Articles
Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
More than 200 results
Article
AP Meary's angle
AP Meary's angle or AP talus-first metatarsal angle is used to assess for midfoot abduction/adduction in pes planus and pes cavus to assist with pre-operative planning 1.
Measurement
On a weight-bearing AP foot radiograph, a line is drawn down the longitudinal axis of the first metatarsal to ...
Article
Posterior tibial line
The posterior tibial line is drawn along the posterior aspect of the distal tibial shaft on a lateral ankle x-ray and can be used to assess the sagittal alignment of the talus when comparing side-to-side and/or calculate the posterior tibial line-talar ratio 1,2.
Article
Hair artifact
Hair artifact and hair-product artifacts are artifacts produced by the presence of the patient's hair, hair accessories (e.g. hair clip) and hair products (e.g. shampoo) within the field of view during acquisition of an image, which can affect all modalities to varying degrees. For example, in m...
Article
Friedman line
The Friedman or scapular line can be used to determine glenoid version and glenoid bone loss 4. Glenoid version angle measured by the Friedman method has better inter-reader reliability than the scapular body method 2.
Measurement
The Friedman line is drawn along the long axis of the scapula ...
Article
Fourth-fifth intermetatarsal angle
The fourth-fifth intermetatarsal angle is used to assess for a bunionette deformity. It should not be confused with the first intermetatarsal angle, used to assess for hallux valgus deformity.
Measurement
The fourth-fifth intermetatarsal angle is formed between the long axis of the fourth and...
Article
Assessment of thyroid lesions (ultrasound)
Ultrasound is the first-line imaging modality for assessment of thyroid nodules found on clinical examination or incidentally on another imaging modality. This article is an overview of ultrasonographic features of thyroid nodules, which are used to determine the need for biopsy with fine needle...
Article
Triple screening
Triple screening refers to a screening blood test that is used to screen pregnant women for possible neural tube defects, Down syndrome and trisomy 18 in the developing fetus. It measures:
alpha-fetoprotein
beta hCG
unconjugated estriol
Interpretation
An abnormal test result doesn't indica...
Article
Hematospermia
Hematospermia (less commonly hemospermia) refers to the presence of blood in semen or ejaculatory fluid. It is a symptom that can cause great anxiety in patients despite usually being of benign etiology.
Pathology
Etiology
Benign
urogenital infections including sexually transmitted disease, ...
Article
Acromiohumeral interval
Acromiohumeral interval is a useful and reliable measurement on AP shoulder radiographs and when narrowed is indicative of subacromial impingement, rotator cuff tear and/or tendinopathy. In patients with rotator cuff repair, a narrow acromiohumeral interval is a risk factor for re-tear 7.
Meas...
Article
Hibbs angle
The Hibbs angle, a.k.a. lateral calcaneo-first metatarsal angle, has been used to identify the apex of deformity in patients with pes cavus on lateral weight-bearing radiographs.
Measurement
The Hibbs angle is formed by the lines running along the axes of the calcaneus and the first metatarsal...
Article
First metatarsal declination angle
The first metatarsal declination angle can be used to assess for metatarsus primus elevatus in hallux rigidus.
Measurement
The first metatarsal declination angle is formed between the longitudinal axis of the first metatarsal and the supporting surface 1-4.
Interpretation
normal: 20-21° 1-...
Article
Cardiac CT (retrospective acquisition)
A retrospective ECG-gated cardiac CT is usually conducted in cases in which adequate control of heart rate cannot be achieved or in which additional information on ventricular or valvular function is required.
Indications
Please refer to our coronary CT angiography article for general indicati...
Article
Talocrural angle
The talocrural angle can be used to assess for fibular shortening after a fracture.
Measurement
The talocrural angle is measured on the mortise view as the angle between a line along the distal tibial plafond articular surface and another line joining the tips of both malleoli 3,4.
Interpret...
Article
Lateral tibiotalar distance
Lateral tibiotalar distance is a measurement on an ankle anterior drawer lateral view to assess for ankle instability.
Measurement
On an ankle anterior drawer lateral view (typically performed using a Telos device 2-4), the distance between the posterior tip of the distal tibial articular sur...
Article
Medial cuneiform to second metatarsal distance
Medial cuneiform to second metatarsal distance is the measurement of the distance between the lateral aspect of the medial cuneiform and the medial aspect of the base of the second metatarsal bone 1,2.
Usage
Medial cuneiform to second metatarsal distance is an important measurement used in ass...
Article
Medial cuneiform-fifth metatarsal height
Medial cuneiform-fifth metatarsal height is the distance between the most inferior part of the medial cuneiform and the most inferior part of the base of the 5th metatarsal and is used to evaluate the height and integrity of the medial vertical arch 1.
Usage
Medial cuneiform-fifth metatarsal h...
Article
Tibiofibular overlap
The tibiofibular overlap (TFO) is the overlapping area between the anterior distal tibial prominence and the medial edge of the distal fibula 1-3.
Usage
Together with the tibiofibular clear space (TFCS) and the medial clear space, the tibiofibular overlap space has been used in the diagnosis a...
Article
Tibiofibular clear space
The tibiofibular clear space is a radiographic measure and defined as the space between the groove of the distal tibial prominence and the medial margin of the distal fibula 1-3.
Usage
Together with the tibiofibular overlap and the medial clear space, the tibiofibular clear space has been used...
Article
Canadian CT head rule
The Canadian CT head rule (CCTHR) is a validated clinical decision rule to determine the need for CT head in adult emergency department patients with minor head injuries.
Inclusion criteria
Patient has suffered minor head trauma with resultant:
loss of consciousness
GCS 13-15
confusion
amn...
Article
MRI of the shoulder (an approach)
MRI of the shoulder is one of the more frequent examinations faced in daily radiological practice. This approach is an example of how to create a radiological report of an MRI shoulder with coverage of the most common anatomical sites of possible pathology.
Systematic review
A systematic revie...
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