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        Anthony A. Mancuso, MD
       Professor of Radiology and Otolaryngology
Chairman, Department of Radiology

       University of Florida College of Medicine

Gainesville, Florida

      mancua@radiology.ufl.edu







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“The Hardest Thing
We Do Is Call A Chest Radiograph Negative”
Leo Rigler, MD circa 1974
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“The Hardest Thing
To Do Is Call An Imaging Study Negative”

  • Assuming you believe this is true you need:
    • To thoroughly know the normal anatomy
    • And normal variants (based on reliable normative data when available)
    • Have clinical information (context)
    • Rules/structure by which to call study negative
    • Reject interpreting studies by “Gestalt” only
    • To be trained in and accept this discipline and value system



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Goals for our reports
  • Set reasonable expectations about what a negative imaging can contribute in specific clinical context
  • Avoid false negatives-which is what this presentation is about
  • State a degree of confidence (whenever  possible) of the negative interpretation for excluding specific pathologies (whether asked or not)
  • Identify specific clinical contexts
    • High error rates –basis for this presentation
      • Interpretive
      • Process (protocol application)
      • Error poses unusually high risk to patients

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As Examples-situations with high error rate for disease exclusion have been chosen
  • Temporal bone- Anatomically a confined, complex (lots of small structures) region with numerous, diverse indications for study
  • Invasive fungal sinus disease in immune compromised patients—critical situation that requires exclusion of a specific condition with a high degree of confidence
  • Perineural cancer spread- specific, high frequency task with few discreet observations necessary but very high prognostic and therapeutic impact
  • Facial pain and otalgia- “screening”of a relatively large anatomic area, requires numerous observations, diverse pathology—incidence of causative pathology relatively low
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Temporal Bone- Confined,complex (lots of small structures) anatomic region with numerous indications
    • Keeping clinical context simple
      • Conductive hearing loss
        • Middle ear
      • Sensorineural hearing loss/Vestibular
        • Inner ear
      • Mixed Hearing loss
        • Both
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Temporal Bone- Jumble of pertinent “exclusionary” (after “Gestalt”) observations
    • Incus long process and incudostapedial joint, modiolus, vestibular aqueduct, SSC dehiscence, ossicular ligaments, region of fissula ante fenestrum, oval window,bony island of LSC and cochlear height, round window, stapes footplate, facial canal position,cochlear aqueduct
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Temporal Bone Specific Observations after “Gestalt”- Organized by Indication/Anatomy
    • Conductive HL/Otosclerosis/Middle ear
      • Incus long process and incudostapedial joint, stapes footplate, oval window, ossicular ligaments, oval window, region of fissula ante fenestrum, round window, stapes footplate, facial canal position
    • Sensorineural, Vestibular Sx/ Inner ear
      • Modiolus, vestibular aqueduct, SSC dehiscence, bony island of LSC (less than 2.6mm), cochlear height (less than 4.4mm), cochlear aqueduct
    • Use these to construct report and/or decision support tool
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Basis for an Accurate Radiology Report
      • Referring HCP (or EMR)must provide relevant clinical information-responsible for setting the clinical context
      • Proper imaging protocol
      • High quality images
      • Workstation interpretation


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Modern/preferred interpretive setting
  • Soft copy (computer workstation) interpretation – much preferred
    • All windows available-soft tissue,bone, brain (Standard of Care +/- workstation reading)
    • Interactive multiplanar viewing
    • Not reliant on technologist choice of filming parameters
    • Portability-secure networks to web, CD
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Clinical Context - Fungal Sinus Disease
in the Immune Compromised Patient- critical situation that requires exclusion of a specific condition with a high degree of confidence
  • Non-invasive (colonization usually with chronic allergic polypoid rhinosinusitis)
  • Invasive
    • Diabetics and the “frail elderly” sometimes intermediately or chronic invasive disease
    • Highly invasive—immune compromised patients—most commonly BMT
    • Key Disease Pattern-Angio-invasive
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Building Blocks of a Clinically Relevant Report
    • Reflective of clinical context
      • Contains information that convinces the reader of interpreter’s understanding of the problem and capability to render a useful response
    • Expresses degree of confidence
      • Positive  and negative predictive values when possible
    • Unambiguous and useful observations in language that supports diagnostic impressions degree of confidence




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Fungal Sinus Disease -combining interpretive disciplines to exclude invasive disease
  • Discipline-Know Anatomy
    • Superficial aponeurotic system of the face-a.k.a. SMAS
    • Periantral fat planes
    • Vessels-distal max, infraorbital, post. sup. alveolar
  • Discipline- Understand Spread Patterns
    • Contiguous mucosal
    • Angio-invasive
    • Follows neurovascular bundles
    • Can leave bone intact

