Histiocitosis pulmonar: más allá de la histiocitosis de células de Langerhans relacionada con el tabaco / Pulmonary histiocytosis: beyond Langerhans cell histiocytosis related to smoking

Objetivo: Revisar los hallazgos de imagen de las diferentes histiocitosis pulmonares. En concreto, además de la conocida histiocitosis de células de Langerhans relacionada con el tabaco y su posible aparición sin antecedentes de este, la enfermedad de Rosai-Dorfman y la enfermedad de Erdheim-Chester. También se revisa su etiopatogenia, histología, clínica y tratamiento. Conclusión: La histiocitosis de células de Langerhans, la enfermedad de Rosai-Dorfman y la enfermedad de Erdheim-Chester son un conjunto de patologías de causa idiopática en las que la proliferación e infiltración de histiocitos es el hallazgo anatomopatológico diagnóstico. La histiocitosis de células de Langerhans se manifiesta en forma de nódulos y quistes que respetan los ángulos costofrénicos, característicamente en pacientes fumadores. Aunque es poco frecuente, debe pensarse en esta entidad en pacientes no fumadores, en tratamiento quimio y radioterapéutico, con nódulos cavitados de nueva aparición e incluirse en el diagnóstico diferencial junto con la enfermedad metastásica y la infección oportunista. La enfermedad de Rosai-Dorfman y la enfermedad de Erdheim-Chester se presentan con hallazgos torácicos más inespecíficos, como adenopatías, engrosamiento intersticial y derrame pleural. En la enfermedad de Erdheim-Chester, las características manifestaciones extratorácicas suelen ser claves en el diagnóstico

Objective: To review the imaging findings for the different types of pulmonary histiocytosis. In particular, in addition to the well-known pulmonary Langerhans cell histiocytosis related to smoking and its possible appearance in nonsmokers, we focus on non-Langerhans cell histiocytosis in Rosai-Dorfman disease and Erdheim-Chester disease. We also review the etiopathogenesis, histology, clinical presentation, and treatment of pulmonary histiocytosis. Conclusion: Langerhans cell histiocytosis, Rosai-Dorfman disease, and Erdheim-Chester disease are idiopathic diseases in which the proliferation and infiltration of histiocytes is the histologic finding that confirms the diagnosis. Langerhans cell histiocytosis manifests as nodules and cysts that spare the costophrenic angles; it typically appears in smokers. Although it is uncommon in nonsmokers, Langerhans cell histiocytosis should also be considered in nonsmokers treated with chemotherapy and radiotherapy in whom cavitated nodules appear and should be included in the differential diagnosis together with metastatic disease and opportunistic infections. Rosai-Dorfman disease and Erdheim-Chester disease present with less specific thoracic findings such as adenopathies, interstitial thickening, and pleural effusion. In Erdheim-Chester disease, the characteristic extrathoracic manifestations are usually key for the diagnosis

Malformaciones vasculares y tumores de partes blandas. Parte 2: lesiones de bajo flujo / Soft-tissue vascular malformations and tumors. Part 2: low-flow lesions

Las malformaciones vasculares y los tumores, también conocidos como "anomalías vasculares", comprenden una extensa variedad de lesiones en diferentes partes del cuerpo. El origen y la histopatología de estas lesiones no es del todo conocido, por ello este campo se ha visto ensombrecido por el uso de una nomenclatura poco clara. Conocer su clasificación, así como las características clínicas y de imagen es de vital importancia para el manejo de estos pacientes. El objetivo de esta serie de dos artículos es revisar la clasificación actual de las anomalías vasculares, describir el papel que desempeñan las pruebas de imagen en su diagnóstico, resumir sus características histopatológicas, clínicas y de imagen y debatir las posibles opciones terapéuticas. El primer artículo de esta serie versó sobre las lesiones de alto flujo. En este segundo artículo nos centraremos en las de bajo flujo, incluidos los síndromes complejos que asocian malformaciones de bajo flujo

