रेडियोलोजी

नेपाली विकिपीडियाबाट
यसमा जानुहोस्: परिचालन, खोज्नुहोस्
Image A: A normal chest X-ray. Image B: Q fever pneumonia.

रेडियोलोजी चिकित्साको एक विषेश क्षेत्र हो। यो क्षेत्रमा मेडिकल इमेजिङ्ग प्रविधि प्रयोग गरेर रोगहरुको पहिचान तथा निदान गरिन्छ। [| मेडिकल] [दवा] विज्ञान एक्स - रे के चिकित्सा उपयोग से निपटनेको लागि एक्स - रे मशीन हो या अन्य यस्तो विकिरण द्वारा उत्सर्जित उपकरणों परंपरागत रूपमा यो शाखा थियोमेडिकल इमेजिंगको भागको रूप दृश्य सूचना प्राप्त गर्ने उद्देश्य. रेडियोलॉजिस्ट अब पनि प्रत्यक्ष (अल्ट्रासाउंड, गणना टोमोग्राफी (सीटी) र चुंबकीय अनुनाद इमेजिंगको रूप मा) अन्य इमेजिंग टेक्निक का पत्ता लगाउनको लागि या बीमारी का इलाज. Interventional रेडियोलोजी (आमतौरमा [न्यूनतम इनवेसिव []]) इमेजिंग प्राविधिक के मार्गदर्शनको साथ चिकित्सा प्रक्रियाहरुको प्रदर्शन हुन्छ. मेडिकल इमेजिंगको दिनचर्या, प्राविधीक पहलुहरु रेडियोग्राफी र बाहिर रेडियोग्राफ़र या टेक्नोलॉजिस्ट द्वारा गरिएको के रूपमा चिनिन्छ. परमाणु दवा सूत्रों के शरीर के भीतर unsealed [] [विकिरण] का प्रयोग हुन्छ

चिकित्सा क्षेत्रको बाहिर, रेडियोलोजी पनि एक्स - रे वा अन्य मर्मज्ञ विकिरण उपयोगको वस्तुहरुको आंतरिक संरचनाको परीक्षा सामिल छन्.

विभाजन[सम्पादन गर्ने]

As a medical specialty, radiology can be classified into subfields.

Radiologist Training[सम्पादन गर्ने]

Diagnostic radiologists must complete four years of medical school (M.D. or D.O.) plus five years of post-graduate training (residency). The first year of residency is a preliminary year in medicine, surgery or both, after which a four-year diagnostic radiology residency follows. During residency, both oral र written national examinations must be passed for board certification in diagnostic radiology. There are two separate written examinations required for certification by the American Board of Radiology, one covering the physics of medical imaging which is usually taken at the beginning of the second or third year, र a second covering clinical diagnostic imaging knowledge which is usually taken at the beginning of the third or fourth year. Both written exams must be passed before being eligible to take the oral examination, which is typically taken at the end of the fourth year.

After completion of residency, radiologists may choose to either practice or enter into a fellowship program in a radiologic subspecialty (such as abdominal CT, MRI, musculoskeletal imaging, interventional radiology, neuroradiology, pediatric radiology, etc.). Fellowship training programs typically last between one-to-two years.

Radiology is currently considered a highly competitive field. Radiologists generally enjoy good compensation as well as a good balance between time required at work र time spent away from work. The field is rapidly expanding due to advances in computer technology which is closely linked to modern imaging.

The exams (radiography) are usually performed by radiologic technologists, (also known as diagnostic radiographers) who in the United States have a 2-year Associates Degree र the UK a 3 year Honours Degree.

Diagnostic radiology[सम्पादन गर्ने]

Commonly used imaging modalities include plain radiography, computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, र nuclear imaging techniques. These techniques are usually non-invasive. Each of these modalities has strengths र limitations which dictate its use in diagnosis.

Acquisition of radiological images[सम्पादन गर्ने]

Patients have the following procedures to provide images for Radiological decisions to be made.

Projection radiography[सम्पादन गर्ने]

Radiographs (or Roentgenographs, named after the discoverer of X-rays, Wilhelm Conrad Roentgen (1845-1923)) are often used for evaluation of bony structures र soft tissues.

Fluoroscopy[सम्पादन गर्ने]

Fluoroscopyangiography are special applications of X-ray imaging, where a fluorescent screen or image intensifier tube is connected to a closed-circuit television system, which allows real-time imaging of structures in motion or augmented with a radiocontrast agent. Radiocontrast agents are administered, often swallowed or injected into the body of the patient, to help delineate anatomy such as the blood vessels, the genitourinary system or the gastrointestinal tract. Specific radiocontrast agents are used for specific types of evaluations; for example, barium in a suspension is administered into the gastrointestinal tract र imaged with fluoroscopy or radiography. Radiocontrast agents, which strongly absorb X-ray radiation, in conjunction with the real-time imaging allows demonstration of dynamic processes, such as peristalsis in the digestive tract or blood flow in arteries र veins.

CT scanning[सम्पादन गर्ने]

CT imaging uses X-rays in conjunction with computing algorithms to image a variety of soft tissues in the body. CT is acquired in the axial plane, while coronal र sagittal images can be rendered by computer reconstruction. Radiocontrast agents are often used with CT for enhanced delineation of anatomy. Intravenous contrast allows 3D reconstructions of arteries र veins. Although radiographs provide higher resolution for bone X-rays, CT can generate much more detailed images of the soft tissues. CT exposes the patient to more ionizing radiation than a radiograph.

Ultrasound[सम्पादन गर्ने]

Medical ultrasonography uses ultrasound (high-frequency sound waves) to visualize soft tissue structures in the body in real time. No ionizing radiation is involved, but the quality of the images obtained using ultrasound is highly dependent on the skill of the person (ultrasonographer) performing the exam. The use of ultrasound in medical imaging has developed mostly within the last 30 years. The first ultrasound images were static र two dimensional (2D), but with modern-day ultrasonography 3D reconstructions can be observed in real-time; effectively becoming 4D.

Because ultrasound does not utilize ionizing radiation, unlike x-rays, nuclear medicine, MRI, र CT scans, it is generally considered safer र therefore the modality plays a vital role in obstetrical imaging. Fetal development can be thoroughly evalauted allowing early diagnosis of fetal anomalies or confirmation of a normal gestation. Color flow Doppler well documents the severity of peripheral vascular disease. Stenosis of the carotid arteries can herald cerebral infarcts (strokes). A DVT in the legs can be found via ultrasound before it dislodges र travels to the brain (creating a stroke), heart (creating coronary blockage), or lungs (pulmonary embolism), all of which are fatal if left untreated. Ultrasound is useful for image-guided interventions like biopsies र drainages such as thoracentesis). It is also used in the treatment of kidney stones (renal lithiasis) via lithotripsy. Small portable ultrasound devices now replace peritoneal lavage in the triage of trauma victims by directly assessing for the presence of hemorrhage in the peritoneum र the integrity of the major viscera including the liver, spleenkidneys. Extensive hemoperitoneum (bleeding inside the body cavity) or injury to the major organs may require emergent surgical exploration र repair.

MRI/NMR[सम्पादन गर्ने]

चित्र:Dicom mr.jpg
MR image of human knee

MRI uses strong magnetic fields to align spinning atomic nuclei (usually hydrogen protons) within body tissues, then uses a radio signal to disturb the axis of rotation of these nuclei र observes the radio frequency signal generated as the nuclei return to their baseline states. MRI scans give the best soft tissue contrast of all the imaging modalities. With advances in scanning speed र spatial resolution, र improvements in computer 3D algorithms र hardware, MRI has great potential for development in the next few years. One disadvantage is that the patient has to hold still for long periods of time in a noisy, cramped space while the imaging is performed. Recent improvements in magnet design like wider, shorter magnet bores र more open magnet designs, have brought some relief for claustrophobic patients. MRI has great benefit in imaging the brain,spine, र musculoskeletal system. The modality can be contraindicated for patients with pacemakers, certain types of cerebral aneurysmal clips or metallic hardware due to the strong magnetic fields. Areas of potential advancement include functional imaging, cardiovascular MRI, as well as MR image guided therapy.

Nuclear medicine[सम्पादन गर्ने]

Nuclear medicine imaging involves the administration into the patient of substances labelled with radioactive tracers which have affinity for particular tissues. The heart, lungs, thyroid, liver, gallbladder, र bones are commonly evaluated for particular conditions using these techniques. While anatomical detail is limited in these studies, nuclear medicine is useful in displaying physiological function. As such, processes such as the growth of a tumor can often be monitored, even when the tumor cannot be adequately visualized using any of the other modalities. The principal imaging device is the gamma camera which detects the radiation emitted by the tracer in the body र displays it as an image. Often the information is converted into a series of slices through the body. In the most modern devices Nuclear Medicine images can be fused with a CT scan taken at the same time so that the physiological information can be overlayed on the anatomical structures to improve diagnostic accuracy.

PET scanning also falls under "nuclear medicine."

The applications of nuclear medicine can include bone scanning which traditionally has had a strong role in the work-up/staging of cancers. Myocardial perfusion imaging is a sensitive र specific screening exam for reversible myocardial ischemia, which when present requires angiographic confirmation र potentially life-saving balloon angioplasty, stenting or cardiac bypass grafting. Molecular Imaging is the new र exciting frontier in this field.

History of Radiology[सम्पादन गर्ने]

Radiology began with Wilhelm Conrad Röntgen’s discovery of xrays in 1895. In 1905 the first English book on chest radiography was published. During World War I, Maria Skłodowska-Curie pushed for the use of mobile radiography units for the treatment of wounded soldiers. She personally provided the radon tubes for the French Army. In 1920 the Society of Radiographers was formed. In 1924 Gilbert Stead published उनका Elementary Physics for medical र radiology students, helping bring radiology to the level of a generally recognized medical specialty. In 1937 a patient with leukemia was treated at the University of California at Berkeley in the first therapeutic use of radioactivity for cancer. Also in 1937, Joseph Gilbert Hamilton started to use radioactive iodine as a diagnostic र therapeutic agent in the treatment of thyroid disease.

See also[सम्पादन गर्ने]

External links[सम्पादन गर्ने]


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