Investigation of diseases in the pharynx, larynx and neck
Plain lateral
X-rays
Plain lateral radiographs of the neck and
cervical spine may show soft-tissue abnormalities; of particular importance is
Barium
swallow
This X-ray has traditionally been used to assess the pharynx and
oesophagus using simple barium liquid and plain X-rays. However, it has now been
superseded in many places by the use of video fluoroscopic studies which record
the moving images of a small quantity of radio-opaque liquid, enabling
evaluation of the oral and pharyngeal phases of swallowing in much more detail (Fig.
43.11).
Manometric
analysis and pH recordings within the pharynx and oesophagus are used in
specialised units and may be coupled with simultaneous video fluoroscopy to
assess changes in luminal pressure and pH to define muscular inco-ordination and
the role of reflux of low-pH gastric contents.
Computerised
tomography (CT) scanning
CT scanning is widely used to assess head and neck disorders, and the increasing quality of the images provides much improved demonstration of disease in the pharynx, larynx and neck. Intravenous contrast given at the same time as the CT scan (dynamic scanning) further improves the demonstration of disease in these areas (Fig. 43.12).
Other
techniques
Magnetic resonance imaging (MRI) is being increasingly used and may give
better soft-tissue definition of some diseases hut poorer definition of bony and
cartilaginous structures. Ultrasound scanning can be useful in differentiating
solid lesions, e.g. malignant lymph nodes from cystic lesions such as a
branchial cyst.
Fine
needle aspiration cytology
This technique can be performed under local anaesthesia either in the
out-patient department or in a cytology clinic.
Angiography
or digital subtraction vascular imaging
These may be indicated if a vascular lesion such as a carotid body
tumour is suspected. Angiography may have a therapeutic role to play by
facilitating embolisation of the lesion.
Voice
analysis
An increasing variety of techniques is now available for the measurement
of vocal function including videostroboscopy. This technique utilises a flexible
or rigid endoscope coupled to a video-camera and a stroboscopic light. This
allows identification of the fine epithelial movements of the vocal folds and
demonstrates this on a monitor to the patient, doctor and speech therapist. This
technique allows very sensitive assessment of laryngeal vocal fold pathology.
Direct
pharyngoscopy and laryngoscopy
An examination of the pharynx, larynx and neck under general anaesthesia
may be required as a result of problems with the routine examination of
patients. This may be due to an inadequate view as a consequence of trismus from
pain, poor patient compliance, or large obstructive pharyngeal or laryngeal
pathology. These examinations may be further aided by the use of an operating
microscope, or rigid telescopes (Hopkin’s rods) which improve the
visualisation of the pharynx and larynx (Fig. 43.13).