Vascular malformations and tumors, also known as "vascular anomalies", comprise an extensive variety of lesions involving all parts of the body. Due to a lack of a complete understanding of the origin and histopathology of such lesions, this field has been traditionally obscured by the use of an unclear nomenclature. Knowledge of the classification and clinical and imaging characteristics of this group of lesions is paramount when managing these patients. The objective of this series of two articles is to review the current classification of vascular anomalies, to describe the role of imaging in their diagnosis, to summarize their distinctive histopathologic, clinical and imaging features, and to discuss the treatment options. High-flow lesions were discussed in the first article of this series. In this second article, we will focus on low-flow lesions, including complex syndromes with associated low-flow malformations

Malformaciones vasculares y tumores de partes blandas. Parte 1: clasificación, papel de las pruebas imagen y lesiones de alto flujo / Soft-tissue vascular malformations and tumors. Part 1: classification, role of imaging and high-flow lesions

Las malformaciones vasculares y los tumores, también conocidos como «anomalías vasculares», comprenden una extensa variedad de lesiones en diferentes partes del cuerpo. Conocer su clasificación y características en las imágenes es de vital importancia. Si bien los hemangiomas son tumores vasculares benignos caracterizados por proliferación celular e hiperplasia, las malformaciones vasculares no son verdaderos tumores y muestran, típicamente, una renovación endotelial normal. Las malformaciones vasculares se clasifican, según el vaso predominante, en arteriales, capilares, venosas, linfáticas o mixtas. La ecografía y la resonancia magnética son las técnicas de imagen que se usan en el diagnóstico y la clasificación de las anomalías vasculares. En esta serie de dos artículos revisaremos la clasificación de las anomalías vasculares, describiremos el papel que desempeñan las pruebas de imagen, resumiremos sus características histopatogénicas, clínicas y de imagen, y comentaremos las posibles opciones terapéuticas. En este primer artículo hablamos de las lesiones de alto flujo, y en el segundo lo haremos de las de bajo flujo. También trataremos los síndromes complejos asociados tanto a los tumores vasculares como a las malformaciones

Vascular malformations and tumors, also known as "vascular anomalies", comprise an extensive variety of lesions involving all parts of the body. Knowledge of their classification and imaging characteristics is paramount. Whereas hemangiomas are benign vascular tumors, characterized by cellular proliferation and hyperplasia; vascular malformations are not real tumors and characteristically exhibit normal endothelial turnover. Vascular malformations are classified according to the predominant vascular channel as arterial, capillary, venous, lymphatic, or mixed. Ultrasound and MRI are the main imaging modalities used in the diagnosis and classification of the vascular anomalies. In this series of two articles we review the classification of vascular anomalies, describe the role of imaging, summarize their distinctive histopathogenic, clinical and imaging features, and discuss the treatment options. On the first article we discuss the high-flow lesions, whereas the slow-flow lesions will be reviewed on the second. Complex syndromes with associated vascular tumors and malformations will be also presented

Pulmonary histiocytosis: beyond Langerhans cell histiocytosis related to smoking. / Histiocitosis pulmonar: más allá de la histiocitosis de células de Langerhans relacionada con el tabaco.

OBJECTIVE: To review the imaging findings for the different types of pulmonary histiocytosis. In particular, in addition to the well-known pulmonary Langerhans cell histiocytosis related to smoking and its possible appearance in nonsmokers, we focus on non-Langerhans cell histiocytosis in Rosai-Dorfman disease and Erdheim-Chester disease. We also review the etiopathogenesis, histology, clinical presentation, and treatment of pulmonary histiocytosis. CONCLUSION: Langerhans cell histiocytosis, Rosai-Dorfman disease, and Erdheim-Chester disease are idiopathic diseases in which the proliferation and infiltration of histiocytes is the histologic finding that confirms the diagnosis. Langerhans cell histiocytosis manifests as nodules and cysts that spare the costophrenic angles; it typically appears in smokers. Although it is uncommon in nonsmokers, Langerhans cell histiocytosis should also be considered in nonsmokers treated with chemotherapy and radiotherapy in whom cavitated nodules appear and should be included in the differential diagnosis together with metastatic disease and opportunistic infections. Rosai-Dorfman disease and Erdheim-Chester disease present with less specific thoracic findings such as adenopathies, interstitial thickening, and pleural effusion. In Erdheim-Chester disease, the characteristic extrathoracic manifestations are usually key for the diagnosis.

