Differential diagnosis of small round cervical lymph nodes: comparison of power Doppler US with contrast-enhanced CT and pathologic results.
OBJECTIVE
The purpose of this study was to differentiate reactive small round lymph nodes (SRLNs) from metastases by power Doppler ultrasonography (PD-US) and contrast-enhanced CT (CE-CT).


METHODS
Both PD-US and CE-CT were performed in 99 cervical lymph nodes (LNs) with a maximum diameter of 1.5 cm or smaller and maximum longitudinal/transverse ratio of 1.5 or smaller in 76 patients with head and neck cancer. At pathologic examinations, 45 were reactive and 54 were metastatic LNs. The vascular patterns on PD-US were classified as hilar, avascular, peripheral, and miscellaneous vascular patterns. The enhancement patterns on CE-CT were classified as homogeneous, heterogeneous, and ring enhancement.


RESULTS
On PD-US, the hilar pattern was more frequently associated with benignancy (91%) and the peripheral, miscellaneous vascular pattern with malignancy (91%). The avascular pattern included both benign (58%) and malignant (42%) LNs. On PD-US, accuracy was 85%. On CE-CT, ring enhancement showed metastasis (100%), and these LNs showed avascular or peripheral patterns on PD-US. On CE-CT, accuracy was 77%. When information on CE-CT results was added to PD-US results, the accuracy rate increased significantly, to 94% (p=0.01).


CONCLUSIONS
Vascular patterns evaluated with PD-US and enhancement patterns on CE-CT can characterize SRLNs. For an avascular pattern on PD-US, information on CE-CT results can significantly increase the accuracy of characterization.
Sakaguchi
T
T
Department of Radiology, Kumamoto University School of Medicine, Honjo, Japan.
Yamashita
Y
Y
Katahira
K
K
Nishimura
R
R
Baba
Y
Y
Arakawa
A
A
Takahashi
M
M
Yumoto
E
E
Shinohara
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods; D018608:Ultrasonography, Doppler
D003287:Contrast Media