Several hand-held based optical imaging devices have been developed towards breast imaging, which are portable,
patient-comfortable, and use non-ionizing radiation. The devices developed to date are limited in that they have flat
probe faces and are incapable of real-time coregistration (as needed for 3-D tomographic imaging). A hand-held based
optical imager has been developed in our lab, which has unique features of (i) simultaneous over sequential source
illumination, which enables rapid data acquisition, (ii) a flexible probe face, which enables it to contour to any tissue
curvature, and (iii) self coregistration facilities towards 3-D tomographic imaging. Real-time coregistration is
demonstrated using the imager via fluorescence-enhanced studies in the continuous-wave mode, performed on slab
phantoms (filled with 1% Liposyn solution) and in vitro samples (chicken breast). Additionally, preliminary studies
were conducted using curved phantoms. In all cases, a 0.45-cc target filled with 1 μM Indocyanine green was used to
represent a tumor. Real-time 2-D surface images of the phantom were obtained via multiple scans at different target
depths. Preliminary surface imaging studies demonstrated that the summation of multiple scans distinctly differentiated
the target from artifacts (up to 3 cm deep), which was not possible from individual scans.
Hand-held based optical imagers have become a new research interest for its maximum patient comfort, less bulky
instrument and potential for clinical translation towards breast cancer diagnostics. However, its ability for optical
tomography is either limited by depth recovery since only reflectance measurements were obtained using a hand-held
design for imaging. In this study, we introduced a self-guided
multi-projection technique, which can take advantage of
potential portability of hand-held probe based system, towards improvement of target depth recovery during
fluorescence optical tomography studies.
Near-infrared (NIR) optical imaging is an emerging noninvasive modality for breast cancer diagnosis. The currently
available optical imaging systems towards tomography studies are limited either by instrument portability, patient
comfort, or flexibility to image any given tissue volume. Hence, a novel hand-held probe based gain modulated
intensified CCD camera imaging system is developed such that it can possibly overcome some of the above limitations.
The unique features of this hand-held probe based optical imaging system are: (i) to perform simultaneous multiple point
illumination and detection, thus decreasing the total imaging time and improving overall signal strength; (ii) to adapt to
the tissue contours, thus decreasing the light leakage at contact surface; and (iii) to obtain trans-illumination
measurements apart from reflectance measurements, thus improving the depth information. Phantom studies are
performed to demonstrate the feasibility of performing fluorescence optical imaging under different target depths using
cubical phantoms (10×6.5×10 cc). The effect of simultaneous multiple point illumination over sequential single point
illumination is demonstrated from experimental phantom studies.
Near-infrared optical imaging is an emerging noninvasive technology toward breast cancer diagnosis. The optical imaging systems available to date are limited either by flexibility to image any given breast volume, patient comfort, or instrument portability. Here, a hand-held optical probe is designed and developed, 1. employing a unique measurement scheme of simultaneous multiple point illumination and collection for rapid data acquisition and minimal patient discomfort, and 2. employing a curved probe head such that it allows flexible imaging of tissue curvatures. Simulation studies are carried out on homogeneous slab phantoms (5×10×8 cc) to determine an appropriate source-detector configuration for the probe head. These design features are implemented in the development of the probe, which consisted of six simultaneous illuminating and 165 simultaneous collecting fibers, spaced 0.5 cm apart on a 5×10 sq-cm probe head. Simulation studies on 3-D slab and curved phantoms demonstrate an increase in the total area of predicted fluorescence amplitude and overall signal strength on using simultaneous multiple point sources over a single point source. The probe is designed and developed such that on coupling with a detection system in the future, the hand-held probe based imager can be clinically assessed toward cancer diagnostic imaging.
Near-infrared (NIR) optical imaging is an emerging noninvasive modality for breast cancer diagnosis. However, the
currently available optical imaging systems towards tomography studies are limited either by instrument portability,
patient comfort, or flexibility to image any given tissue volume. Herein, a hand-held based optical imaging system is
developed such that it can possibly overcome some of the above limitations. The unique features of the hand-held
optical probe are: (i) to perform simultaneous multiple point illumination and detection, thus decreasing the total imaging
time and improving the overall signal strength; (ii) to adapt to the contour of tissue surface, thus decreasing the leakage
of excitation and emission signal at contact surface; and (iii) to obtain trans-illumination measurements apart from
reflectance measurements, thus improving the depth information. The increased detected signal strength as well as total
interrogated tissue volume is demonstrated by simulation studies (i.e. forward model) over a 5×10×10 cc slab phantom.
The appropriate number and layout of the source and detection points on the probe head is determined and the hand-held
optical probe is developed. A frequency-domain ICCD (intensified charge coupled device) detection system, which
allows simultaneous multiple points detection, is developed and coupled to the hand-held probe in order to perform
fluorescence-enhanced optical imaging of tissue phantoms. In the future, imaging of homogenous liquid phantoms will
be used for the assessment of this hand-held system, followed by extensive imaging studies on different phantoms types
under various experimental conditions.