Soft-tissue vascular malformations and tumors. Part 1: classification, role of imaging and high-flow lesions. / Malformaciones vasculares y tumores de partes blandas. Parte 1: clasificación, papel de las pruebas imagen y lesiones de alto flujo.

Vascular malformations and tumors, also known as "vascular anomalies", comprise an extensive variety of lesions involving all parts of the body. Knowledge of their classification and imaging characteristics is paramount. Whereas hemangiomas are benign vascular tumors, characterized by cellular proliferation and hyperplasia; vascular malformations are not real tumors and characteristically exhibit normal endothelial turnover. Vascular malformations are classified according to the predominant vascular channel as arterial, capillary, venous, lymphatic, or mixed. Ultrasound and MRI are the main imaging modalities used in the diagnosis and classification of the vascular anomalies. In this series of two articles we review the classification of vascular anomalies, describe the role of imaging, summarize their distinctive histopathogenic, clinical and imaging features, and discuss the treatment options. On the first article we discuss the high-flow lesions, whereas the slow-flow lesions will be reviewed on the second. Complex syndromes with associated vascular tumors and malformations will be also presented.

Soft-tissue vascular malformations and tumors. Part 2: low-flow lesions. / Malformaciones vasculares y tumores de partes blandas. Parte 2: lesiones de bajo flujo.

Vascular malformations and tumors, also known as "vascular anomalies", comprise an extensive variety of lesions involving all parts of the body. Due to a lack of a complete understanding of the origin and histopathology of such lesions, this field has been traditionally obscured by the use of an unclear nomenclature. Knowledge of the classification and clinical and imaging characteristics of this group of lesions is paramount when managing these patients. The objective of this series of two articles is to review the current classification of vascular anomalies, to describe the role of imaging in their diagnosis, to summarize their distinctive histopathologic, clinical and imaging features, and to discuss the treatment options. High-flow lesions were discussed in the first article of this series. In this second article, we will focus on low-flow lesions, including complex syndromes with associated low-flow malformations.

Papel de los estudios de imagen en el diagnóstico etiológico de las bronquiectasias: la distribución es la clave / The role of imaging in the diagnosis of bronchiectasis: the key is in the distribution

La patología de las vías respiratorias de medio calibre (bronquios segmentarios y subsegmentarios) es común y se presenta con síntomas respiratorios poco específicos, como tos, infecciones de repetición y en ocasiones hemoptisis. La dilatación permanente del árbol bronquial se conoce como «bronquiectasia» y representa un reto diagnóstico. El análisis de la distribución regional de las bronquiectasias en los diferentes lóbulos pulmonares es la guía diagnóstica más útil. El objetivo de este trabajo es describir los hallazgos de imagen de las bronquiectasias y sus diferentes tipos, revisar las situaciones más comunes y proponer un algoritmo diagnóstico basado en su distribución anatómica. Las bronquiectasias son un hallazgo frecuente, resultado de un amplio espectro de enfermedades. Los estudios de imagen desempeñan un papel esencial en su detección, clasificación y orientación diagnóstica hacia la patología subyacente (AU)

Diseases that involve the medium caliber airways (segmental and subsegmental bronchi) are common and present clinically with nonspecific respiratory symptoms such as cough, recurrent respiratory infections and occasionally, hemoptysis. The abnormal and irreversible dilation of bronchi is known as "bronchiectasis". The diagnosis can be challenging and the analysis of the regional distribution of the bronchiectasis is the most useful diagnostic guide. The objective of this manuscript is to describe the main imaging findings of bronchiectasis and their classification, review the diseases that most commonly present with this abnormality, and provide an approach to the diagnosis based on their imaging appearance and anatomic distribution. Bronchiectasis is a frequent finding that may result from a broad range of disorders. Imaging plays a paramount role in diagnosis, both in the detection and classification, and in the diagnosis of the underlying pathology (AU)

The role of imaging in the diagnosis of bronchiectasis: the key is in the distribution. / Papel de los estudios de imagen en el diagnóstico etiológico de las bronquiectasias: la distribución es la clave.

