title: Real-time MRI navigated US: role in diagnosis and guided biopsy of incidental breast lesions and axillary lymph nodes detected on breast MRI but not on second look US.
abstract: OBJECTIVE
  To prospectively evaluate the accuracy of real-time ultrasound combined with supine-MRI using volume navigation technique (RtMR-US) in diagnosis and biopsy of incidental breast lesions (ILSM) and axillary lymph nodes (LNSM) suspicious of malignancy on contrast enhanced magnetic resonance imaging (CE-MRI).
  
  
  METHODS
  Five hundred and seventy-seven women were examined using breast CE-MRI. Those with incidental breast lesions not identified after second-look ultrasound (US) were recruited for RtMR-US. Biopsy was performed in ILSM. Breast lesions were categorized with BI-RADS system and Fisher' exact test. Axillary lymph nodes morphology was described. To assess efficacy of RtMR-US, diagnostic accuracy, sensitivity, specificity, detection rate and Kappa index of conventional-US and RtMR-US were calculated.
  
  
  RESULTS
  Forty-three lesions were detected on CE-MRI before navigation. Eighteen were carcinomas and 25 ILSM. Of these, 21 underwent a RtMR-US. Detection rate on RtMR-US (90.7%) was higher than on conventional-US (43%) (p<0.001). Agreement between both techniques was low (k=0.138). Twenty ILSM and 2 LNSM were biopsied. Sixty-five percent were benign (100% of BI-RADS3 and 56% of BI-RADS4-5). Diagnostic performance of RtMR-US identifying malignant nodules for overall lesions and for the subgroup of ILSM was respectively: sensitivity 96.3% and 100%, specificity 18.8% and 30.7%, positive predictive value 66.7% and 43.7%, negative predictive value 75% and 100%. In addition RtMR-US enabled biopsy of 2 metastatic lymph nodes.
  
  
  CONCLUSIONS
  Real time-US with supine-MRI using a volume navigation technique increases the detection of ILSM. RtMR-US may be used to detect occult breast carcinomas and to assess cancer extension, preventing unnecessary MRI-guided biopsies and sentinel lymph node biopsies. Incidental lesions BI-RADS 3 non-detected on conventional-US are probably benign.
authors.affiliation: University Hospital Virgen de las Nieves, Servicio de Radiodiagnóstico Hospital Materno Infantil, Avenida de las Fuerzas Armadas s/n, 18004 Granada, Spain. Electronic address: elenapastorpons@gmail.com.
authors.forename: Elena Pastor
authors.initials: EP
authors.lastname: Pons
authors.affiliation: University Hospital Virgen de las Nieves, Servicio de Radiodiagnóstico Hospital Materno Infantil, Avenida de las Fuerzas Armadas s/n, 18004 Granada, Spain. Electronic address: frmiaz00@gmail.com.
authors.forename: Francisco Miras
authors.initials: FM
authors.lastname: Azcón
authors.affiliation: University Hospital Virgen de las Nieves, Servicio de Radiodiagnóstico Hospital Materno Infantil, Avenida de las Fuerzas Armadas s/n, 18004 Granada, Spain. Electronic address: mariacc1980@gmail.com.
authors.forename: María Culiañez
authors.initials: MC
authors.lastname: Casas
authors.affiliation: University Hospital Virgen de las Nieves, Servicio de Radiodiagnóstico Hospital Materno Infantil, Avenida de las Fuerzas Armadas s/n, 18004 Granada, Spain. Electronic address: isalvaa@hotmail.com.
authors.forename: Salvador Martínez
authors.initials: SM
authors.lastname: Meca
authors.affiliation: University Hospital Virgen de las Nieves, Servicio de Radiodiagnóstico Hospital Materno Infantil, Avenida de las Fuerzas Armadas s/n, 18004 Granada, Spain. Electronic address: gespona@hotmail.com.
authors.forename: José Luis García
authors.initials: JLG
authors.lastname: Espona
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla / Q000000981:diagnostic imaging / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis*; D002277:Carcinoma / Q000175:diagnosis* / Q000556:secondary*; D003199:Computer Systems; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D061705:Image-Guided Biopsy / Q000379:methods*; D033162:Incidental Findings; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*
keywords: Breast cancer; Magnetic resonance imaging fusion; Magnetic resonance navigated ultrasound; Real-time ultrasound; Second look ultrasound