The most commonly used examination for kidney cancer is X-ray angiography

The most commonly used test for kidney cancer is X-ray angiography, which is the most effective way to diagnose kidney cancer. Of course, with the development of modern technology, the test for kidney cancer is more than that. So what else is there for kidney cancer? Let the experts explain it in detail.

There are several ways to detect kidney cancer:

1. General examination: Hematuria is an important symptom, and polycythemia often occurs in 3% to 4%; progressive anemia may also occur. In bilateral renal tumors, total renal function usually does not change, and the erythrocyte sedimentation rate increases. Some renal cancer patients do not have bone metastasis, but may have symptoms of hypercalcemia and increased serum calcium levels. After renal cancer resection, the symptoms are quickly relieved and the blood calcium returns to normal. Sometimes it may develop into liver dysfunction, which can return to normal if the tumor kidney is removed.

2. X-ray angiography is the main examination for kidney cancer

(1) X-ray films: X-ray films can show that the kidney is enlarged and its contour is changed. Occasionally, there is tumor calcification, which may be localized or widespread flocculent shadows within the tumor. It may also form calcification lines or shells around the tumor. Kidney cancer is more common in young people.

(2) Intravenous urography. Intravenous urography is a routine examination method for renal cancer. However, it cannot show tumors that have not yet caused the renal pelvis and calyces to deform, and it is difficult to distinguish whether the tumor is renal cancer, renal angiomyolipoma, or renal cyst. Therefore, its importance is reduced, and ultrasound or CT examination must be performed at the same time for further identification. However, intravenous urography can understand the function of both kidneys and the condition of the renal pelvis, calyces, ureters, and bladder, which has important reference value for diagnosis.

(3) Renal artery angiography: Renal artery angiography can detect tumors that are not deformed by urinary system angiography. Renal cancer manifests itself in neovascularization, arteriovenous fistulas, pooling of contrast agents, and increased capsular blood vessels. Angiography varies greatly, and sometimes renal cancer may not be visualized, such as tumor necrosis, cystic changes, arterial embolism, etc. During renal artery angiography, adrenaline can be injected into the renal artery when necessary to cause normal blood vessels to contract while tumor blood vessels do not react. This is the case for relatively large renal cancers. Selective renal artery angiography can also be followed by renal artery embolization, which can reduce bleeding during surgery. Renal artery embolization can be performed as a palliative treatment for patients with renal cancer that cannot be surgically removed and who have severe bleeding.

3. Ultrasound scanning: Ultrasound examination is the simplest and non-invasive method for kidney cancer examination and can be used as part of routine physical examination. Any mass in the kidney that is larger than 1 cm can be found by ultrasound scanning. It is important to distinguish whether the mass is kidney cancer. Kidney cancer is a solid mass. Because it may have bleeding, necrosis, and cystic changes inside, the echo is uneven and generally low-echo. The boundary of kidney cancer is not very clear, which is different from kidney cysts. Space-occupying lesions in the kidney may cause deformation or rupture of the fat of the renal pelvis, calyx, and renal sinus. The ultrasound examination of renal papillary cystadenocarcinoma resembles a cyst and may have calcification. When it is difficult to distinguish between kidney cancer and cyst, puncture can be performed. Puncture under ultrasound guidance is relatively safe. The puncture fluid can be examined for cytology and cyst contrast. The cyst fluid is usually clear, free of tumor cells and low in fat. The smooth cyst wall during contrast imaging can be confirmed as a benign lesion. If the puncture fluid is bloody, a tumor should be considered. Tumor cells may be found in the aspirate. If the cyst wall is not smooth during contrast imaging, it can be diagnosed as a malignant tumor. Renal angiomyolipoma is a solid tumor in the kidney. Its ultrasound manifestation is a strong echo of fat tissue, which is easy to distinguish from renal cancer. When renal cancer is found by ultrasound examination, attention should also be paid to whether the tumor has penetrated the capsule and perirenal fat tissue, whether there are enlarged lymph nodes, whether there are cancer thrombi in the renal vein and inferior vena cava, and whether there is liver metastasis.

4. CT scan: CT plays an important role in the examination of renal cancer. It can detect renal cancer that has not caused changes in the renal pelvis and calyx and has no symptoms. It can accurately measure the tumor density and can be performed in outpatient clinics. CT can accurately stage. Some people have calculated its diagnostic accuracy: 91% of invasion of the renal vein, 78% of perirenal spread, 87% of lymph node metastasis, and 96% of involvement of nearby organs. The CT examination of renal cancer shows a mass in the renal parenchyma, which can also protrude from the renal parenchyma. The mass is round, quasi-round or lobed, with clear or blurred boundaries. It is a soft tissue mass with uneven density during plain scanning. The CT value is >20Hu, usually between 30 and 50Hu, slightly higher than the normal renal parenchyma, or similar or slightly lower. The internal unevenness is caused by hemorrhage, necrosis or calcification. Sometimes it can be manifested as a cystic CT value, but there are soft tissue nodules on the cyst wall. After intravenous injection of contrast agent, the CT value of normal renal parenchyma reaches about 120Hu, and the CT value of the tumor also increases, but it is significantly lower than the normal renal parenchyma, making the tumor boundary clearer. If the CT value of the mass does not change after enhancement, it may be a cyst. The diagnosis can be confirmed by combining the CT value before and after contrast medium injection as liquid density. In necrotic foci in renal cancer, renal cystadenocarcinoma, and after renal artery embolization, the CT value does not increase after contrast medium injection. Because renal angiomyolipoma contains a large amount of fat, the CT value is often negative and the interior is uneven. After enhancement, the CT value increases, but it still shows fat density. During CT examination, oncocytoma has clear edges and uniform internal density, and the CT value increases significantly after enhancement.

The above is the explanation given by experts on the examination of kidney cancer. I hope it can help you answer your questions. Experts suggest that some diseases have no early symptoms or are not obvious. For your health, the best way is to have regular physical examinations to detect the disease early and prescribe the right medicine.

For more information, please visit the kidney cancer special topic at http://www..com.cn/zhongliu/sa/ or consult an expert for free. The expert will then give a detailed answer based on the patient's specific situation.