Diseases that involve the medium caliber airways (segmental and subsegmental bronchi) are common and present clinically with nonspecific respiratory symptoms such as cough, recurrent respiratory infections and occasionally, hemoptysis. The abnormal and irreversible dilation of bronchi is known as "bronchiectasis". The diagnosis can be challenging and the analysis of the regional distribution of the bronchiectasis is the most useful diagnostic guide. The objective of this manuscript is to describe the main imaging findings of bronchiectasis and their classification, review the diseases that most commonly present with this abnormality, and provide an approach to the diagnosis based on their imaging appearance and anatomic distribution. Bronchiectasis is a frequent finding that may result from a broad range of disorders. Imaging plays a paramount role in diagnosis, both in the detection and classification, and in the diagnosis of the underlying pathology.

Anomalías congénitas de las arterias pulmonares: espectro de hallazgos en tomografía computarizada / Congenital anomalies of the pulmonary arteries: spectrum of findings on computed tomography

Las anomalías congénitas de las arterias pulmonares (AP) son poco frecuentes y pueden presentarse aisladas o asociadas a defectos cardiacos congénitos. En general, si son aisladas, suelen pasar clínicamente inadvertidas hasta la adolescencia y ser un hallazgo incidental en exploraciones radiológicas. Nuestro objetivo es revisar las bases embriológicas del desarrollo de las AP, su anatomía normal y el espectro de hallazgos por tomografía computarizada (TC) de sus anomalías congénitas, en concreto la interrupción unilateral de la AP, el origen anómalo de la AP izquierda (sling pulmonar), el aneurisma idiopático de la AP y otras anomalías asociadas a defectos cardiacos congénitos. Las anomalías congénitas de las AP representan un reto diagnóstico, tanto clínico como radiológico. La TC es una herramienta útil en su diagnóstico y el radiólogo general debe estar familiarizado con su apariencia, ya que pueden ser un hallazgo incidental (AU)

Objective. Congenital anomalies of the pulmonary arteries are uncommon. They can occur in isolation or in association with congenital heart defects. Isolated congenital anomalies remain undiscovered until they are reported as incidental findings on imaging tests, usually not until adolescence. We review the embryological development and normal anatomy of the pulmonary arteries as well as the spectrum of computed tomography findings for various congenital anomalies: unilateral interruption of the pulmonary artery, anomalous origin of the left pulmonary artery (pulmonary artery sling), idiopathic aneurysm of the pulmonary artery, and other anomalies associated with congenital heart defects. Conclusion. Congenital anomalies of the pulmonary arteries represent a diagnostic challenge for clinicians and radiologists. Computed tomography is useful for their diagnosis, and general radiologists need to be familiar with their imaging appearance because they are often discovered incidentally (AU)

Congenital anomalies of the pulmonary arteries: spectrum of findings on computed tomography. / Anomalías congénitas de las arterias pulmonares: espectro de hallazgos en tomografía computarizada.

OBJECTIVE: Congenital anomalies of the pulmonary arteries are uncommon. They can occur in isolation or in association with congenital heart defects. Isolated congenital anomalies remain undiscovered until they are reported as incidental findings on imaging tests, usually not until adolescence. We review the embryological development and normal anatomy of the pulmonary arteries as well as the spectrum of computed tomography findings for various congenital anomalies: unilateral interruption of the pulmonary artery, anomalous origin of the left pulmonary artery (pulmonary artery sling), idiopathic aneurysm of the pulmonary artery, and other anomalies associated with congenital heart defects. CONCLUSION: Congenital anomalies of the pulmonary arteries represent a diagnostic challenge for clinicians and radiologists. Computed tomography is useful for their diagnosis, and general radiologists need to be familiar with their imaging appearance because they are often discovered incidentally.

