A randomized clinical trial evaluating the short-term results of ureteral stent encrustation in urolithiasis patients undergoing ureteroscopy: micro-computed tomography evaluation

AbstractAlthough many ureteral stents are commercially available, the actuality of encrustation is yet to be elucidated in humans. This study compared the Tria Ureteral Stent with PercuShield and the Polaris Ultra Ureteral Stent with HydroPlus Coating for short-term encrustation formation. Eighty-four patients, who required ureteral stent placement after ureteroscopy, were randomized into two stent groups. After stent removal on postoperative day 14, the encrustation volume on the stent surface was measured by micro-computed tomography. The primary outcome was the inner luminal encrustation volume. Secondary outcomes were encrustation volume on the outer or total surfaces and occurrence of adverse events. Clinical factors related to encrustation were also assessed as a post-hoc analysis. Finally, of the 82 patients analyzed, 75 (91.5%) had encrustation in the inner lumen of the stent. The difference in median inner encrustation volume between the Tria and Polaris Ultra stents was comparable (0.56 vs. 0.37 mm3, P = 0.183). There was no difference observed in the encrustation volume on the outer/total surfaces and stent-related adverse events. In both ureteral stents, the shaft body showed significant inner luminal encrustation compared to the proximal or distal loop (all, P < 0.05). Dyslipidemia (P = 0.027), elevated urine pH (P = 0.046), and crystalluria (P = 0.010) were associated with encrustation formation. The Tria and Polaris Ultra stents had similar efficacy for preventing encrustation in the short-term. Further studies are required to compare their long-term patency.

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Comparison of Orthodontic Root Resorption of Root-filled and Vital Teeth Using Micro–computed Tomography

The Angle Orthodontist ◽

10.2319/022819-153.1 ◽

2019 ◽

Vol 90 (1) ◽

pp. 56-62 ◽

Cited By ~ 2

Author(s):

Kadir Kolcuoğlu ◽

Aslihan Zeynep Oz

Keyword(s):

Computed Tomography ◽

Tooth Extraction ◽

Root Resorption ◽

Cervical Region ◽

Control Group ◽

Micro Computed Tomography ◽

Mean Values ◽

The Mean ◽

The Difference ◽

Experimental Group

ABSTRACT Objective To evaluate the difference in orthodontic root resorption between root-filled and vital teeth. Material and Methods Sixteen individuals who required bilateral premolar tooth extraction due to orthodontic treatment and had a previously root-filled premolar tooth on one side were included in the study. The experimental group consisted of root-filled premolar teeth, and the control group consisted of contralateral vital premolar teeth. A 150-g buccally directed force was applied to these teeth using 0.017 × 0.025-inch TMA cantilever springs. The premolars were extracted 8 weeks after the application of force. Images were obtained using micro–computed tomography. Resorption measurements were obtained using the Image J program. Results The mean values for resorption were 0.08869 mm3 for the root-filled teeth and 0.14077 mm3 for the contralateral teeth, indicating significantly less resorption for the root-filled teeth compared with the contralateral teeth after the application of orthodontic force (P = .003). In both groups, the most resorption was seen on the cervical-buccal and apical-lingual surfaces. The mean resorption value of the cervical region was 0.06305 mm3 in the control group and 0.0291 mm3 in the experimental group, and the difference was statistically significant (P = .002). Conclusions Root-filled teeth showed significantly less orthodontic root resorption than vital teeth.

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Computed tomography versus ureteroscopy in identification of renal tract stone with ureteral stent in situ

Annals of The Royal College of Surgeons of England ◽

10.1308/003588411x13165261993996 ◽

2011 ◽

Vol 93 (8) ◽

pp. 639-641 ◽

Cited By ~ 4

Author(s):

VCY Tang ◽

A Attwell-Heap

Keyword(s):

Computed Tomography ◽

Positive Predictive Value ◽

Negative Predictive Value ◽

Predictive Value ◽

Gold Standard ◽

Ureteral Stent ◽

The Difference ◽

Contrast Ct ◽

Sensitivity Specificity

INTRODUCTION The aim of this study was to validate the use of non-contrast computed tomography (CT) with a ureteral stent in situ instead of ureteroscopy for identification of renal tract stones. METHODS All patients who had stents inserted for renal tract stones and underwent non-contrast CT with the stent in situ followed by ureteroscopy between May 2008 and October 2009 at The Canberra Hospital, Australia, were analysed retrospectively. Statistical analysis was performed to compare any differences between CT and ureteroscopy in the identification of stones. RESULTS Overall, 57 patients were included in the study. The difference between CT and ureteroscopy findings was statistically significant. CT identification of stones with a stent in situ had a sensitivity of 86%, a specificity of 46%, a positive predictive value of 63%, a negative predictive value of 76% and an accuracy of 67%. CONCLUSIONS Our study suggests that non-contrast CT is inferior to the ‘gold standard’ of ureteroscopy. It lacks sensitivity, specificity, positive predictive value, negative predictive value and accuracy. Therefore, we cannot recommend using non-contrast CT to replace ureteroscopy.

