Reverse total shoulder arthroplasty (RTSA) is a type of total shoulder replacement. It is often the preferred method when there has been advanced damage to the rotator cuff as seen in rotator cuff arthropathy.
The reverse total shoulder flips the normal mechanical arrangement of the ...
Functional endoscopic sinus surgery (FESS) is performed intranasally using a rigid endoscope. Its primary objective is to restore physiological ventilation and mucociliary transport 1.
Sinus imaging is crucial in preoperative planning and is increasingly being used intraoperatively.
Umbilical arterial (UA) Doppler assessment is used in surveillance of fetal well-being in the third trimester of pregnancy. Abnormal umbilical artery Doppler is a marker of uteroplacental insufficiency and consequent intrauterine growth restriction (IUGR) or suspected pre-eclampsia.
CT perfusion in ischaemic stroke has become established in most centres with stroke services as an important adjunct, along with CT angiography (CTA), to conventional unenhanced CT brain imaging.
It enables differentiation of salvageable ischaemic brain tissue (the penumbra) from irrevocably d...
Focal areas of signal intensity (FASI), alternatively called focal abnormal signal intensity or unidentified bright objects (UBO), are bright areas on T2-weighted images commonly identified in the basal ganglia (often the globus pallidus), thalamus, brainstem (pons), cerebellum, and subcortical ...
Various types of brain tumours may cause haemorrhage. Increased tumour vascularisation with dilated, thin-walled vessels and tumour necrosis are the most important mechanisms of haemorrhage. The list includes:
choroid plexus carc...
Haemorrhagic infarct or haemorrhagic transformation of an infarct is seen following breakdown of the lamina of the microvessels.
Intracerebral haemorrhage (ICH) may overlap with a haemorrhagic infarct and hence needs to be differentiated as the line of treatment will vary.
The haemorrhage exclusion sign can be a useful MRI finding following prostate biopsy.
The normal prostate produces high concentrations of citrate, which among other properties, acts as an anticoagulant 1. As tumour cells are dysfunctional, they will produce lower levels of citrate th...
Hindfoot equinus describes abnormal plantarflexion (calcaneotibial angle >90°) of the foot that occurs in the hindfoot. It occurs in congenital talipes equinovarus and congenital vertical talus.
Haematuria in a child is evaluated differently than in an adult in two main respects:
there is a lower likelihood of a malignancy (renal or bladder) causing the haematuria
preference is given to nonionizing radiation
Haematuria can be considered in three main forms:
Getting a film with left upper lobe collapse in the exam is one of the many exam set-pieces that can be prepared for.
This frontal chest radiograph shows a hazy (or veil-like*) opacification of the left hemithorax that is associated with superior displacement left hilum and horizon...
Left upper lobe collapse has distinctive features but can be challenging to identify on chest radiographs by the uninitiated.
For a general discussion refer to the article on lobar collapse.
The left upper lobe collapses anteriorly becoming a thin sheet...
Atrial situs refers to the relative position of the cardiac atria in relation to abdominal viscera and the midline.
Identification of atrial situs is an important initial step in the antenatal and postnatal diagnosis of cardiac structural and situs anomalies.
Gunshot injuries often require imaging assessment, and this evaluation has both clinical relevance (assessment of organ damage, surgical planning and prognostication), and often also forensic implications.
Incidence of gunshot injuries to the head is increasing in some countries, ...
Focussed Assessment with Sonography for Trauma (FAST) scan is a point-of-care ultrasound examination performed at the time of presentation of a trauma patient.
It is invariably performed by a clinician, who should be formally trained, and is considered as an 'extension' of the trauma clinical ...
Ultrasound guided percutaneous breast biopsy is a widely used technique for an accurate histopathological assessment of suspected breast pathology. It is a fast, safe and economical procedure.
Ultrasound guidance is limited to lesions visible on ultrasound study, such as:
Ultrasound along with nuclear medicine, is an important modality for assessment of thyroid lesions, and it is also frequently used to guide biopsy. Diagnostic criteria for thyroid nodules continue to evolve with improving ultrasound technology.
