Resonancia magnética de la pancreatitis autoinmune: una revisión de la literatura / Magnetic resonance imaging of autoimmune pancreatitis: a review of literature

La pancreatitis autoinmune (PAI) es una forma distinta de pancreatitis crónica, que se caracteriza por un mecanismo patogénico autoinmune. Su frecuencia es levemente mayor en los pacientes de sexo masculino (60%) y la edad promedio de presentación oscila entre los 40 y 60 años, aunque el rango etario es mucho más amplio (de 14 a 80 años). Desde el punto de vista histológico, la PAI se presenta con un infiltrado inflamatorio denso, de extensión variable, que puede ser focal o comprometer difusamente todo el páncreas. Su presentación clínica en la mayoría de los casos es inespecífica: dolor abdominal leve y rara vez síntomas de pancreatitis aguda, pérdida de peso o ictericia. Varios estudios han descrito un compromiso multiorgánico por el proceso autoinmune, indicando la naturaleza sistémica de la enfermedad. En 2011 el Consenso Internacional de Criterios Diagnósticos de la Pancreatitis Autoinmune (ICDC, por sus siglas en inglés) establecieron las directrices o guías diagnósticas, estipulando que la resonancia magnética (RM) y la colangiopancreatografía por RM (CPRM) constituyen las técnicas diagnósticas cardinales. En este trabajo presentamos las características imagenológicas de la PAI, sus diagnósticos diferenciales y hallazgos en imágenes luego del tratamiento y seguimiento. Adicionalmente, comunicamos nuestra experiencia en esta enfermedad problemática y poco frecuente.

Autoimmune pancreatitis (AIP) is a distinct form of chronic pancreatitis caused by an autoimmune pathogenetic mechanism. It affects males (60%) slightly more frequently, and generally occurs between 40 to 60 years, although the possible range is much wider (14-80 years). Histologically AIP is characterised by the presence of a dense inflammatory infíltrate, with variable extensión. It can be focal or diffuse throughout the whole páncreas. Clinical presentation in most cases is non-specific, with patients presenting with mild abdominal pain, rarely, acute pancreatitis symptoms, weight loss, and jaundice. Several studies reported múltiple organ involvement due to the autoimmune process, suggesting a systemic nature of the disease. In 2011 the International Consensus Diagnostic Criteria for autoimmune pancreatitis (ICDC) defined the guidelines, and magnetic resonance imaging (MRI) and MR-cholangiopancreatography (MRCP) became the reference diagnostic technique in the diagnosis of the disease. This paper will review the imaging characteristics, the differential diagnosis, and the imaging features after treatment and follow up. Furthermore, our experience in this uncommon and challenging disease is reviewed.

Detection and localization of deep endometriosis by means of MRI and correlation with the ENZIAN score.

PURPOSE: To determine the accuracy of ENZIAN score, as detected on MR imaging, compared to surgical-pathologic findings. MATERIALS AND METHODS: This retrospective study was approved by the investigational review board and the requirement for informed patient consent was waived. 115 patients were included according to following criteria: tubo-ovarian and/or deep endometriosis suspected at physical examination and transvaginal ultrasound; availability of MR examination; histopathological results from laparoscopic or surgical treatment. EXCLUSION CRITERIA: lack of available MR examination, and/or (b) lack of a definitive histopathological results. Histopathological findings from bioptic specimens obtained during laparoscopic or laparotomic treatment were considered as reference standard. For all detected lesions a score according to ENZIAN score (revised 2010) was assigned both for MRI and histopathological findings. By comparing MRI-ENZIAN score and histopathological-ENZIAN score the overall sensitivity, specificity, accuracy, positive and negative predictive values in relation to presence/absence of deep endometriosis in each patient were calculated. k-Cohen to evaluate the degree of concordance between MRI-ENZIAN score and histopathological-ENZIAN score was also measured. Moreover the sensitivity, specificity, accuracy, positive and negative predictive values for each specific localization provided by ENZIAN score were also calculated. RESULTS: At histopathology, the diagnosis of deep endometriosis was confirmed in 82/115 (71.3%) patients. The sensitivity, specificity, accuracy, PPV and NPV of MRI were 94%, 97%, 95%, 99%, 86%, respectively. The highest accuracy was for adenomyosis (100%) and endometriosis of utero-sacral ligaments (USLs) (98%), slightly lower for vagina-rectovaginal septum an colo-rectal walls (96%), and the lowest for bladder endometriosis (92%). The concordance between histopathological and MRI ENZIAN score was excellent (k=0.824); in particular it was 0.812 for lesions in vagina-rectovaginal space, 0.890 for lesions in USL, 0.822 for lesions in rectum-sigmoid colon, 1.000 for uterine adenomyosis, and 0.367 for lesions located in the bladder wall. CONCLUSION: MRI correlates with the ENZIAN score and has an accuracy of 95% in the detection and localization of deep endometriosis, allowing to minimize false negative results (4%) in patients with deep endometriosis and to obtain a correct preoperative staging.