请教大家，比如我有一列文本数据（如下英文，只是某个单元格的内容），每个单元格都有这么多文字。我现在想把文本中的Conclusions这个关键词之后的文字保留，并单独作为一列，Conclusions之前的文字都舍弃。这用R该怎么做呢？

PATIENT/TEST INFORMATION:
Indication: 78 year-old man with atrial fibrillation off anticoagulation, please evaluate for thrombus.
Height: (in) 66
Weight (lb): 130
BSA (m2): 1.67 m2
BP (mm Hg): 163/63
HR (bpm): 80
Status: Inpatient
Date/Time: [**2173-9-2**] at 09:47
Test: Portable TTE (Complete)
Doppler: Full Doppler and color Doppler
Contrast: None
Technical Quality: Adequate

Conclusions:
The left atrium is mildly dilated. No left atrial mass/thrombus seen (best
excluded by transesophageal echocardiography). The right atrium is moderately
dilated. There is mild symmetric left ventricular hypertrophy. The left
ventricular cavity is mildly dilated. There is moderate global left
ventricular hypokinesis (LVEF = 30%). [Intrinsic left ventricular systolic
function is likely more depressed given the sever