The sonographic "bright band sign" of splenic infarction.

OBJECTIVES

To evaluate the frequency of the "bright band sign" in patients with splenic infarcts as well as control patients and to thereby assess whether the bright band sign has potential utility as a sonographic sign of splenic infarction.

METHODS

Using an electronic search engine and image review, 37 patients were retrospectively identified with noncystic parenchymal splenic infarcts on sonography. Nineteen abnormal control patients with noninfarcted splenic lesions on sonography and 100 normal control patients with sonographically normal spleens were also identified. The sonographic appearance of each splenic lesion was evaluated by 2 reviewers and assessed for the bright band sign, defined as thin specular reflectors perpendicular to the sound beam within hypoechoic parenchymal lesions, and for the presence or absence of the classic sonographic appearance of splenic infarction. Possible histologic counterparts of the bright band sign were assessed in archival infarct specimens.

RESULTS

The bright band sign was present in 34 (91.9%; 95% confidence interval [CI], 78.1%-98.3%) of 37 patients with splenic infarcts on sonography, including 12 (85.7%; 95% CI, 57.2%-98.2%) of 14 with classic and 22 (95.7%; 95% CI, 78.1%-99.9%) of 23 with nonclassic infarct appearances. No normal or abnormal control patients had the bright band sign. Histologic sections suggested that preserved splenic trabeculae within infarcts may generate the bright band sign.

CONCLUSIONS

The bright band sign is a potentially useful sonographic sign of splenic infarction, which may confer additional sensitivity and specificity and may be particularly helpful with infarcts having nonclassic appearances.