Luis Martí-Bonmatí

ESGAR consensus statement on liver MR imaging and clinical use of liver-specific contrast agents

ObjectivesTo develop a consensus and provide updated recommendations on liver MR imaging and the clinical use of liver-specific contrast agents.MethodsThe European Society of Gastrointestinal and Abdominal Radiology (ESGAR) formed a multinational European panel of experts, selected on the basis of a literature review and their leadership in the field of liver MR imaging. A modified Delphi process was adopted to draft a list of statements. Descriptive and Cronbach’s statistics were used to rate levels of agreement and internal reliability of the consensus.ResultsThree Delphi rounds were conducted and 76 statements composed on MR technique (nu2009=u200917), clinical application of liver-specific contrast agents in benign, focal liver lesions (nu2009=u20097), malignant liver lesions in non-cirrhotic (nu2009=u20099) and in cirrhotic patients (nu2009=u200918), diffuse and vascular liver diseases (nu2009=u200912), and bile ducts (nu2009=u200913). The overall mean score of agreement was 4.84 (SD ±0.17). Full consensus was reached in 22xa0% of all statements in all working groups, with no full consensus reached on diffuse and vascular diseases.ConclusionsThe consensus provided updated recommendations on the methodology, and clinical indications, of MRI with liver specific contrast agents in the study of liver diseases.Key points• Liver-specific contrast agents are recommended in MRI of the liver.• The hepatobiliary phase improves the detection and characterization of hepatocellular lesions.• Liver-specific contrast agents can improve the detection of HCC.

Abnormal activation of the motor cortical network in idiopathic scoliosis demonstrated by functional MRI

The aetiology of idiopathic scoliosis (IS) remains unknown, but there is growing support for the possibility of an underlying neurological disorder. Functional magnetic resonance imaging (fMRI) can characterize the abnormal activation of the sensorimotor brain network in movement disorders and could provide further insights into the neuropathogenesis of IS. Twenty subjects were included in the study; 10 adolescents with IS (mean age of 15.2, 8 girls and 2 boys) and 10 age-matched healthy controls. The average Cobb angle of the primary curve in the IS patients was 35° (range 27°–55°). All participants underwent a block-design fMRI experiment in a 1.5-Tesla MRI scanner to explore cortical activation following a simple motor task. Rest periods alternated with activation periods during which participants were required to open and close their hand at an internally paced rate of approximately 1xa0Hz. Data were analyzed with Statistical Parametric Mapping (SPM5) including age, sex and laterality as nuisance variables to minimise the presence of bias in the results. Compared to controls, IS patients showed significant increases in blood oxygenation level dependent (BOLD) activity in contralateral supplementary motor area when performing the motor task with either hand. No significant differences were observed when testing between groups in the functional activation in the primary motor cortex, premotor cortex and somatosensory cortex. Additionally, the IS group showed a greater interhemispheric asymmetry index than the control group (0.30 vs. 0.13, pxa0<xa00.001). This study demonstrates an abnormal pattern of brain activation in secondary motor areas during movement execution in patients with IS. These findings support the hypothesis that a sensorimotor integration disorder underlies the pathogenesis of IS.

Automated Glioblastoma Segmentation Based on a Multiparametric Structured Unsupervised Classification

Automatic brain tumour segmentation has become a key component for the future of brain tumour treatment. Currently, most of brain tumour segmentation approaches arise from the supervised learning standpoint, which requires a labelled training dataset from which to infer the models of the classes. The performance of these models is directly determined by the size and quality of the training corpus, whose retrieval becomes a tedious and time-consuming task. On the other hand, unsupervised approaches avoid these limitations but often do not reach comparable results than the supervised methods. In this sense, we propose an automated unsupervised method for brain tumour segmentation based on anatomical Magnetic Resonance (MR) images. Four unsupervised classification algorithms, grouped by their structured or non-structured condition, were evaluated within our pipeline. Considering the non-structured algorithms, we evaluated K-means, Fuzzy K-means and Gaussian Mixture Model (GMM), whereas as structured classification algorithms we evaluated Gaussian Hidden Markov Random Field (GHMRF). An automated postprocess based on a statistical approach supported by tissue probability maps is proposed to automatically identify the tumour classes after the segmentations. We evaluated our brain tumour segmentation method with the public BRAin Tumor Segmentation (BRATS) 2013 Test and Leaderboard datasets. Our approach based on the GMM model improves the results obtained by most of the supervised methods evaluated with the Leaderboard set and reaches the second position in the ranking. Our variant based on the GHMRF achieves the first position in the Test ranking of the unsupervised approaches and the seventh position in the general Test ranking, which confirms the method as a viable alternative for brain tumour segmentation.

