Items tagged “measurement”
18 results found
Skull base angle
The skull base angle allows the diagnosis of platybasia and basilar kyphosis. There are several different techniques that may be used on sagittal images from MRI or CT. Standard technique Angle formed by: line joining the nasion with the center of the pituitary fossa line joining the anteri...
The tentorial angle is measured between a line connecting the nasion with the tuberculum sellae and the the angle of the straight sinus. Normally it should measure between 27° and 52°. Abnormalities of the posterior fossa / base of skull can alter this. For example this angle is elevated in ach...
Caudate–right lobe ratio
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 line 1...
Caudate-right lobe ratio (diagram)
Diagnosis not applicable
Published 06 Jan 2010
Line of Klein
The line of Klein describes a line along the superior edge of the neck of the femur. It is useful in detecting early slipped upper femoral epiphysis in adolescents. The line should normally intersect the lateral part of the superior femoral epiphysis. If the line of Klein fails to intersect the...
The rectosigmoid ratio is a measurement of the diameter of the rectum divided by that of the sigmoid colon during contrast enema. It is of particular use in the diagnosis of Hirschsprung disease. Normal children have a rectum that is larger than the sigmoid (i.e. rectosigmoid ratio >1). In fact...
Flattening of the diaphragm
Flattening of the diaphragm is the most sensitive sign on chest radiographs for the presence of hyperinflation of the lungs, usually due to emphysema 1-2. The normal dome of each hemidiaphragm should rise at least 1.5 cm above a line connecting the costophrenic angle posteriorly and sternophren...
Normal Bohler's angle
Diagnosis not applicable
Published 03 Jun 2010
Normal Chauveaux–Liet angle
Diagnosis not applicable
Published 08 Nov 2010
The cardiothoracic ratio (CTR) aids in the detection of enlargement of the cardiac silhouette, which is most commonly from cardiomegaly but can be due to other processes such as a pericardial effusion. Terminology Some report CTR as a percentage, however this is incorrect, as it is a ratio. ...
Widening of the presacral space (differential)
Widening of the presacral space is one of the diagnostic indicators of the diseases involving pelvic pathology and rectal involvement. It is ideally measured on barium studies at the level of S3/4 disk level on lateral radiographs and the normal value of the presacral space is <15 mm in adults....
Midbrain to pons area ratio (PSP)
Midbrain to pons area ratio as measured on midline sagittal images has been found useful in confirming a small midbrain in the setting of progressive supranuclear palsy (PSP) 1. This reduction in the size of the midbrain leads to the hummingbird sign. In the method described by Oba et al. the ...
Frontal horn width to intercaudate distance ratio
Frontal horn width to intercaudate distance ratio (FH/CC) is used in assessing patients with suspected Huntington disease. On the same axial plane obtained on the ACPC (anterior commissure and posterior commissure) line, the ratio between the distance between the caudate heads (where they are ...
Intercaudate distance to inner table width ratio
Intercaudate distance to inner table width ratio (CC/IT) is used in assessing patients with neurodegenerative diseases that affect the caudate nuclei. It is best known for assessing individuals with suspected Huntington disease but is in no way specific for the diagnosis, also seen in other less...
Acromiohumeral interval is a useful and reliable measurement on AP shoulder radiographs and when narrowed is indicative of rotator cuff tear or tendinopathy. Pathology Measurements of the acromiohumeral interval in the following intervals are suggestive of pathology 1,2: >12 mm: shoulder dis...
The intermetatarsal (IM) angle refers to the angle measured between the 1st and 2nd metatarsal shaft on an axial view of the foot. In normal situations it is considered to be under 9°. The angle can increase with hallux valgus and metatarsus adductus deformities.
Optic nerve sheath diameter
Optic nerve sheath diameter has significance in the assessment of papilloedema in cases of elevated intracranial pressure. Pathology The optic nerve sheath demonstrates changes in diameter with CSF pressure changes as there is a layer of subarachnoid space between the nerve and its sheath, whi...
Condyle-C1 interval (CCI)
Measurement of the interval between condyle and C1 at four equidistant points on the joint surface in sagittal and coronal reconstructions of computed tomography. The CC is reported to have a high lateral symmetry in children 1. Used with a cut-off of 4 mm, the CC has a high diagnostic accuracy...