Automatic Multi-Atlas Liver Segmentation and Couinaud Classification from CT Volumes.

Primary Live Cancer (PLC) is the sixth most common cancer worldwide and its occurrence predominates in patients with chronic liver diseases and other risk factors like hepatitis B and C. Treatment of PLC and malignant liver tumors depend both in tumor characteristics and the functional status of the organ, thus must be individualized for each patient. Liver segmentation and classification according to Couinaud's classification is essential for computer-aided diagnosis and treatment planning, however, manual segmentation of the liver volume slice by slice can be a time-consuming and challenging task and it is highly dependent on the experience of the user. We propose an alternative automatic segmentation method that allows accuracy and time consumption amelioration. The procedure pursues a multi-atlas based classification for Couinaud segmentation. Our algorithm was implemented on 20 subjects from the IRCAD 3D data base in order to segment and classify the liver volume in its Couinaud segments, obtaining an average DICE coefficient of 0.94.Clinical Relevance- The final purpose of this work is to provide an automatic multi-atlas liver segmentation and Couinaud classification by means of CT image analysis.

Determination of Non-Invasive Biomarkers for the Assessment of Fibrosis, Steatosis and Hepatic Iron Overload by MR Image Analysis. A Pilot Study.

The reference diagnostic test of fibrosis, steatosis, and hepatic iron overload is liver biopsy, a clear invasive procedure. The main objective of this work was to propose HSA, or human serum albumin, as a biomarker for the assessment of fibrosis and to study non-invasive biomarkers for the assessment of steatosis and hepatic iron overload by means of an MR image acquisition protocol. It was performed on a set of eight subjects to determine fibrosis, steatosis, and hepatic iron overload with four different MRI sequences. We calibrated longitudinal relaxation times (T1 [ms]) with seven human serum albumin (HSA [%]) phantoms, and we studied the relationship between them as this protein is synthesized by the liver, and its concentration decreases in advanced fibrosis. Steatosis was calculated by means of the fat fraction (FF [%]) between fat and water liver signals in "fat-only images" (the subtraction of in-phase [IP] images and out-of-phase [OOP] images) and in "water-only images" (the addition of IP and OOP images). Liver iron concentration (LIC [µmol/g]) was obtained by the transverse relaxation time (T2* [ms]) using Gandon's method with multiple echo times (TE) in T2-weighted IP and OOP images. The preliminary results showed that there is an inverse relationship (r = -0.9662) between the T1 relaxation times (ms) and HSA concentrations (%). Steatosis was determined with FF > 6.4% and when the liver signal was greater than the paravertebral muscles signal, and thus, the liver appeared hyperintense in fat-only images. Hepatic iron overload was detected with LIC > 36 µmol/g, and in these cases, the liver signal was smaller than the paravertebral muscles signal, and thus, the liver behaved as hypointense in IP images.

Neoadjuvant treatment for locally advanced unresectable and borderline resectable pancreatic cancer: oncological outcomes at a single academic centre.

INTRODUCTION: Pancreatic cancer (PC), even in the absence of metastatic disease, has a dismal prognosis. One-third of them are borderline resectable (BRPC) or locally advanced unresectable PC (LAUPC) at diagnosis. There are limited prospective data supporting the best approach on these tumours. Neoadjuvant chemotherapy (ChT) is being increasingly used in this setting. METHODS: This is a retrospective series of consecutive patients staged as BRPC or LAUPC after discussion in the multidisciplinary board (MDB) at an academic centre. All received neoadjuvant ChT, followed by chemoradiation (ChRT) in some cases, and those achieving enough downstaging had a curative-intent surgery. Descriptive data about patient's characteristics, neoadjuvant treatments, toxicities, curative resections, postoperative complications, pathology reports and adjuvant treatment were collected. Overall survival (OS) and progression-free survival was calculated with Kaplan-Meier method and log-rank test. RESULTS: Between August 2011 and July 2019, 49 patients fulfilled the inclusion criteria, and all of them received neoadjuvant ChT. Fluorouracil+folinic acid, irinotecan and oxaliplatin was the most frequently used scheme (77%). The most prevalent grade 3 or 4 toxicities were neutropenia (26.5%), neurotoxicity (12.2%), diarrhoea (8.2%) and nausea (8.2%). 18 patients (36.7%) received ChRT thereafter. In total, 22 patients (44,9%) became potentially resectable and 19 of them had an R0 or R1 pancreatic resection. One was found to be unresectable at surgery and two refused surgery. A vascular resection was required in 7 (35%). No postoperative deaths were observed. Postoperative ChT was given to 12 (66.7%) of resected patients. Median OS of the whole cohort was 24,9 months (95% CI 14.1 to 35.7), with 30.6 months for resected and 13.1 months for non-resected patients, respectively (p<0.001). CONCLUSION: A neoadjuvant approach in BRPC and LAUPC was well tolerated and allowed a curative resection in 38.8% of them with a potential improvement on OS.

