Incidentally detected focal fundal gallbladder wall thickening: Differentiation contrast enhanced ultrasound features with high-resolution linear transducers

AIM: To investigate the value of contrast enhanced ultrasound with high resolution linear transducers (HF-CEUS) for differential diagnosis of focal fundal gallbladder (GB) wall thickening. METHODS: A total of 32 patients with incidentally detected focal fundal GB wall thickening were included. After conventional B mode ultrasound (BMUS) examinations, HF-CEUS were performed with a 7.5-12 MHz 9L4 linear transducer (S2000 HELX OXANA unit, Siemens). Two radiologists independently reviewed the HF-CEUS enhancement patterns to determine the differential features between malignancy and benignity with a five-point confidence scale. The diagnostic accuracy of BMUS and HF-CEUS for GB wall thickening was compared. The final gold standard was surgery with histological examination. RESULTS: Final diagnoses included GB adenocarcinoma (n = 16), adenomyomatosis (n = 12), Xanthogranulomatous (n = 2) and cholecystitis (n = 2). HF-CEUS features associated with GB adenocarcinoma including arterial phase inhomogeneous hyperenhancement, venous phase hypoenhancement and disruption of GB wall layer structure (P <  0.05). Two small (5 mm) liver metastasis were confirmed by HF-CEUS during the late phase liver sweep as hypoenhanced lesions. Nonenhanced Rokitansky-Aschoff sinuses were clearly observed in 83.3% focal adenomyomatosis. Overall sensitivity, specificity and accuracy for differentiation between malignant and benign focal fundal GB wall thickening of HF-CEUS and BMUS were 84.3% vs 53.1%, 90.6% vs 59.3% and 87.5% vs 56.2% (P <  0.005). CONCLUSIONS: CEUS performed with high frequency linear transducers could be a useful alternative in the differential diagnosis of focal fundal GB wall thickening on conventional ultrasound.