The approach taken to interpreting a CT scan of the head is no doubt different depending on the circumstances and the reading clinician, however, most radiologists will go through the same steps. What follows is merely a suggested approach to interpreting a CT of the head.
An important aspect ...
Imaging in liver transplantation is aimed to evaluate donor and recipient for successful transplantation and its outcome.
volume of liver
parenchymal disease (diffuse or focal)
The anatomic position, also referred to as the standard anatomic position, is the consistent position of the human body in which positional reference is made for anatomical nomenclature. It is not reliant on whether the patient is standing, supine, prone, sitting, etc.
The position is defined a...
Testicular and scrotal ultrasound is the primary modality for imaging most of the male reproductive system. It is relatively quick, relatively inexpensive, can be correlated quickly with the patient's signs and symptoms, and, most importantly, does not employ ionising radiation.
MRI is occasion...
In breast imaging, forbidden, check or review areas are zones that, according to Tabár, require special attention in mammographic interpretation.
on a mediolateral oblique (MLO) view
the "milky way" (retromammary fat): a 3-4 cm wide band parallel to the edge of the pectoral muscle...
The Fleischner society pulmonary nodule recommendations are for the follow-up and management of pulmonary nodules smaller than 8 mm detected incidentally in patients >35 years on non-screening CT. The initial guidelines for the management of solid nodules were released in 2005 1, and guidelines...
Ground glass opacification/opacity (GGO) is a descriptive term referring to an area of increased attenuation in the lung on computed tomography (CT) with preserved bronchial and vascular markings. It is a non-specific sign with a wide aetiology including infection, chronic interstitial disease a...
Trabecular pattern of proximal femur refers to the five groups of trabeculae that are demonstrable within the femoral head and neck.
Trabecula is a supportive and connective tissue element which form in cancellous bone. Trabeculae develop in a normal bone and also in a healing bo...
Coxa magna is the asymmetrical, circumferential enlargement and deformation of the femoral head and neck. Definitions in the literature vary but enlargement with asymmetry >10% in size is a reasonable cut-off for diagnosis 1.
Ultrasound evaluation of breast cysts is the modality of choice. Obstruction of the ducts, often appearing as the result of epithelial hyperplastic processes or the stromal fibrosis, or both processes lead to the formation of cysts, disabling the drainage of the terminal ducts of the lobules.
Chest x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Chest radiographs are frequently performed and a fantastic tool for making diagnoses of acute and chronic conditions, as well as acting as a tool for follow-up.
Chest x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using A, B, C, D, E is a helpful and systematic method for chest x-ray review:
B: breathing (the lungs and pleural spaces)
C: circulation (cardiomediastinal contour)
CT angiography of the cerebral arteries is a noninvasive technique allows visualization of the internal and external carotid arteries and vertebral arteries and can include just the intracranial compartment or also extend down to the arch of the aorta.
By using multidetector CT after intravenou...
The lateral projection is part of the three view series examining the phalanges, metatarsals and tarsal bones that make up the foot.
The lateral projection additionally examines the talocrural joint.
the patient may be supine or upright depending on comfort
the affected le...
Assessment of nasogastric (NG) tube positioning is a key competency of all doctors as unidentified malpositioning may have dire consequences, including death.
The ideal position should be in the sub-diaphragmatic position in the stomach - identified on a plain chest radiograph as overlying the ...
Abdominal radiographs can be challenging examinations to look at. It is always best to approach radiographs in a systematic way.
Bowel gas pattern
Gas within the bowel forms a natural contrast with surrounding tissues since it has a very low density. Bowel can only be seen if it contains air/g...
Many patients, particularly in developing countries, can present late with giant breast masses. They may be single or multiple and either benign or malignant. Many of these conditions are indistinguishable on physical examination alone. Some of these lesions require mastectomy while others can b...
ABC/2 is a fast and simple method for estimating the volume of intracerebral haemorrhage (or any other ellipsoid lesion for that matter) which does not require volumetric 3D analysis or software. Intracerebral haemorrhage volume is an important predictor of morbidity and mortality (and thus tria...
Errors in diagnostic radiology occur for a variety of reasons related to human error, technical factors and system faults.