RM con gases hiperpolarizados: nuevas perspectivas en el estudio de enfermedades pulmonares / New insights into lung diseases using hyperpolarized gas MRI

Los gases hiperpolarizados (HP) son una nueva clase de agentes de contraste que permiten obtener imágenes por resonancia magnética (RM) de alta resolución temporal y espacial de los espacios aéreos pulmonares. La RM con gas HP se ha convertido en una importante herramienta de investigación no solo para la evaluación morfológica y funcional pulmonar normal sino también para cuantificar los cambios patológicos regionales que se dan en las enfermedades pulmonares. El propósito de este trabajo es introducir la RM con gases nobles HP, describiendo, para ello, tanto los principios técnicos básicos como la información sobre las enfermedades pulmonares que ofrecen los estudios clínicos realizados. También hacemos una revisión de sus aplicaciones en sujetos normales, en enfermedades pulmonares secundarias al tabaco, el asma y la fibrosis quística (AU)

Hyperpolarized (HP) gases are a new class of contrast agents that permit to obtain high temporal and spatial resolution magnetic resonance images (MRI) of the lung airspaces. HP gas MRI has become important research tool not only for morphological and functional evaluation of normal pulmonary physiology but also for regional quantification of pathologic changes occurring in several lung diseases. The purpose of this work is to provide an introduction to MRI using HP noble gases, describing both the basic principles of the technique and the new information about lung disease provided by clinical studies with this method. The applications of the technique in normal subjects, smoking related lung disease, asthma, and cystic fibrosis are reviewed (AU)

New insights into lung diseases using hyperpolarized gas MRI.

Hyperpolarized (HP) gases are a new class of contrast agents that permit to obtain high temporal and spatial resolution magnetic resonance images (MRI) of the lung airspaces. HP gas MRI has become important research tool not only for morphological and functional evaluation of normal pulmonary physiology but also for regional quantification of pathologic changes occurring in several lung diseases. The purpose of this work is to provide an introduction to MRI using HP noble gases, describing both the basic principles of the technique and the new information about lung disease provided by clinical studies with this method. The applications of the technique in normal subjects, smoking related lung disease, asthma, and cystic fibrosis are reviewed.

Fontan procedure: imaging of normal post-surgical anatomy and the spectrum of cardiac and extracardiac complications.

Univentricular congenital heart diseases include a range of entities that result in a functionally single ventricular chamber. Although the only curative therapy is cardiac transplantation, there are several palliative surgical techniques that prevent ventricular volume overload, diverting part or all the systemic venous circulation into the pulmonary arteries. The modern Fontan procedure, which consists of anastomosing both the superior (SVC) and inferior vena cava (IVC) to the right pulmonary artery (RPA), is nowadays the last step before transplantation. The importance of imaging in these entities lies not only in the understanding of the new circuit established after surgical correction, but also in the early detection of the wide spectrum of cardiac and extracardiac complications that can occur due to the new physiological condition. Due to the increased survival of these patients, long-term complications are becoming more common. The main cardiac complications are atrial enlargement, ventricular dysfunction, and stenosis or thrombosis of the conduit. Pulmonary artery stenosis, pulmonary arteriovenous fistulae (PAVF), systemic-pulmonary veno venous shunts (VVS), hepatic congestion, cardiac cirrhosis, and protein-losing enteropathy are potential extracardiac complications.

