WOTD: Phaeochromocytoma

Phaeochromocytoma on an MRI scan. Photograph: endocrinediseases.org

"Phaeochromocytoma" - A rare tumour of cells that secrete epinephrene (adrenaline) and norepinephrine (noradrenaline). It causes increased production of these hormones, leading to hypertension. The tumours usually develop in the medulla (core) of the adrenal glands, and are most common in young to middle-aged adults.

Hypertension is the only sign most of the time, but pressure on the tumour, emotional upset, change in posture, or taking beta-blocker drugs can cause a surge of hormones. This surge brings on a sudden rise in blood pressure, palpitations, headache, nausea, vomiting, facial, flushing, sweating, and, sometimes, a feeling of impending death.

Blood tests and urinalysis are used to make a diagnosis, CT scanning, MRI, and radioisotope scanning may be used to locate the tumours, which are then usually removed surgically. Follow-up medical checks are required because the condition occasionally recurs.

"phaeochromocytoma". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p445.

Fluoroscopy

An example of a fluoroscopy. Photograph: spineuniverse.com

Fluoroscopy is an imaging technique commonly used to obtain real-time moving images of the body's internal structures through a fluoroscope. In its simplest form, a fluoroscope consists of an x-ray source and a fluorescent screen. Modern fluoroscopes combine the screen with an x-ray image intensifier and a CCD video camera, which allows the images to be recorded and played on a monitor.

The use of the x-rays requires that the potential risks be balanced against the benefits the fluoroscope to the patient. Although low doses are always tried to be used during a fluoroscopic procedure, the general length of a typical procedure results in a high absorbed dose to the patient.

They can be used to:

• investigate the gastrointestinal tract
• aid fracture reduction and the placement of metalwork during orthopaedic surgery
• carry out an angiography of the heart, leg and cerebral vessels
• aid urological surgery

WOTD: Scoliosis

A scoliosis x-ray. Photograph: thefamilychiro.com.au

"Scoliosis" - A deformity in which the spine is bent to one side. The thoracic or lumbar regions are most commonly affected. Scoliosis usually starts in childhood or adolescence and becomes progressively more marked until growth stops. In many cases, another part of the spine curves to compensate, resulting in an S-shaped spine. The cause of juvenile scoliosis is unknown. Rarely, scoliosis is due to a congenital abnormality of the vertebrae.

In some cases, physiotherapy may be sufficient to control scoliosis. Progressive or severe scoliosis may require immobilisation of the spine in a brace, followed by surgery (spinal fusion) to straighten it.

"scoliosis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p500-501.

WOTD: Bronchiectasis

A chest x-ray of a patient suffering cystic fibrosis with bronchiectasis. Photograh: learningradiology.com

"Bronchiectasis" - A lung disorder in which one or more bronchi (the air passages leading from the trachea) are abnormally widened, distorted, and have damaged linings. Bronchiectasis most often develops during childhood and was once commonly associated with infections such as measles and pertussis (whooping cough). The condition is also a complication of cystic fibrosis. It results in pockets of long-term infection which the airways and the continuous production of large volumes of green or yellow sputum (phlegm), Extensive bronchiectasis causes shortness of breath. The symptoms are usually controlled with antibiotic drugs and postural drainage. If the condition is confined to one area of the lung, surgical removal of the damaged area may be recommended. 

"bronchiectasis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p98.

Arthrograms

The injection of an iodine-based contrast medium arthrogram. Photograph: Zezounet

An arthrogram is a series of images (mainly x-rays) of a joint after it has been injected with a contrast medium. These injections are usually administered under local anaesthetic. It is performed by a radiologist who uses fluroscopy and ultrasound to guide the placement of the needle into the joint, to then inject the contrast fluid.

Shoulder arthrograms are used to study tears of the rotator cuff (mainly tears of four tendons rather than the muscles in the shoulder). They can also define whether there are abnormalities of the glenoid labrum and bicipital tendon. 

Arthrograms (like radiography) can either be diagnostic or therapeutic. Therapeutic arthrograms are often joint distension and cortisone injection procedures. This procedure is most common for the shoulder. Diagnostic arthrograms can be direct or indirect, by a venous injection of contrast material and then followed by a CT or MRI scan.

Arthrograms are not not recommended to patients who are allergic or sensitive to:

• medications
• contrast dyes
• local anaesthesia
• iodine
• latex

Infection in the puncture site where the radiopaque substance is injected is a small risk, as is bleeding.

There have been reports that gadolinium contrast agents cause Neophrogenic Systemic Fibrosis (NSF). This has only occurred in cases where the patients have moderate-to-end-stage kidney disease; there have been no reports stating any case of NSF in those with healthy kidneys. Other than the risk of NSF for those enduring kidney disease, arthrograms carry the same risks as any ordinary X-ray scans.

WOTD: Spondylolysis

A sagittal x-ray of a female patient with L4 spondylolysis. Photograph: Spineuniverse.com

"Spondylolysis" - A disorder of the spine in which the arch of the 5th (or, rarely, the 4th) lumbar vertebra consists of soft fibrous tissue instead of normal bone. As a result, the arch is weak and prone to damage, which may produce spondylolisthesis (the slipping forward of a vertebra over the one below it.) Otherwise, spondylolysis is usually symptomless.

"spondylolysis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p522.

John Wild: The Father of Ultrasound

John J. Wild. Photograph: Boston.com

John Julian Cuttance Wild (11 August 1914 - 18 September 2009) was an English-born American physician, who was part of the first group to use ultrasound for imaging the body, most notably for diagnosing cancer. The modern ultrasonic diagnostic medical scans are improvements upon the equipment Wild developed in the 1950s. He has since been referred to as the "Father of Medical Ultrasound".

Wild was born in Kent, United Kingdom in 1914. He attended Merchant Taylor's School and took out his first patent at the age of 14, for a device to distribute an even amount of hot and cold water in a bathtub. He received a Bachelor of Arts degree in Natural Sciences Tripos from the University of Cambridge in 1936. In 1940, he was awarded a Master of Arts. And he also became a Doctor of Medicine in 1942. He was elected a member of the Royal Society of Medicine in 1944 and then, in the same year joined the Royal Army Medical Corps. 

In 1946, he emigrated to the US and began working at the University of Minnesota in the department of surgery. In 1950, he switched to the electrical engineering department. During World War II he had seen many patients that had suffered with bowel failure and he had developed a technique called the "Wild Tube". In the US, he saw patients with the same conditions, and so he conceived the idea of using ultrasound as a non-invasive means of determining the intestinal injuries of patients. The sound bounced back from the tissue, identifying its thickness and resilience of the portion of intestine being scanned. He had developed his idea, after hearing of high-frequency sounds being used as a means to identify cracks in tank armour. 

The first machines did not have a strong enough resolution to scan the intestines, but by 1951 Wild and Dr. John Reid gained access to equipment that operated at 15 MHz, which providing the detail needed to carry out internal scans and differentiate between cancerous and healthy tissue. 

In 1991, Wild earned the Japan Prize, in recognition of his work within the field of ultrasound imaging. 

WOTD: Osteochondroma

An osteochondroma on the fibula. Photograph: tumorlibrary.com

"Osteochondroma" - A noncancerous bone tumour, which is formed from a stalk of bone capped with cartilage, and appears as a hard round swelling near a joint. An osteochondroma develops in late childhood and early adolescence, usually from the side of a long bone near the knee or shoulder. The tumour causes problems only if it interferes with movement of tendons or the surrounding joint, in which case it may be removed surgically. Large osteochondromas can interfere with skeletal growth, causing deformity.

"osteochondroma". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p422.

Paul Lauterbur & MRI

Paul Christian Lauterbur. Photograph: Michigan State University

I decided to look into the development of MRI today, and I learnt about somebody new!

Paul Christian Lauterbur (6 May 1929 - 27 March 2007) was an American chemist who shared the Nobel Prize in Physiology or Medicine in 2003 with Peter Mansfield for his work which made the development of MRI possible.

Lauterbur was born and raised in Sidney, Ohio and graduated from Sidney High School where a new wing for Chemistry, Physics and Biology was dedicated in honour of him. He studied as an undergraduate at Case Institute of Technology  in Cleveland. He built his own laboratory as a teenager in his parent's basement, and he enjoyed doing chemistry experiments on his own. While in the Army in the 1950s, he began his work developing one of the early MRI machines. 

He graduated from the University of Pittsburgh in 1962 and credits the idea of the MRI to a brainstorm he had one day, which he wrote down on a napkin (as scientists do!) He continued this research, which earned him the Nobel Prize at Stony Brook University, during the 1970s.

The Nobel Prize in Physics in 1952, which was awarded to Felix Bloch and Edward Purcell, was for the development of nuclear magnetic resonance (NMR), the scientific principle behind MRI. However, NMR was mainly for studying the chemical structure of substances. It wasn't until the 1970s with Lauterbur's and Mansfield's developments that NMR could be used to produce images of the body.

