Electrocardiogram

Hi friends!!!

In our previous blogs, we have discussed about MRI scanner. Please check out for the links below.

MRI scan 

MRI With Contrast

Brain MRI

Types of MRI scanners

In today's blog we are going to discuss about electrocardiogram.

The human heart is the most essential and valuable organ of our body. Electrocardiogram is used to diagnose the disorders in the functioning of heart. Therefore it is important for every healthcare professionals to know about electrocardiogram.

 

Let's get into the topic. 

 

WHAT IS 

ELECTROCARDIOGRAM?

The electrocardiogram is a painless procedure used to monitor and measure the electrical activity of the heart. The electrocardiogram is used to record the heart rhythm in a continuous moving sheet of paper or electronically displays it in a monitor. Heart irregularities and other cardiac problems can also be detected using electrocardiogram.

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WHY DO WE NEED

ELECTROCARDIOGRAM?

The electrocardiogram is used to detect the time taken for electrical signal to pass through the heart and how much electrical signal passes through the heart.

The electrocardiogram is used to detect the abnormal heart rhythm (arrhythmia), blockages in the coronary arteries, enlargement of heart, damages in heart muscle and proper functioning of implantable devices like pacemakers. The abnormal amount of electrolytes like potassium and calcium can also be detected using electrocardiogram. The condition of heart after heart attack and heart surgery can also be detected using electrocardiogram.

The electrocardiogram is also used to evaluate the reasons for following problems.

1. Chest pain.

2. Breathing problem.

3. Tiredness.

4. Dizziness.

HOW ELECTROCARDIOGRAM

WORKS?

Our human cells communicate with each other using electrical signals. Likewise, each time when heat beats, the electrical signal travels through the heart. These electrical signals are sent by a group of cells into the right atrium of the heart called as sinoatrial node. These electrical signals spread around the heart and causes atria to contract first and then ventricle. The effects of these signal passage can also be seen on the skin surface, which can be measured using electrocardiogram.

In electrocardiogram procedure at least four electrodes are placed on the chest or four extremities of the patients. Generally, a set of colour codes are used for electrode placement. For right arm – white, left arm – black, right leg – green, left leg – red. Variations in this setup can also be made to have more flexible electrocardiogram procedure.

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These electrodes placed on the patient’s body tracks the electrical signal moving through the heart and records the timing and strength of the signal in a graph called P wave.

The ECG waveform has 3 patterns as following: P wave, QRS complex, T wave.

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Generally wet electrodes are used in ECG procedure which requires a adhesive to increase conductivity between electrode and skin surface.

WHAT HAPPENS DURING 

ELECTROCARDIOGRAM?

During electrocardiogram patient’s will be asked to remove any objects from their body that may interfere the ECG recordings like watches, chains etc.

Patient’s will be instructed to remove the clothes from waist up and lie down flat on the bed. Meanwhile the technicians will ensure the privacy of the patient’s by covering the patient’s with bedsheets.

Patients will be instructed to remain still and silent during the procedure so as to not interrupt the ECG signal acquisition.

A gel will be applied on some specific areas of the patient’s body where the electrodes will be connected to improve the adhesiveness between electrode and the patient’s body.

The electrodes will be attached on patient’s legs, arms and chest. The lead wire will be connected to the electrodes.

Now I hope you have acquired some knowledge about electrocardiogram. We will discuss in detail about ECG leads placement, ECG waveform and interpretation, types of ECG machine in our future blogs.

NOTE: Dear friends!!!... Please do comment a topic related to Biomedical, so that we can discuss it in future blogs.

Check out for this blog about Computed Tomography and x ray.

Generations of CT Scanners

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Types of MRI Scanners

Hi friends!!!

In our previous blogs, we have discussed about MRI scanner. Please check out for the links below.

MRI scan 

MRI With Contrast

Brain MRI

In today's blog we are going to discuss about types of MRI scanners.

The innovation of MRI scanners has created a revolution in the field of medical diagnostics. In that there are various types of MRI scanners which adds value to the medical diagnostics field. Therefore it is important for every healthcare professionals to know about types MRI scanners.

 

Let's get into the topic. 

WHAT ARE THE TYPES OF MRI

SCANNERS?

We can classify different types MRI scanners based on the strength of magnetic fields and based on the structure and design. With respect to strength of the magnetic fields, most of the MRI scanners available today are from 0.2 Tesla – 3 Tesla. The 1.5 Tesla magnetic strength is commonly used in most MRI scanners which is ideal for abdomen and chest imaging.

Based on the structure and design there are five different types of MRI scanners. They are as follows.

