Blind spots on CT imaging of the head: Insights from 5 years of report addenda at a single institution


      • There is sparse literature describing patterns of missed findings on head imaging.
      • We review report addenda over 5 years, summarizing revealed patterns of detection error.
      • Attention to recurring and common blind spots may reduce diagnostic error.



      Errors of detection (“misses”) are the major source of error in radiology. There is sparse prior literature describing patterns of detection error on CT head imaging.


      The objective of this study was to gain insight to areas on CT head imaging where radiologists are most likely to miss clinically relevant findings.


      We performed a cross-sectional study of consecutive reports of CT imaging of the head at a single institution spanning 5/1/2013–5/1/2018 (5 years). Detection errors described in addenda were categorized according to anatomic location, type of pathology, and potential impact on management. Blind spots were defined by the most common sites of missed findings.


      A total of 165,943 reports for CT head imaging were obtained. Addenda were found in 1658 (~1%) of reports, of which 359 (21.7%) described errors of detection. Within the extracranial soft tissues (n = 73) the most common “misses” were at incidentally imaged parotid glands and the frontal scalp. Within osseous structures (n = 149), blind spots included the nasal and occipital bones. Vascular lesions (n = 47) which passed detection were most common at the distal MCA, carotid terminus and sigmoid sinus/jugular bulb. No predisposition was seen for anatomic subsites within the CSF space (n = 60) and brain parenchyma (n = 65).


      Consistent patterns of blind spots are revealed. Radiologic teaching and search patterns to account for these sites of error may accelerate trainee competence and improve accuracy in the practice of radiology.


      CT (computed tomography), CPT (current procedural terminology), CSF (cerebrospinal fluid), MCA (middle cerebral artery)


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        • Kohn L.T.
        • Corrigan J.M.
        • Donaldson M.S.
        To err is human: building a safer health system.
        National Academies Press (US), Washington (DC)2000 (Copyright 2000 by the National Academy of Sciences. All rights reserved)
        • Makary M.A.
        • Daniel M.
        Medical error-the third leading cause of death in the US.
        Bmj. 2016; 353: i2139
        • Sabih D.E.
        • et al.
        Image perception and interpretation of abnormalities; can we believe our eyes? Can we do something about it?.
        Insights Imaging. 2011; 2: 47-55
        • Garland L.H.
        On the scientific evaluation of diagnostic procedures.
        Radiology. 1949; 52: 309-328
        • Berlin L.
        Accuracy of diagnostic procedures: has it improved over the past five decades?.
        AJR Am J Roentgenol. 2007; 188: 1173-1178
        • Waite S.
        • et al.
        Interpretive error in radiology.
        AJR Am J Roentgenol. 2017; 208: 739-749
        • Brady A.P.
        Error and discrepancy in radiology: inevitable or avoidable?.
        Insights Imaging. 2017; 8: 171-182
        • Rosenkrantz A.B.
        • Bansal N.K.
        Diagnostic errors in abdominopelvic CT interpretation: characterization based on report addenda.
        Abdom Radiol (NY). 2016; 41: 1793-1799
        • de Groot P.M.
        • et al.
        Pitfalls in chest radiographic interpretation: blind spots.
        Semin Roentgenol. 2015; 50: 197-209
        • Del Ciello A.
        • et al.
        Missed lung cancer: when, where, and why?.
        Diagn Interv Radiol. 2017; 23: 118-126
        • Erly W.K.
        • et al.
        Radiology resident evaluation of head CT scan orders in the emergency department.
        AJNR Am J Neuroradiol. 2002; 23: 103-107
        • Wysoki M.G.
        • et al.
        Head trauma: CT scan interpretation by radiology residents versus staff radiologists.
        Radiology. 1998; 208: 125-128
        • Meyer R.E.
        • et al.
        Discrepancy rates of on-call radiology residents’ interpretations of CT angiography studies of the neck and circle of Willis.
        AJR Am J Roentgenol. 2009; 193: 527-532
        • Jenny C.
        • et al.
        Analysis of missed cases of abusive head trauma.
        JAMA. 1999; 281: 621-626
        • Malatt C.
        • et al.
        Head computed tomography in the emergency department: a collection of easily missed findings that are life-threatening or life-changing.
        J Emerg Med. 2014; 47: 646-659
        • Loevner L.A.
        • Yousem D.M.
        Overlooked metastatic lesions of the occipital condyle: a missed case treasure trove.
        Radiographics. 1997; 17: 1111-1121
      1. ACR Practice Parameter for Communication of Diagnostic Imaging Findings. American College of Radiology, (Revised 2020, Resolution 37).

        • Bruno M.A.
        • Walker E.A.
        • Abujudeh H.H.
        Understanding and confronting our mistakes: the epidemiology of error in radiology and strategies for error reduction.
        Radiographics. 2015; 35: 1668-1676
        • Thomassen O.
        • et al.
        Implementation of checklists in health care; learning from high-reliability organisations.
        Scand J Trauma Resusc Emerg Med. 2011; 19: 53
        • Lin E.
        • Powell D.K.
        • Kagetsu N.J.
        Efficacy of a checklist-style structured radiology reporting template in reducing resident misses on cervical spine computed tomography examinations.
        J Digit Imaging. 2014; 27: 588-593
        • Leape L.L.
        • et al.
        Perspective: a culture of respect, part 2: creating a culture of respect.
        Acad Med. 2012; 87: 853-858
        • Reason J.
        Human error: models and management.
        West J Med. 2000; 172: 393-396