Sabharwal, Sanjeev; Caixia Zhao; McKeon, John J.; McClemens, Emily; Edgar, Michele; Behrens, Fred
October 2006
Journal of Bone & Joint Surgery, American Volume;Oct2006, Vol. 88-A Issue 10, p2243
Academic Journal
Background: Although a scanogram is commonly used to measure limb-length discrepancy, there are several potential pitfalls associated with this imaging technique. The purpose of the present study was to evaluate the results obtained with use of a full-length standing anteroposterior radiograph of the lower extremities and to compare them with those obtained with use of a scanogram. Both imaging studies were performed using computed radiography. Methods: One hundred and eleven patients with limb-length discrepancy had a full-length standing anteroposterior radiograph and a scanogram made on the same day. The patients included seventy-nine children and thirty-two adults in whom the discrepancy was secondary to trauma (55%), congenital shortening (18%), Blount disease (14%), or another cause (13%). Limb length and limb-length discrepancy were measured utilizing both imaging studies. The agreement between the standing anteroposterior radiograph and the scanogram was assessed with use of the correlation coefficient r, and the limits of agreement between the two imaging studies were assessed. Results: An average magnification of 4.6% (3.3 cm) was observed in association with the measurement of lower extremity length with use of the full-length standing anteroposterior radiograph. The mean difference in limb-lengthdiscrepancy measurements between the two techniques was 0.5 cm, and the limits of agreement (that is, the mean plus or minus two standard deviations) were 0.5 to 1.5 cm. When the limb-length discrepancy on the standing anteroposterior radiograph was compared with that on the scanogram, the correlation coefficient r was 0.96. A difference of >0.5 cm between the limb-length discrepancy measured on the standing radiograph and that measured on the scanogram was associated with a mechanical axis deviation of >2 cm. Remaining variables, including age, gender, etiology, and scanogram ruler inclination, did not correlate with a difference in the measurement of limb-length discrepancy with use of these two imaging studies. Conclusions: The measurement of limb-length discrepancy on a standing anteroposterior radiograph was very similar to that on a scanogram, especially in the absence of substantial mechanical axis deviation. These findings support the use of a standing anteroposterior radiograph of the lower extremities as the initial imaging study for patients presenting with unequal limb lengths. This approach allows for a more comprehensive radiographic evaluation of the lower extremity, including deformity analysis, while reducing the expense and radiation exposure as compared with the use of additional imaging studies for the assessment of limb-length discrepancy.


Related Articles

  • Behind the Mask. Peart, Olive // Radiologic Technology;Sep/Oct2009, Vol. 81 Issue 1, p90 

    The article focuses on the advantages and benefits of digital radiography. It states that digital radiography could eliminate the lost images, reduce physical storage, correct the overexposure and underexposure, and offers postprocessing options. It notes that radiologic technologists can use...

  • Exposure Indicator Degradation From CR Plate Processing Delays. Kowalczyk, Nina; Comer, Elizabeth // Radiologic Technology;May/Jun2009, Vol. 80 Issue 5, p401 

    Purpose To determine the percentage of exposure indicator (EI) degradation that occurs during a delay between exposure and processing of the imaging receptor. Methods Twenty-six images of a hand phantom, stepwedge and resolution test tool were created using a computed radiography (CR) system...

  • Walking on thin ice! Identifying methamphetamine "drug mules" on digital plain radiography. S. N. ABDUL RASHID; S. B. MOHAMAD SAINI; S. ABDUL HAMID; S. J. MUHAMMAD; MAHMUD, R.; THALI, M. J.; FLACH, P. M. // British Journal of Radiology;Apr2014, Vol. 87 Issue 1036, p1 

    Objective: The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of identifying methamphetamine (MA) internal payloads in "drug mules" by plain abdominal digital radiography (DR). Methods: The study consisted of 35 individuals suspected of internal...

  • Three-dimensional measurements of the lower extremity in children and adolescents using a low-dose biplanar X-ray device. Gheno, Ramon; Nectoux, Eric; Herbaux, Bernard; Baldisserotto, Matteo; Glock, Luiz; Cotten, Anne; Boutry, Nathalie // European Radiology;Apr2012, Vol. 22 Issue 4, p765 

    Objective: To evaluate three-dimensional (3D) measurements of the lower extremity using a biplanar low-dose X-ray device in children and adolescents. Methods: Firstly, 3D measurements of eight dried bones were analysed by a biplanar low-dose X-ray device (LDX) using stereoscopic software and...

  • Regulations and Poignancy. Murphy, Debra L. // Radiology Management;Mar/Apr2014, Vol. 36 Issue 2, p6 

    An introduction to the journal is presented wherein the editor discusses various reports published within the issue including "Physician Supervision of Radiology Services," "Radiologist Assistant: Best Fit for Medical Imaging" and "Digital Radiography and Accountable Care."

  • Exploring your Options. Puchalski, Sarah M. // Veterinary Medicine;Apr2009, Vol. 104 Issue 4, p179 

    The article explains the functions of primary capture imaging systems used in veterinary digital radiography. These technologies include computed radiography (CR), direct X-ray (DX) and charge-couple device (CCD) camera radiographic systems. Moreover, it notes the efficacy of each radiographic...

  • Weighing the Costs Between Standard Film or Computed Radiography. Fischer, Fred // American Chiropractor;Nov2005, Vol. 27 Issue 12, p10 

    Presents information regarding the advantages of digital and computed radiography imaging systems (CR)over standard x-ray films used in diagnostic laboratories. Elimination of disposables such as films and chemicals; Enhancement of the image to bring out diagnostic detail; Quick access of the image.

  • Image plate characterization and absolute calibration to low kilo-electron-volt electrons. Busold, S.; Philipp, K.; Otten, A.; Roth, M. // Review of Scientific Instruments;2014, Vol. 85 Issue 11, p1 

    We report on the characterization of an image plate and its absolute calibration to electrons in the low keV energy range (1-30 keV). In our case, an Agfa MD4.0 without protection layer was used in combination with a Fuji FLA7000 scanner. The calibration data are compared to other published data...

  • Medical Imaging: Digital Subtraction Radiology. Hart, Geoffrey // Image Technology;Jan1989, Vol. 71 Issue 1, p9 

    The article focuses on the need for digital subtraction radiology in medical imaging in Great Britain. The X-radiation is considered as a diagnostic tool despite the contributions from far safer energies. Thus, a photographic technique has been introduced in 1930's to eliminate the unwanted...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics