Necrosis in metastatic neck nodes: diagnostic accuracy of CT, MR imaging, and US.
OBJECTIVE
To compare the diagnostic accuracy of computed tomography (CT), magnetic resonance (MR) imaging, and ultrasonography (US) in the detection of necrosis in metastatic cervical nodes from patients with head and neck squamous cell carcinoma.


METHODS
Twenty-seven patients (age range, 39-85 years; mean age, 62 years) with squamous cell carcinoma in the head and neck underwent CT, MR imaging, and US. Three radiologists evaluated the images for nodal necrosis. The results of each modality were analyzed for sensitivity, specificity, and accuracy. Pathologic analysis of the surgical resection served as the reference standard. The three modalities were compared for specificity and sensitivity with the McNemar test.


RESULTS
Pathologic examination revealed 903 nodes, of which 89 were malignant. Of the malignant nodes, 43 were necrotic. Analysis of the detection of necrosis in the 89 malignant nodes showed an accuracy, sensitivity, and specificity of 92%, 91%, and 93% for CT; 91%, 93%, and 89% for MR imaging; and 85%, 77%, and 93% for US, respectively. All imaging modalities failed to depict necrotic areas of 3 mm or smaller in three nodes, and necrosis was missed in an additional seven nodes with US and in one node with CT. Necrosis could not be distinguished from other components of malignancy, such as viable tumor and scar tissue, in seven nodes (CT, 3; MR imaging, 5; US, 3). The sensitivity of both MR imaging and CT was significantly better than that of US (P =.0082 and P =.0339, respectively). There was no significant difference in sensitivity (P =.3173) between MR imaging and CT, or in the specificity of the three modalities.


CONCLUSIONS
MR imaging is comparable to CT for the detection of necrosis. The sensitivity of MR imaging and CT is better than that of US.
Department of Diagnostic Radiology and Organ Imaging, Faculty of Medicine, Chinese University of Hong Kong, Prince of Wales Hospital, Ngan Shing St, Shatin, New Territories, Hong Kong SAR, China. b834756@mailserv.cuhk.hk
Ann D
AD
King
Gary M K
GM
Tse
Anil T
AT
Ahuja
Edmund H Y
EH
Yuen
Alexander C
AC
Vlantis
Edward W H
EW
To
Andrew C
AC
van Hasselt
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D010039:Otorhinolaryngologic Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography