Comparison of the advantages and disadvantages of imaging diagnostic methods for tongue cancer

Tongue cancer is the most common type of oral cancer. The cause may be precancerous lesions such as white spots, uneven teeth, repeated local friction and stimulation of dentures, as well as factors such as smoking and drinking. The incidence of tongue cancer ranks first among oral cancers. It is relatively easy to detect clinically, but it is difficult to accurately determine the scope of invasion and its lymph node metastasis. CT, MRI plain scan and enhanced examination, pET-CT scan and ultrasound examination can provide certain information on the location, scope of invasion and lymph node metastasis of tongue cancer, and provide certain help in determining the clinical treatment plan for tongue cancer. So what are the advantages and disadvantages of these methods?

Early lesions are difficult to detect in CT examinations, the scope of larger lesions is unclear, and enhanced scanning of lesions is different due to different blood supply, which is prone to false positives or false negatives. In addition, CT examinations have a single scanning section, poor display of soft tissues, and are easily affected by involuntary movements of the tongue and mandible. The tongue tissue display on the image is not ideal, and the diagnostic value is limited. The ability to detect lymph node metastasis in the early stage is limited.

MRI shows that the lesion is a localized tumor with clear or unclear lesion margins. The tumor shows T1 and T2 signals, and there is mild to moderate edema around the lesion. Enhanced scanning shows obvious enhancement, mild enhancement, or ring-shaped enhancement. The lesion range appears larger than the actual lesion, and the ability to identify lesions is greater than CT, and the false positive and false negative rates are significantly lower than CT.

pET-CT displays lesions from the perspective of metabolic function. It is significantly better than the previous two in displaying the morphology and range of lesions, and the display range is significantly larger than the actual range of the lesions, which is suitable for determining the scope of surgery. There are no false positives or false negatives. It can also better detect lymph node metastasis and distant metastasis, and is the best method for imaging examination of tongue cancer. pET-CT scanning has obvious advantages over simple CT plain scan diagnosis in the diagnosis of tongue cancer. In view of the high sensitivity and high specificity of pET in the diagnosis of head and neck malignant tumors, a medical center in Germany has listed pET as a routine examination item for the diagnosis of head lymph node metastasis. However, it is expensive and only suitable for some people.

Ultrasound can show the boundary of the lesion through the difference in grayscale values. Even a very small mass can be distinguished as long as there is a grayscale difference and the operator is familiar with the anatomy of the affected area and can examine it carefully. In addition, intraoral ultrasound examination directly places the probe on the surface of the tumor, making imaging more direct, so the biggest advantage of ultrasound over CT and MR is the discovery of small lesions. High-frequency ultrasound percutaneous suprahyoid examination method can clearly image the important structures of the tongue and floor of the mouth, with a detection rate of 100% for tongue cancer lesions. T staging is performed according to the size of the cancer with an accuracy rate of 93.54%. Preoperative examination can accurately provide the location, size, depth and range of the lesion, whether it crosses the midline of the tongue, and lymph node metastasis, which are of great significance for clinical treatment decisions.