Reproducibility of Sonographic Measurement of the Substantia Nigra

Školoudík, David; Fadrná, Táňa; Bártová, Petra; Langová, Kateřina; Ressner, Pavel; Zapletalová, Olga; Hluštı́k, Petr; Herzig, Roman; Kaňnovský, Petr

doi:10.1016/j.ultrasmedbio.2007.03.013

Cited by 41 publications

(40 citation statements)

References 21 publications

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“…In our study intra-rater reliability in experienced neurosonographer was relatively good but inter-observer reliability (qualified vs. inexperienced sonographer in TCS) was moderate. This is consistent with previous reports that SN hyperechogenicity measurement reproducibility is high when performed by 1 experienced investigator [26,27].…”

Section: Discussionsupporting

confidence: 93%

Substantia nigra hyperechogenicity in Polish patients with Parkinson’s disease

et al. 2014

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Section: Discussionsupporting

confidence: 93%

Substantia nigra hyperechogenicity in Polish patients with Parkinson’s disease

et al. 2014

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“…Compared to studies assessing the consistency of visual evaluation of SN features 14,19 , we found higher interand intra-observer agreement using the newly developed application. In previous studies using visual evaluation, inter-observer SN echogenicity correlations ranged from r=0.55-0.82, while area measurement correlations ranged from r=0.31-0.74.…”

Section: Discussioncontrasting

confidence: 67%

“…In previous studies using visual evaluation, inter-observer SN echogenicity correlations ranged from r=0.55-0.82, while area measurement correlations ranged from r=0.31-0.74. Furthermore, intra-observer echogenicity and area measurement correlations (r=0.85-0.96 and r=0.51-0.69) were statistically significant (P<0.001) only for experienced sonographers 14 . In the study of van de Loo et al (2010), inter-observer correlations for SN area measurements ranged from r=0.84-0.89, inter-observer correlations of SN echogenicity from r=0.33-0.51, and intra-observer correlations for planimetric measurements and echogenicity evaluations from r=0.93-0.97 and r=0.74-0.80, respectively.…”

Section: Discussionmentioning

confidence: 86%

“…In the study of van de Loo et al (2010), inter-observer correlations for SN area measurements ranged from r=0.84-0.89, inter-observer correlations of SN echogenicity from r=0.33-0.51, and intra-observer correlations for planimetric measurements and echogenicity evaluations from r=0.93-0.97 and r=0.74-0.80, respectively. The results of both studies showed that semi-quantitative evaluations of SN echogenicity and planimetric area using TCS were highly dependent on the experience of the sonographer 14,19 . Only an experienced sonographer was able to generate reproducible results with statistically significant correlations.…”

Section: Discussionmentioning

confidence: 99%

“…Dependence of image quality on both the sonographer's experience and the quality of the patient's bone window are the main limitation of TCS in the evaluation of SN hyperechogenicity [12][13][14] . Several automatic computer programs have been developed to circumvent this limitation.…”

Section: Introductionmentioning

confidence: 99%

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A new program for highly reproducible automatic evaluation of the substantia nigra from transcranial sonographic images

Blahuta¹,

Soukup²,

Jelínková³

et al. 2014

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Aims. Recent studies report increased echogenicity of the substantia nigra (SN) in patients with Parkinson's disease (PD) using transcranial sonography (TCS). However, the main limitation to TCS is its dependence on the sonographer's experience. Experimental software for quantitative evaluation of the echogenic SN area was thus developed by us. The aim of this study was to test the reliability of the data using developed B-Mode Assist software in patients with parkinsonism and in healthy volunteers. Methods. The SN was imaged from the right temporal bone window in mesencephalic plane using TCS. DICOM images of SN were saved, converted into JPEG format, encoded and processed. Two observers performed 3 automatic evaluations of the SN area (measurements of SN area in each gray scale intensity inside the region of interest) by counting the standard deviation of all 6 measurements using developed software. The average value of all 3 measurements of each observer was used for computing Cohen's kappa coefficient to determine inter-observer correlations. Cohen's kappa coefficients as an intra-observer correlation for observer 1 and observer 2 were counted from the first 2 measurements of both observers. Results. In total, 92 images were evaluated using this software. The mean of the standard deviations was 3.87; Cohen's kappa for intra-observer agreement of two observers were 0.947, and 0.943, resp.; Cohen's kappa for inter-observers agreement was 0.880. The agreement between visual and automatic detection of SN pathology was in 97.8% images. The sensitivity, specificity, positive and negative predictive values of automatic measurement were 100, 96.2, 95.1, 100%, resp. Conclusions. The results show very reliable measurement of SN features using designed application with "almost perfect" inter-observer and intra-observer agreements.

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