“…A negative result cannot therefore refute the presence of an RPA or other deep space abscess in the neck, but the investigation, if positive, can provide a simple, cheap and non-irradiating form of investigating the patient. 40,46,47 Some authors have presented it in a positive light in the context of RPAs, 48 even rating it above CT scanning 49 and this is simply due to its ability to distinguish fluid from solid. One study used colour Doppler ultrasonography to effectively confirm the diagnosis in a group of 50 patients.…”