title: Diagnostic Accuracy of Various Imaging Modalities for Suspected Lower Extremity Stress Fractures: A Systematic Review With Evidence-Based Recommendations for Clinical Practice.
abstract: BACKGROUND
  The literature is filled with conflicting findings regarding diagnostic accuracy and protocols for imaging suspected lower extremity stress fractures. The absence of systematic reviews on this topic has limited the development of evidence-based recommendations for appropriate imaging protocols in cases of suspected lower extremity stress fractures.
  
  
  OBJECTIVE
  To determine the diagnostic accuracy statistics of imaging modalities used to diagnose lower extremity stress fractures and to synthesize evidence-based recommendations for clinical practice.
  
  
  METHODS
  Systematic review.
  
  
  METHODS
  A generic search strategy for published studies was performed using multiple databases. A study was eligible for inclusion if it met all of the following criteria: (1) at least 1 diagnostic imaging modality was studied, (2) at least 1 radiological reference standard was used, (3) the study reported or allowed computation of diagnostic accuracy statistics (sensitivity, specificity, positive likelihood ratio, negative likelihood ratio), (4) a full-text version was available, (5) the article was written in English, and (6) the study included lower extremity stress fractures. Studies that examined asymptomatic individuals or patients with fractures due to disease or pharmacologic intervention were excluded.
  
  
  RESULTS
  Reported sensitivity and specificity (95% CI) were as follows: For conventional radiography, sensitivity ranged from 12% (0%-29%) to 56% (39%-72%) and specificity ranged from 88% (55%-100%) to 96% (87%-100%). For nuclear scintigraphy (NS), sensitivity ranged from 50% (23%-77%) to 97% (90%-100%) and specificity from 33% (12%-53%) to 98% (93%-100%). For magnetic resonance imaging (MRI), sensitivity ranged from 68% (45%-90%) to 99% (95%-100%) and specificity from 4% (0%-11%) to 97% (88%-100%). For computed tomography, sensitivity ranged from 32% (8%-57%) to 38% (16%-59%) and specificity from 88% (55%-100%) to 98% (91%-100%). For ultrasound, sensitivity ranged from 43% (26%-61%) to 99% (95%-100%) and specificity from 13% (0%-45%) to 79% (61%-96%).
  
  
  CONCLUSIONS
  MRI was identified as the most sensitive and specific imaging test for diagnosing stress fractures of the lower extremity. When MRI is available, NS is not recommended because of its low specificity, high dosage of ionizing radiation, and other limitations. Conventional radiographs are likely to result in false negatives upon initial presentation, particularly in the early stages of stress fracture, and in some cases may not reveal an existing stress fracture at any time. A diagnostic imaging algorithm was developed with specific recommendations for cost-efficient imaging of low-risk and high-risk suspected stress fractures.
authors: Department of Physical Therapy, High Point University, High Point, North Carolina, USA.
authors: Alexis A
authors: AA
authors: Wright
authors: Department of Physical Therapy, High Point University, High Point, North Carolina, USA.
authors: Eric J
authors: EJ
authors: Hegedus
authors: Department of Radiology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina, USA.
authors: Leon
authors: L
authors: Lenchik
authors: Internal Medicine Department, Oakland Medical Center-Kaiser Permanente, Oakland, California, USA.
authors: Karin J
authors: KJ
authors: Kuhn
authors: Department of Exercise Science, High Point University, High Point, North Carolina, USA.
authors: Laura
authors: L
authors: Santiago
authors: Department of Physical Therapy, High Point University, High Point, North Carolina, USA jsmoliga@highpoint.edu.
authors: James M
authors: JM
authors: Smoliga
mesh_terms: D000328:Adult; D000465:Algorithms; D015510:Clinical Medicine / Q000379:methods; D003952:Diagnostic Imaging / Q000379:methods / Q000592:standards*; D005260:Female; D015775:Fractures, Stress / Q000175:diagnosis*; D006801:Humans; D035002:Lower Extremity / Q000293:injuries*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
keywords: algorithm; diagnosis; overuse; radiology; stress fractures