BACKGROUND: COVID-19 is a systemic viral infection which mainly targets the 
human respiratory system with many secondary clinical manifestations especially 
affecting the hematopoietic system and haemostasis. Few studies have highlighted 
the prognostic value of blood findings such as lymphopenia, 
neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, LDH, CRP, cardiac 
troponin, low-density lipoproteins and chest radiographic abnormality. A study 
of progressions of blood and radiological results may help to identify patients 
at high risk of severe outcomes. This systematic review aimed to assess the 
temporal progression of blood and radiology findings of patients with COVID-19.
METHODS: Comprehensive systematic literature search was conducted on Medline, 
Embase and Cochrane databases to identify articles published for peripheral 
blood investigation and radiological results of COVID-19 patients.
RESULTS: A total of 27 studies were included in this review. The common 
laboratory features reported include lymphopenia, elevated levels of C-reactive 
proteins and lactate dehydrogenase. For radiological signs, ground-glass 
opacifications, consolidations, and crazy paving patterns were frequently 
reported. There is a correlation between lymphocyte count, neutrophil count and 
biomarkers such as C-reactive proteins and lactate dehydrogenase; at a later 
phase of the disease (more than 7 days since onset of symptoms), lymphopenia 
worsens while neutrophil count, C-reactive protein levels and lactate 
dehydrogenase levels increase. Frequencies of ground-glass opacifications and 
ground-glass opacifications with consolidations decrease at a later phase of the 
disease while that of consolidation and crazy paving pattern rises as the 
disease progresses. More extensive lung involvement was also seen more 
frequently in the later phases.
CONCLUSION: The correlation between temporal progression and the reported blood 
and radiological results may be helpful to monitor and evaluate disease 
progression and severity.