Lauterbur is credited for the idea of introducing gradients in the magnetic field which allows us to determine the origin of the radio waves emitted from the nuclei of the object of study. This spatial information allows two-dimensional pictures to be produced.

While Lauterbur was at Stony Brook, the best NMR machine on campus belonged to the chemistry department (which resulted in him using it at night!) The original MRI machine is located in the Chemistry building at State University of New York in Stony Brook, New York.

Some of the first images taken by Lauterbur included a clam his daughter had collected, green peppers and two test tubes of heavy water within a beaker of ordinary water; no other imaging technique at that time could distinguish between two different kinds of water. This was particularly important as the human body consists mostly of water.

Peter Mansfield of the University of Nottingham in England took Lauterbur's initial work further, and developed a mathematical process to speed the image reading.

Sorry again for the long posts about historical figures in Radiography, but it is quite fascinating to find out what they developed and how! It also helps to understand how they work... kind of... Maybe...

WOTD: Astrocytoma

An MRI scan showing an astrocytoma. Photograph: Mayfield Clinic

"Astrocytoma" - A type of cancerous brain tumour. Astrocytomas are the most common type of glioma, a tumour arising from glial (supporting) cells in the nervous system. They most commonly develop in the cerebrum (the main mass of the brain). Astrocytomas are classified in four grades (I-IV) according to their rate of growth and malignancy. The most severe and common type is called glioblastoma multiforme. Symptoms are similar to those of other types of brain tumour. Diagnostic tests include CT scanning or MRI. Treatment is with surgery and, in some cases, radiotherapy and/or chemotherapy.

"astrocytoma". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p56.

Wilhelm Röntgen: The Father of the X-Ray

Wilhelm Conrad Röntgen. Photograph: Wikipedia

Wilhelm Röntgen (27 March 1845 -10 February 1923) was a German physicist, who is known for his discovery of a type of electromagnetic radiation in a wavelength range, known today as the x-ray. This discovery earned him the first Nobel Prize in Physics in 1901. The radioactive element 111, Roentgenium, which has multiple unstable isotopes, is named after him.

Röntgen was brought up in a Catholic family from Lennep, Germany. In 1848, his family moved to Apeldoorn, and so Wilhelm was brought up in the Netherlands. After attending the Institute of Martinus Herman van Doorn, Wilhelm went to school in Utrecht. Here he was expelled for refusing to identify a classmate who had drawn an unflattering portrait of their teacher. And because of this expulsion, he was unable to attend a Dutch or German gymnasium.  He tried to attend the University of Utercht, without the correct requirements for regular students, but instead, he began his studies as a mechanical engineering student at the Federal Polytechnic Institute in Zurich. He graduated with a Ph.D in 1869 from the University of Zurich. He then became a lecturer at the University of Strassburg. 

In November 1895, Röntgen was repeating an experiment he had been doing with one of Philipp von Lenard's tubes. It was during this experiment that Röntgen wondered what was causing the fluroscent effect. So he decided to test this idea on the 8 Novemeber 1895. Röntgen constructed a black cardboard covering. He covered a Hittorf-Crookes tube with the cardboard and attached electrodes to a Ruhmkorff coil to generate an electrostatic charge. Before setting up the barium platinocyanide screen, Röntgen darkened the room to test the cardboard cover's opacity. As the Ruhmkorff coil charge passed through the tube, he determined that the cover was light-tight and proceeded to prepare the next step of the experiment. It was at this point that Röntgen noticed a faint shimmering from a nearby bench. Being the experimental scientist he was, he tried several more discharges and saw the same shimmering each time. Striking a match, he discovered the shimmering had come from the location of the barium platinocyanide screen he had been intending to use next.

Röntgen theorised that a new type of ray could be responsible. He then, during the next few weeks, investigated many properties of the new rays he temporarily termed "X-rays", using the mathematical designation for something unknown. Although the new rays were eventually named after him as "Röntgen Rays", he preferred the term X-rays. And nearly two weeks after their discovery, Wilhelm took the very first picture using X-rays of his wife's hand, Anna Bertha. When she saw her skeleton she exclaimed "I have seen my death!"

Röntgen's original paper, "On A New Kind Of Rays" (Über eine neue Art von Strahlen), was published on 28 December 1895. Röntgen was awarded an honorary Doctor of Medicine degree from the University of Würzburg after his discovery. He published a total of three papers on X-rays between 1895 and 1897. 

Today, Röntgen is considered the father of diagnostic radiology, the medical specialty which uses imaging to diagnose disease.

