Table of Contents
Introduction
CT (computed tomography) scans are diagnostic procedures for various medical conditions. CT scan, or CAT scan, or computed tomography, is a non-penetrative diagnostic procedure that uses a combination of X-rays and computer technology to produce images of the body. It is also called renal scan, renal imaging, or renal scintigraphy. It shows a detailed image of a particular body part, such as the bones, muscles, fat, and other organs. Compared to other radiological tests such as X-rays and ultrasound, a CT scan gives in-depth information about the organ.
How Is Kidney CT Scan Performed?
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A kidney CT Scan is generally performed to detect the presence of any abnormality in the kidneys.
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At the beginning of the procedure, a radioactive substance is injected into the body of the individual intravenously or orally.
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The radioactive substance, dye, contrast media, or tracer gives a metallic taste to the mouth for some time.
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The substance eventually settles in the kidneys.
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The individual is made to lie on the table that scans.
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The X-ray is moved around the individual to get pictures through various angles.
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This data is then sent to the computer, which converts it into an image.
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The intravenous (into the vein) line is removed from the individual after the scan.
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The individual is advised to drink plenty of water to flush the substance out of the system.
What Do Various Spots on the Kidney CT Scan Reveal?
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Kidney CT (computed tomography) scans are a diagnostic modality for various kidney conditions.
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Sometimes, some light or dark spots appear on the CT (computed tomography) scan image of the kidneys.
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The interpretation of the light and dark spots depends on the scanning technique.
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When the scanning is done with the help of contrast media, the appearance of these spots could mean cancer.
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When the media usually settles at the cancer site, it looks like a bright or white spot on the scan. However, if the media cannot reach certain places, those places may appear as dark or black spots on the kidney.
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These black-and-white spots help recognize the difference between a cyst and a tumor. CT scan is done with the help of sound waves.
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The soundwaves help to identify the compactness of the internal structures.
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As sound waves travel, on meeting a solid object, they cannot pass through it. Thus, they reflect.
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The resulting image shows a bright or white area in the CT scan.
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These solid areas are tumors or cancer masses.
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In the case of cysts, the sound waves pass through them, giving the appearance of black or dark spots. However, these interpretations are not a marker of a definitive diagnosis.
What Are Kidney Cysts?
Kidney cysts are fluid-filled sacs that develop in the kidney. Kidney cysts are divided into simple kidney cysts and complex kidney cysts. Simple kidney cysts are non-cancerous. One or multiple simple kidney cysts can form in one or both kidneys. They are generally harmless. At the same time, complex kidney cysts could change into cancer.
Symptoms:
Smaller cysts in the kidney do not show any symptoms. As the cyst grows, there could be:
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Pain in the back or sides.
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Pain in the stomach.
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Fever.
Causes:
The cause of the development of kidney cysts is not known. It is believed that a kidney cyst is formed when a part of the layer of the kidney is detached, and fluid fills within it.
How Are Kidney Cysts Diagnosed?
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Kidney function tests measure how well the kidneys work. This test involves a 24-hour urine, blood, or both tests.
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Radio imaging tests include MRI (magnetic resonance imaging), CT (computed tomography) scan, and ultrasound. These tests help determine if the kidney mass is a tumor or a cyst.
How Are Kidney Cysts Treated?
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In case the cyst is small and asymptomatic, no treatment is necessary.
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In the case of symptomatic cysts, the cyst is pierced with a fine needle, and the fluid inside it is removed. The cyst is then refilled with a solution to stop it from growing again.
What Is Kidney Cancer?
Kidney cancer is cancer that grows within the kidney. The kidneys are bean-shaped organs situated behind the abdomen's organs on either side of the backbone. In adults, kidney cancer, also known as renal cell carcinoma, is one of the most common types of cancer. The kidney cancers are of various types:
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Transitional Cell Cancer: This type usually accounts for six to seven percent of all kidney cancers. The origin of this cancer is in an area (renal pelvis) where ureters meet the central part of the kidney. It can also occur in the bladder or ureters.
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Renal Cell Carcinoma: This type accounts for 85 percent of all kidney cancers and is primarily familiar in adults. It usually develops in one kidney and later involves both kidneys, beginning in the kidney tubules that carry fluid and nutrients back to the blood.
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Wills Tumor: It accounts for approximately five percent of all kidney cancers and is most common in children.
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Renal Sarcoma: This is the least common type of kidney cancer, affecting only one percent of kidney cancer cases. The cancer begins in the connective tissues of the kidneys and, if not treated, can spread to other nearby bones and organs.
What Are the Symptoms of Kidney Cancer?
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Pinkish or reddish urine.
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Persistent back or side pain.
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Decreased appetite.
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Weight loss.
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Presence of unexplained fever.
What Causes Kidney Cancer?
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The cause of renal cancer is not well understood.
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It is thought that cancer in the kidney begins when some of the kidney cells change, also known as mutations in their DNA (deoxyribonucleic acid).
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DNAs are particles within the cells that contain genetic information for the development and growth of the body.
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These mutations make specific cells divide rapidly.
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These masses of rapidly dividing cells accumulate to form a tumor.
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Some tumor cells detach themselves from the site of origin and spread to different parts of the body.
How Is Kidney Cancer Diagnosed?
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Blood tests.
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Urine tests.
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Radio Imaging Tests- Tests such as ultrasound, X-ray, CT scan, or MRI (magnetic resonance imaging)can help diagnose a tumor's presence. A CT scan shows a white or bright spot in case of kidney tumors.
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Biopsy or removing a part of the tissue and sent to the laboratory for testing for any growth.
How Is Kidney Cancer Treated?
There are two broad aspects of treating kidney cancer.
Surgical
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Nephrectomy- Removing the affected kidney.
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Partial Nephrectomy- Removing the tumor and a small part of the kidney from the affected kidney.
Non-Surgical
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Cryoablation- The cancerous cells within the kidney are frozen with the help of a specific gas.
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Radiofrequency Ablation- Burning of the cancer cells with the help of electrical current.
Conclusion
Spots found in the kidney com scans are suggestive of the presence of specific abnormalities. A light spot may indicate the presence of a tumor or cancerous growth. In contrast, a darker or black spot suggests the presence of a fluid-filled cavity within the kidneys or cyst. However, these imaging diagnostic procedures alone do not imply the presence of a tumor or cyst. Many factors and these test modalities are needed to arrive at a correct diagnosis. Hence, these spots alone are not conclusive of any diagnosis.
