (p-values between <0.001 and 0.03), with no difference between the 100-125 and >125kg groups (p = 0.892 and 1). Subjective image quality and diagnostic confidence were not different among the BW groups (p = 0.225 and 1). CNR was lower (p < 0.006) in obese patients than in normal weight or overweight subjects. Diagnostic confidence was not different in the BMI groups (p = 0.105). CONCLUSION: CTPA at 100 kVp tube voltage can be used in patients weighing up to 125kg with no significant deterioration of subjective image quality and confidence. The applicability of 100 kVp in the 125-150kg BW range needs further testing in larger collectives.
Asunto(s)
Angiografía/normas , Sobrepeso/diagnóstico por imagen , Arteria Pulmonar/diagnóstico por imagen , Tomografía Computarizada por Rayos X/normas , Adulto , Anciano , Angiografía/métodos , Índice de Masa Corporal , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/diagnóstico por imagen , Embolia Pulmonar/diagnóstico por imagen , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodosAsunto(s)
Aneurisma/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador , Arteria Pulmonar/diagnóstico por imagen , Intensificación de Imagen Radiográfica , Tomografía Computarizada por Rayos X , Tuberculosis Pulmonar/complicaciones , Tuberculosis Pulmonar/diagnóstico por imagen , Adulto , Angiografía , Diagnóstico Diferencial , Embolización Terapéutica , Femenino , Hemoptisis/etiología , Humanos , Tuberculosis Pulmonar/terapiaRESUMEN
PRINCIPLES: Computed tomography (CT) is inferior to the fibroscan and laboratory testing in the noninvasive diagnosis of liver fibrosis. On the other hand, CT is a frequently used diagnostic tool in modern medicine. The auxiliary finding of clinically occult liver fibrosis in CT scans could result in an earlier diagnosis. The aim of this study was to analyse quantifiable direct signs of liver remodelling in CT scans to depict liver fibrosis in a precirrhotic stage. METHODS: Retrospective review of 148 abdominal CT scans (80 liver cirrhosis, 35 precirrhotic fibrosis and 33 control patients). Fibrosis and cirrhosis were histologically proven. The diameters of the three main hepatic veins were measured 1-2 cm before their aperture into the inferior caval vein. The width of the caudate and the right hepatic lobe were divided, and measured horizontally at the level of the first bifurcation of the right portal vein in axial planes (caudate-right-lobe ratio). A combination of both (sum of liver vein diameters divided by the caudate-right lobe ratio) was defined as the ld/crl ratio. These metrics were analysed for the detection of liver fibrosis and cirrhosis. RESULTS: An ld/crl-r <24 showed a sensitivity of 83% and a specificity of 76% for precirrhotic liver fibrosis. Liver cirrhosis could be detected with a sensitivity of 88% and a specificity of 82% if ld/crl-r <20. CONCLUSION: An ld/crl-r <24 justifies laboratory testing and a fibroscan. This could bring forward the diagnosis and patients would profit from early treatment in a potentially reversible stage of disease.
Asunto(s)
Cirrosis Hepática/diagnóstico por imagen , Hígado/diagnóstico por imagen , Hígado/patología , Tomografía Computarizada por Rayos X , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Fibrosis/diagnóstico por imagen , Fibrosis/patología , Venas Hepáticas/diagnóstico por imagen , Venas Hepáticas/patología , Humanos , Cirrosis Hepática/patología , Masculino , Conceptos Matemáticos , Persona de Mediana Edad , Tamaño de los Órganos , Vena Porta/diagnóstico por imagen , Vena Porta/patología , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
The discussion about setting up a program for lung cancer screening was launched with the publication of the results of the National Lung Screening Trial, which suggested reduced mortality in high-risk subjects undergoing CT screening. However, important questions about the benefit-harm balance and the details of a screening program and its cost-effectiveness remain unanswered. A panel of specialists in chest radiology, respiratory medicine, epidemiology, and thoracic surgery representing all Swiss university hospitals prepared this joint statement following several meetings. The panel argues that premature and uncontrolled introduction of a lung cancer screening program may cause substantial harm that may remain undetected without rigorous quality control. This position paper focuses on the requirements of running such a program with the objective of harmonizing efforts across the involved specialties and institutions and defining quality standards. The underlying statement includes information on current evidence for a reduction in mortality with lung cancer screening and the potential epidemiologic implications of such a program in Switzerland. Furthermore, requirements for lung cancer screening centers are defined, and recommendations for both the CT technique and the algorithm for lung nodule assessment are provided. In addition, related issues such as patient management, registry, and funding are addressed. Based on the current state of the knowledge, the panel concludes that lung cancer screening in Switzerland should be undertaken exclusively within a national observational study in order to provide answers to several critical questions before considering broad population-based screening for lung cancer.