This classification was proposed by Renfrew et al. 5 in 1992, and at the time of writing (July 2016) remains the most widely accept...
Caudate-right lobe ratio (C/RL) is used in the assessment of livers, usually in the setting of cirrhosis, in which there is atrophy of the right lobe with hypertrophy of the caudate lobe.
Method for measuring
image: axial slice immediately below the bifurcation of the main portal vein
Penile Doppler in erectile dysfunction or papaverine-induced colour duplex Doppler, is a highly accurate means of assessing patients with erectile dysfunction (ED).
Penile erection is a result of a complex interaction between the nervous, arterial, venous and sinusoidal systems. Any ...
Breast echotexture according to the BI-RADS lexicon is usually classified into three categories 1:
Distinguishing between enchondromas and low-grade conventional chondrosarcomas is a frequent difficulty as the lesions are both histologically and radiographically very similar.
It is important to remember, though, that differentiating between them may be a moot point since both can either be c...
Radiological evaluation of the posterior fossa is an essential part of the routine fetal assessment, including vermian maturity assessment.
Ultrasonography is a readily available diagnostic tool in the assessment of the fetal posterior fossa but is sometimes limited due t...
Umbilical venous flow in the physiological situation comprises of a monophasic non-pulsatile flow pattern with a mean velocity of 10-15 cm/s. The presence of pulsatility implies a pathological state unless in the following situations:
early in pregnancy: up to ~13 weeks gestation
The International Ovarian Tumour Analysis (IOTA) group ultrasound rules for ovarian masses are a simple set of ultrasound findings that classify ovarian masses into benign, malignant or inconclusive masses. These rules apply to masses that are not a classical ovarian mass (e.g. corpus luteum, en...
Blumensaat line is the line drawn along the roof of the intercondylar notch of the femur as seen on lateral radiograph of the knee joint. It can been used for:
indicating the relative position of the patella as normally this line intersects the lower pole of the patella
suggesting ACL injury a...
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review:
A: air - where it should and shouldn't be
B: bowel - position, size and wall thickness
D: dense st...
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review, where B refers to the assessment of the bowel loops.
This is a summary article; w...
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review, where A refers to the assessment of the presence and location of air.
This is a s...
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review, where D refers to the assessment of dense structures such as the bones and areas of calcification.
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review, where X refers to the assessment of external objects and artifacts.
This is a sum...
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review, where O refers to the assessment of the intra-abdominal organs and soft tissues.
Transcatheter aortic valve implantation or replacement (TAVI/TAVR) is a technique to replace the aortic valve through a transvascular or transapical approach. Compared to traditional open aortic valve replacement with sternotomy and a heart-lung bypass machine, the TAVI technique is less invasiv...
The Amsterdam wrist rules are validated clinical decision rules for determining which patients require radiographic imaging (wrist radiography) for acute wrist pain following trauma. The initial study evaluated 882 patients and were published in 2015 1. The decision rules assessed different clin...
Unilateral hypertranslucent hemithorax has many potential causes. It may be the result of rotation away from an optimal position or because of pathology.
A unilateral hypertranslucent hemithorax may be caused by the positioning of the patient. Rotation away from the radiation beam alt...
Chest x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using A, B, C, D, E is a helpful and systematic method for chest x-ray review where A refers to the assessment of the airways.
This is a summary article; we do n...
In chest radiology, reticular and linear opacification refers to a broad subgroup of pulmonary opacification caused by a decrease in the gas to soft tissue ratio due to a pathological process centred in or around the pulmonary interstitium. This includes thickening of any of the interstitial com...
Isomerism is a term which in general means 'mirror-image'. It is used in the context of heterotaxy and is of two types:
Mirror image of the structures on the left side of the chest along the left-right axis of the body, i.e. patients with isomeri...
Coronary Artery Disease - Reporting and Data System (CAD-RADSTM) classification is proposed by the Society for Cardiovascular Computed Tomography (SCCT), the American College of Radiology (ACR), and the North American Society for Cardiovascular Imaging (NASCI), last updated in 2016.
Cardiac MRI consists of using MRI to study heart anatomy, physiology and pathology.
