Investigating the relationship between virtual cystoscopy image quality and CT slice thickness

Lalondrelle, Susan; Sohaib, S.A.; Castellano, Isabel; Mears, Dana C.; Huddart, Robert; Khoo, Vincent

doi:10.1259/bjr/99567374

Cited by 12 publications

(11 citation statements)

References 26 publications

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“…However, some studies revealed a noise-limited minimum thickness, such as the slice thickness of 1.2 mm superior to 0.6 mm because of increasing dimpling artifacts. 18 Similarly, the slice thickness with the range of 0.8–2 mm had no considerable impact on the residual setup error of stereotactic radiosurgery target localization. 19 In brain cancer, previous studies suggested 2.5 mm for tumor of <25 cm 3 in three-dimensional conformal radiation therapy and 1 or 2 mm in stereotactic body radiotherapy with small targets.…”

Section: Discussionmentioning

confidence: 90%

Impact of CT slice thickness on volume and dose evaluation during thoracic cancer radiotherapy

Luo

Jin

et al. 2018

CMAR

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IntroductionAccurate delineation of targets and organs at risk (OAR) is required to ensure treatment efficacy and minimize risk of normal tissue toxicity with radiotherapy. Therefore, we evaluated the impacts of computed tomography (CT) slice thickness and reconstruction methods on the volume and dose evaluations of targets and OAR.Patients and methodsEleven CT datasets from patients with thoracic cancer were included. 3D images with a slice thickness of 2 mm (2–CT) were created automatically. Images of other slice thickness (4–CT, 6–CT, 8–CT, 10–CT) were reconstructed manually by the selected 2D images using two methods; internal tumor information and external CT Reference markers. Structures and plans on 2–CT images, as a reference data, were copied to the reconstructed images.ResultsThe maximum error of volume was 84.6% for the smallest target in 10–CT, and the maximum error (≥20 cm3) was 10.1%, 14.8% for the two reconstruction methods, internal tumor information and external CT Reference, respectively. Changes in conformity index for a target of <20 cm3 were 5.4% and 17.5% in 8–CT. Changes on V30 and V40 of the heart were considerable. In the internal tumor information method, volumes of hearts decreased by 3.2% in 6–CT, while V30 and V40 increased by 18.4% and 46.6%.ConclusionThe image reconstruction method by internal tumor information was less affected by slice thickness than the image reconstruction method by external CT Reference markers. This study suggested that before positioning scanning, the largest section through the target should be determined and the optimal slice thickness should be estimated.

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Section: Discussionmentioning

confidence: 90%

Impact of CT slice thickness on volume and dose evaluation during thoracic cancer radiotherapy

Luo

Jin

et al. 2018

CMAR

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“…In our present study, we used 16-MDCT to perform urinary bladder scanning, with a section thickness of ∼1.25 mm and virtual reconstruction using a volume-rendering technique. Lalondrelle et al [6] suggested that the optimum slice thickness is 1.2 mm, as it usually results in the best image quality. On the other hand, decreasing the slice thickness (0.6 mm), leads to loss of tumour definition and results in appearance of dimpling artefacts due to increased noise.…”

Section: Discussionmentioning

confidence: 99%

Computed tomography virtual cystoscopy for follow-up of patients with superficial bladder tumours in comparison to conventional cystoscopy: An exploratory study

Elawady

Mahmoud

Mostafa

et al. 2016

Arab Journal of Urology

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ObjectiveTo evaluate and analyse the efficacy of computed tomography (CT) virtual cystoscopy in comparison to conventional cystoscopy for the follow-up of patients with non-muscle-invasive bladder cancer.Patients and methodsThe study was done over 3 years, from April 2010 to June 2013, and included 30 patients who all had non-muscle-invasive transitional cell carcinoma (Ta, T1). The patients all underwent complete transurethral resection of the tumour and presented for first follow-up check cystoscopy. The examination was performed using a 16-slice multi-detector (MD) CT scanner. The results were compared for sensitivity and specificity in relation to the site, size, and shape of the tumour.ResultsIn all, 20 lesions were detected by CT virtual cystoscopy in 18 patients, whilst the remaining 12 were lesion free. Conventional cystoscopy, detected 23 lesions in 19 patients. The sensitivity of the virtual images was 87%; its specificity in identifying lesions was 100%, with a positive predictive value of 100% and negative predictive value of 78.5%.ConclusionCT virtual cystoscopy is a promising technique for detecting bladder tumours and some other bladder lesions. However, the detection rate for recurrent NMIBC does not appear to be adequate to replace conventional cystoscopy.