1. Closed MRI scanner.

2. Open MRI scanner.

3. Open upright MRI scanner.

4. Wide bore MRI scanner.

5. 3 Tesla MRI scanner.

CLOSED MRI SCANNER

The closed MRI scanners are one of the traditional types of MRI scanners. In closed MRI scanner, the patient’s will be laid down in a large fully enclosed MRI tube. Since the tube is fully enclosed, claustrophobic patient’s might feel discomfort.

Because of the smaller opening in closed MRI scanner, it is difficult to examine the obese and over weighted patient’s. This type of closed MRI scanner also requires patients to be still without any movement. 

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OPEN MRI SCANNER

The open MRI scanner is one of the types of MRI scanners introduced to provide comfort for claustrophobic patient’s. The open MRI scanner has opening on the sides. The patient’s may still require to lie down on the sliding MRI table, but the MRI tube is not fully enclosed which allows patient’s to feel comfortable in open MRI scanner.

The image quality of open MRI scanner is little less when compared to the closed MRI scanner. The open design of MRI tube does not help in providing strong magnetic fields like closed MRI scanner which results in lesser image quality.

OPEN UPRIGHT MRI SCANNER

The open upright MRI scanner allows patient’s to sit upright during the imaging procedure similar to sitting in a chair. These types of open upright MRI scanner is completely open on front side. Open upright MRI scanner has the lowest magnetic strength among the alternatives. The open upright MRI scanner is mainly used for imaging the spine and joints.

WIDE BORE MRI SCANNER

The wide bore MRI scanner is similar to open MRI scanner with wider openings and better head space than closed MRI scanner. The wide bore MRI scanner has a bore diameter of 70 cm providing more headroom space than open and closed MRI scanners. The wide bore MRI scanner is specially designed to accommodate the obese patient’s. These types of wide bore MRI scanners mostly operate at 1.5 Tesla magnetic strength.

3 TESLA MRI SCANNER

The unit of measurement used to define the strength of magnetic fields is Tesla. Mostly all the types of MRI scanners use 1.5 Tesla whereas 3 Tesla MRI scanner uses magnetic fields having double the strength of traditional MRI scanners. The 3 Tesla MRI scanner is also a type of closed MRI scanner.

These types of 3 Tesla MRI scanner produces high quality images which eliminates the need for repeated scans. The 3 Tesla MRI scanner can produce smaller details of brain as much as 1 millimeter. The 3 Tesla MRI scanners are also used for imaging the spine, soft tissue of bone joints, inside of bones and blood vessels.

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Now I hope you have acquired some knowledge about types of MRI scanners. We will discuss in detail about a topic related to Biomedical Engineering in our next blog.

NOTE: Dear friends!!!... Please do comment a topic related to Biomedical, so that we can discuss it in future blogs.

Check out for this blog about Computed Tomography and x ray.

Generations of CT Scanners

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Brain MRI

Hi friends!!!

In our previous blog, we have discussed about MRI scan and MRI With Contrast. 

In today's blog we are going to discuss about MRI of brain.

One of the important application of MRI scan is the imaging of brain. Therefore it is important for every healthcare professionals to know about MRI of brain.

 

Let's get into the topic. 

WHAT IS MRI OF BRAIN?

Magnetic Resonance Imaging (MRI) of brain is a non-invasive and painless procedure used to produce three dimensional cross sectional images of brain without the use of radiation unlike CT scan and X ray. Doctors use MRI of brain to study the brain structures like cerebrum, brainstem, cerebellum.

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WHY DO WE NEED MRI OF BRAIN?

Since MRI can produce better images of soft tissues, MRI of brain is used to study different complications of brain. Here soft tissue means muscles, blood vessels, nerves, fat and other tissues. MRI of brain is mainly done because nearly 60 percent of brain is made up of fat. Another important fact which adds value to MRI of brain is that brain has nearly 100 million nerve cells which makes MRI of brain most suitable for brain study.

The MRI of brain is used to identify various brain conditions like cysts, tumors, swelling, aneurysm, multiple sclerosis, hemorrhage. The MRI of brain is also used to study brain condition after brain surgery or after accidents which causing severe damage to head and brain. The MRI of brain is used to study the damages of brain due to stroke.

The MRI of brain is also used to gain deeper insights about conditions like chronic headaches, dizziness and vision problems.

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WHAT ARE THE PREPARATIONS FOR

MRI OF BRAIN?

The preparation for MRI of brain is same like normal MRI scan. Patients will be asked to remove all the metal objects from their body like jewelry, belt, watch etc. Patients will also be questioned about having any metal implants in their body like cochlear implants, pacemaker. Patients who have implants will not be allowed for MRI scan.

