Detection of pulmonary nodules at multirow-detector CT: effectiveness of double reading to improve sensitivity at standard-dose and low-dose chest CT
The purpose of this study was to assess the effectiveness of double reading to increase the sensitivity of lung nodule detection at standard-dose (SDCT) and low-dose multirow-detector CT (LDCT). SDCT (100 mAs effective tube current) and LDCT (20 mAs) of nine patients with pulmonary metastases were obtained within 5 min using four-row detector CT. Softcopy images reconstructed with 5-mm slice thickness were read by three radiologists independently. Images with 1.25-mm slice thickness served as the gold standard. Sensitivity was assessed for single readers and combinations. The effectiveness of double reading was expressed as the increase of sensitivity. Average sensitivity for detection of 390 nodules (size 3.9±3.2 mm) for single readers was 0.63 (SDCT) and 0.64 (LDCT). Double reading significantly increased sensitivity to 0.74 and 0.79, respectively. No significant difference between sensitivity at SDCT and LDCT was observed. The percentage of nodules detected by all three readers concordantly was 52% for SDCT and 47% for LDCT. Although double reading increased the detection rate of pulmonary nodules from 63% to 74–79%, a considerable proportion of nodules remained undetected. No difference between sensitivities at LDCT and SDCT for detection of small nodules was observed.
KeywordsComputed tomography Pulmonary nodule Sensitivity
The authors would like to express their thanks to Robert Kralemann for his support in the practical realization of the study and for entering the data into the computer system.
- 8.Takashima S, Sone S, Li F, Maruyama Y, Hasegawa M, Kadoya M (2003) Indeterminate solitary pulmonary nodules revealed at population-based CT screening of the lung: using first follow-up diagnostic CT to differentiate benign and malignant lesions. Am J Roentgenol 180:1255–1263Google Scholar
- 10.Diederich S, Semik M, Lentschig MG, Winter F, Scheld HH, Roos N, Bongartz G (1999) Helical CT of pulmonary nodules in patients with extrathoracic malignancy: CT-surgical correlation. Am J Roentgenol 172:353–360Google Scholar
- 18.Altman DG (1991) Practical statistics for medical research. Chapman & Hall, LondonGoogle Scholar
- 21.Wormanns D, Beyer F, Diederich S, Ludwig K, Heindel W (2004) Diagnostic performance of a commercially available computer-aided diagnosis system for automatic detection of pulmonary nodules: comparison with single and double reading. Fortschr Roentgenstr 176:953–958Google Scholar
- 22.Marten K, Seyfarth T, Auer F, Wiener E, Grillhosl A, Obenauer S, Rummeny EJ, Engelke C (2004) Computer-assisted detection of pulmonary nodules: performance evaluation of an expert knowledge-based detection system in consensus reading with experienced and inexperienced chest radiologists. Eur Radiol 14:1930–1938CrossRefPubMedGoogle Scholar