Diagnosis of necrotizing soft tissue infections by computed tomography.
OBJECTIVE
In contrast to previous beliefs, we hypothesize that computed tomography (CT) scanning is sensitive and specific for the diagnosis of necrotizing soft tissue infections (NSTIs).


METHODS
Retrospective and prospective case series.


METHODS
Academic medical center.


METHODS
Patients who were clinically suspected of having NSTIs from January 1, 2003, through April 30, 2009, and who underwent imaging with a 16- or 64-section helical CT scanner were studied. The CT result was considered positive if inflamed and necrotic tissue with or without gas or fluid collections across tissue planes was found. The disease (NSTI) was considered present if surgical exploration revealed elements of infection and necrosis of the soft tissues and pathological analysis confirmed the findings. The disease was considered absent if surgical exploration and pathological analysis failed to identify any of these findings or the patient was successfully treated without surgical exploration.


METHODS
Sensitivity and specificity of CT for diagnosing NSTI.


RESULTS
Of 67 patients with study inclusion criteria, 58 underwent surgical exploration, and NSTI was confirmed in 25 (43%). The remaining 42 patients had either nonnecrotizing infections during surgical exploration (n = 33) or were treated nonoperatively with successful resolution of the symptoms (n = 9). The sensitivity of CT to identify NSTI was 100%, specificity was 81%, positive predictive value was 76%, and negative predictive value was 100%. No differences were found in demographics, white blood cell count on admission, symptoms, or site of infection between those with a false- or true-positive CT result.


CONCLUSIONS
A negative CT result reliably excludes the diagnosis of NSTI. A positive CT result correctly identifies the disease with a high likelihood.
Zacharias
Nikos
N
Division of Trauma, Emergency Surgery, and Surgical Critical Care, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge St, Ste 810, Boston, MA 02114, USA.
Velmahos
George C
GC
Salama
Ahmed
A
Alam
Hasan B
HB
de Moya
Marc
M
King
David R
DR
Novelline
Robert A
RA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005205:Fascia / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000000981:diagnostic imaging / Q000473:pathology*; D009336:Necrosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018461:Soft Tissue Infections / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D040521:Subcutaneous Tissue / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D055815:Young Adult