الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 169 |  |  |
| | | from | 169 | | |
Abstract
Ultrasonography is an alternative diagnostic tool that is widely available, relatively inexpensive, non-invasive and easily reproducible. Recently, it has been used in maxillofacial imaging and has obtained acceptance as a diagnostic tool in the evaluation of head and neck lesions. It is recognized as one of the most risk free. It is value is well recognized in inflammatory soft tissue conditions of the head and neck region.
Ultrasonography has many clinical applications as in space infections it is an effective diagnostic tool to confirm abscess formation in facial spaces and highly predictable in detecting the stage of infection, cervical lymph nodes metastasis, soft tissue masses of the neck, inflammation and in lymphadenitis as lymph nodes are enlarged (axial diameter more than 10 mm) with an ovoid to round shape.
The ultra-sonographic features of metastatic lymph nodes that can be depicted are the increased size, a rounder shape and heterogeneity caused by tumor necrosis or cystic degeneration inside the tumor. Generally, round shape is considered to be more suspicious than oval or flat shape. The size criteria may vary between 5 and 30mm. the lymph node status is one of the most important predictors of poor prognosis in head and neck tumors and important for treatment plan.
This study was conducted in clinic of Minia University hospital and hospital of faculty of dentistry, Minia University from February 2017 to January. 2018. The study was consisted of two groups; the first group was the control group 25 cases free from any diseases from (2.3 years to 51 years) (21 females- 4 males). The second group was the diseased group 100 diseased patients (54 females- 46 males) from (9 months to 60 years) have swellings in the orofacial region irrespective of age and socioeconomic status. The diseased group was divided into 6 age groups. The patients were evaluated with ultrasound diagnostic modality using linear array transducer, operating at frequency of (7.5-12) MHZ.
The results showed that, the first decade was the most frequently occurring age-class in the diseased group with 56 % followed by the second decade with 20 %. While, in the control group the most frequently occurring age-class was the third decade with 32% followed by the first decade with 28%. The most frequently affected lymph node group in the diseased group was the submandibular lymph nodes with 63% followed by the upper deep cervical lymph nodes with 18%.While in the control group the most frequently lymph node group was the upper deep cervical and the submandibular lymph nodes with 44% and 40% respectively.
In diseased group, there was a significant correlation between short dimension of submandibular lymph node group and S/L ratio with gender. Also, there was significant correlation between other lymph node group with both long and short dimension. While in the control group there was a significant correlation between age and short dimension only. The study also showed that 90% of cases in the diseased group were oval in shape and 80% were with S/L ratio with ≤ 0.5 and 93% without abscess formation. While in the control group 100% of cases were oval in shape and 56% with S/L ratio with ≤ 0.5 and 44% with S/L ratio >0.5.
Also, 100% of cases in the diseased group were with S/L ratio ≤ 0.5and without abscess formation and 97.5% of cases were S/L ratio with ≤ 0.5 and oval in shape. Moreover, 65% of cases were with S/L ratio >0.5 and without abscess formation. While, 40% of cases with S/L ratio >0.5 and rounded in shape.
Also, 93% of lymph nodes in the diseased group with a preserved central fatty hilum, while in the control group 100 % of cases with a preserved fatty hilum. 100% of cases in both diseased and control group with a smooth outline and hypoechoic with hyperechoic central fatty hilum.
The mean average size of normal cervical lymph nodes were 0.8 cm (8mm) .While , the mean average size of inflammatory lymph nodes (in the diseased group) were 2.05 cm (20.5 mm).the maximal short axis diameter of control group was 8mm or less. None of cases (100%) of lymph nodes in the diseased group with intra-nodal necrosis.
from this study we can concluded that distinction between normal and abnormal lymph nodes can be made on basis of shape, size, borders, fatty hilum and the internal echoes. Normal and inflammatory lymph nodes tend to have oval or cigar shape, smooth outlines, hypoechoic with hyperechoic central fatty hilum, no intra nodal necrosis and a preserved central fatty hilum.
While metastatic nodes tend to be more rounded in shape, sharp outlines and absence of fatty hilum. But in case of nodal adenitis with abscess formation there was central break down with necrotic inner margin and internal echoes but this will be reversible after treatment. Nodes with S/L ratio >0.5 tend to be more rounded in shape so more suspicious.
There was a asignifant correlation between gender with predominance toward females with short axis diameter and S/L ratio. The submandibular lymph node followed by the upper deep cervical lymph node group was the most frequently affected lymph nodes.