Transillumination

定义

Transillumination is the shining of a light through a body area or organ to check for abnormalities.

How the Test is Performed

The room lights are dimmed or turned off so that the area of the body may be seen more easily. A bright light is then pointed at that area. Areas where this test is used include the:

• Head
• 阴囊
• Chest of a premature or newborn infant
• Breast of an adult female

Transillumination is also sometimes used to find blood vessels.

In some locations in the stomach 和 intestine, the light can be seen through the skin 和 tissues at the time of upper endoscopy 和 结肠镜检查.

How to Prepare for the Test

No preparation is necessary for this test.

How the Test will Feel

There is no discomfort with this test.

Why the Test is Performed

This test may be done along with other tests to diagnose:

• 脑积水 in newborns or infants
• Fluid-filled sac in the scrotum (积水) or a tumor in the testicle
• Breast lesions or cysts in women

在新生儿, a bright halogen light may be used to transilluminate the chest cavity if there are signs of a collapsed lung or air around the heart. (Transillumination through the chest is only possible on small newborns.)

In general, transillumination is not an accurate enough test to rely on. Further tests, such as an x射线, CT扫描, or 超声波, are needed to confirm the diagnosis.

正常的结果

Normal findings depend on the area being evaluated 和 the normal tissue of that area.

What Abnormal Results Mean

Areas filled with abnormal air or fluid light up when they should not. 例如, in a darkened room, the head of a newborn with possible hydrocephalus will light up when this procedure is done.

When done on the breast:

• Internal areas will be dark to black if there is a lesion 和 bleeding has occurred (because blood does not transilluminate).
• 良性的 tumors tend to appear red.
• Malignant tumors are brown to black.

风险

There are no risks associated with this test.

参考文献

Ball JW, Dains JE, Flynn JA, Solomon BS, Stewart RW. Examination techniques 和 equipment. In: Ball JW, Dains JE, Flynn JA, Solomon BS, Stewart RW, eds. Seidel's Guide to Physical Examination. 10日艾德. St Louis, MO: Elsevier; 2023:chap 3.

Lissauer T, Hansen A. Physical examination of the newborn. In: Martin RJ, Fanaroff AA, Walsh MC, eds. Fanaroff 和 Martin's Neonatal-Perinatal Medicine: Diseases of the Fetus 和 Infant. 11日艾德. Philadelphia, PA: Elsevier; 2020:chap 28.