Comparación de la capacidad diagnóstica precoz de los biomarcadores de la enfermedad de Alzheimer en resonancia magnética cerebral y líquido cefalorraquídeo / A comparison of early diagnostic utility of Alzheimer disease biomarkers in brain magnetic resonance and cerebrospinal fluid

Introducción: Nuestros objetivos fueron comparar la capacidad de diagnóstico precoz de los biomarcadores (BMC) de enfermedad de Alzheimer (EA) en LCR y RM cerebral, en condiciones posibles de nuestra práctica clínica y, además, conocer la precisión diagnóstica de la combinación de ambas técnicas. Métodos: Entre 2008 y 2009, estudiamos a 30 pacientes con deterioro cognitivo leve (DCL) mediante RM cerebral de 1,5 teslas y análisis de BMC de EA en el LCR. Las RM fueron valoradas por 2 neurorradiólogos, atendiendo a la escala visual de Korf (2004). Los BMC de EA en LCR se analizaron mediante reactivos INNOTEST para proteínas A 1-42, total-tau y fosfo-tau. Se evaluó la evolución clínica (según criterios NINCDS-ADRDA) a los 2 a˜nos tras la inclusión. Resultados: Entre los 30 pacientes iniciales, 15 evolucionaron a EA (criterios NINCDS-ADRDA) a los 2 a˜nos de la inclusión. La capacidad predictiva de los BMC en LCR (RR 2,7; IC del 95%, 1,1-6,7; p < 0,01) es superior a los de RM (RR 1,5; IC del 95%, 0,7-3,4; p < 0,2), y la combinación de ambas técnicas alcanza una sensibilidad y valor predictivo negativo del 100%. La normalidad de ambas pruebas complementarias descartó al 100% el desarrollo de EA, en los 2 a˜nos siguientes a la realización de las mismas. Conclusiones: Siguiendo nuestra metodología, la precisión diagnóstica de los BMC en LCR es superior a los de la RM para el diagnóstico precoz de EA. La combinación de ambas técnicasconsigue una precisión diagnóstica muy alta, tanto para diagnosticar como para excluir precozmente EA, en pacientes con DCL

Introduction: The goals of this study were to compare the early diagnostic utility of Alzheimer disease biomarkers in the CSF with those in brain MRI in conditions found in our clinical practice, and to ascertain the diagnostic accuracy of both techniques used together. Methods: Between 2008 and 2009, we included 30 patients with mild cognitive impairment (MCI) who were examined using 1.5 Tesla brain MRI and AD biomarker analysis in CSF. MRI studies were evaluated by 2 radiologists according to the Korf s visual scale. CSF biomarkers were analysed using INNOTEST reagents for A 1-42, total-tau and phospho-tau181p. We evaluated clinical changes 2 years after inclusion. Results: By 2 years after inclusion, 15 of the original 30 patients (50%) had developed AD (NINCDS-ADRA criteria). The predictive utility of AD biomarkers in CSF (RR 2.7; 95% CI, 1.1-6.7; P < .01) was greater than that of MRI (RR 1.5; 95% CI 95%, 0.7-3.4; P < .2); using both techniques together yielded a sensitivity and a negative predictive value of 100%. Normal results on both complementary tests ruled out progression to AD (100%) within 2 years of inclusion. Conclusions: Our results show that the diagnostic accuracy of biomarkers in CSF is higher than that of biomarkers in MRI. Combined use of both techniques is highly accurate for either early diagnosis or exclusion of AD in patients with MCI

Dental flat panel conebeam CT in the evaluation of patients with inflammatory sinonasal disease: Diagnostic efficacy and radiation dose savings.