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“…Image noise is inversely relational with the variation square root in the beam thickness (slice thickness). Thinner slice thickness increases image noise [8]. Despite thinner slices increasing image noise, the visibility of a small lesion was improved by providing more diagnostic content [9].…”

Section: Effect Of Image Noise and Slice Thickness On Dect Imagesmentioning

confidence: 99%

Effect of slice thickness on image noise and diagnostic content of single-source-dual energy computed tomography

Alshipli

Kabir

2017

J. Phys.: Conf. Ser.

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Abstract.Computed tomography (CT) employs X-ray radiation to create cross-sectional images. Dual-energy CT acquisition includes the images acquired from an alternating voltage of X-ray tube: a low-and a high-peak kilovoltage. The main objective of this study is to determine the best slice thickness that reduces image noise with adequate diagnostic information using dual energy CT head protocol. The study used the ImageJ software and statistical analyses to aid the medical image analysis of dual-energy CT. In this study, ImageJ software and F-test were utilised as the combination methods to analyse DICOM CT images. They were used to investigate the effect of slice thickness on noise and visibility in dual-energy CT head protocol images. Catphan-600 phantom was scanned at different slice thickness values; .6, 1, 2,3,4,5 and 6 mm, then quantitative analyses were carried out. The DECT operated in helical mode with another fixed scan parameter values. Based on F-test statistical analyses, image noise at 0.6, 1, and 2 mm were significantly different compared to the other images acquired at slice thickness of 3, 4, 5, and 6 mm. However, no significant differences of image noise were observed at 3, 4, 5, and 6 mm. As a result, better diagnostic image value, image visibility, and lower image noise in dual-energy CT head protocol was observed at a slice thickness of 3 mm. IntroductionComputed tomography scan (CT) is a cross-sectional medical imaging technology introduced in 1972 by British engineer Godfrey Hounsfield. Computed tomography is the first radiologic modality that requires the use of computers to scan the internal organ of the body. This technology creates data depending on the different attenuation levels of the scanned area [1]. CT is classified according to the type of energy technology; the classifications are single-(SECT) and dual-energy CT (DECT). DECT provides two different attenuation levels (low and high) that construct two data sets for the same scanned area. Therefore, DECT presents more advantages to improve image quality in comparison with SECT, including the correction of the beam-hardening artifact, reduction in the radiation dose level and increase of the diagnostic content [2]. In addition, DECT developed additional techniques, such as the reduction in the number of slices and virtual non-enhanced images techniques, for reducing the radiation dose level while increasing the image quality [3].Image noise impacts the image quality in CT images. This appears as an irregular granular pattern that degrades image quality. Image noise is based on the standard deviation of pixel intensity values or CT number for uniform anatomical region. Although DECT improves image quality, it still has approximately the same or slightly lower image noise level compared with single-energy CT [4,5]. Despite the thinner slices increased the image noise, the image visibility of a small lesion has been improved by provide more diagnostic information. As a result, a balance between the change in slice

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Investigating the relationship between virtual cystoscopy image quality and CT slice thickness

Cited by 12 publications

References 26 publications

Impact of CT slice thickness on volume and dose evaluation during thoracic cancer radiotherapy

Impact of CT slice thickness on volume and dose evaluation during thoracic cancer radiotherapy

Computed tomography virtual cystoscopy for follow-up of patients with superficial bladder tumours in comparison to conventional cystoscopy: An exploratory study

Effect of slice thickness on image noise and diagnostic content of single-source-dual energy computed tomography

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