Differential diagnosis of an acute lymphadenitis of the maxillofacial area in children by means of ultrasound elastography

Abstract

Purpose – to determine the nature of the lymph nodes (LN) lesion in the differential diagnosis of an acute lymphadenitis (LA) stage of the maxillofacial region in children by means of a shear wave elastography (SWE).

Material and methods. A total of 30 patients aged 2 to 16 years were studied. Among them there were 12 patients that made up 40% with reactive changes (lymph-node hyperplasia), 10 children (33%) with the serous stage of LA (infiltrative inflammatory processes), and 8 patients (27%) with suppurative forms of LA. Examination was performed by means of the «ULTIMA PA» scanners feature the real-time shear wave elastography mode that can be used for linear probe L 3–12 MHz (produced by the company «Radmir», Ukraine). Size, form, quantity, structure, cortical and medullary layers of LN, their blood flow and stiffness (elasticity) on both intact and contralateral sides were estimated. We analysed colour flow mapping and quantitative assessment of tissue stiffness of LN (kPa). A standard range of colour scale was used in all cases – from dark blue (0 kPa) to bright red (60 kPa).

Results. The reactive processes in the LN (a lymph-node hyperplasia) were distinguished by such changes as enlargement, a hyperechogenic core with intensified vascularization, alongside preserved shape and architectonics of LN. Besides, the LN was painless when pressing it by probe during the screening. The stiffness of LN using SWE was 7.55±0.58 kPa. When the acute serous LA was identified, a significant enlargement of LN, either preserved or altered differentiation of its structure, a significant increase of mixed type vascularization were revealed, but without perinodular changes. External compression of tissues with the ultrasound probe was accompanied by mild pain. The LN stiffness was 17.98±1.59 kPa. In cases of glandular abscesses, at the initial stage of destructive changes, which were observed in 5 patients, shape and size of LN was the same as for acute serous LA. The structure change was determined by the complicated lymph sinus differentiation and tissue heterogeneity in the form of small hypoechogenic areas with decreased blood flow. The SWE stiffness was 19.35±1.11 kPa. To differ these hypoechogenic areas in case of preserved tissue structure from destructive changes is of considerable complexity. When carrying out SWE of these areas, the Young's modulus of 4.8±0.58 kPa, associated with increased tissue stiffness, is an indicator of the initial stage of abscess formation. In 3 cases of suppurative LA, the LN enlarged dramatically with the structure violation in the form of hypo- and anechogenic area(s) alternation without differentiation of lymph sinus and blood flow, violation of the capsule structure and severe symptoms of periadenitis.

Conclusions. Using SWE provides distinction between reactive changes of lymph node, acute serous LA and glandular abscess, as well as to identify the early stages of the destructive lesion that significantly affect the treatment modalities and possible planned surgery.