Preparation before, during and after MRI scan.  

WHAT IS THE PROCEDURE FOR MRI

OF BRAIN?

Typical MRI procedure usually takes 15-20 minutes. Like normal MRI scan, in MRI of brain also patients will be given contrast agents based on the requirements. Patients will be asked to remain still during the MRI scan. Patients will be given two way intercom connection to communicate with the technician. Patients will also be given ear phones to prevent hearing damage due to loud noise produced by MRI scan.

MRI With Contrast

WHAT IS FUNCTIONAL MRI OF

BRAIN?

The functional MRI of brain (fMRI) is used to produce images of blood flow in certain areas of brain. The functional MRI of brain is used to identify which part of brain handles what kind of functions. For example MRI of brain can identify the particular  area of brain responsible for specific body movement, speech and language. Functional MRI of brain identifies this by imaging the metabolic changes of brain which takes place when we do these body movements. During functional MRI of brain patients will be asked several brain teasing questions or asked to make some body movements like finger movements etc. to image the metabolic changes of brain.

HOW MRI OF BRAIN DONE IN

CHILDREN?

The MRI of brain for children are almost same like the one for adults and other age group peoples. Only difference is that in MRI of brain, a coil will be fitted around the child’s head when they sit in the machine. It is done because their heads are small. Doctors may recommend intravenous sedation due to lack of recommendation from children.  

 

Now I hope you have acquired some knowledge about MRI of brain. We will discuss in detail about a topic related to Biomedical Engineering in our next blog.

NOTE: Dear friends!!! ...Please do comment a topic related to Biomedical, so that we can discuss it in future blogs.

Check out for this blog about Computed Tomography and x ray.

Generations of CT Scanners

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MRI With Contrast

 

Hi friends!!!

In our previous blog, we have discussed about MRI scan. Please check out for the link given below.

MRI scan

In today's blog we are going to discuss about MRI with contrast.

MRI scan is usually done in two methods, with contrast and without contrast. One main difference between both methods is that a special type of dye is injected in MRI with contrast which yields better results in terms of image quality and image interpretation. Therefore it is important for every healthcare professionals to know about MRI with contrast. 

Let's get into the topic. 

WHAT IS AN MRI WITH CONTRAST?

The first MRI scan on humans was done on 1977. Later in 1988, Gadolinium based contrast agents are used to enhance MRI images. In MRI with contrast, a gadolinium based contrast agents, a paramagnetic metal ion which is used because of its property to travel with magnetic fields. It is a MRI dye used to enhance the image quality during MRI scan.

Generally bones and air spaces in human body appears as black colour in MRI scan. Soft tissues based on the amount of fat and water present, will appear from gray to black in MRI scan. When MRI contrast is injected into the bloodstream, the tissues targeted will appear brighter.

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HOW CONTRAST IS INJECTED?

In MRI with contrast, the contrast agents are admitted intravenously in the arm or administered orally. The contrast agents are injected with a use of IV or butterfly needle. Injection process will take 10 to 30 seconds. Approximately around 10 to 20 millilitres of gadolinium based contrast agents are injected into the veins.

WHO NEEDS MRI WITH CONTRAST?

Generally MRI with contrast is preferred for patient’s based on doctor’s prescription. When a doctor feels that his patient requires a contrast agent to increase the image quality, he prescribes it. And also doctor considers the patient’s past medical history to prescribe the use of contrast agents. Contrast agents do not change the colour of the organs, instead it changes the way in which imaging modalities views your organs. Later these contrast agents are excreted via urine.

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WHAT ARE THE ADVANTAGES OF

MRI WITH CONTRAST?

1. The MRI with contrast is mostly preferred  for tumor patient’s. Because the doctors can identify even a smallest tumors with the help of contrast agents. Generally tumors are more vascularized. They have lot of blood vessels feeding into them. If a contrast agent is injected, a lot of it will flow through the blood vessels and reach the tumors. So in MRI with contrast, tumors appears more brighter than surrounding tissues.  Useful in determining the growth stage of tumors.

2. MRI with contrast can visualize moving blood in arteries whereas normal MRI without contrast can produce the images of arteries as a void space.

3. The MRI with contrast is said to be most useful in imaging of multiple sclerosis.

4. No other additional scans required because MRI with contrast provides an enhanced image quality. With that doctors can easily interpret all the details in a single scan.

5. Interpretation time and difficulty also decreases.

WHAT ARE THE SAFETY CONCERNS OF MRI WITH CONTRAST?