WOTD: Vasculitis

Cutaneous Vasculitis. Photograph: aic.cuhk.edu.hk

"Vasculitis" - Inflammation of blood vessels. Vasculitis usually leads to damage to the lining of vessels, with narrowing or blockage, that restricts or stops blood flow. As a result, the body tissues supplied by the affected vessels are damaged or destroyed by ischaemia.

Vasculitis is thought to be caused in most cases by the presence of minute bodies, called immune complexes (consisting of antigens bound to antibodies) are normally destroyed by white blood cells, but sometimes adhere to the walls of blood vessels, where they cause inflammation. In some cases, the antigens are viruses. Vasculitis is the basic disease process in a number of disorders, including  polyarteritis nodosa, erythema nodosum, Henoch-Schönlein purpura, serum sickness, temporal arteritis, and Buerger's disease.

"vasculitis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p578.

WOTD: Periodontitis

A 60 year old patient with severe chronic periodontitis. Photograph: Augustin Zeron

"Periodontitis" - Inflammation of the periodontium (the tissues surrounding the teeth.) There are two types: periapical and chronic. Periapical periodontitis results from neglected dental caries and occurs when bacteria enter the tooth pulp and spread to the root tip, sometimes causing a dental abscess, granuloma, or cyst. Chronic periodontitis is a result of untreated gingivitis, in which bacteria attack the periodontal tissues. This type is the major cause of adult tooth loss.

Periapical periodontitis may cause toothache, especially on biting. An abscess may make the tooth loss; a large dental cyst may cause swelling of the jaw. In chronic periodontitis, the signs of gingivitis are present.

Periodontitis is diagnosed by a dental examination and dental x-rays. Periapical periodontitis is treated by draining pus and filling the tooth or by extraction. 

Regular teeth cleaning can prevent advanced chronic periodontal disease and further destruction of the tissues. Treatment may include root planing, scaling, gingivectomy, or curettage. Sometimes, loose teeth can be anchored to firmer teeth by splinting.

"periodontitis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p441.

WOTD: Osteomalacia

X-ray appearances of the wrist and knee in osteomalacia (A) before treatment (B) after six months of treatment

Photograph: BMJ

"Osteomalacia" - Softening, weakening, and demineralisation of bones in adults due to vitamin D deficiency. Osteomalacia is rare in developed countries. It is most commonly affects housebound, elderly, and dark-skinned people live in countries that have less sunlight than their country of origin.

Healthy bone production requires calcium and phosphorus, which cannot be absorbed from the diet without sufficient vitamin D. Causes of osteomalacia include a diet low in vitamin D; malabsorption in conditions like coeliac disease or after intestinal surgery; or insufficient exposure to sunlight.

Osteomalacia causes bone pain, muscle weakness, and, if the blood level of calcium is very low, tetany. Weakened ones are vulnerable to distortion and fractures. Treatment is with a diet rich in vitamin D and increased exposure to sunlight; vitamin D supplements may also be given if osteomalacia is due to malabsorption.

"osteomalacia". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p423.

WOTD: Myxoma

An x-ray of an atrial myxoma. Photograph: radiopaedia.com

"Myxoma" - A noncancerous, jelly-like tumour composed of soft mucous material and loose fibrous strands. Myxomas usually occur singly, and may sometimes grow very large. They may develop under the skin, in the abdomen, in the bones or, very rarely, inside the cavities of the heart. In this case, thrombi (blood clots) may form, and the flow of blood through the heart may be obstructed. Myxomas can usually be successfully removed by surgery.

"myxoma". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p387.

Riveting Reads

A brilliant book to read due to its depth. Photograph: plodit.com

Hey all! I apologise for not posting anything yesterday. I was incredibly tired out and in pain from a Taekwon-do session, so I ended up falling asleep as soon as I got home!

Anyway, people at my college are all in the same boat as me, and are wondering what textbooks are good and which aren't for different things. At the moment, I can only really suggest Anatomy and Physiology textbooks, and other books of interest (these are pretty vital, and also highly interesting!).