Non invasive blood flow measurement in cerebellum detects minimal hepatic encephalopathy earlier than psychometric tests.

AIM: To assess whether non invasive blood flow measurement by arterial spin labeling in several brain regions detects minimal hepatic encephalopathy. METHODS: Blood flow (BF) was analyzed by arterial spin labeling (ASL) in different brain areas of 14 controls, 24 cirrhotic patients without and 16 cirrhotic patients with minimal hepatic encephalopathy (MHE). Images were collected using a 3 Tesla MR scanner (Achieva 3T-TX, Philips, Netherlands). Pulsed ASL was performed. Patients showing MHE were detected using the battery Psychometric Hepatic Encephalopathy Score (PHES) consisting of five tests. Different cognitive and motor functions were also assessed: alterations in selective attention were evaluated using the Stroop test. Patients and controls also performed visuo-motor and bimanual coordination tests. Several biochemical parameters were measured: serum pro-inflammatory interleukins (IL-6 and IL-18), 3-nitrotyrosine, cGMP and nitrates+nitrites in plasma, and blood ammonia. Bivariate correlations were evaluated. RESULTS: In patients with MHE, BF was increased in cerebellar hemisphere (P = 0.03) and vermis (P = 0.012) and reduced in occipital lobe (P = 0.017). BF in cerebellar hemisphere was also increased in patients without MHE (P = 0.02). Bimanual coordination was impaired in patients without MHE (P = 0.05) and much more in patients with MHE (P < 0.0001). Visuo-motor coordination was impaired only in patients with MHE (P < 0.0001). Attention was slightly affected in patients without MHE and more strongly in patients with MHE (P < 0.0001). BF in cerebellar hemisphere and vermis correlated with performance in most tests of PHES [(number connection tests A (NCT-A), B (NCT-B)and line tracing test] and in the congruent task of Stroop test. BF in frontal lobe correlated with NCT-A. Performance in bimanual and visuomotor coordination tests correlated only with BF in cerebellar hemisphere. BF in occipital lobe correlates with performance in the PHES battery and with CFF. BF in cerebellar hemisphere correlates with plasma cGMP and nitric oxide (NO) metabolites. BF in vermis cerebellar also correlates with NO metabolites and with 3-nitrotyrosine. IL-18 in plasma correlates with BF in thalamus and occipital lobe. CONCLUSION: Non invasive BF determination in cerebellum using ASL may detect MHE earlier than the PHES. Altered NO-cGMP pathway seems to be associated to altered BF in cerebellum.

Focal cortical damage parallels cognitive impairment in minimal hepatic encephalopathy.

Little attention has been paid to cortical integrity in patients with minimal hepatic encephalopathy (MHE), although cognitive functions affected in early stages of liver disease are mainly allocated in different neocortical structures. Here we used cortical surface-based analysis techniques to investigate if patterns of cortical thinning accompany the mildest form of HE. To aim this goal, cortical thickness obtained from high-resolution 3T magnetic resonance imaging (MRI) was measured in patients with no MHE (NMHE), MHE, and healthy controls. Further correlation analyses were performed to examine whether scores in the critical flicker frequency (CFF) test, and blood ammonia levels accounted for the loss of cortical integrity in different stages of liver disease. Finally, we assessed group differences in volume of different subcortical regions and their potential relationships with CFF scores/blood ammonia levels. Results showed a focal thinning of the superior temporal cortex and precuneus in MHE patients when compared with NMHE and controls. Relationships between blood ammonia levels and cortical thickness of the calcarine sulcus accounted for impaired visual judgment in patients with MHE when compared to NMHE. Regression analyses between cortical thickness and CFF predicted differences between controls and the two groups of HE patients, but failed to discriminate between patients with NMHE and MHE. Taking together, these findings provide the first report of cortical thinning in MHE patients, and they yield novel insights into the neurobiological basis of cognitive impairment associated with early stages of liver diseases.