Asunto(s)
Detección Precoz del Cáncer/normas , Neoplasias Pulmonares/diagnóstico por imagen , Hospitales Universitarios , Humanos , Tamizaje Masivo , Guías de Práctica Clínica como Asunto , Medición de Riesgo , Suiza , Tomografía Computarizada por Rayos XRESUMEN
Leptospirosis pulmonary haemorrhage syndrome (LPHS) is a frequent manifestation of Leptospira infection in dogs and is associated with a high morbidity and mortality. Three helical 16-slice thoracic CT scans were performed in 10 dogs naturally infected with Leptospira, within 24 hours of admission, and three and seven days later. Patients were sedated and scanned without breathhold, with a protocol adapted for rapid scanning. One dog died of respiratory failure on the morning following the first scan. On the initial scan, imaging features of LPHS included ground-glass nodules (10/10), peribronchovascular interstitial thickening (10/10), diffuse or patchy ground-glass opacity (9/10), solid nodules (8/10) and consolidation (7/10). Temporary bronchiolar dilation was observed in all dogs in association with peribronchovascular interstitial thickening, which had completely resolved at day 7. Nodules were with few exceptions assigned to the centrilobular region. Regression of lesion severity was observed after each subsequent scan. Consolidation and solid nodules changed over time into lesions of ground-glass attenuation. Pleural effusion (3/10) and mediastinal effusion (2/10) were mild and transient. Lesion severity appeared unassociated with survival to discharge.
Asunto(s)
Enfermedades de los Perros/diagnóstico por imagen , Leptospirosis/veterinaria , Enfermedades Pulmonares/veterinaria , Tomografía Computarizada por Rayos X/veterinaria , Animales , Perros , Femenino , Leptospirosis/diagnóstico por imagen , Enfermedades Pulmonares/diagnóstico por imagen , Masculino , Índice de Severidad de la Enfermedad , Análisis de SupervivenciaRESUMEN
Over the last decade, a plethora of computer-aided diagnosis (CAD) systems have been proposed aiming to improve the accuracy of the physicians in the diagnosis of interstitial lung diseases (ILD). In this study, we propose a scheme for the classification of HRCT image patches with ILD abnormalities as a basic component towards the quantification of the various ILD patterns in the lung. The feature extraction method relies on local spectral analysis using a DCT-based filter bank. After convolving the image with the filter bank, q-quantiles are computed for describing the distribution of local frequencies that characterize image texture. Then, the gray-level histogram values of the original image are added forming the final feature vector. The classification of the already described patches is done by a random forest (RF) classifier. The experimental results prove the superior performance and efficiency of the proposed approach compared against the state-of-the-art.