The main advantages of cardiac MRI in comparison with other techniques are:
better definition of soft tissues
use of different types of sequences improves diagnostic accuracy
no ionising radiation...
The Brock model, also known as the PanCan model, is a multivariable model that estimates the risk that a pulmonary nodule on CT scan is a lung cancer.
The model was developed from participants enrolled in the Pan-Canadian Early Detection of Lung Cancer Study 1, has been validated in lung cancer...
Satisfaction of search (a.k.a. SOS) error is a common error in diagnostic radiology. It occurs when the reporting radiologist fails to continue to search for subsequent abnormalities after identifying an initial one. This initial detection of an abnormality satisfies the "search for meaning" and...
Computed tomography (CT) of the chest is a cross-sectional evaluation of the heart, airways, lungs, mediastinum, and associated bones and soft tissues.
Two key methods of image acquisition include:
standard CT with 5 mm slice thickness for mediastinum and gross evaluation of lungs
Nasogastric (NG) tube position on chest x-ray should be assessed following initial placement and on subsequent radiographs.
This is a summary article; we do not have a more in-depth reference article.
x-rays are only performed when the position ...
Fetal cardiothoracic (C/T) circumference ratio is a parameter than can be used in assessment of fetal cardiac and thoracic/chest wall anomalies. It is the ratio of the cardiac circumference to the thoracic circumference and may be easily measured on fetal ultrasound/echocardiography.
Renal artery stenosis (RAS) refers to a narrowing of a renal artery. When the process occurs slowly, it leads to secondary hypertension. Acute renal artery stenosis does not lead to hypersecretion of renin.
When the stenosis occurs slowly, collateral vessels form and supply the kidne...
Computed tomography texture analysis (or CTTA) is a new useful biomarker that provides an objective and quantitative assessment of tumour heterogeneity by analysing the differences in the pixel values of an image.
Gray-level frequency distribution: pixel intensity histogra...
Radiomics is a new emerging field of oncological medicine in which medical images are converted into multidimensional data by data-characterisation algorithms. The data is assessed for improved decision support. Radiomics has the potential to uncover disease characteristics that fail to be recog...
Getting a film with traumatic aortic injury in the exam is one of the many exam set-pieces that can be prepared for.
This is one of the cases you should look and not speak for 10 seconds as there tends to be a lot of findings on the film of patients with traumatic aortic injury.
Adult chest radiograph common exam pathology is essential to consider in the build up to radiology exams. The list of potential diagnoses is apparently endless, but there are some favourites that seem to appear with more frequency.
When dealing with the adult chest radiograph in the exam settin...
The amniotic fluid index (AFI) is an estimate of the amniotic fluid volume in a fetus. It is part of the fetal biophysical profile.
uterus is divided into four imaginary quadrants with linea nigra and umbilicus acting as the vertical and the horizontal axis respectively
Evacuation proctography (defecography) is a fluoroscopic technique to evaluate pelvic floor disorders. The technique traditionally involves fluoroscopy and barium, but an analogous MRI technique has also been developed (see: MR defaecating proctography).
incomplete defecation / con...
Magnetic resonance neurography (MRN) is a relatively new non-invasive imaging technique for dedicated assessment of peripheral spinal nerves.
It is used to assess peripheral nerve entrapments and impingements as well as localization and grading of nerve injuries and lesions.
ACR TI-RADS is a reporting system for thyroid nodules on ultrasound proposed by the American College of Radiology (ACR) 1.
This uses a standardised scoring system for reports providing users with recommendations for when to use fine needle aspiration (FNA) or ultrasound follow-up of suspicious ...
Below is an approach used for the "primary survey" of a CT polytrauma/multitrauma (also called trauma CT), often performed at the CT console with the patient still on the CT table. It allows rapid communication of significant findings to the trauma team as well as the decision to perform additi...
Due to the overlap in clinical presentation of Crohn disease (CD) and ulcerative colitis (UC), imaging often has a role to play in distinguishing the two. Distinguishing features include:
CD: small bowel 70-80%, only 15-20% have only colonic involvement
UC: rectal involvement 9...