So far, I've managed to find 5 books that I've thoroughly enjoyed and have taught me a great deal (and help me to write and understand my posts!). For anyone who just wants to understand the Human Body a little bit more, my favourite book (complete with an overused spine) is DK's 'The Human Body' (ISBN 9781405316255). I have had this book (both in paperback, which has been passed down to my brother, and hardback) for over three years, and there is so much to learn and look at. Being a visual learner, it does help having colour and diagrams to better my understanding :)

For Anatomy and Physiology on the other hand, I recommend two specialised textbooks. These are:

• Anatomy & Physiology Made Incredibly Easy (I have the 3rd Edition, but they have released a 4th recently ISBN 1451147260)- This book really is amazing. I love it, and it isn't too heavy to carry around. It utilises diagrams and quizzes, too.
• Ross and Wilson Anatomy & Physiology in Health and Illness- This book is highly detailed, and is recommended by many college and university students.
• Ross and Wilson Anatomy & Physiology Colouring and Workbook- I kid you not, this book does wonders :) It is a companion to the above book, but you can use it with others if need be.

And finally, I do recommend the BMA's Illustrated Medical Dictionary. This book is where I find my WOTD, and also if I'm bored, I like to flick through and learn something new. Only problem is the spine is on its way out now...

So there we are for now :) These books are very helpful and interesting, and yes, I do own them 
all (Play.com is good). I also own the Anatomy & Physiology for Dummies, but I do prefer the others. 

Eventually, I'll get round to amassing a list of Radiography specific books (e.g. Clark's), but for 
now, I'm focusing on getting to Radiography beginning standard of understanding the body.

Sorry this entry wasn't as interesting! I'll try to have something more fun tomorrow for you!

WOTD: Encephalopathy

A CT scan of an 11 year old child with progressive encephalopathy secondary to HIV.
Photograph: rihes.cmu.ac.th

"Encephalopathy" - Any disorder affecting the brain, especially chronic degenerative conditions.

Wernicke's encephalopathy is a degenerative condition of the brain caused by deficiency of Vitamin B1. It's most common in those with chronic alcohol dependence. Hepatic encephalopathy is caused by the effect on the brain of toxic substances that have built up in the blood as a result of liver failure. It may lead to impaired consciousness, memory loss, a change in personality tremors and seizures.

Bovine spongiform encephalopathy, or BSE, is a disorder contracted by cattle after they are given feed containing material from other cattle or sheep. 

Other causes of encephalopathy include HIV infection, chickenpox, and Reye's syndrome. Treatment of encephalopathy depends on the cause.

"encephalopathy". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p199.

WOTD: Neurosyphilis

An MRI scan showing neurosyphilis. Photograph:  Dr Roberto Schubert

"Neurosyphilis" - Infection of the brain or spinal cord that occurs in untreated syphilis many years after initial infection.

Damage to the spinal cord due to neurosyphilis may cause tabes dorsalis, characterised by poor co-ordination of leg movements, urinary incontinence, and pains in the abdomen and limbs. Damage to the brain may cause dementia, muscle weakness, and, in rare cases, total paralysis of the limbs.

"neurosyphilis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p400.

DEXA Scans

A DEXA scan involves lying on an X-ray table so that the affected area of the body can be scanned.
Photograph: Bupa

A DEXA scan (Dual Energy X-Ray Absorptiometry) is a special type of X-ray that measures bone density. DEXA scans are most commonly used to diagnose osteoporosis. They can can also be used to assess the risk of osteoporosis developing in a patient.

DEXA scans involve x-rays being passed through the body, meaning that some radiation will be absorbed by the bones. Specialised detectors measure the dose of radiation the patient receives during the DEXA scan. This measurement is then compared with the average range for bone density in a healthy adult of the same age and gender. 

DEXA scans, like most medical imaging techniques, is safe and painless and is more effective in measuring low density in comparison to an ordinary X-ray scan. It also uses a lower level of radiation. 

DEXA scans are not recommended for pregnant women, as they are not considered safe for an unborn child, as they can cause the foetus damage.

WOTD: Osteoporosis

The neck of the right femur is fractured due to osteoporosis. Photograph: medlib.med.utah.edu

"Osteoporosis" - An inherited disorder in which bones harden and become denser. Deficiency of one of the two types of bone cell responsible for healthy bone growth results in a disruption of normal bone structure. In its mildest form, there may be no symptoms, more severe forms of osteoporosis result in abnormally high susceptibility to fractures, stunted growth; deformity; and anaemia. Pressure on nerves may cause blindness, deafness, and facial paralysis.

Most treatments for osteoporosis aim to reduce the severity of symptoms. Bone marrow transplants of cells from which healthy bone cells might develop are undertaken in some cases.

"osteoporosis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p423-424.

MRI: Who Can Use It?

