Digital tomosynthesis in diagnosis of occult hip fractures

Transcription

1 Digital tomosynthesis in diagnosis of occult hip fractures Poster No.: B-0781 Congress: ECR 2013 Type: Authors: Keywords: DOI: Scientific Paper M. Geijer 1, D. Collin 2, J. H. Göthlin 2 ; 1 Lund/SE, 2 Mölndal/SE Musculoskeletal bone, Trauma, Conventional radiography, CT, Observer performance, Comparative studies, Diagnostic procedure /ecr2013/B-0781 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 13

2 Purpose Tomosynthesis for evaluation of suspect occult hip fracture has previosly been evaluated in a master thesis from our institution [1]. The purpose of the current study was to retrospectively further explore the possible clinical utility of digital tomosynthesis in patients with occult hip fractures. Page 2 of 13

3 Methods and Materials In a retrospective review all cases with tomosynthesis of the hip performed for suspect occult hip fracture were retrieved from the hospital picture and archiving communication system (PACS). Seventy cases with suspect occult hip fracture and normal or equivocal pelvis and hip radiography were included, on 49 women and 21 men. Mean age was 81 years (range years). For tomosynthesis 60 low-dose projection images from tube angles from # 17.5 to were used to reconstruct up to 60 coronal sectional images without overlap, with a nominal thickness of 2 mm. The added utility of tomosynthesis to conventional radiography was assessed by evaluating the tomosynthesis sections without the AP scout radiograph. Three observers scored the tomosynthesis studies independently as A) no proximal femur fracture, B) suspect proximal femur fracture, or C) definite proximal femur fracture. Iliac wing, obturator ring and acetabular fractures were also noted. The accuracy of the tomosynthesis results was assessed by comparing with follow-up studies including CT or MRI, or surgical or clinical outcome. Observer agreement was evaluated with the kappa statistic. Page 3 of 13

4 Images for this section: Fig. 1: 79-year old male with equivocal radiographs after hip trauma. Tomosynthesis and CT (following film clips) clearly reveals a cervical hip fracture. Page 4 of 13

5 Fig. 2: 79-year old male with hip trauma. Tomosynthesis reveals a cervical hip fracture. Fig. 3: 79-year old male with hip trauma. CT confirms a cervical hip fracture. Page 5 of 13

6 Results Interobserver agreements for tomosynthesis of suspect occult hip fractures for the three observer pairs were almost perfect with kappa values 0.95, 0.92, and 0.90 for the three observer pairs. Intraobserver agreements for two of the observers were equally good. Agreements for cervical hip fractures were slightly better than for trochanteric fractures. In 57 patients with complete observer agreement and confirmation by follow-up, tomosynthesis identified all nine pelvic fractures, scored 10 cervical fractures correctly, detected 12 trochanteric fractures correctly while one scored trochanteric fracture was negative and one was cervical. In 34 cases, scored as negative with tomosynthesis, one trochanteric and one cervical fracture were missed. Page 6 of 13

7 Images for this section: Fig. 4: 84-year old male with hip trauma. The cervical hip region cannot be properly evaluated due to external rotation of the hip with inconclusive imaging. Page 7 of 13

8 Fig. 5: 84-year old male with hip trauma. Tomosynthesis clearly reveals the cervical hip fracture. Page 8 of 13

9 Conclusion Observer variation for tomosynthesis as measured by the kappa statistic was almost perfect to substantial with narrower confidence intervals and with less observer variation than previously presented for radiography [2]. As secondary imaging after hip trauma in the elderly, MRI is usually the modality of choice [3, 4]. CT may also be used [5, 6] with reliable results. As shown in the current study, also tomosynthesis may assist in making the diagnosis of hip fracture or normal outcome, or may help by strengthening the radiographic diagnosis. The advantage of tomosynthesis over both MRI and CT is that it is performed in the same examination room as radiography, using the same equipment, and adding only about one minute to the examination time. The patient is only required to remain immobile during 12 seconds for the sweep of the X-ray tube. This facilitates and expedites the supplementary examination for the radiology staff, but, more importantly, also for the patient, who does not have to be subjected to sometimes painful transfers to other examination tables. In conclusion, tomosynthesis has the possibility to aid in diagnosis and strengthen the diagnosis in suspect occult hip fracture. Page 9 of 13

10 Images for this section: Fig. 6: A 96-year old female with hip trauma and unremarkable radiographs. Tomosynthesis displays a cortical fracture medial to the greater trochanter suggestive of an incomplete trochanteric fracture. Page 10 of 13

11 Fig. 7: A 96-year old female with hip trauma. MRI confirms the incomplete trochanteric fracture. Page 11 of 13

12 References 1. Bazzi M (2009) Clinical utility of tomosynthesis in diagnosis of occult hip fractures. A pilot study with appraisal of the VolumeRad technique. Clinical utility of tomosynthesis in diagnosis of occult hip fractures. A pilot study with appraisal of the VolumeRad technique. Örebro University, School of Health and Medical Sciences, Örebro Collin D, Dunker D, Göthlin JH, Geijer M (2011) Observer variation for radiography, computed tomography, and magnetic resonance imaging of occult hip fractures. Acta Radiol 52: Verbeeten KM, Hermann KL, Hasselqvist M, Lausten GS, Joergensen P, Jensen CM, Thomsen HS (2005) The advantages of MRI in the detection of occult hip fractures. Eur Radiol 15: Chana R, Noorani A, Ashwood N, Chatterji U, Healy J, Baird P (2006) The role of MRI in the diagnosis of proximal femoral fractures in the elderly. Injury 37: Dunker D, Collin D, Göthlin JH, Geijer M (2011) High clinical utility of computed tomography compared to radiography in elderly patients with occult hip fracture after lowenergy trauma. Emerg Radiol 19: Geijer M, Collin D, Dunker D, Göthlin JH (2012) Bone bruise, lipohemarthrosis, and joint effusion in CT of non-displaced hip fracture. Acta Radiol 53: Page 12 of 13

13 Personal Information Mats Geijer, M.D., Ph.D. Center for Medical Imaging and Physiology, Skåne University Hospital and Lund University, Lund, Sweden. David Collin, M.D., Department of Radiology, Sahlgrenska University Hospital, Mölndal, Sweden Jan H. Göthlin, M.D., Ph.D., Department of Radiology, Sahlgrenska University Hospital, Mölndal, Sweden Page 13 of 13