Hyperspectral Diagnostic Imaging of the Cervix: Initial Observations

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Hyperspectral Diagnostic Imaging of the
CervixInitial Observations

• Project AKAMAI
• Tripler Army Medical Center
• Science Technology International

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Cervical Dysplasia Cervical Intra-epithelial
Neoplasia (CIN)

• Incidence clinical relevance
• Standard approach to diagnosis
• Pap smear
• Colposcopy
• White light illumination
• Magnification of cervix
• Topical application of acetic acid
• Recognition of reflected light patterns
• Biopsies of abnormal areas endocervical
  curettage (ECC)

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Diagnosis of CIN

• Shortcomings of traditional approach
• Subjective pathologic colposcopic
  interpretations
• Uncomfortable invasive
• Multiple visits
• Waiting time for results
• Specialized training required

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Principles of Spectral Imaging
UV Light
Tissue
Fluorescence
White Light
Reflectance
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Spectral Imaging

• Phenomenology known for decades
• Potential clinical utility for the detection of
  precancerous changes
• Previous limitations
• Suboptimal spatial resolution
• Preselected point assessment rather
  thancomprehensive survey of tissue at risk

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Hyperspectral Diagnostic Imaging (HSDI)

• Denser spatial sampling
• In vivo scanning of entire surface of cervix
• Advantages over standard approach to diagnosis of
  CIN
• Objective
• Non-contact
• One visit
• Immediate results
• No extensive prior medical training required

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HSDI Technique

• Patient positioning
• Fluorescence scanning
• Mercury vapor lamp ? 365nm UV light
• Pushbroom imager scans 40 x 40 mm area line by
  line for 1224 sec
• Intensities of fluorescence emission from each
  pixel measured
• Data binned to optimize SNR, maintaining adequate
  spatial/spectral resolution
• Fluorescence images of contiguous bands generated
• Intensity vs. wavelength graphically displayed

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HSDI Technique (cont.)

• Reflectance scanning
• White light illumination
• Reflected light within visible range collected
  line by line from each pixel for 815 sec
• Binning display of collected data analogous to
  fluorescence scanning

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HSDI Technique (cont.)

• Colposcopic examination
• White light illumination
• Magnification of cervix
• Topical application of acetic acid
• Recognition of reflected light patterns
• Biopsies of abnormal areas ECC
• Data analysis

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HSDI Data - PT 1
o
Colposcopic View of Cervix
Fluorescence Image
Fluorescence Spectra
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HSDI Data - PT 2
o
Colposcopic View of Cervix
Fluorescence Image
Fluorescence Spectra
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HSDI Data - PT 3
Reflectance Spectra
Colposcopic View of Cervix
Reflectance Image
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Clinical Application

• HSDI as screening modality
• Detect abnormal cells
• Assess transformation zone
• Achieve comparability to Pap smear
• HSDI for localizing diagnosing CIN
• Discriminate dysplastic from non-dysplastic
  tissue
• Distinguish between high grade low grade
  dysplasia
• Assess transformation zone
• Achieve comparability to colposcopy with
  biopsies/ECC

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Future Direction

• Continued development of technique to achieve
  adequate estimated device effectiveness
• Multi-institutional trial comparisons of HSDI to
  conventional colposcopy
• Additional studies based upon results of initial
  trial need to be pursued