MRI scans of the brain. Photograph: NHS

MRI scans are safe and generally most people are able to use them. However, some patients are recommended not to use MRI. These patients usually have medical devices in their bodies, which the MRI scanner's powerful magnets can interfere with. Some of these devices are:

• a drug pump - delivers painkilling medication directly to an area of the body
• a pacemaker - electrical device which controls irregular heartbeats
• a nerve stimulator - electrical implant that treats nerve pain
• a cochlea implant - similar to a hearing aid, but surgically implanted in the air

In some cases (though in many it is not possible), it is safe for some patient's with pacemakers and implanted defibrillators if certain procedures are followed.  This usually involves a cardiologist (heart specialist) making the device MRI-safe. During the procedure they will also monitor the patient's heart rhythm. 

MRI may also not be recommended for patients who have:

• metallic fragments - usually if they are near the eyes or any blood vessels
• prosthetic metal heart valves
• penile implants
• brain aneurysm clips - used to seal blood vessels in the brain
• an intrauterine device (IUD) - a plastic contraceptive device in the womb

Some patients with tattoos also need to tell the Radiographer if their tattoo contains any traces of metal, and also during their procedure if they feel any discomfort or heat on the tattoo's area.

Although MRI scans are suggested to pose no risk to pregnant women, as a precaution, women who are three months pregnant are not recommended to undergo an MRI scan.

WOTD: Pericarditis

An x-ray of a Pericardial effusion. Photograph: wikidoc.org

"Pericarditis" - Inflammation of the pericardium, which often leads to chest pain and fever. There may also be an increased amount of fluid (effusion) in the pericardial space, which may restrict the heart. Long-term inflammation can cause constrictive pericarditis, a condition in which the pericardium becomes scarred, thickens, and contracts, interfering with the heart's action.

Causes of pericarditis include infection: myocardial infarction; cancer spreading from another site; and injury to the pericardium. The disorder may accompany rheumatoid arthritis, systemic lupus erythematosus, and kideny failure. 

Pericarditis causes pain behind the breastbone, and sometimes in the neck and shoulders. There may also be a fever. Constrictive pericarditis causes oedema of the legs and abdomen.

Diagnosis is made from a physical examination and an ECG and chest X-rays or echocardiography. If possible, treatment is aimed at the cause. Analgesic drugs or anti-inflammatory drugs may be given. If an effusion is present, fluid may be drawn off through a needle. In constructive pericarditis, part of the pericardium may be removed.

"pericarditis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p440.

How An X-Ray Is Performed

An x-ray machine in a hospital's radiology department. 

Photograph: GustoImages/Sciene Photo Library

During an x-ray examination, the patient is asked to either lie down or stand against a flat surface. This is so that the body part being scanned is between the x-ray machine and the photographic plate. X-rays are carried out by radiographers (health professionals trained in medical imaging technologies).

The x-ray machine has many parts, which includes

• an x-ray tube - a large light bulb which generates x-rays by using high-voltage electricity.
• a  photographic plate - captures the the produced image. This used to be made from the same film as a traditional camera, but these days, this plate is connected to computer  to produce a digital image.
• and lead shielding - directs the x-ray to the body part being scanned and prevents them from going in all directions.

The patient is exposed to radiation during the examination for only a fraction of a second. As I always say, x-rays are completely safe and painless! 

An x-ray image is produced when the x-rays hit the photographic plate. The plate will then capture the image. This image is then transferred to a computer, so that it can be studied on screen, though it can be printed if necessary.

The patient being examined needs to be still, as movement will blur the image. X-rays of the same part can be taken from different directions, so as to provide as much information as possible. These images are then studied by a Radiologist (a doctor who has been specially trained to carry out examinations and interpret medical images). The radiologist will then discuss the findings with their patient or send their report to the patient's GP.

WOTD: Osteomyelitis

Osteomyelitis is a medical term that describes an infection of bone. Photograph: learningradiology.com

"Osteomyelitis" - Infection, usually by bacteria of bone and bone marrow. It is relatively rare in developed countries, but is more common in children, most often affecting the long arm and leg bones, and vertebrae. In adults, it usually affects the pelvis and vertebrae. In acute osteomyelitis, the infection (usually Staphylococcus Aureus) enters the bloodstream via a skin wound or as a result of infection elsewhere in the body. The infected bone and marrow become inflamed, and pus forms, causing fever, severe pain and tenderness in the bone, and inflammation and swelling of the skin over the affected area.

Prompt treatment over several weeks or months with high doses of antibiotic drugs usually cures acute osteomyelitis. If the condition fails to respond, surgery is performed to expose the bone, clean-out areas of infected and dead bone, and drain the pus.

