This paper proposes a Medical Concept Aligned Radiology Report Generation (MCA-RG) framework to address the challenges of accurately mapping pathological and anatomical features to textual descriptions in applying large-scale language models (LLMs) to medical image report generation (RRG) and the difficulty of generating accurate diagnostic reports due to semantically irrelevant feature extraction. MCA-RG leverages two curated concept banks—a pathology bank containing pathology-related knowledge and an anatomy bank containing anatomical descriptions—to explicitly align visual features with individual medical concepts. It proposes an anatomy-based contrastive learning procedure to improve anatomical feature generalization and a matching loss for pathological features to prioritize clinically relevant regions. Furthermore, it employs a feature gating mechanism to filter out low-quality concept features and utilizes visual features corresponding to individual medical concepts to guide the report generation process. Experiments on two publicly available benchmarks, MIMIC-CXR and CheXpert Plus, demonstrate that MCA-RG achieves excellent performance.