Welcome to Classifications and Online Calculators in Radiology

This site was build along with the Atlas of Radiology Images to support your knowledge in radiology.

You will find here:

that are used in radiology and related fields with free access.


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The concept of this website is based on a previous site that was founded in 2008 and is still up and running. The website is composed as a book, where all sources are properly referenced, according to a good practice in scientific publications.

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    Criteria of midgut malrotation (volvulus, malrotation) detected on fluoroscopy in children (Katz)

    Katz et al. described nine findings for distinguishing normal and abnormal duodenal / jejunal positioning on upper gastrointestinal studies to detect subtle abnormalities indicative of midgut malrotation.

    • One abnormality represents normal variation
    • Two abnormalities represent indeterminate finding
    • Three and more abnormalities found together indicate malrotation


    1) pylorus to left of the midline

    Duodenojejunal flexure:

    2) below level of L1-L2 intervertebral disk space in child under 18 years
    3) >1.3 corrected distance below apex of the duodenal bulb
    4) to right of the left pedicle

    Segment between inferior and duodenojejunal flexures:

    5) Intervening obstruction
    6) Connecting line not longest side of triangle
    7) Connecting line <2.6 (corrected distance)


    8) Corkscrewing or zigzagging beyond duodenojejunal flexure
    9) To right of the spine


    1. Katz ME, Siegel MJ, Shackelford GD, McAlister WH. The position and mobility of the duodenum in children. AJR Am J Roentgenol 1987; 148: 947–951. http://www.ajronline.org/doi/pdf/10.2214/ajr.148.5.947

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