Incidentally detected enhancing lesions found in breast MRI: analysis of apparent diffusion coefficient and T2 signal intensity significantly improves specificity.
OBJECTIVE
To evaluate the value of adding T2- and diffusion-weighted imaging (DWI) to the BI-RADS® classification in MRI-detected lesions.


METHODS
This retrospective study included 112 consecutive patients who underwent 3.0T structural breast MRI with T2- and DWI on the basis of EUSOMA recommendations. Morphological and kinetic features, T2 signal intensity (T2 SI) and apparent diffusion coefficient (ADC) findings were assessed.


RESULTS
Thirty-three (29.5 %) patients (mean age 57.0 ± 12.7 years) had 36 primarily MRI-detected incidental lesions of which 16 (44.4 %) proved to be malignant. No single morphological or kinetic feature was associated with malignancy. Both low T2 SI (P = 0.009) and low ADC values (≤0.87 × 10-3mm2s-1, P < 0.001) yielded high specificity (80.0 %/80.0 %). The BI-RADS classification supplemented with information from DWI and T2-WI improved the diagnostic performance of the BI-RADS classification as sensitivity remained 100 % and specificity improved from 30 % to 65.0 %. The numbers of false positive lesions declined from 39 % (N = 14) to 19 % (N = 7).


CONCLUSIONS
MRI-detected incidental lesions may be challenging to characterize as they have few specific malignancy indicating features. The specificity of MRI can be improved by incorporating T2 SI and ADC values into the BI-RADS assessment.


CONCLUSIONS
• MRI-detected incidental lesions have few specific malignancy indicating features. • ≥ 1 suspicious morphologic or kinetic feature may warrant biopsy. • T2 signal intensity and DWI assessment are feasible in primarily MRI-detected lesions. • T2 SI and DWI assessment improve the BI-RADS specificity in MRI-detected lesions.
Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland. otso.arponen@kuh.fi.|University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland. otso.arponen@kuh.fi.
Otso
O
Arponen
Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.|University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.
Amro
A
Masarwah
Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.
Anna
A
Sutela
Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.|University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.
Mikko
M
Taina
Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.
Mervi
M
Könönen
Kuopio University Hospital, Department of Pathology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.|University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Clinical Pathology and Forensic Medicine, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.|University of Eastern Finland, Cancer Center of Eastern Finland, Yliopistonranta 1, 70210, Kuopio, Finland.
Reijo
R
Sironen
Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.
Juhana
J
Hakumäki
Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.|University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.|University of Eastern Finland, Cancer Center of Eastern Finland, Yliopistonranta 1, 70210, Kuopio, Finland.
Ritva
R
Vanninen
Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, Kuopio University Hospital, PO Box 1777, Puijonlaaksontie 2, 70210, Kuopio, Finland.
Mazen
M
Sudah
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000473:pathology*; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D033162:Incidental Findings; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
D003287:Contrast Media
Breast cancer; DWI; Incidental MRI-detected lesions; Magnetic resonance imaging; T2