Abstract: Ｏｂｊｅｃｔｉｖｅ：To investigate the value of cardiac magnetic resonance (CMR) diffusion weighted imaging (DWI) in lupus nephritis patients with lupus myocarditis.
Ｍｅｔｈｏｄｏｌｏｇｙ：CMR examination data of 66 patients with lupus nephritis (LN) and 42 healthy volunteers were retrospectively analyzed. According to the diagnostic criteria for myocarditis, patients were divided into LN with LM group and LN without LM group. Apparent diffusion coefficient (ADC) value were measured in anterior, posterior, lateral wall and global left ventricular on the standard cardiac short axis images. The difference ADC value between three groups were compared. Assess the diagnostic efficacy of ADC value and calculated its diagnostic cut off point using ROC curve for myocarditis.
Ｒｅｓｕｌｔｓ：49(742％) suffered from nephrotic syndrome, 38(576％) suffered from AKI, and 8(121％) suffered from chronic renal insufficiency. Symptoms of myocarditis consisted of dyspnea (642％), palpitation (333％) and chest pain (95％). Indicators of renal injury were more serious in LM patients, always associated with TMA, with the younger age, higher SLEDAI, urinary protein quantity and serum creatinine. LN group ADC value were significantly higher than those in control group (P<005). LM group ADC value were higher than those in nonLM group (P>005). The area under ROC curve of LV circumferential ADC in the diagnosis of LN patients was 0876 (95％CI 0799-0932, P<0001), the cut off point were 5×10-3 mm2／s. The area under ROC curve of LV circumferential ADC in the diagnosis of LN patients with LM was 0746 (95％CI 0654-0825, P<0001), the cut off point were 685×10-3 mm2／s.
Ｃｏｎｃｌｕｓｉｏｎ：DWI can quantify myocardial injury. The ADC value has good diagnostic value for LN complicated with myocardial injury.

Key words: lupus myocarditis,lupus nephritis,cardiac magnetic resonance,diffusion weighted imaging