Producción española sobre diagnóstico por la imagen en cardiología y radiología (1994-1998)

Introduccion y objetivos El proposito de este estudio es realizar un analisis comparativo de la productividad de los autores espanoles en articulos sobre diagnostico por la imagen en el periodo 1994-1998 en: a) las revistas oficiales de 2 sociedades medicas espanolas, la de Cardiologia (R EVISTA E SPANOLA DE C ARDIOLOGIA ) y la de Radiologia Medica (Radiologia), y b) revistas extranjeras sobre las especialidades incluidas en Journal Citation Reports. Material y metodo Para la recuperacion de los articulos se disenaron perfiles de busqueda especificos para las bases de datos IME y MEDLINE, y se valoro en las revistas extranjeras el factor de impacto por especialidad normalizado al numero de trabajos publicados. Resultados Se analizaron 967 trabajos, 301 sobre imagen diagnostica cardiovascular (el 50,5% publicado en R EVISTA E SPANOLA DE C ARDIOLOGIA ) y 666 sobre radiodiagnostico (el 55,1% publicado en Radiologia), con diferencias que no fueron significativas. El factor de impacto medio por especialidad fue de 2,46 para cardiologia y 0,98 para radiodiagnostico. El porcentaje de trabajos en el primer cuartil de las revistas de mayor impacto fue del 38,6% (cardiologia) y del 17,2% (radiologia), con diferencias significativas (p Discusion La tendencia progresiva de los radiologos hacia la publicacion en revistas extranjeras (aunque cardiologos y radiologos publican la mitad de su produccion en la revista de su sociedad nacional) y las diferencias en la produccion internacional en revistas del primer cuartil de su disciplina (el doble en cardiologia respecto a radiologia) sugieren una incorporacion a la comunidad cientifica internacional mas tardia en radiologia.

Diagnóstico y tratamiento del carcinoma hepatocelular. Actualización del documento de consenso de la AEEH, SEOM, SERAM, SERVEI y SETH

Hepatocellular carcinoma is the most common primary malignancy of the liver and one of the most frequent causes of death in patients with liver cirrhosis. Simultaneously with the recognition of the clinical relevance of this neoplasm, in recent years there have been important developments in the diagnosis, staging and treatment of HCC. Consequently, the Asociación Española para el Estudio del Hígado has driven the need to update clinical practice guidelines, continuing to invite all the societies involved in the diagnosis and treatment of this disease to participate in the drafting and approval of the document (Sociedad Española de Trasplante Hepático, Sociedad Española de Radiología Médica, Sociedad Española de Radiología Vascular e Intervencionista y Sociedad Española de Oncología Médica). The clinical practice guidelines published in 2009 accepted as Clinical Practice Guidelines of the National Health System has been taken as reference document, incorporating the most important advances that have been made in recent years. The scientific evidence for the treatment of HCC has been evaluated according to the recommendations of the National Cancer Institute (www.cancer.gov) and the strength of recommendation is based on the GRADE system.

Does radiographic location ensure precise anatomic location of the femoral fixation site in medial patellofemoral ligament surgery

PurposeTo correlate the location of the medial patellofemoral ligament femoral fixation site in knees suffering a chronic lateral patellar instability, by using radiographic references and by using the most important anatomic reference point (i.e. the adductor tubercle) identified by means of 3-dimensional (3D) surface reconstructions by computed tomography (CT) imaging.MethodsThirty consecutive knee 3D-CT examinations at 0º of knee extension were obtained from patients (20 females, 10 males; median age of 23.5xa0years; range, 14–48xa0years) treated for chronic lateral patellar instability with at least two documented patellar dislocations. For each knee, three virtual 7-mm-diameter femoral tunnels were created. One of the tunnels used an anatomic fixation landmark (anatomic fixation), while the other two used established radiologic methods. We calculated the percentage of the anatomic tunnel covered by the tunnel created according to the method described by Schoettle, and the percentage of the anatomic tunnel covered by the tunnel created according to the method described by Stephen. These percentages were compared using paired Student’s t test.ResultsThe percentage of anatomic tunnel area covered by the femoral tunnel created using Schoettle’s method was 36.7xa0±xa025.2xa0%. When using Stephen’s method, the percentage of overlap with the anatomic femoral tunnel was 25.5xa0±xa021.5xa0%. There were no significant differences between the two radiographic methods (n.s.).ConclusionNone of the standard radiographic methods allowed a precise anatomic femoral placement. Conventional radiographic identification of the femoral graft placement site is only an approximation and should not be the sole basis for femoral attachment location.Level of evidenceIV