Estudio de la grasa abdominal mediante resonancia magnética: comparación con parámetros antropométricos y de riesgo cardiovascular / Abdominal fat assessment by magnetic resonance: comparison with biometric profiles and cardiovascular risk markers

FUNDAMENTO: La obesidad se asocia a numerosas complicaciones. En la frecuencia e intensidad de las mismas parece influir el depósito de grasa intraabdominal. La resonancia magnética es una técnica con una gran resolución espacial y capacidad de discriminación tisular. El objetivo del presente trabajo es estudiar el depósito graso abdominal y cuantificar su distribución relativa en un grupo de pacientes obesos, relacionando los hallazgos con la presencia de marcadores clínicos y analíticos de riesgo cardiovascular. PACIENTES Y MÉTODO: A todos los pacientes se les realizó un estudio de resonancia magnética abdominal, adquiriéndose imágenes axiales potenciadas en T1. Mediante el empleo de un programa de tratamiento de imágenes (ASYMED 3.0, Valencia) se cuantificó la distribución de la grasa en los compartimientos subcutáneo e intraabdominal. Se compararon los resultados de la resonancia magnética con los valores medios de diferentes marcadores de riesgo cardiovascular mediante la prueba de la t de Student para datos no apareados. Se fijó el nivel de significación en p < 0,05. RESULTADOS: El 12 por ciento de los pacientes presentaban una acumulación grasa de predominio intraabdominal. Se detectaron diferencias significativas en las cifras medias de edad, índice de cintura-cadera, y los valores de colesterol total, lipoproteínas de baja y muy baja densidad, triglicéridos y apoproteínas B entre los grupos determinados por ésta. CONCLUSIÓN: Mediante la resonancia magnética se obtuvieron imágenes adecuadas para calcular la distribución de grasa abdominal. Existe una relación estadísticamente significativa entre una mayor proporción de grasa intraabdominal y un perfil lipídico más aterogénico (AU)

TC helicoidal del sector vascular aortoilíaco: optimación del retraso en la adquisición mediante el método del bolo de prueba / Helical computed tomography of the aortoiliac vessels: optimization of the scan delay using the test bolus method

Objetivo: Optimar el tiempo de retraso en la adquisición de estudios de tomografía computarizada (TC) helicoidal del sector vascular aortoilíaco utilizando el método del bolo de prueba. Material y Métodos: Se estudiaron 90 pacientes consecutivos remitidos para evaluación del sector vascular aortoilíaco. En todos se calculó el tiempo de llegada del contraste a la aorta (T0 pico) de acuerdo con un protocolo predefinido utilizando el método del bolo de prueba, aplicándose distintos retrasos en la adquisición de la hélice. Se midieron los valores de atenuación en tres zonas de la aorta abdominal de todos los pacientes. Los resultados de captación por zonas y tiempos de retraso se compararon mediante la prueba ANOVA y Student-Newman- Keuls. El nivel de significación se fijó en p < 0,05.Resultados: El tiempo medio de llegada del contraste fue de 22,3 segundos (intervalo, 13-40). La captación media para las regiones inicial, central y distal de la aorta fue de 231, 260, y 254 UH en los grupos con retraso de T0 pico +5 segundos; de 275, 287 y 287 UH para un retraso de T0 pico + 10 segundos; y de 266, 259 y 276 UH para un retraso de T0 pico + 15 segundos, respectivamente. Conclusiones: La aplicación del método del bolo de prueba en la optimación de la captación intravascular en el sector vascular aortoilíaco permite lograr un elevado grado de realce. Cuando se utiliza un retraso de T0 pico + 10 segundos la opacificación vascular es homogénea en toda la aorta abdominal y mayor que con otras formulaciones (AU)