• 096262 - METHODS FOR BIOMEDICAL IMAGING AND COMPUTER AIDED SURGERY [1]

The course aim is to consolidate the basic elements furnished by the Bioimaging course and show the main trends in advanced applications for functional exploration, tridimensional (3D) reconstruction, and multimodal integration.

Students will gain knowledge and understanding of:

• the potentials and limits of imaging systems and methods;
• their relevance to clinical diagnostics, physiological coomprehension, and therapeutical planning.

Students will acquire the capability to:

• handle analytical and numerical image reconstruction problems in 3D;
• apply the main mathematical tools in image formation;
• choose the correct modalities, in MRI.

Students will also develop skills relevant to the interdisciplinary interaction with both bio-medical experts and computed aided therapy experts.

Introduction – Trends of imaging: 3D, functional, multi–modality.

Advanced Methods for 3D Reconstruction from Projections

– A general frame–work of the problem: discrete to continuous, discrete to discrete, continuous to continuous.

– Iterative (discrete to discrete) Maximum Likelihood methods, Aglebraic reconstruction technique (ART); maximum likelihood (ML) methods in nuclear medicine imaging.

–  Fundamentals of analytical (continuous to continuous) 3D methods; approximated cone–beam Feldkamp, Davis, Kress (FDK) algorithm.

Principles of MRI

– Introduction, application overview, physical principles and instrumentation.

– Generation of nuclear magnetic resonance signal.

– Signal characteristics: FID, Spin Echo, Stimulated Echo, Gradient Echo.

– Signal localization: slice selection, frequency encoding, phase encoding, k–space.

– MRI contrast. Proton density, T1, T2, T2*. Recall of main sequence introduced in the previous course.

– PSF, Gibbs ringing artefact, chemical shift artefact, movement artefacts, SNR.

In vivo MR Spectroscopy (MRS) e Chemical Shift Imaging (CSI)

– Chemical shift artefact; signal: absorption mode; applications C–13, P–31, H–1; localization

Functional MRI (fMRI)

– Echo Planar Imaging (EPI) sequence, BOLD signal, smoothing, registration, filtering, hemodynamic response.

– Introduction to Statistical Parametric Mapping (SPM), regressors, confounding effects, contrast testing.

MR Angiography (MRA) and perfusion studies

– Principles: phase contrast, time of light (TOF),  Dynamic Contrast Enhanced (DCE) angiography.

– General perfusion concepts: regional blood flow, volume, mean transit time. DCE and dynamic suscettivity contrast (DSC) perfusion studies.

Diffusion Weighted Imaging (DWI), Diffusion Tensor Imaging (DTI) e Tractography

– General concepts: attenuation due to diffusion and DWI.

– Diffusion tensor, principal directions and anisotropy indexes, tractography.

Image Registration

– Principles, linear and non–linear transforms, point based estimates.

– Surface based and volume (gray level) based estimates, mutual information.

The course is organized in frontal classes. Course material will be enriched by monographic seminars, possibly in external labs. 

Prerequisites are given by the basic elements of reconstruciton methods in diagnostic imaging scanners.

Written Test     – Imaging: 10 open questions - 3 points each - laude upon quality; CAS: see specific program

                      – No mid-term exam is scheduled

                      – The written test is valid 1 year. It can be improved in a subsequent call, but a new delivered test will substitute the former one.

                      – Questions in English; answers either in English or in Italian

Oral Discussion – After passing both the written tests on imaging and that on CAS; in the same call or in a further one.

                       – The student may have the oral either in English or in Italian.

The open questions (generally in sequences of 2-4 items) and the oral discussion are aimed to assess the comprehension of the physical and mathematical principles and the acquired capabilities in evaluating the different image modalities.