Femoral insertion site of the graft used to replace the medial patellofemoral ligament influences the ligament dynamic changes during knee flexion and the clinical outcome.

AbstractPurposenThis study’s purpose was to investigate how an ideal anatomic femoral attachment affects the dynamic length change pattern of a virtual medial patellofemoral ligament (MPFL) from an extended to a highly flexed knee position; to determine the relative length and length change pattern of a surgically reconstructed MPFL; and to correlate femoral attachment positioning, length change pattern, and relative graft length with the clinical outcome.MethodsnTwenty-four knees with isolated nonanatomic MPFL reconstruction were analysed by three-dimensional computed tomography at 0°, 30°, 60°, 90°, and 120° of knee flexion. The lengths of the MPFL graft and a virtual anatomic MPFL were measured. The pattern of length change was considered isometric if the length distance changed <5xa0mm through the entire dynamic range of motion.ResultsKnee flexion significantly affected the path lengths between the femoral and patellar attachments. The length of the anatomic virtual MPFL decreased significantly from 60° to 120°. Its maximal length was 56.4xa0±xa06.8xa0mm at 30°. It was isometric between 0° and 60°. The length of the nonanatomic MPFL with a satisfactory clinical result decreased during flexion from 0° to 120°. Its maximal length was 51.6xa0±xa04.6xa0mm at 0° of knee flexion. The lengths measured at 0° and 30° were isometric and statistically greater than the lengths measured at higher flexion degrees. The failed nonanatomic MPFL reconstructions were isometric throughout the dynamic range, being significantly shorter (27.1xa0±xa013.3xa0%) than anatomic ligaments.ConclusionThe femoral attachment point significantly influences the relative length and the dynamic length change of the grafts during knee flexion–extension and graft isometry. Moreover, it influences the long-term outcome of the MPFL reconstructive surgery. A nonanatomic femoral fixation point should not be considered the cause of persistent pain and instability after MPFL reconstruction in all cases.Level of evidenceIII.

Accurate simultaneous quantification of liver steatosis and iron overload in diffuse liver diseases with MRI.

PurposeTo evaluate the diagnostic performances of 3xa0Tesla multi-echo chemical shift-encoded gradient echo magnetic resonance (MECSE-MR) imaging to simultaneously quantify liver steatosis and iron overload in a wide spectrum of diffuse liver diseases having biopsy as reference standard.MethodsMECSE-MR-acquired images were used to calculate fat fraction and iron content in a single breath-hold in 109 adult patients. Proton density fat fraction (PDFF) was prospectively estimated using complex-based data reconstruction with multipeak fat modeling. Water R2* was used to estimate iron content. Biopsy was obtained in all cases,xa0grading liver steatosis, siderosis, inflammation, and fibrosis. Differences in PDFF and R2* values across histopathological grades were analyzed, and ROC curves analyses evaluated the MR diagnostic performance.ResultsCalculated fat fraction measurements showed significant differences (pxa0<xa00.001) among steatosis grades, being unaffected by the presence of inflammation or fibrosis (pxa0≥xa00.05). A strong correlation was found between fat fraction and steatosis grade (RSxa0=xa00.718, pxa0<xa00.001). Iron deposits did not affect fat fraction quantitation (pxa0≥xa00.05), except in cases with severe iron overload (grade 4). A strong positive correlation was also observed between R2* measurements and iron grades (RSxa0=xa00.704, pxa0<xa00.001). Calculated R2* values were not different across grades of steatosis, inflammation, and fibrosis (pxa0≥xa00.05).ConclusionA MECSE-MR sequence simultaneously quantifies liver steatosis and siderosis, regardless coexisting liver inflammation or fibrosis, with high accuracy in a wide spectrum of diffuse liver disorders. This sequence can be acquired within a single breath-hold and can be implemented in the routine MR evaluation of the liver.