Chronic osteomyelitis may develop if acute osteomyelitis is neglected or fails to respond to treatment; after a compound fracture; or, occasionally, as a result of tuberculosis spreading from another part of the body. The condition causes constant pain in the affected bone. Complications include persistent deformity and, in children, arrest of growth in the affected bone. In the later stages of the disease, amyloidosis may develop. Chronic osteomyelitis requires surgical removal of all affected bone, sometimes followed by a bone graft, antibiotic drugs are also prescribed.

"osteomyelitis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p423.

Angiography Scans

The heart is one of the most common areas that can be checked by angiography.
Photograph: uremicfrost.com

An angiography is a type of x-ray that is used to examine the blood vessels. Due to the blood vessels not being visible on an ordinary x-ray, the area being examined is injected with contrast fluid that highlights the blood vessels. 

The heart is the most common area to be checked using angiography (coronary angiography), but there are other areas in the body that are checked using this imaging technique:

• brain (cerebral angiography)
• lungs (pulmonary angiography)
• kidneys (renal angiography)
• arms or legs (extremity angiography)

Although they are mainly carried out during x-rays, angiograms can also be carried out using MRI and CT. They help to diagnose conditions that affect the blood flow and vessels. This can include:

• coronary heart disease
• atherosclerosis
• aneurysm

They are also helpful to plan surgeries that involve the blood vessels.

Angiographies can take up to 2 hours, and are carried out in hospital. In most cases, local anaesthetic is used, however if a child is having the procedure, general anaesthetic is used. The procedure is carried out be a radiologist who inserts and guides a catheter into a small cut into one of your arteries (usually in the groin or leg). 

They are generally safe and painless, and the risk of a serious complication occurring is low. Of course, due to the catheter insertion, there may be minor bruising. Some patients may on occasion have an allergic reaction to the contrast fluid, but this is easily treated with medication, and is not a serious risk to worry about.

WOTD: Craniosynostosis

An x-ray view of craniosynostosis. Photograph: emedicine.medscape.com

"Craniosynostosis" - The premature closure of one or more of the joints (sutures) between the curved, flattened bones of the skull in infants. If all the joints are involved, the growing infant's brain may be compressed and there is a risk of brain damage from pressure inside the skull. If the abnormality is localised, the head may be deformed. Craniosynostosis may occur before birth and, in some cases is associated with other birth defects. It may also occur in an otherwise healthy baby, or in a baby affected by a disorder such as rickets. If the brain is compressed, an operation may be performed to separate the fused skull bones.

"craniosynostosis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p151.

Ultrasound Scans

Ultrasound is a useful technique for looking at the growth of a foetus. Photograph: babyscans.co.uk

Ultrasound uses high-frequency sound waves that are inaudible to the human ear. These waves travel through the body and the echoes create images of the internal structures or of a foetus. Ultrasound are beneficial for imaging organs that are situated deep within body cavities, and as ultrasound doesn't involve ionising radiation, is believed to be completely safe.

Ultrasound works by a transducer (the handheld device that is held against the skin surface) converting an electric current into high-frequency sound waves. The sound waves emitted by the transducer are focused in a narrow beam that passes through the body's soft tissues and fluid, and are then reflected at a point where different densities meet. The transducer also acts as a receiver by converting the reflected echoes into electrical signals, which is processed by a computer as a 2D image. 

Most pregnant women will have at least one ultrasound scan during their pregnancy. Ultrasound can also be used to image a newborn baby's brain. Using ultrasound in this way can identify any bleeding into the brain, which can a potential problem in newborns.

Ultrasound is also commonly used to look at internal organs and fluid-filled structures. It is also used to examine the heart's structure and movement. 

Ultrasound is not thought to have any risks, and can be repeated as often as necessary. Because of this, it is the only imaging technique believed to be safe for routine foetus screening.

WOTD: Atelectasis

An x-ray of atelectasis of the right lung. Photograph: Valencia Institute of Oncology

"Atelectasis" - Collapse of part or all of a lung caused by obstruction of one or more air passages in the lung. Obstruction may be caused by accumulation of mucus, by an accidentally inhaled foreign body, by a tumour in the lung, or by enlarged lymph nodes exerting pressure on the airway.

The main symptom is shortness of breath. There may also be a cough and chest pain. The condition can be diagnosed by chest x-ray. Treatment is aimed at removing the cause of the blockage and may include physiotherapy or bronchoscopy. If the obstruction can be removed, the lung should reinflate normally.

"atelectasis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p56.

