Rectal cancer at the peritoneal reflection. Preoperative MRI accuracy and histophatologic correlation. Prospective study.

INTRODUCTION: To investigate magnetic resonance imaging (MRI) accuracy for determining the location of rectal tumors with respect to the peritoneal reflection (PR) and its potential involvement. METHODS: Prospective study of 161 patients ongoing surgery for rectal cancer. A double-ink method has been aplied to examine surgical specimen, orange ink for the serosal surface and indian ink for the mesorrectal margin, and assess preoperative MRI accuracy. RESULTS: Twenty-two tumors were located above, 65 at and 74 below PR. MRI accuracy was 90.6% for determining tumor's location with respect to the PR and 80.5% for defining peritoneal involvement. For classifying tumors according to their intra or extraperitoneal location an accuracy of 92.5% was set for MRI. Histophatologic peritoneal involvement was found in 28.7% of tumors located above or at the PR. CONCLUSIONS: Magnetic resonance imaging accurately predicts the location of rectal tumors with respect to the PR and its potential involvement. The double-ink method is useful to assess serosal involvement (pT4a) and to distinguish mesorrectal fascia from the peritonealized surface.

Rectal cancer at the peritoneal reflection. Preoperative MRI accuracy and histophatologic correlation. Prospective study. / Cáncer de recto a nivel de la reflexión peritoneal. Exactitud de la RM preoperatoria y correlación anatomopatológica. Estudio prospectivo.

INTRODUCTION: To investigate magnetic resonance imaging (MRI) accuracy for determining the location of rectal tumors with respect to the peritoneal reflection (PR) and its potential involvement. METHODS: Prospective study of 161 patients ongoing surgery for rectal cancer. A double-ink method has been aplied to examine surgical specimen, orange ink for the serosal surface and indian ink for the mesorrectal margin, and assess preoperative MRI accuracy. RESULTS: Twenty-two tumors were located above, 65 at and 74 below PR. MRI accuracy was 90.6% for determining tumor's location with respect to the PR and 80.5% for defining peritoneal involvement. For classifying tumors according to their intra or extraperitoneal location an accuracy of 92.5% was set for MRI. Histophatologic peritoneal involvement was found in 28.7% of tumors located above or at the PR. CONCLUSIONS: Magnetic resonance imaging accurately predicts the location of rectal tumors with respect to the PR and its potential involvement. The double-ink method is useful to assess serosal involvement (pT4a) and to distinguish mesorrectal fascia from the peritonealized surface.

Pancreatic necrosis volume - A new imaging biomarker of acute pancreatitis severity.

OBJECTIVE: Determine if the pancreatic necrosis volume (PNV) in computed tomography scan (CT) is a useful marker to predict the severity of acute pancreatitis (AP) comparing its predictive value with current clinical scoring systems. METHODS: This retrospective study was conducted in a tertiary hospital, including patients hospitalized with AP during the period of 24 months. Demographic, clinical data, length of hospital stay and analytical parameters were collected from the hospital clinical information digital systems. Other information on the severity of the disease was also reviewed, including BISAP score, organ failure (OF) or admission to the ICU, as well as, complications during hospitalization as infected necrotic collections, surgical procedure or death. The quantification of the necrosis volume, CT severity index and Balthazar score were assessed in the CT studies. ROC curves were carried to compare the correlation between different scoring systems and the acute complications. RESULTS: This study included 163 patients with AP. The calculated average value of PNV in the CT studies was 242 cc (0-1575 cc). PNV showed lineal correlation with hospital stay (Pearson 0.696) and statistically significant association with acute complications as OF, multiple organ failure, infection, need of treatment or hospitalization at ICU (P < 0.05). The optimal cut-off value for predicting complications of necrosis as infections or need of surgery treatments was 75 cc. Sensibility and specificity were 100 % and 78 %, respectively. ROC curves showed that PNV was the best radiological finding correlated with AP complications. CONCLUSION: Necrosis volume is a radiological biomarker highly correlated with AP complications.

