scholarly journals Role of diffusion-weighted MR imaging in diagnosis of acute pancreatitis

Author(s):  
Hanan M. Abuzeid ◽  
Aya Yassin ◽  
Omar F. Kamel ◽  
Kareem A. Sabry

Abstract Background The role of diffusion-weighted magnetic resonance imaging (DW-MRI) in the diagnosis of acute pancreatitis is assessed in this study by measuring the apparent diffusion coefficient (ADC) values in acute pancreatitis and comparing them with a control group. The aim of this study is to compare those two groups thus supporting the diagnosis of this disease. Sixteen patients with acute pancreatitis and 16 control participants underwent diffusion-weighted imaging with b values of 0, 200, and 800. ADC maps were generated from the DW-MRI and ADC values, which were calculated for the pancreas, and the results of the two groups of patients were compared. Results The mean pancreatic ADC value in the acute pancreatitis group (1.15 10(−3) mm(2)/s ± 0.28) was significantly lower than in the normal group (1.6 10−3 mm(2)/s ± 0.2). A threshold ADC value of 1.38 10−3 mm(2)/s yielded 81.25%, specificity of 93.75%, positive predictive value of 92.9%, negative predictive value of 83.3%, and accuracy of 91.8%. Pancreatic ADC values were significantly lower in patients with acute pancreatitis than in the control group. Conclusion Diffusion-weighted magnetic resonance imaging could be an important supportive tool in the diagnosis of acute pancreatitis.

Author(s):  
Jitendra K. Meena ◽  
Anil Taneja

Background: Diffusion-weighted magnetic resonance imaging (DWI) is a valuable tool to narrow down the differential diagnosis of renal masses. Studies have shown that benign renal masses have higher Apparent diffusion coefficient (ADC) value than malignant renal masses. Aim of study was to evaluate the role of diffusion-weighted magnetic resonance imaging in the characterization of renal masses.Methods: The study was conducted in department of Radio diagnosis at ABVIMS and Dr. RML Hospital, New Delhi between June 2017 to March 2019. This was a cross-sectional observational study comprising of 28 patients. Patients found to have renal mass on ultrasound and computed tomography (CT) were evaluated further on 3T siemens Magnetic resonance imaging (MRI) scanner. In addition to routine sequences, DWI using b value of 0,500,1000 s/mm2 sequence was used to study to differentiate benign and malignant renal masses.Results: Of a total of 28 cases, the most common malignant mass was renal cell carcinoma (RCC). Angiomyolipoma (AML) was the most common benign masses. DWI showed low ADC values in most of the malignant masses and high ADC values in most of the benign masses. The cut-off level of ADC value for differentiation among benign and malignant renal masses was 1.08×10-3 mm2/s. DWI-MR findings were correlated with histopathological diagnosis.Conclusion: DWI with ADC measurements are a non-invasive, problem solving tool for characterization of renal masses helping to differentiate malignant from benign masses. 


