Abstract:

Objective To evaluate the value of MR diffusion-weighted imaging (DWI) in the diagnosis of cervical lymph node tuberculosis. Methods From May 2016 to May 2018, a total of 132 patients with cervical lymph node tuberculosis diagnosed clinically in Wuhan Pulmonary Hospital were collected as the study object, including 33 males (25.0%) and 99 females (75.0%), with the age of 15 to 73 years old and the median age (M(Q₁,Q₃)) of 27 (22, 48) years. The course of disease was 14 days to 6 years, and the median (M(Q₁,Q₃)) was 60 (30, 180) days. The clinical information of the subjects, the size, quantity, distribution characteristics of lymph nodes, as well as MR imaging signal characteristics and apparent diffusion coefficient (ADC) value of cervical lymph node tuberculosis were collected, and the imaging characteristics were analyzed. Results DWI showed that among the 132 patients with cervical lymph node tuberculosis, there were 2032 abnormal lymph nodes, including 1127 on the right and 905 on the left, and the average diameter of lymph nodes was (21.32±6.50) mm. According to the imaging subarea, a total of 503 subarea were involved, which mainly distributed in Ⅱ areas (161 cases, 32.01%) and Ⅳ areas (113 cases, 22.47%). In accordance with the imaging morphology and pathology, four stages were divided and the total frequency of stage was 292 cases, including 100 cases (34.25%) in stage Ⅰ, 71 cases (24.32%) in stage Ⅱ, 71 cases (24.32%) in stage Ⅲ (24.32%), and 50 cases (17.12%) in stage Ⅳ. In stage Ⅰ of cervical lymph node tuberculosis, the signal intensity was slightly hypo-intensity in T₁WI sequence, high signal intensity in T₂WI and DWI sequence, and slit-shaped Hypo-intensity in some lymph nodes of DWI sequence; meanwhile, the low signal intensity in T₁WI sequence, as well as high signal intensity in T₂WI and DWI sequence were found in necrotic area of lymph nodes at stage Ⅱ, Ⅲ and Ⅳ. After the recovery of some cervical lymph node tuberculosis, the fibrosis nodules and calcification showed “four low” phenomena, that was, T₁WI, T₂WI, DWI, and ADC images all showed low signal intensity. The abscess area showed slightly hypo-intensity signal in T₁WI and T₂WI sequence, and significantly hyper-intensity in DWI, while annular hypo-intensity could be seen between parenchyma and necrotic region. Based on DWI scanning, when the diffusion sensitivity coefficients (b values) were 0, 200, 500, 1000, 2000 s/mm ², the corresponding ADC values (M(Q₁,Q₃)) were 0.935 (0.787, 1.504)×10 ^-3 mm ²/s, 1.254 (0.970, 1.565)×10 ^-3 mm ²/s, 1.039 (0.769, 1.290)×10 ^-3 mm ²/s, 0.842 (0.625, 1.193)×10 ^-3 mm ²/s, and 0.687 (0.337, 0.859)×10 ^-3 mm ²/s, respectively. There was significant difference in ADC values between 5 groups (H=34.16, P<0.01). Conclusion MR routine sequence combined with DWI and ADC value exhibits great value in the diagnosis and differential diagnosis of cervical lymph node tuberculosis.

Key words: Tuberculosis,lymph node, Neck, Diffusion magnetic resonance imaging, Disease attributes, Diagnostic imaging