BACKGROUND AND PURPOSE: CT is the imaging modality of choice to study the paranasal sinuses; unfortunately, it involves significant radiation dose. Our aim was to assess the diagnostic validity, image quality, and radiation-dose savings of dental conebeam CT in the evaluation of patients with suspected inflammatory disorders of the paranasal sinuses. MATERIAL AND METHODS: We prospectively studied 40 patients with suspected inflammatory disorders of the sinuses with dental conebeam CT and standard CT. Two radiologists analyzed the images independently, blinded to clinical information. The image quality of both techniques and the diagnostic validity of dental conebeam CT compared with the reference standard CT were assessed by using 3 different scoring systems. Image noise, signal-to-noise ratio, and contrast-to-noise ratio were calculated for both techniques. The absorbed radiation dose to the lenses and thyroid and parotid glands was measured by using a phantom and dosimeter chips. The effective radiation dose for CT was calculated. RESULTS: All dental conebeam CT scans were judged of diagnostic quality. Compared with CT, the conebeam CT image noise was 37.3% higher (P < .001) and the SNR of the bone was 75% lower (P < .001). The effective dose of our conebeam CT protocol was 23 µSv. Compared with CT, the absorbed radiation dose to the lenses and parotid and thyroid glands with conebeam CT was 4%, 7.8%, and 7.3% of the dose delivered to the same organs by conventional CT (P < .001). CONCLUSIONS: Dental conebeam CT is a valid imaging procedure for the evaluation of patients with inflammatory sinonasal disorders.

A comparison of early diagnostic utility of Alzheimer disease biomarkers in brain magnetic resonance and cerebrospinal fluid.

INTRODUCTION: The goals of this study were to compare the early diagnostic utility of Alzheimer disease biomarkers in the CSF with those in brain MRI in conditions found in our clinical practice, and to ascertain the diagnostic accuracy of both techniques used together. METHODS: Between 2008 and 2009, we included 30 patients with mild cognitive impairment (MCI) who were examined using 1.5 Tesla brain MRI and AD biomarker analysis in CSF. MRI studies were evaluated by 2 radiologists according to the Korf́s visual scale. CSF biomarkers were analysed using INNOTEST reagents for Aß1-42, total-tau and phospho-tau181p. We evaluated clinical changes 2 years after inclusion. RESULTS: By 2 years after inclusion, 15 of the original 30 patients (50%) had developed AD (NINCDS-ADRA criteria). The predictive utility of AD biomarkers in CSF (RR 2.7; 95% CI, 1.1-6.7; P<.01) was greater than that of MRI (RR 1.5; 95% CI 95%, 0.7-3.4; P<.2); using both techniques together yielded a sensitivity and a negative predictive value of 100%. Normal results on both complementary tests ruled out progression to AD (100%) within 2 years of inclusion. CONCLUSIONS: Our results show that the diagnostic accuracy of biomarkers in CSF is higher than that of biomarkers in MRI. Combined use of both techniques is highly accurate for either early diagnosis or exclusion of AD in patients with MCI.

Nocardiosis in solid-organ transplant recipients: spectrum of imaging findings.

Nocardiosis is an infrequent but severe infection that primarily affects the lung and thence is able to produce disseminated disease. Prompt diagnosis of pulmonary and disseminated nocardiosis is of utmost importance in solid-organ transplant recipients to reduce mortality. Knowledge of the different radiological manifestations in the appropriate clinical setting is key to successful management of these patients. The aim of this review is to describe the radiological features of nocardiosis in immunosuppressed patients, particularly in solid-organ transplant recipients.

Pulmonary blood volume imaging with dual-energy computed tomography: spectrum of findings.

Dual-energy (DE) pulmonary blood volume (PBV) computed tomography (CT) has recently become available on clinical CT systems. The underlying physical principle of DECT is the fact that the photoelectric effect is strongly dependent on the CT energies resulting in different degrees of x-ray attenuation for different materials at different energy levels. DECT thus enables the characterization and quantification of iodine within tissues via imaging at different x-ray energies and analysis of attenuation differences. Technical approaches to DECT include dual-source scanners acquiring two scans with different energy levels simultaneously, and single-source CT scanners using sandwich detectors or rapid voltage switching. DE PBV CT enables the creation of iodine maps of the pulmonary parenchyma. Experience to date shows that these studies can provide additional physiological information in patients with acute or chronic pulmonary embolism beyond the pure morphological assessment a standard CT pulmonary angiography (CTPA) provides. It appears also to be promising for the evaluation of patients with obstructive airways disease. This article reviews the physics and technical aspects of DE PBV CT as well as the appearance of normal and abnormal lung tissue on these studies. Special consideration is given to pitfalls and artefacts.