"DWI-MR AND ADC VALUE IN CHARACTERIZATION OF DIFFERENT PANCREATIC MASSES"

Abstract

Purpose: Our work was aiming to assess DWI and ADC values in characterization of different pancreatic masses.
Patients & methods; This cross sectional study carried out on 20 patients (9 males & 11 females), with a mean age of 48 years (ranged from 35 years to 67 years), from December 2013 till October 2015. All the patients were referred from general surgery, internal medicine, oncology departments and outpatient clinics of Zagazig University hospitals to radiology department for conventional MRI, DWI & ADC mapping. All patients gave a written consent before scanning.
.Results: The mean ADC value of benign pancreatic masses was 2.49x10-3 mm2/sec (at b= 1000 mm2/sec) and 3.006 x10-3 mm2/sec.(at b= 500 mm2/sec). The malignant pancreatic masses mean ADC value was 1.24x10-3 mm2/sec (b= 1000 mm2/sec) and was 1.34x10-3 mm2/sec (b= 500 mm2/sec). So, there is a significant difference between benign and malignant pancreatic masses and the mean ADC values of benign and malignant lesions done by using b=1000 are statistically higher than done by b=500. Sensitivity, specificity, PPV and NPV were 92.8%, 83.33%, 92.8%, 83.33% respectively at b value 500 mm2/sec. However, sensitivity, specificity, PPV, NPV were 100%, 83.33%, 93.33%, 100%, respectively at b value 1000 mm2/sec.
By using ADC cutoff value of 1.5x10-3 mm2/sec in differentiating benign and malignant pancreatic masses, the p value was < 0.001 at b value 1000 mm2/sec.
Conclusion: DWI has the advantage that it can be obtained without breath-holding, using respiratory triggered technique and it is simple and non-invasive. So, we recommend adding of DWI and ADC value in conjunction to conventional MRI as a useful modality in assessment and characterization of pancreatic masses, specially at b value 1000 s/mm2 to get a highest sensitivity and specificity.
Key words: Pancreatic carcinoma; pseudocysts; MRI; DWI and ADC values.