Gissane angle, also known as the "critical angle", is an angular measurement made directly inferior to the lateral process of the talus. It is formed by the downward and upward slopes of the calcaneal superior surface. It is better seen on a lateral plain film of the calcaneus and hindfoot. Its ...
Böhler angle, also written as Bohler angle or Boehler angle, is also called the calcaneal angle or tuber joint angle 1, and is the angle between two lines tangent to the calcaneus on the lateral radiograph. These lines are drawn tangent to the anterior and posterior aspects of the superior calca...
Elbow radiographs are common plain films that are obtained frequently in the emergency department.
anterior humeral line
drawn down the anterior surface of the humerus
should intersect the middle 1/3 of the capitellum
if it does not, think distal humeral fracture...
The interseptal distance (ISD) is a measurement used to assess septal area atrophy as a marker for neurodegenerative conditions in patients with memory problems 1.
It is proposed that atrophy of the septal nuclei can commonly be seen in conditions associated with hippocampal atrophy, particular...
Chest x-ray lines and tubes can be easily assessed and should be the first thing that you look at when reviewing a chest x-ray. Assessment of their position is important, but they also give you an idea about how sick the patient is and narrow down the differential diagnosis.
Abnormal bowel wall attenuation patterns on CT scan can be grouped under five categories:
water halo sign
fat halo sign
The first three patterns are seen on contrast studies.
It is defined as uniform enhancement of th...
Wrist radiographs are ubiquitous on any night of the week in emergency departments, especially when pavements are icy!
Distal radial contour
Check the contour of the distal radius:
the distal radial articular surface should cup the carpals
the articular surface should ...
Intradural spinal mass lesions are relatively uncommon, compared to intracranial or extradural masses, and can be challenging to diagnose. Additionally, the need for a pre-operative/non-operative diagnosis is in many ways greater as biopsy of lesions within the cord has the potential of devastat...
Lymph node imaging has become an important task for the radiologist in present days, aiding the clinician in determining whether they are benign or malignant. Multiple modalities are being used for the assessment and characterization of lymph nodes, each with its advantages and drawbacks.
Physiological pelvic intraperitoneal fluid refers to the presence of a small volume of free fluid in the pelvis, particularly the pouch of Douglas. It occurs in young females of reproductive age and can be a mimic of traumatic free fluid in abdominal trauma.
Unfortunately, pelvic free fluid may...
Isolated free fluid in trauma may or may not represent a significant injury, and this creates a diagnostic dilemma in determining appropriate treatment for these patients.
The presence of isolated free fluid in trauma occurs in 3-5% of blunt trauma patients 1-4.
Small bowel follow through (SBFT) is a fluoroscopic technique designed to obtain high resolution images of the small bowel. The function of the small bowel can also be evaluated.
The small bowel follow through can be used for evaluation of small bowel abnormalities, including:
Myelination of the brain during infancy progresses in an orderly and predictable fashion which can be assessed with MRI.
At birth only certain structures are myelinated:
central corticospinal tracts
posterior limb of the internal ca...
Computed tomographic (CT) colonography, also called CTC, virtual colonoscopy (VC) or CT pneumocolon, is a powerful minimally invasive technique for colorectal cancer screening.
screening test for colorectal carcinoma
colon evaluation after incomplete or unsuccessful conventional c...
This mnemonic will help with the sonographic approach to the critically ill patient with dyspnoea:
C: collapsed lung (pneumothorax)
absent anterior lung sliding / anterior B lines
lung point present 1
H: heart failure (acute pulmonary oedema)
diffuse bilateral anterior B ...
In 2017, the Adrenal Subcommittee of the Incidental Findings Committee of the American College of Radiology published a revised algorithm for the management of incidental adrenal masses in patients who are:
adults (i.e. 18-year-old or over)
asymptomatic for adrenal pathology
referred for imag...
Concurrent suprasellar and pineal region lesions have a relatively short differential to be considered, including:
other germ cell tumours
embryonal cell carcinoma
yolk sac tumour (endodermal sinus tumour)
primary CNS lymphoma
The imaging characteristics of blood on MRI can be variable and change with the age of the blood.
In general, five stages of haematoma evolution are recognised:
isointense on T1
isointense to hyperintense on T2
acute (1 to 2 days)