1. In MRI with contrast, the injected contrast agents are excreted via urine, patient’s with poor kidney functions may have problem in excreting the contrast agents. As a result the Gadolinium based contrast agents may remain in the body and cause a condition called Nephrogenic systemic failure. It causes thickening of skin and tissues.

2. MRI with contrast in some cases may cause allergic reactions, skin irritations and pain in the injection site.

3. In MRI with contrast, the use of gadolinium based contrast agents are considered to be harmful for pregnant women’s and fetus. However MRI without contrast agents is proved to be safe for pregnant women’s and fetus.

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Now I hope you have acquired some knowledge about MRI with contrast. We will discuss in detail about MRI scan of various body parts in our next blog.

NOTE: Dear friends!!! ...Please do comment a topic related to Biomedical, so that we can discuss it in future blogs.

Check out for this blog about Computed Tomography and x ray.

Generations of CT Scanners

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MRI Scan

Hi friends!!!

In our previous blog, we have discussed about audiometer and types of audiometric tests. Please check out for the link given below.

Audiometer

Types of Audiometric tests

In today's blog we are going to discuss about MRI scan.

The introduction of Magnetic Resonance Imaging (MRI) scan has created a revolution in the field of diagnostic radiology. MRI is an important equipment to view soft tissues inside the body.  Therefore it is important for every healthcare professionals to know about Magnetic Resonance Imaging (MRI) scan. 

Let's get into the topic. 

WHAT IS MRI SCAN?

The Magnetic resonance imaging (MRI) scan uses a strong magnetic fields and radio waves to produce detailed cross sectional images of organs and soft tissues inside the body. MRI scanning is a non invasive and painless procedure. MRI scans does not use ionizing radiation like CT scans and X rays.

During MRI scan, the scanner produces loud noise due to electric current in the scanner coils turning on and off. Because of this, during MRI scan patients will be instructed to use earplugs or ear phone to prevent the hearing damage.

Typical MRI scan takes between 15-20 minutes. In some cases it may extend up to 1 hour based on the area of scanning and number of images required.

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HOW MRI SCAN WORKS?

MRI scan works based on the principle of alignment and realignment of protons in the hydrogen molecule due to magnetic fields. Most part of our human body is made up of water molecules. The water molecules consists of hydrogen and oxygen atoms.

MRI scan consists of powerful magnets which produces strong magnetic field. The magnetic field makes protons in the hydrogen molecule to align with the same direction of magnetic field. Then the radio frequency waves are passed on to the specific region of interest in the patient’s body.

These burst of radio waves disturbs the alignment of protons. When radio waves are turned off, these protons are again realigned to the direction of magnetic field. These realignment of protons produces radio signals, which are then received by the receivers.

The protons in different parts of body realign at different speeds and emits different levels of radio signals. The time it takes for the protons to realign and level of energy released depends on the environment and chemical mature of the proton molecule.

Contrast agents may be given to the patients before and during the MRI scan procedure to increase the speed of proton realignment. Faster the process of realignment, better will be the image quality.

Based on this, the MRI scan algorithm distinguishes the different tissues of the body and provide information on the location of the proton molecule. This is how MRI scan works.

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WHAT IS THE PREPARATION

BEFORE MRI SCAN?

During MRI scan patient’s will be asked to remove metals objects from the body such as jewellery, watches etc. Patient’s having implants like pacemakers, cochlear implant, artificial bone joint, artificial heart valves, vascular stents will not be allowed to undergo MRI scan.

Patient’s are provided with earphones to prevent hearing damage due to loud noise created during MRI scan procedure.

Sometimes, contrast agents will be given to improve the visibility of tissues.

DURING MRI SCAN

During MRI scan patient’s will be asked to remain still without any movement. Sometimes based on the requirement of area being imaged, patients are requested to hold their breath.

The technician and patients can communicate via two way intercom connection during MRI scan. The patient’s are provided with an alarm button to alert the technicians in case of discomfort.

AFTER MRI SCAN

If IV Catheter is used for contrast injection, it is removed after the MRI scan procedure. And patient’s will be given instructions to observe any allergic reaction due to contrast usage.

If sedation was given, patients are asked to wait for sometime until they gain their consciousness.

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Now I hope you have acquired some knowledge about MRI scan and how MRI scan works. We will discuss in detail about MRI scan of various body parts and MRI scan with and without contrast in our next blog.

NOTE: Dear friends!!! ...Please do comment a topic related to Biomedical, so that we can discuss it in future blogs.

Check out for this blog about Computed Tomography and x ray.

Generations of CT Scanners

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