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Fungal Sinus Disease -combining interpretive disciplines to exclude invasive disease-specific observations to call a study low risk (negative)
  • Goal of exclusion-avoid an ENT consult
  • Observations
    • Unilateral (more risk) v. Bilateral (low risk)
    • Mucosal spread
      • Posterior nasal cavity (small unproven risk)
      • Nasopharynx
    • Perivascular venues
      • Infraorbital-extraconal fat orbital floor, anterior antral fat pad
      • Post. Sup. Alveolar-retroantral fat
      • Maxillary-sphenopalatine foramen, pterygopalatine fossa
    • Bone erosion



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Fungal Sinus Disease -combining interpretive disciplines to exclude invasive disease-specific observations to call a study low risk (negative)


Illustrative cases—Gradation of Disease from Obviously Positive to Negative (low risk-not requiring ENT consult)
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Clinical Context- Perineural Cancer Spread

  • High frequency task with few discreet observations necessary but very high prognostic and therapeutic impact
  • Specific clinical context where to this date there continues to be high interpretive and process (protocol application) error rate and high risk to patients


  • Set expectations about what imaging can contribute-exclusion of macroscopic perineural tumor spread


  • Anatomic pattern of disease SMAS still works because it identifies perivascular and perineural mechanism
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Clinical Context- Perineural Cancer Spread-How do we call the study negative

  • Know anatomy normative observations about SMAS and related deeper fat pads
  • Check fat planes deep to SMAS- supraorbital, infraorbital, mental
  • Know that facial nerve runs with SMAS peripherally
  • Check for abnormal thickening of SMAS
  • Know anatomy of auriculotemporal nerve connection between facial nerve and V3
  • Check anatomic region of auriculotemporal nerve
  • Know normative data about Facial and Trigeminal nerve more proximally
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Vth CN Variations – example - normative data
  •  V2-branch
    • nerve visualized 97%, (k = 1.00)
    • enhances 9%, (k = 0.667)
    • average size nerve = 1.61 mm (+/-0.4)
    • equal size bilaterally (P = 0.045)
  • Perineural vascular plexus
    • visualized 79% (k = 0.637)
    • usually incomplete, 57% (P = 0.008)
    • size = 0.71 mm


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Facial Pain and Otalgia
  •   “Screening”of a relatively large anatomic area, requires numerous observations, diverse pathology—incidence of causative pathology relatively low


  • Highlight greatest source of errors:
  • Failure to recognize deeply infiltrating pharyngeal pathology
  • Protocols not inclusive of ,or tailored, to all possible pain generators
  • Anatomic Highlights-Parotid/auriculotemporal nerve source, pharyngeal variations





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Facial Pain and Otalgia Pain Generators & Protocol Impact
  • Clinical pain pattern as specific as possible
  • Otalgia-otogenic and referred-pain generators
    • Intracranial/meningeal (MR)
    • Temporal bone and skull base (CT)
    • Odontogenic (CT)
    • TMJ (MRI)
    • Salivary gland (CT)
    • Pharyngeal (CT)
    • Vascular (CTA or MRI/MRA)
    • Cervical spine (CT or MRI)
  • Otalgia Imaging exam-Craniofacial plus neck to pyriform sinus apex (C5/6) with detailed temporal bone /skull base images





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Facial Pain v. Otalgia Pain Generators & Report Impact-What do you need to do to call the study negative with a reasonable degree of confidence?
  • Know the pain generators, all pertinent anatomy including SMAS and related fat pads and how to exclude subtle infiltrating pharyngeal pathology


  • Otalgia— specific report language related to potential pain generators
    • Vth ,IXth and Xth CN nuclei to pertinent peripheral branches (e.g. auriculotemporal nerve)
    • Referred-skull and meninges, odonotgenic (TMJ), pharynx, salivary glands (parotid in particular)


  • Craniofacial— specific report language related to potential pain generators
    • Vth nerve nucleus to all peripheral branches
    • Referred-skull and meninges, face, sinonasal, odonotgenic

  • Consider using a structured report as a decision support tool to be sure all sources have been checked—have exclusionary rules for sources
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Auriculotemporal Nerve as a bridge between V3 and the Facial Nerve
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Auriculotemporal nerve as a bridge between V3 and the Facial nerve
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PHARYNX
Detection of Aggressive Pathology
  • Deep planes symmetric-recognize aggressive pathology by invasion of the parapharyngeal fat
    • Nasopharynx
    • Upper oropharynx
    • Less reliable lower oropharynx
  • Airway contours vary markedly – lymphoid tissue
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Summary
  • Knowledge
    • Normal anatomy and variants, normative data, disease patterns, clinical context
  • Discipline
    • Inclusive, detailed imaging protocols for the given clinical context
    • Orderly complete interpretation with best exclusionary rules
    • Reports that properly reflect these processes
  • Medical Wisdom (experience and a physician’s compassion)
    • Ability to be sure impact of imaging information is integrated properly into medical decision making


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