Asunto(s)
Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Estudios de Casos y Controles , Árboles de Decisión , Humanos , Pulmón/diagnóstico por imagen , Reconocimiento de Normas Patrones Automatizadas , Interpretación de Imagen Radiográfica Asistida por Computador , Tomografía Computarizada por Rayos X/métodosRESUMEN
OBJECTIVES: To find the best pairing of first and second reader at highest sensitivity for detecting lung nodules with CT at various dose levels. MATERIALS AND METHODS: An anthropomorphic lung phantom and artificial lung nodules were used to simulate screening CT-examination at standard dose (100 mAs, 120 kVp) and 8 different low dose levels, using 120, 100 and 80 kVp combined with 100, 50 and 25 mAs. At each dose level 40 phantoms were randomly filled with 75 solid and 25 ground glass nodules (5-12 mm). Two radiologists and 3 different computer aided detection softwares (CAD) were paired to find the highest sensitivity. RESULTS: Sensitivities at standard dose were 92%, 90%, 84%, 79% and 73% for reader 1, 2, CAD1, CAD2, CAD3, respectively. Combined sensitivity for human readers 1 and 2 improved to 97%, (p1=0.063, p2=0.016). Highest sensitivities--between 97% and 99.0%--were achieved by combining any radiologist with any CAD at any dose level. Combining any two CADs, sensitivities between 85% and 88% were significantly lower than for radiologists combined with CAD (p<0.03). CONCLUSIONS: Combination of a human observer with any of the tested CAD systems provide optimal sensitivity for lung nodule detection even at reduced dose at 25 mAs/80 kVp.
Asunto(s)
Detección Precoz del Cáncer/métodos , Neoplasias Pulmonares/diagnóstico por imagen , Competencia Profesional , Dosis de Radiación , Programas Informáticos , Nódulo Pulmonar Solitario/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Relación Dosis-Respuesta en la Radiación , Detección Precoz del Cáncer/instrumentación , Femenino , Humanos , Masculino , Variaciones Dependientes del Observador , Reconocimiento de Normas Patrones Automatizadas , Fantasmas de Imagen , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Validación de Programas de Computación , Tomografía Computarizada por Rayos X/instrumentaciónRESUMEN
BACKGROUND AND PURPOSE: The surgical approach to parotid tumors is different for benign and malignant neoplasms, but the clinical symptoms do not correlate well with histology. Difficulties in tumor classification also arise in imaging modalities, in which sonography has the lowest and MR imaging, the highest accuracy. The purpose of this study was to review our experience using conventional MR imaging of the neck in the evaluation of parotid tumors and to evaluate which MR imaging findings are best able to predict malignant histology. MATERIALS AND METHODS: Eighty-four consecutive patients (43 males, 41 females; median age, 56 years; range, 9-85 years) with parotid gland tumors who underwent MR imaging before surgery were prospectively included in the present study and retrospectively analyzed. Histology was available for all tumors. We analyzed the following MR imaging parameters: signal intensity, contrast enhancement, lesion margins (well-defined versus ill-defined), lesion location (deep/superficial lobe), growth pattern (focal, multifocal, or diffuse), and extension into neighboring structures, perineural spread, and lymphadenopathy. RESULTS: The 57 (68%) benign and 27 (32%) malignant tumors consisted of 29 pleomorphic adenomas, 17 Warthin tumors, 11 various benign tumors, 5 mucoepidermoid carcinomas, 3 adenoid cystic carcinomas, 1 acinic cell carcinoma, 1 carcinoma ex pleomorphic adenoma, 9 metastases, and 8 various malignant neoplasms. Specific signs predictive of malignancy were the following: T2 hypointensity of the parotid tumor (P = .048), ill-defined margins (P = .001), diffuse growth (P = .012), infiltration of subcutaneous tissue (P = .0034), and lymphadenopathy (P = .012). CONCLUSIONS: Low signal intensity on T2-weighted images and postcontrast ill-defined margins of a parotid tumor are highly suggestive of malignancy.
Asunto(s)
Adenoma/patología , Imagen por Resonancia Magnética/métodos , Neoplasias/patología , Neoplasias de la Parótida/patología , Adenolinfoma/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Acinares/patología , Carcinoma Adenoide Quístico/patología , Carcinoma Mucoepidermoide/patología , Niño , Diagnóstico Diferencial , Femenino , Humanos , Imagen por Resonancia Magnética/normas , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estudios Retrospectivos , Adulto JovenRESUMEN
As the auditory ossicles are difficult to display without harming them in conventional autopsies, lesions of these minute bones and the ossicular chain are regularly missed. In this study, the method of choice in clinical medicine for the examination of such lesions, namely multislice computed tomography, was applied to 100 corpses. The hereby obtained results regarding ossicle luxation and petrous bone fracture indicated that the lesions were not dependant on the amount, but rather on the type of energy inflicted to the head.