Author(s):  
Rania Sobhy Abou khadrah ◽  
Haytham Haroon Imam

Abstract Background Differentiation between malignant and benign masses is essential for treatment planning and helps in improving the prognosis of malignant tumors; the aim of this work is to determine the role of diffusion-weighted magnetic resonance imaging (DW-MRI) and the apparent diffusion coefficient (ADC) in the differentiation between benign and malignant solid head and neck masses by comparing diagnostic performance of low b values (0.50 and 400 s/mm2) versus high b values (800 and 1000 s/mm2) and comparing the result with histopathological finding. Results The study included 60 patients (34 male and 26 female) with solid head and neck masses > 1 cm who referred to radiodiagnosis department for MRI evaluation. Multiple b values were used 50, 400, 800, and 1000 s/mm2 (at least 2 b values). DWI and ADC value of all 60 patients were acquired. Mean ADC values of both malignant and benign masses were statistically measured and compared, and cut off value was determined. Solid head and neck masses in our study DWI with the use of high b value 800 and 1000 s/mm2 were of higher significance (P value 0.001*). There was a significant difference in the mean ADC value between benign and malignant masses (P < 0.01); solid masses were divided into 2 categories: (a) malignant lesions 46.7% (n = 28) with mean ADC value (0.82 ± 0.19) × 10−3 s/mm2 and (b) benign lesions 53.3% (n = 32) with mean ADC value (2.05 ± 0.46) × 10−3 s/mm2) with ADC cutoff value of 1.0 × 10−3 s/mm2 and 94% sensitivity, 93% specificity, negative predictive value (NPV) = 94%, positive predictive value (PPV) 93%, and an accuracy of 93.5%. Conclusion The DWI with ADC mapping were valuable as non-invasive tools in differentiating between benign and malignant solid head and neck masses. The use of high b value 800 and 1000 s/mm2 was of higher significance (P value 0.001*) in differentiation between benign and malignant lesion than that with low b values 0, 50, and 400 s/mm2 (0.01). The mean ADC values were significantly lower in malignant solid masses. Attention had to be paid to the choice of b values in MRI-DWI in the head and neck region.


2011 ◽  
Vol 18 (4) ◽  
pp. 139-146
Author(s):  
Vaida ATSTUPĖNAITĖ ◽  
Algidas BASEVIČIUS ◽  
Adrijus KRIMELIS ◽  
Artūras INČIŪRA ◽  
Daiva VAITKIENĖ

Background. Diffusion-weighted magnetic resonance imaging (DW–MRI) has been employed in the diagnostics of malignant tumors of abdomen and pelvis relatively recently. Nowadays, there exists a particular interest in adaptation DW–MRI for assessing the response of tumors to chemoradiaton therapy. The aim of our study was to compare the mean value of the apparent diffusion coefficient (ADC) in a healthy cervix, cancer-affected cervix and a cervix after chemoradiation therapy, as well as to identify the ADC range typical of cervical cancer. Materials and methods. The study enrolled 108 female patients who underwent pelvic MRI in the Lithuanian University of Health Sciences Kaunas Clinics Hospital in 2008–2010. The study group consisted of 65 patients in whom cervical cancer had been clinically suspected and confirmed by biopsy before MRI examination. All these patients underwent pelvic MRI twice: before the chemoradiation therapy and 6 months after the therapy. The control group consisted of 43 patients in whom cervical cancer had been not suspected and MRI was performed because of other pelvic diseases. Results. The mean ADC value of the study group (0.658 ± 0.118 × 10–3 mm2/s) was lower than of the control group (1.171 ± 0.143 × 10–3 mm2/s) (t = 20.315, p = 0.03). The ADC threshold value of 0.945 × 10–3 mm2/s was defined, differentiating the cancer-affected cervical tissue from the normal. The mean ADC value of the patients who responded to chemoradiation therapy (1.111 ± 0.138 × 10–3 mm2/s) increased and in those who did not respond it remained lower (0.733 ± 0.073 × 10–3 mm2/s) (t = 9.518, p = 0.04). The ADC threshold value of 0.830 × 10–3 mm2/s was defined, differentiating the residual tumor tissue from the healthy cervical tissue after chemoradiation therapy. Conclusions. The ADC value in the case of cervical cancer was significantly lower than in the non-affected cervical tissue. The ADC value increases after effective chemoradiation therapy and becomes closer to the coefficient value of non-affected cervical tissue, but still remains lower. The 0.945 × 10–3 mm2/s ADC threshold was detected while differentiating between cancer-affected and normal cervical tissues, while the ADC threshold was 0.830 × 10–3 mm2/s when differentiating between residual tumor tissue and healthy cervical tissue after chemoradiation therapy at a high sensitivity and specificity. Keywords: diffusion-weighted magnetic resonance imaging, apparent diffusion coefficient, cervical cancer, chemoradiation therapy


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