Narrative review of multiparametric ultrasound in parotid gland evaluation

Abstract

Disorders affecting parotid gland represent a heterogeneous group comprising congenital, inflammatory and neoplastic diseases which show a focal or diffuse pattern of appearance. The differentiation of neoplastic from non-neoplastic conditions of parotid glands is pivotal for the diagnostic imaging. Frequently there is evidence of overlapping between the clinical and the imaging appearance of the various pathologies. The parotid gland is also often object of study with the combination of different techniques [ultrasound-computed tomography-magnetic resonance imaging (US-CT-MRI), ex.]. Compared to other dominant methods of medical imaging, US has several advantages providing images in real-time at lower cost, and without harmful use of ionizing radiation and of contrast enhancement. B-mode US, and the microvascular pattern color Doppler are usually used as first step evaluation of parotid lesions. Elastography and contrast-enhanced US (CEUS) has opened further possible perspectives to improve the differentiationbetween benign and malignant parotid lesions. The characterization of the parotid tumors plays a crucial role for their treatment planning and for the prediction of possible surgical complications. We present, here an updated review of the most recurrent pathologies of parotid gland focusing on the diagnostic power of multiparametric US including CEUS and ultrasound elastography (USE); limitations, advantages and the main key-points will be presented

The Diagnostic Value of Ultrasound-Based Deep Learning in Differentiating Parotid Gland Tumors

“…On Doppler US, malignant tumors and Warthin tumors have rich vascularization, whereas pleomorphic adenoma appears reduced vascularization. One study reported that there was appreciable overlap between the US features of benign tumors and that of malignant tumors within the histological heterogeneous [ 19 ]. Therefore, it is difficult to differentiate malignant and benign lesions based on B-mode and Doppler US.…”

Preoperative Multiparametric Ultrasound and Fine Needle Aspiration Cytology evaluation of parotid gland tumors: which is the best technique?

“…They concluded that there was a correlation between the micro-and the macro-vascularization of the lesions respectively evaluated with CEUS and Color-Doppler US, but the predictive value of each single technique was not so effective and a multiparametric assessment was required to increase the specificity and PPV in the diagnosis of malignant parotid lesions and the sensitivity in the differential diagnosis between pleomorphic adenomas and Warthin's tumors [37]. Another recent review confirmed that MPUS, specially if includes CEUS, enables the differential diagnosis of parotid tumors [1,20].…”

“…We also tried to identify a specific pattern of vascularization in order to distinguish between benign lesions as follows: marked and homogeneous vascularization for Warthin's tumor while mild and peripheral flow for pleomorphic adenoma [19][20][21]. USE USE was performed using a semi-quantitative quasistatic technique by the same experienced radiologist.…”

Sonografische Diagnostik im Kopf-Hals-Bereich – Teil 2: Transzervikale Sonografie

“…Dies zeigt die Herausforderung in der sonografischen Differenzialdiagnostik einer neu aufgetretenen Läsion. der Regel aber gut möglich [36,37]. Auch die Unterscheidung der Lage einer Läsion (intra-versus extraglandulär, superfiziell versus tief) gelingt problemlos unter Beachtung wichtiger Landmarken (z.…”

“…▶ Tab. 3 Sonografische Charakteristiken der häufigsten Tumorentitäten der Speicheldrüsen [22,36,41,42,43]. Zur besseren Übersichtlichkeit werden entzündliche (akute Lymphadenitis, seltene Infektionserkrankungen, Abszesse) von malignen Lymphknotenerkrankungen (Lymphome und Metastasen) unterschieden.…”