La resonancia magnética y el índice MaRIA en la valoración preoperatoria de la enfermedad de Crohn ileal / Use of magnetic resonance index of activity (MaRIA) in the preoperative assessment of small bowel Crohn's disease

Introducción: Es necesaria la correcta cuantificación de la actividad inflamatoria de las lesiones de la enfermedad de Crohn para establecer cuál es el tratamiento más adecuado para cada paciente. El objetivo del presente estudio es valorar la relación entre el índice de actividad inflamatorio por resonancia magnética (MaRIA) preoperatorio y el grado de inflamación histológico de las lesiones obtenidas en la cirugía. Métodos: Estudio prospectivo observacional consecutivo que incluye una serie de pacientes con enfermedad de Crohn ileal. Se realizó una enterografía mediante resonancia magnética, con protocolo y secuencias preestablecidas, en los 3 meses previos a la cirugía y se calculó el índice MaRIA. Todos los pacientes fueron intervenidos quirúrgicamente y se remitieron muestras de cada lesión parietal completa a estudio anatomopatológico. En el análisis histológico se empleó la clasificación de Chiorean. Se realizó un análisis de regresión ordinal e intergrupos. Resultados: Se incluye a 35 pacientes con 59 lesiones. A medida que aumenta el grado de inflamación, se obtienen, de forma significativa (p = 0,002), valores mayores de MaRIA. El índice de MaRIA fue considerablemente diferente (p < 0,001) en los diferentes tipo de lesiones por enfermedad de Crohn (inflamatoria/fibrótica). El mejor valor de corte del índice MaRIA para establecer la existencia de inflamación grave en una lesión ha resultado ser 20 (ABC, 0,741; sensibilidad, 74,1%, y especificidad, 78,1%). Conclusiones: En el estudio de la enfermedad de Crohn ileal, la resonancia y el índice MaRIA son herramientas de gran utilidad para diferenciar entre lesiones inflamatorias y fibrosas, y por tanto, imprescindible para decidir el tratamiento más adecuado

Background: Accurate quantification of the inflammatory activity in Crohn's Disease is essential to determine adequate treatment for each patient. The aim of the present study is to assess the correlation between the pre-operative Magnetic Resonance Index of Activity (MaRIA) and the histologic degree of inflammation from surgically resected intestinal Crohn's Disease lesions. Methods: This is a prospective study including a consecutive case series of patients with small bowel Crohn's Disease, who underwent surgical resection. Magnetic resonance enterography was performed in the 3months prior to surgery, applying a pre-established protocol. Relative contrast enhancements, wall thickness, presence of edema or ulcerations were the parameters used to calculate the MaRIA Index. All patients underwent surgery and every specimen was analyzed. The modified Chiorean classification was applied for the histological analysis and an ordinal regression analysis was used to correlate MaRIA and the grade of inflammation for each lesion. Results: 59 lesions from 35 different patients were analyzed. The degree of inflammation of the lesions was statistically correlated to the MaRIA values (P = .002). The MaRIA index was significantly different (P < .001) between the different histological types of the Crohn's Disease lesions (inflammatory/ fibrotic). The best cut-off for detecting severe inflammation using MaRIA was 20 (AUC: 0.741; 74.1% sensitivity and 78.1% specificity). Conclusion: MaRIA is a reliable tool to distinguish inflammatory from fibrotic lesions. Therefore, it could be considered essential for determining the most appropriate Crohn's Disease treatment for each patient

Use of magnetic resonance index of activity (MaRIA) in the preoperative assessment of small bowel Crohn's disease. / La resonancia magnética y el índice MaRIA en la valoración preoperatoria de la enfermedad de Crohn ileal.

BACKGROUND: Accurate quantification of the inflammatory activity in Crohn's Disease is essential to determine adequate treatment for each patient. The aim of the present study is to assess the correlation between the pre-operative Magnetic Resonance Index of Activity (MaRIA) and the histologic degree of inflammation from surgically resected intestinal Crohn's Disease lesions. METHODS: This is a prospective study including a consecutive case series of patients with small bowel Crohn's Disease, who underwent surgical resection. Magnetic resonance enterography was performed in the 3months prior to surgery, applying a pre-established protocol. Relative contrast enhancements, wall thickness, presence of edema or ulcerations were the parameters used to calculate the MaRIA Index. All patients underwent surgery and every specimen was analyzed. The modified Chiorean classification was applied for the histological analysis and an ordinal regression analysis was used to correlate MaRIA and the grade of inflammation for each lesion. RESULTS: 59 lesions from 35 different patients were analyzed. The degree of inflammation of the lesions was statistically correlated to the MaRIA values (P=.002). The MaRIA index was significantly different (P<.001) between the different histological types of the Crohn's Disease lesions (inflammatory/ fibrotic). The best cut-off for detecting severe inflammation using MaRIA was 20 (AUC: 0.741; 74.1% sensitivity and 78.1% specificity). CONCLUSION: MaRIA is a reliable tool to distinguish inflammatory from fibrotic lesions. Therefore, it could be considered essential for determining the most appropriate Crohn's Disease treatment for each patient.