title: Feasibility and potential limitations of abbreviated breast MRI: an observer study using an enriched cohort.
abstract: BACKGROUND
  Breast cancer screening using magnetic resonance imaging (MRI) has been introduced in Western countries primarily for populations with an elevated risk of breast cancer. We conducted an observer study involving an experimental abbreviated MRI interpretation by Japanese radiologists, using an enriched cohort, to evaluate its feasibility in a screening setting.
  
  
  METHODS
  Eighty-eight breast MRI examinations including 28 cases with breast cancer were enrolled as study subjects. Two radiologists independently reviewed the MR images, first with only two sequences (abbreviated series), and then with all of the images provided for clinical care (full diagnostic series). The difference in sensitivity and specificity was evaluated using McNemar's test. Interobserver agreement was assessed by calculating κ values.
  
  
  RESULTS
  A total of 176 breasts including 31 cancers (3 cases with bilateral disease) were included. No significant difference in sensitivity or specificity for either observer was observed between the abbreviated series and the full diagnostic series (observer 1: sensitivity 87.1 vs 87.1 %, p = 1.00, specificity 91.7 vs 90.3 %, p = 0.791; observer 2: sensitivity 93.5 vs 96.8 %, p = 1.00, specificity 83.4 vs 89.7 %, p = 0.064). Moderate interobserver agreement (κ = 0.56) was observed for the abbreviated series, whereas substantial agreement (κ = 0.69) was observed for the full diagnostic series.
  
  
  CONCLUSIONS
  The diagnostic accuracy of the abbreviated breast MRI was not inferior to that of the conventional full diagnostic interpretation, although a slight decline in interobserver agreement was observed.
authors.affiliation: Kameda Kyobashi Clinic, Tokyo Square Garden 4F, 3-1-1 Kyobashi, Chuo City, Tokyo, 104-0031, Japan. machida.yoichi@kameda.jp.|Kameda Medical Center, 929 Higashi-cho, Kamogawa City, Chiba, 296-0041, Japan. machida.yoichi@kameda.jp.
authors.forename: Youichi
authors.initials: Y
authors.lastname: Machida
authors.affiliation: Kameda Kyobashi Clinic, Tokyo Square Garden 4F, 3-1-1 Kyobashi, Chuo City, Tokyo, 104-0031, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Shimauchi
authors.affiliation: Kameda Kyobashi Clinic, Tokyo Square Garden 4F, 3-1-1 Kyobashi, Chuo City, Tokyo, 104-0031, Japan.|St. Marianna University School of Medicine Breast and Imaging Center, 6-7-2 Mampukuji, Aso-ku, Kawasaki City, Kanagawa, 215-0004, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Kanemaki
authors.affiliation: Kameda Kyobashi Clinic, Tokyo Square Garden 4F, 3-1-1 Kyobashi, Chuo City, Tokyo, 104-0031, Japan.|The Jikei University School of Medicine, 3-2-58, Nishi-Shimbashi, Minato City, Tokyo, 105-8461, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Igarashi
authors.affiliation: Kameda Kyobashi Clinic, Tokyo Square Garden 4F, 3-1-1 Kyobashi, Chuo City, Tokyo, 104-0031, Japan.
authors.forename: Marie
authors.initials: M
authors.lastname: Harada
authors.affiliation: Kameda Medical Center, 929 Higashi-cho, Kamogawa City, Chiba, 296-0041, Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Fukuma
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity
keywords: Abbreviated breast MRI; Breast cancer; Diagnostic accuracy; Interobserver agreement; Observer study