The Risks of X-Rays

Although they are safe, people are still concerned about radiation exposure during an x-ray.
Photograph: NHS.uk

When they were first discovered, going for an X-ray wasn't as safe as it is today. People are still worried about being exposed to dangerous amounts of radiation. But, everyday people are exposed to natural radiation without even knowing it. These natural radiation sources include:

• radon - a gas found in low levels in the atmosphere 
• cosmic rays - radiation that originates from space (sun and stars)
• the earth - soil and rocks contain radioactive materials
• food and water - e.g. red meat and potatoes contain tiny traces of radiation

But, people do have a reason to worry about x-rays, as being exposed to them does carry a risk of possibly triggering cancer later on in life. But this risk is exceedingly low. With most x-rays, there is a 1 in a 1,000,000 chance of causing cancer. More than 1 in 3 people in the UK develop some form of cancer during their lifetime, but this development depends on many different factors.

There are also precautions taken with x-rays when targeting the womb in women and the pelvis in both genders. This is just a precaution to ensure the x-rays do not affect the individual's fertility, as x-rays can affect the cells in the reproductive system. Not only that, but it is also to ensure that if the woman is unknowingly pregnant, the foetus is not harmed in any way. But x-rays that do directly target the womb are generally avoided unless they are clinically necessary. Instead, ultrasound is used.

Those who work with x-rays regularly (the most obvious people being Radiographers) therefore must thoroughly understand how x-rays work, how they work on, around and in the body. Radiographers are protected by a lead screen when carrying out the x-ray, as this screen absorbs the scattered x-ray beams. 

Although x-rays seem dangerous, even the most powerful of x-rays do not seem to have adverse affects and the dosages you receive are very small, given the background radiation you receive already!

WOTD: Hydrocephalus

An MRI scan of a brain with hydrocephalus (left) and a normal MRI scan (right). The large dark area on the left is the ventricles, made bigger by a build-up of Cerebrospinal fluid. Photograph: Seattle Children's Hospital

"Hydrocephalus" - An excessive amount of cerebrospinal fluid, usually under increased pressure, within the skull. The condition may be present at birth, when it is often associated with other abnormalities, such as spina bifida, or it may develop as a result of major head injury, brain haemorrhage, infection (such as meningitis), or a tumour.

With congenital hydrocephalus, the main feature is an enlarged head that continues to grow rapidly. Other features include rigidity of the legs, vomiting, epilepsy, irritability, lethargy, and the absence of normal reflex actions. If it is not treated, hydrocephalus progresses to severe brain damage, which may result in death within weeks. When the condition occurs later in life, symptoms include headache, vomiting, loss of co-ordination, and the deterioration of mental function.

In most cases, treatment of hydrocephalus is by draining the fluid from the brain to another part of the body, such as the abdominal cavity, where it can be absorbed.

"hydrocephalus". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p288-289.

Radiography: A Very Brief History

A chest x-ray examination. Photograph: 19thcenturychange.wordpress.com

Radiography itself hasn't been around for very long. X-rays, or Röntgen rays, as they are also known, (after Wilhelm Conrad Röntgen who discovered them in 1895) were found to be a type of electromagnetic radiation. One of the first pictures that Röntgen took using these rays was of his wife's right hand, which showed her rings and bones easily. The rays were given the name X-ray because not much was known about them at the time of their discovery.

The first radiograph (or roentgenogram) used to assist in surgery was taken in 1896 after its invention in Birmingham by the British pioneer of medical X-Rays, Major John Hall-Edwards (he eventually had to have his left arm amputated in 1908 due to X-ray dermatitis). Also in June that year, only 6 months after Röntgen announced his discovery, X-rays were being used by battlefield physicians to locate bullets in wounded soldiers. 

Shortly after, French scientist Henri Becquerel discovered natural radioactivity. Becquerel was researching fluorescence, where certain minerals glow when exposed to sunlight. He utilised photographic plates to record this fluorescence. Marie Curie also became interested in his work and tried to find other radioactive elements.

Inevitably, the widespread and unrestrained use of X-rays led to serious injuries. Often injuries were not attributed to X-ray exposure. Some early experimenters did tie X-ray exposure and skin burns together. The first warning of possible adverse effects of X-rays came from Thomas Edison, William J. Morton, and Nikola Tesla who each reported eye irritations from experimentation with X-rays and fluorescent substances.

When new diagnostic tests were developed, it was natural for radiographers to be trained in and to adopt this new technology. 

Another interesting fact: The term "radiographer" has only really been in use since 1918. Before that, the term "skiagrapher" was used, derived from the Ancient Greek words "shadow" and "writer".

Radiographers now often do fluoroscopy, CT, mammography, ultrasound, nuclear medicine and MRI.