Introduction:
Diagnostic radiology is a branch of medicine that involves diagnostic imaging and treatment procedures using X-rays, high-frequency sound waves, and the magnetic properties of the human body. Tumor cells can be imaged in various ways, including X-ray imaging, positron emission tomography (PET), magnetic resonance imaging (MRI), and fluorescence imaging. The development of highly fluorescent nanoparticles has facilitated in vivo fluorescence imaging of tumor cells. Radiological methods can show where tumors are located and even deep inside the body. These methods help to know the cancer’s staging (how far the cancer has spread). They can be used to plan treatment and to indicate where the radiotherapy beam should be focused.
What Is an MRI?
MRI scan is a medical diagnostic imaging test that involves the use of a magnetic field and radio waves to view the internal structures of the body. Used to study or diagnose conditions that affect soft tissue, such as tumors and brain diseases. It is a painless procedure that takes between 15 and 90 minutes, depending on the size of the area scanned and the number of images taken. Some MRI scans require a contrast agent (dye) injection. As a result, specific tissues and blood vessels appear sharper and more detailed. Contrast agents may cause side effects such as:
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Feeling unwell or sick.
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Rash.
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Dizzy.
These side effects of MRI are usually mild and do not last for a very long time.
What Is a Hepatocellular Adenoma?
Hepatic adenoma, also called hepatocellular adenoma, is a rare but benign epithelial tumor of the liver that is often associated with oral contraceptive use. They are also found in patients treated with performance-enhancing anabolic steroids, aplastic anemia (lack of blood), or Fanconi anemia. Although they are benign, they carry the risk of bleeding and malignancy (cancer that spreads to other organs). Elective resection is recommended for all men with adenomas and women with adenomas larger than 5 cm. Ruptured hepatic adenomas cause severe abdominal pain and hypotension (reduced blood pressure), and shock, especially in patients taking oral contraceptives. This is not an uncommon occurrence and may be associated with significant mortality requiring prompt detection.
What Is the Role of MRI in the Evaluation of Hepatocellular Adenoma?
Gadolinium-enhanced magnetic resonance imaging (MRI) is optimal for identifying and characterizing most liver lesions. Certain characteristics, such as arterial enlargement and the presence of fat and hemorrhage, suggest that the lesion represents a hepatic adenoma. A diagnosis of focal nodular hyperplasia (FNH) can be made when there is a clear central scar. Nuclear medicine research can also help. Most hepatic adenomas do not show colloidal sulfur and gallium-67 uptake. MR imaging is usually performed using Gd-BOPTA and Gd-EOB-DTPA-T1 relaxation-time contrast agents and 2D or 3D gradient-echo sequences. However, with fat saturation, dynamic and delayed hepatobiliary Phase imaging has been shown to increase CNR. Clinical studies and clinical routines have shown that dynamic phase imaging is of particular importance for lesion characterization. In contrast, delayed phase imaging of the hepatobiliary phase enhances the sensitivity of MRI for liver detection. However, delayed-phase imaging can also help improve lesion characterization, especially when unenhanced dynamic sequence results are inconclusive or when dynamic imaging reveals atypical contrast patterns.
What Are the Benefits of MRI in the Diagnosis of Hepatocellular Adenoma?
MRI scanners allow the doctor to capture images of any part of the body (head, joints, abdomen, legs, etc.) in any scanning direction. MRI provides a better soft tissue contrast than a CT scan and is better at distinguishing between fat, water, muscle, and other soft tissue than a CT scan (CT is better at showing bone). These images provide information to doctors and help diagnose various diseases and conditions.
What Are the Risks of MRI in Diagnosis of Hepatocellular Adenoma?
MR images are created without the use of ionizing radiation, so the patient is not exposed to the harmful effects of ionizing radiation. Temporary exposure to radiation does not have any known health effects. The MR environment contains strong static magnetic fields, time-varying magnetic fields (pulsed gradient fields), and radio-frequency energy, each of which has specific effects. They have safety concerns listed below :
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Strong static magnetic fields attract magnetic objects (from small objects such as keys and mobile phones to large and heavy objects such as oxygen tanks and ground buffers).
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Time-varying magnetic fields produce loud knocking noises that can damage hearing without proper hearing protection. It can also irritate peripheral muscles and nerves that feel like a spasm. The radio frequency energy used during an MRI scan can cause the patient's body to heat up. Longer MRI scans increase the likelihood of heating.
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Using gadolinium-based contrast agents (GBCA) also carries certain risks, including side effects such as allergic reactions to the contrast agent. See GBCA for more information.
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The magnetic fields and radio frequency energy produced by MRI scanners can also cause malfunctions in electrically active medical devices, resulting in the devices failing to deliver their intended therapy.
What Is the Diagnostic Accuracy of MRI in the Evaluation of Hepatocellular Adenoma?
MRI is slightly more accurate than a CT scan and is preferable because MRI can detect premalignant nodules. MRI scans are better than CT scans in the detection of cancer. MRIs also show brain and bone metastases (meaning cancer has spread from its original site) more clearly than CT scans. This is because MRI uses radio waves and powerful magnets to create images. Researchers look at three properties to determine the accuracy of an MRI. Sensitivity, specificity, and positive predictive value (PPV).
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Sensitivity - It measures how often a cancer patient test gives a correct positive result. This is known as the true positive rate. It is an extremely sensitive test that detects all types of cancer and has very low chances of false negative results.
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Specificity - It measures the test's ability to give a correct negative result (the true negative rate) in people who do not have cancer. A highly specific test correctly identifies nearly everyone who does not have the disease and does not produce many false-positive results.
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Positive Predictive Value (PPV) - It reflects the proportion of cancer patients with positive results.
MRI has several advantages over CT:
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High safety.
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No ionizing radiation.
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No risk of renal damage.
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No known cases of systemic renal fibrosis in patients scanned with chronic liver disease and especially small or diffuse tumors.
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HCC, a more consistent and better visualization of the tumor involvement of the portal vein, yields a better distinction between tumors and bland thrombi.
Conclusion:
MRI performed before the biopsy allows the radiologist to see exactly where the cancer may be. Marking suspicious areas supports targeted needle biopsy. The most important advantage of MRI is whole-body imaging. Being able to scan from head to toe means an MRI can detect cancer anywhere on the body. Often, a healthcare provider will order an MRI scan for her, but one can also schedule the scan oneself. Detecting cancer before symptoms appear leads to better treatment plans and a better prognosis.
