الفهرس 
Acknowledgement
The Genus KlebsiellaOnly 14 pages are availabe for public view
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Abstract
Magnetic resonance imaging (MRI) has become an important tool in assessment of diseases of the mediastinum, pleura, and chest wall. Strengths of MRI include excellent tissue contrast, multi planar imaging capability, sensitivity to blood flow, and lack of ionizing radiation.
Recently, DW-MRI has become a useful adjunct for assessing tumors with magnetic resonance imaging. DW-MRI involves the acquisition of a magnetic resonance signal related to random thermal motion (Brownian motion) or the “diffusion” of water protons in tissue. The signal obtained with DW-MRI is a measure of the net displacement of water molecules, it can be quantified with apparent diffusion coefficient (ADC) measurements.
In this study sixty patients were included in this study, 73.3% of them were males (n. 44) and 26.7% of them were females (n. 16) with mean age (53.8 ±14.4). The studied patients were divided into two main groups;
Pulmonary group (n=42): (34 (81%) males and 8 (19%) female) with mean age (57.9 ± 10.6 years) and 33 (78.6%) of them were smokers and 9 (21.4%) were nonsmokers.
Mediastinal group (n=18): (10 (55.6%) males and 8 (44.4%) female) with mean age (44.3±17.7 years), and 8 (44.4%) of them were nonsmokers and 10 (55.6%) were smokers).
All patients included in the study were subjected to through clinical history and physical examination, routine laboratory investigation (as Complete blood picture, liver and kidney functions…..etc),pulmonary function test, CT chest, DW-MRI, Bronchoscopy and/or CT guided biopsy and sometimes LN or even open lung biopsy for taking tissue for pathological examination.
The results of this study revealed the following:
(1) The pathologic diagnosis among benign lesions (n 15) in this study was reported with predominant pathologic diagnosis was Non specific inflammation in 8.3% and Lung abcesses 6.7%. While Hydatid cyst, Thymic cyst, Hamartoma and Aspergilloma have the same frequency 1.7%.
(2) The pathologic profile among malignant lesions (n 45) was adenocarcinoma (33.3%) represent the predominant histopathology followed by squamous cell carcinoma (31.1%), Non Hodgkin lymphoma represent the lowest one reported (6.7%), small cell carcinoma represent 11.1% and Hodgkin lymphoma 17.8%.
(3) Comparison between the mean ADC value in total benign and malignant lesions and was statistically significant (p value <0.001) .P value was higher in benign than malignant lesions.
(4) Comparison between the mean ADC value in benign and malignant mediastinal lesions was statistically significant (P value <0.001) lower ADC value was reported in malignant lesions.
(5) In case of malignant mediastinal masses, it was found that the cut off value of the ADC between benign and malignant mediastinal masses using receiver operating curve (ROC) is 0.90 x 10–3 mm2/s with an area under the curve of 0.733. So; the ADC value for any mediastinal mass > 0.90 x 10–3 mm2/s could be exclude the possibility of malignancy and a value below this threshold was considered to indicate malignancy with 100% sensitivity, 66.7% specificity.
(6) In this study comparison between mean ADC value in benign and malignant pulmonary lesions. It was statistically significant (P value <0.001).Lower ADC value reported in malignant pulmonary lesions.
(7) In case of malignant pulmonary masses, it was found that the cut off value of the ADC between benign and malignant pulmonary masses using receiver operating curve (ROC) is 1.1 x 10–3 mm2/s with an area under the curve of 0.864. So; the ADC value for any pulmonary mass > 1.1 x 10–3 mm2/s could decrease the possibility of malignancy and a value below this threshold increase the possibility of malignancy with 96.7% sensitivity, 83.3% specificity.
(8) Comparison between mean ADC value between Non small cell lung cancer and small cell lung cancer. It was statistically significant (p value< 0.05).lower ADC value was reported in small cell lung cancer.
(9) Comparison between the mean ADC value and squamous cell carcinoma, adenocarcinoma and small cell carcinoma. There is no statistical significant between squamous cell carcinoma and adenocarcinoma (p value 0.692). There is statistical significant between squamous cell carcinoma and small cell lung cancer (p value< 0.05) and also there is statistical significant between adenocarcinoma and small cell lung cancer (p value< 0.05).
(10) There is statistically significant (p value< 0.05) between grade of NSCLC and ADC value. High grade NSCLC have low ADC value while low grade NSCLC have high ADC value.
(11) There is statistically in significant relation (p value= 0.483) between ADC value and T stage of NSCLC. Increase T stage of the malignant tumor associated with low ADC value.
(12) There is statistically significant relation (p value<0.05) between ADC value and N stage of NSCLC. Increase N stage associated with decrease ADC value of NSCLC.