Evaluation of fibrosis and inflammation in diffuse liver diseases using intravoxel incoherent motion diffusion-weighted MR imaging

PurposeThe purpose of the study was to evaluate the role of intravoxel incoherent motion (IVIM) diffusion model for the assessment of liver fibrosis and inflammation in diffuse liver disorders, also considering the presence of liver steatosis and iron deposits.MethodsSeventy-four patients were included, with liver biopsy and a 3 Tesla abdominal magnetic resonance imaging examination, with an IVIM diffusion-weighted sequence (single-shot spin-echo echo-planar sequence, with gradient reversal fat suppression; 6 b-values: 0, 50, 200, 400, 600, and 800xa0s/mm2). Histological evaluation comprised the Ishak modified scale, for grading inflammation and fibrosis, plus steatosis and iron loading classification. The liver apparent diffusion coefficient (ADC) and IVIM parameters (D, D*, f) were calculated from the IVIM images. The relationship between IVIM parameters and histopathological scores were evaluated by ANOVA and Spearman correlation tests. A test–retest experiment assessed reproducibility and repeatability in 10 healthy volunteers and 10 randomly selected patient studies.ResultsADC and f values were lower with higher fibrosis stages (pxa0=xa00.009, pxa0=xa00.006, respectively) and also with higher necro-inflammatory activity grades (pxa0=xa00.02, pxa0=xa00.017, respectively). Considered together, only fibrosis presented a significant effect on ADC and f measurements (pxa0<xa00.05), whereas inflammation had no significant effect (pxa0>xa00.05). A mild correlation was found between ADC and f with fibrosis (RSxa0=xa0−0.32 and RSxa0=xa0−0.38; pxa0<xa00.05) and inflammation (RSxa0=xa0−0.31 and RSxa0=xa0−0.32, pxa0<xa00.05; respectively). The AUROC for ADC and f measurements with the different dichotomizations between fibrosis or inflammation grades were only fair (0.670 to 0.749, pxa0<xa00.05). Neither D nor D* values were significantly different between liver fibrosis or inflammation grades. D measurements were significantly different across histologic grades of steatosis (pxa0<xa00.001) and iron overload (pxa0<xa00.001), whereas f measurements showed significant differences across histologic steatosis grades (pxa0=xa00.005). There was an excellent agreement between the different readers for ADC, f, and D.ConclusionsAlthough fibrosis presented a significant effect on ADC and f, IVIM measurements are not accurate enough to stage liver fibrosis or necro-inflammatory activity in diffuse liver diseases. D values were influenced by steatosis and iron overload.

Human AAT gene transfer to pig liver improved by using a perfusion isolated organ endovascular procedure

AbstractObjectiveThe efficiency of endovascular liver gene transfer in pigs is evaluated by comparing two models of retrograde catheterization: single lobe catheterization with portal inflow (open procedure) versus whole liver isolation with portal and inferior vena cava blockage (close procedure).MethodsPercutaneous endovascular catheterization was performed in pigs. Open procedure (nu2009=u20093): 8Fr balloon catheter placement in a suprahepatic branch through the jugular vein. Closed procedure (nu2009=u20093): simultaneous catheterization of the intrahepatic portal vein (transhepatic catheterization, 10Fr balloon catheter), the supra- and infrahepatic cava veins (8Fr balloon catheters through the jugular and femoral veins). In both models, 200xa0ml of hAAT DNA solution (20xa0μg/ml) were retrogradely injected at 20xa0ml/s. Tissue samples (8 per liver) were obtained 14xa0days later and the exogenous DNA, RNA and protein per cell were quantified. Blood samples were collected periodically for transaminase determination in all the animals.ResultsThe open procedure achieved lower (approx. 1000-fold) DNA delivery, resulting in a significantly lower (pu2009<u20090.001) gene transcription (>100-fold). The closed model also achieved a higher translation index, although differences were smaller (pu2009<u20090.001).ConclusionsPortal inflow blockage increased the delivery, transcription and translation indexes, significantly improving the final procedure efficacy when compared with an open procedure.Key Points• Endovascular hydrodynamic pig liver gene transfer: open procedure versus closed proceduren • Open procedure resulted in much lower DNA delivery than closed modeln • Open procedure reached significantly lower gene transcription indexn • Translation index with closed model was higher than with the open