Predicting deep neck space abscess using computed tomography

To investigate objective measures that could increase the positive predictive value of computed tomography (CT) in diagnosing deep neck space infections (DNSIs).

A retrospective analysis of patients surgically treated at a tertiary care hospital for DNSIs for more than 2 years were reviewed. Patients who had had CT with contrast scanning suggestive of deep neck space abscess within 24 hours before surgery were included. The average Hounsfield units for each abscess were calculated. Based on the intraoperative finding of pus, the patients were divided into groups. Student t tests compared the average Hounsfield units, white blood cell count, and maximum temperature between the groups. Outcomes were measured by comparing overall length of hospital stay, length of postoperative stay, and complications.

Of the 32 patients surgically drained, 24 (75%) had discreet collections of pus, whereas 12 (25%) did not. Hounsfield unit measurement was not reliable in distinguishing abscess from phlegmon. None of the other clinical variables studied to distinguish abscess from phlegmon were statistically different either. A statistical difference between the 2 groups was not identified.

Although CT with contrast plays an important role in the diagnosis and management of DNSIs, the decision for surgical drainage of an abscess should be made clinically. A negative exploration rate of nearly 25% despite careful selection criteria should be expected.