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DIAGNOSTIC ROLE OF STATIC AND DYNAMIC CONTRAST ENHANCED MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF SOFT TISSUE TUMOURS Abstract No. IRIA -1033 1 Slide 2 WHY THE STUDY? Imaging and pathological diagnosis of soft tissue tumours is an integral part of the management strategy but however, pose a great challenge. Routine MR imaging after contrast administration (Static contrast enhanced MRI- (SCE-MRI)) is unable to discriminate between benign and malignant lesions adequately Dynamic contrast enhanced MRI (DCE MRI) uses the Time intensity curve which helps in predicting the tumour characteristics, thus can differentiate between benign and malignant soft tissue tumours. 2 Slide 3 AIMS & OBJECTIVES 1.To characterize soft tissue tumours by dynamic enhanced contrast MRI 2.To assess the diagnostic role of dynamic and static contrast enhanced MRI in differentiating benign from malignant soft-tissue lesions 3.To compare the diagnostic power of different MRI parameters in predicting the malignant nature of soft tissue tumours 3 Slide 4 RESEARCH HYPOTHESIS Dynamic contrast enhanced MRI is superior to Static contrast enhanced MRI in predicting the benign / malignant nature of soft tissue tumours 4 Slide 5 MATERIALS AND METHODS 5 Slide 6 6 61 SOFT TISSUE TUMOURS 54 soft tissue tumours 37 MALIGNANT 17 BENIGN CONVENTIONAL MRI DYNAMIC MRI STATIC MRI TRUCUT BIOPSY IMAGING & HISTOPATHOLOGICAL CORRELATION 7 excluded soft tissue tumours in the extremity/body who are referred for MRI Informed consent obtained Contra-indication for MRI (those with pace makers, cochlear implants ) or gadolinium contrast (0) Poor quality MR images(2) Lesions originating from bone (1) Recurrent lesions following chemotherapy or radiotherapy (2) Inconclusive / non-availability of HPE findings (2) IMAGE INTERPRETATION blinded Slide 7 CONVENTIONAL MRI 7 Location of the lesion ( body / extremity) lesion size margins signal intensity characteristics (T1 & T2) with respect to muscle involvement of bone, joint, neurovascular structures hemorrhage (+/-) T1 T2 STIR Slide 8 DYNAMIC CONTRAST ENHANCED MRI T1 WEIGHTED FAT SUPPRESSED 2D SEQUENCES CONTRAST dose 0.2 mmol/kg @ 2 ml/s 20 ml saline flush inversion preparatory pulse with a delay of 360 ms (TI); TR/TE of 518/1ms; flip angle 30 0 ; slice thickness 8mm, matrix 192 176 30-60 measurements in a scan time of ~ 5 minutes where each dynamic series had a scan time of ~ 5- 10 sec based on the number of measurements. 8 Slide 9 9 no enhancement gradual increase of enhancement rapid initial enhancement followed by a plateau phase rapid initial enhancement followed by a washout phase rapid initial enhancement followed by sustained late enhancement. # with permission from vanRijswijk C.S.P et al.(2004) # TYPE 4 Slide 10 STATIC CONTRAST ENHANCED MRI 3 DIMENSIONAL T1 WEIGHTED FAST GRE SEQUENCE (VIBE) WITH FAT SUPPRESSION Acquired 5 minutes after the intravenous administration of contrast (TR/TE of 14.7-15/6.5; flip angle 10 0 ; FOV 400-420mm; slice thickness 1mm; NEX 1; matrix 384 X 448) STATIC ENHANCEMENT PATTERNS DIFFUSE / PERIPHERAL / HETEROGENEOUS / ABSENT NECROSIS PRESENT / ABSENT 10 Slide 11 STATIC ENHANCEMENT PATTERN 11 Diffuse when the lesion enhanced uniformly Peripheral - when only the rim of the lesion showed enhancement Absent - no intralesional enhancement Heterogeneous Slide 12 DATA ANALYSIS 12 Images were interpreted by a radiologist blinded to the histopathology static enhancement pattern Time signal intensity curve of dynamic MRI Overall MR imaging parameters CORRELATED WITH HISTOPATHOLOGY BENIGN / MALIGNANT Slide 13 RESULTS 13 Slide 14 14 MRI PARAMETERBENIGN (n=17)MALIGNANT (n=37)P VALUE Mean Age (years)28.4440.05 100% Homogeneous64 Intermediate820 > 50% Heterogeneous313 T 2 homogeneity50% Heterogeneous227 Slide 15 15 MRI PARAMETERBENIGN (n=17)MALIGNANT (n=37)P VALUE MRI PARAMETER BENIGN (n=17) MALIGNANT (n=37) P VALUE Bone involvement >0.05 Nil1728 Erosion or periosteal reaction05 Invasion04 Neurovascular involvement 0.05 Present04 Absent1733 Hemorrhage