Lateral Neck X-RaySoft Tissues

Mark Bromley PGY4November 19, 2009

Outline

Relevant Anatomy Cases

Epiglottitis Retropharyngeal Abscess Bacterial Tracheitis Croup FB

Test Characteristics

Case 1

4 year old male Inspiratory stridor Unwell for past 24 hours Mom found him in his room with increased

work of breathing

When to order films…

Sub-acute presentation Diagnosis is unclear

Impending airway embarrassment something else

Epiglottitis Enlarged epiglottis Loss of valecular airspace Thickened aryepiglotic folds Distended hypopharynx Straightening of the cervical spine

Sensitivity (38-88%) Specificity (78%)

Croup and epiglottitis: a radiologic study. AU Stankiewicz JA; Bowes AK SO Laryngoscope 1985 Oct;95(10):1159-60.Epiglottitis and croup. AU Sobol SE; Zapata S SO Otolaryngol Clin North Am. 2008 Jun;41(3):551-66, ix.Adult epiglottitis: the Toronto Hospital experience. AU Solomon P; Weisbrod M; Irish JC; Gullane PJ SO J Otolaryngol. 1998 Dec;27(6):332-6.

Case 1

4 year old male Inspiratory stridor Unwell for past 24 hours Mom found him in his room with increased

work of breathing

Retropharyngeal Infection

Widened retropharyngeal space C2 – 7mm or C6 – 14mm (kids) C6 – 22mm (adults)

Reversal of normal cervical lordosis Foreign body Air-fluid level Gas

False Pre-vertebral Swelling

Oblique lateral Neck flexion Crying

Case 1

4 year old male Inspiratory stridor Unwell for past 24 hours Mom found him in his room with increased

work of breathing

Case 1

3 year old male Inspiratory stridor Unwell for past 24 hours Mom found him in his room with increased

work of breathing

Case 1

4 year old male Inspiratory stridor Unwell for past 24 hours Mom found him in his room with increased

work of breathing

Foreign Body

Visualization of radiopaque FB Widened pre-vertebral shadow Loss of lordosis Location

Esophagus – coronal plane Trachea – sagittal plane (best seen on lateral)

Test Characteristics

Sensitivity SpecificityEpiglottitis 33-88% 78%Retropharyngeal abscess 80% 100%CroupForeign Body 84%

Questions?Thank You!

Triple blinded prospective study 100 elective surgery patients Lateral neck x-ray compared with Mallampati Anesthesiologist gold standard (grade III or IV) Results

Mallampati sens: 26% spec: 100% Lateral neck film: sens: 100% spec:100%

Adult EpiglottitisRadiographic Criteria

Epiglottic height-to-width ratio >0.6 Epiglottic to C4 vertebral body width ratio >0.33 Aryepiglottic fold to C3 vertebral body width ratio

>0.35 Prevertebral soft-tissue to C4 vertebral body width

ratio >0.25 Hypopharyngeal airway to C4 vertebral body width

ratio >1.5