Asunto(s)
Osículos del Oído/lesiones , Luxaciones Articulares/diagnóstico por imagen , Hueso Petroso/lesiones , Fracturas Craneales/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adolescente , Adulto , Anciano , Niño , Preescolar , Osículos del Oído/diagnóstico por imagen , Patologia Forense , Humanos , Procesamiento de Imagen Asistido por Computador , Lactante , Persona de Mediana Edad , Hueso Petroso/diagnóstico por imagen , Heridas y Lesiones/mortalidad , Heridas y Lesiones/patología , Adulto JovenRESUMEN
Homicides with a survival of several days are not uncommon in forensic routine work. Reconstructions of these cases by autopsy alone are very difficult and may occasionally lead to unsatisfying results. For the medico-legal reconstruction of these cases, ante-mortem and post-mortem radiological imaging should always be included in the expertise. We report on a case of fatal penetrating stab wounds to the skull in which a case reconstruction was only possible by combining the radiological ante- and post-mortem data with the autopsy findings.
Asunto(s)
Patologia Forense/métodos , Cráneo/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Heridas Punzantes/diagnóstico por imagen , Adulto , Autopsia , Diagnóstico , Homicidio , Humanos , Masculino , Cráneo/lesiones , TiempoRESUMEN
Decisions about the treatment of neck pain are largely made on the basis of information gained from plain X-rays and magnetic resonance imaging (MRI), which are used routinely as part of preliminary investigation. We performed a descriptive cadaveric study to compare histology with radiography and MRI. We correlated plain radiography, disc height [Farfan index (FI)] and MRI findings with histology to assess the ability of radiology to detect significant pathologic lesions. The study included 52 motion segments from nine subjects over the age of 50, who underwent routine hospital autopsy. Disc degeneration was assessed by histology, radiography, disc height (FI: anterior disc height plus posterior disc height divided by anterioposterior diameter) and MRI using established grading systems. Most of the discs were classified radiologically as grade 1 (19/52), grade 2 (13/52), grade 3 (9/52) or grade 4 (3/52). Eight of the discs were graded as normal. The distribution of MRI grades was grade 0 (9/36), grade 1 (9/36), grade 2 (7/36), grade 3 (8/36) and grade 4 (3/36). Half of the discs (26/52) showed advanced (grade 4) degeneration histologically. FI correlated with histological grade (P = 0.013), MRI grade (P = 0.02) and radiological grade (P < 0.001) of degeneration. Radiological and histological grade of degeneration showed a weak correlation (r = 0.3, P = 0.033). MRI correlated with overall histological grade (r = 0.41, P = 0.015, n = 34). Histological features (e.g., tears, rim lesions, prolapse of nucleus material) were poorly recognised by MRI, which had a sensitivity for disc material prolapse and annulus tears of less than 40%. Our study showed that discs from patients over 50 years are histologically severely degenerated; however, these changes may not be detected by conventional radiography and MRI.
Asunto(s)
Vértebras Cervicales , Disco Intervertebral/diagnóstico por imagen , Disco Intervertebral/patología , Imagen por Resonancia Magnética , Anciano , Cadáver , Femenino , Humanos , Masculino , Persona de Mediana Edad , RadiografíaRESUMEN
The most common causes of pulmonary edema are cardiac failure, renal failure and injury edema (diffuse alveolar damage). The injury edema typically shows airspace consolidation due to exsudation of fluid in the periphery of the lung with air bronchograms, no interstitial fluid accumulation can be found and only rarely pleural effusions are present. Cardiac and renal edemas often show a mixed interstitial and alveolar transudation without air bronchograms. Pleural effusions are often present. Both usually have an increased heart-size and an increased vascular pedicle width. To distinguish them better one has to look at the distribution of the pulmonary edema: The cardiac edema typically shows a gravitational and the renal edema a central distribution.