Radiology References

Imaging atlases, normal values, and reporting templates.

302 references · Page 3 of 11

C

Normal Common Cavity Inner Ear Size on CT
Normal CT dimensions of the common cavity inner ear malformation: average vertical diameter 4 mm and horizontal diameter 10 mm in axial plane.
Normal Common Hepatic Duct Size on Ultrasound, CT & MRI
The normal common hepatic duct measures less than 5 mm in diameter on ultrasound, CT, and MRI in adults without biliary pathology.
Normal Common Iliac Artery Diameter: Ultrasound, CT & MRI
Normal common iliac artery diameter ranges 7.9–12.1 mm on axial imaging; learn measurement technique and clinical thresholds across ultrasound, CT, and MRI.
Normal Coracoclavicular Distance Size on Radiography
Normal coracoclavicular distance on AP radiography measures 11–13 mm, with a side-to-side difference of less than 5 mm indicating ligamentous integrity.

D

Normal Descending Right Pulmonary Artery Size on Radiography
Normal descending right pulmonary artery diameter on PA chest radiograph is up to 16 mm — a key landmark for detecting pulmonary hypertension.
Normal Diaphragm Flattening Size on Chest Radiography
Normal diaphragm flattening on PA chest radiography measures less than 1.5 cm, serving as a key indicator of pulmonary hyperinflation.
Normal Digastric Line Cervical Measurements on X-ray, CT, MRI
Learn normal digastric line thresholds for atlanto-occipital and odontoid distances on radiography, CT, and MRI in cervical spine assessment.
Normal Distal Tibial Angle Size on Radiography
Normal distal tibial angle on AP and mortise radiography ranges from 45–65°, a key measure for ankle alignment assessment.
Normal Djian-Annonier's Angle Size on Radiography
Normal Djian-Annonier's angle on lateral foot radiography measures 120–130°, a key reference for assessing foot arch morphology.
Normal Dublin's Distance Size: Radiography, CT & MRI
Normal Dublin's Distance ranges 2–5 mm (mandible–atlas) and 9–12 mm (mandible–axis) on lateral cervical imaging across radiography, CT, and MRI.
Normal Duct of Wirsung Diameter: Ultrasound, CT & MRI
Normal Duct of Wirsung diameter is <3 mm at the pancreatic head and <2 mm in the body/tail on ultrasound, CT, MRI, and cholangiography.

E

Normal Elbow Carrying Angle Size on Radiography
Normal elbow carrying angle on radiography measures 154–178°, with deviations indicating cubitus valgus or varus deformity in clinical practice.
Normal Elbow Joint Space Size on Radiography
Normal elbow joint space measures up to 3 mm on lateral radiography; values exceeding this threshold may indicate effusion or joint pathology.
Normal Endometrium Thickness on Ultrasound and MRI
Reference guide to normal endometrial thickness by menopausal status on ultrasound and MRI, with clinical thresholds for workup.
Normal Endotracheal Tube Position on Chest Radiography
Normal endotracheal tube tip position on chest radiography is 3–5 cm above the carina, minimizing risks of endobronchial intubation or accidental extubation.
Normal Epididymis Resistance Index on Ultrasound
Normal epididymis resistance index on Doppler ultrasound ranges from 0.46 to 0.68, a key parameter for evaluating scrotal pathology.
Normal Epididymis Size on Ultrasound: Key Dimensions
Reference guide to normal epididymis dimensions on scrotal ultrasound, including head, body, and tail measurements for clinical practice.
Normal Esophageal Diameter in Children: Barium Swallow
Reference values for normal esophageal maximal diameter on barium swallow in pediatric patients, from neonates through adolescents aged 16 years.
Normal Esophageal Wall Thickness on CT: Key Reference
Normal esophageal wall thickness on CT is less than 5 mm; values exceeding this threshold warrant further evaluation for pathology.

F

Normal Fallopian Tube Size on Ultrasound, CT & MRI
Normal fallopian tube length is <14 cm and diameter <4 mm; learn measurement techniques across ultrasound, CT, MRI, and hysterosalpingography.
Normal Feeding Tube Position on Radiography
Normal nasogastric feeding tube tip should lie >10 cm beyond the gastroesophageal junction on radiography to confirm safe gastric placement.
Normal Femoral Angle Size on Radiography and MRI
Normal femoral angle at the knee measures 75–85° on AP radiography; learn measurement technique, clinical significance, and common pathologies.
Normal Femoral Artery Diameter on Ultrasound, CT & MRI
Reference values for normal femoral artery diameter on ultrasound, CT, and MRI: common femoral 6.6–9.6 mm, superficial femoral 4.3–7.2 mm.
Normal Femoral Artery Peak Systolic Velocity on Ultrasound
Normal femoral artery peak systolic velocity ranges 89–141 cm/s (common) and 77–108 cm/s (superficial) on duplex ultrasound.
Normal Femoral Intercondylar Sulcus Depth Size on Radiography
Normal femoral intercondylar sulcus depth on sunrise radiography measures greater than 5 mm; shallowing is a key marker of trochlear dysplasia.
Normal Femoral Neck Anteversion by Age: X-ray, CT, MRI
Normal femoral neck anteversion decreases from 30–50° at birth to ~18° in adults; learn measurement thresholds across radiography, CT, and MRI.
Normal Femoral Neck Torsion Angle Size on CT
Normal femoral neck torsion angle on CT ranges from 34–40° in newborns, with values declining through childhood into adulthood.
Normal Femoropatellar Joint Space Size on Radiography
Normal femoropatellar joint space measures greater than 5 mm on sunrise radiograph — a key threshold for detecting patellofemoral pathology.
Normal Fetal Heart/Thorax Area Ratio Size on Ultrasound
Normal fetal heart/thorax area ratio on ultrasound measures 0.2–0.35, a key four-chamber view parameter for detecting cardiomegaly or small heart.
Normal Fetal Heart/Thorax Circumference Ratio Ultrasound
Normal fetal heart circumference to thorax circumference ratio is less than 0.5 on ultrasound, a key marker for cardiomegaly assessment.