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Evolution of crystal orientation in snow during temperature gradient metamorphism

Journal of Glaciology ◽

10.3189/2013jog12j116 ◽

2013 ◽

Vol 59 (213) ◽

pp. 47-55 ◽

Cited By ~ 16

Author(s):

Fabienne Riche ◽

Maurine Montagnat ◽

Martin Schneebeli

Keyword(s):

Computed Tomography ◽

Temperature Gradient ◽

Crystal Orientation ◽

Initial Density ◽

Snow Sample ◽

Micro Computed Tomography ◽

Thin Sections ◽

Two Samples ◽

The Difference ◽

Snow Samples

AbstractThe physical properties of snow are tied to its microstructure. Especially for the slow, plastic deformation of snow and firn, the crystal orientation is an important factor in addition to the geometry of the ice matrix. While micro-computed tomography measures the snow microstructure precisely, it gives no information about the orientation of the ice crystals. In this study, we applied a temperature gradient of 50 K m−1 to large blocks of undisturbed decomposed snow and sieved snow during 3 months. The mean temperature of the snow samples during the temperature gradient experiment was −20°C. Two closely spaced snow samples were taken before the experiment, then every week during the first month and afterwards every month. From each sampling, one sample was analyzed by micro-computed tomography and the other was used for thin sections. The orientation of the c-axis was measured in the thin sections using an automatic ice texture analyzer. Initial density was 30% higher in the sieved snow sample. Density and specific surface area evolved alike, while the fabric showed a different evolution between the two samples. The undisturbed snow evolved from a weak single-maximum fabric towards a weak girdle fabric, while the sieved sample showed no evolution. The undisturbed snow sample converged toward the sieved sample fabric after 6 weeks, but continued its evolution thereafter. We suggest that the main factor causing this different behavior is the difference in density and in pore size.

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The Study of Specific Surface Area from Carbonat Rock Using Micro Computed Tomography (µ-CT)

Proceeding International Conference on Science and Engineering ◽

10.14421/icse.v1.278 ◽

2017 ◽

Vol 1 ◽

pp. 111-113

Author(s):

Mahendra Risky Habibi ◽

Thaqibul Fikri Niyartama

Keyword(s):

Computed Tomography ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Calculation Result ◽

Carbonate Rocks ◽

Programming Algorithm ◽

Micro Ct ◽

Micro Computed Tomography ◽

The Difference

Carbonate rocks have been scanned and reconstructed in order to get the value of specific surface area. We get it from the reservoir at a depth of 1000 metres in South Sumatra. Skyscan Micro-CT 1173 is used for throwing and thresholding images using Global Otshu to characterize rocks. Our calculation result shows that the value of specific surface area of carbonate rocks show results 100 to 10-2 using the programming Algorithm Fuzzy C-Mean. The difference in values far enough that it can be assumed that the carbonate rocks have a heterogeneous surface area. In addition, histogram model shows the similarity of the sample. The macro sample has the same characteristics as the micro sample.

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Cardiac Micro–Computed Tomography for Morphological and Functional Phenotyping of Muscle LIM Protein Null Mice

Molecular Imaging ◽

10.2310/7290.2007.00022 ◽

2007 ◽

Vol 6 (4) ◽

pp. 7290.2007.00022 ◽

Cited By ~ 20

Author(s):

Cristian T. Badea ◽

Laurence W. Hedlund ◽

Julie F. Boslego Mackel ◽

Lan Mao ◽

Howard A. Rockman ◽

...

Keyword(s):

Computed Tomography ◽

Three Dimensional ◽

Blood Pool ◽

Micro Ct ◽

Micro Computed Tomography ◽

Isotropic Resolution ◽

Lim Protein ◽

Muscle Lim Protein ◽

The Difference ◽

Time Required

The purpose of this study was to investigate the use of micro–computed tomography (micro-CT) for morphological and functional phenotyping of muscle LIM protein (MLP) null mice and to compare micro-CT with M-mode echocardiography. MLP null mice and controls were imaged using both micro-CT and M-mode echocardiography. For micro-CT, we used a custom-built scanner. Following a single intravenous injection of a blood pool contrast agent (Fenestra VC, ART Advanced Research Technologies, Saint-Laurent, QC) and using a cardiorespiratory gating, we acquired eight phases of the cardiac cycle (every 15 ms) and reconstructed three-dimensional data sets with 94-micron isotropic resolution. Wall thickness and volumetric measurements of the left ventricle were performed, and cardiac function was estimated. Micro-CT and M-mode echocardiography showed both morphological and functional aspects that separate MLP null mice from controls. End-diastolic and -systolic volumes were increased significantly three- and fivefold, respectively, in the MLP null mice versus controls. Ejection fraction was reduced by an average of 32% in MLP null mice. The data analysis shows that two imaging modalities provided different results partly owing to the difference in anesthesia regimens. Other sources of errors for micro-CT are also analyzed. Micro-CT can provide the four-dimensional data (three-dimensional isotropic volumes over time) required for morphological and functional phenotyping in mice.

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A comparative study of efficacy and safety of topical calcitriol and topical calcipotriol in stable chronic plaque type psoriasis

International Journal of Basic & Clinical Pharmacology ◽

10.18203/2319-2003.ijbcp20190509 ◽

2019 ◽

Vol 8 (3) ◽

pp. 402

Author(s):

Leela Hugar ◽

Ramesh H.

Keyword(s):

Adverse Events ◽

Safety Profile ◽

Similar Efficacy ◽

Efficacy And Safety ◽

Point Scale ◽

Global Improvement ◽

Local Tolerance ◽

Plaque Type ◽

The Subject ◽

The Difference

Background: Topical calcitriol and calcipotriol, the two vitamin D derivatives although considered efficient in treating psoriasis, their comparative studies are relatively scanty. The objective of the present study was to evaluate and compare the efficacy and safety of calcitriol and calcipotriol in stable chronic plaque-type psoriasis.Methods: Total 50 patients of chronic stable plaque-type psoriasis were randomly divided into two groups of 25 each. One group received calcitriol 3µg/g ointment and the other group received calcipotriol 50µg/g ointment twice daily for 12 weeks. Efficacy evaluations comprised global improvement (on a 4-point scale from 0: no change, to 3: clear or almost clear) assessed clinically and by the subject. Efficacy further included the ‘dermatological sum score’ (DSS) at each study visit. Safety evaluations (on a 5-point scale from 0: none, to 4: very severe) included clinical assessment of cutaneous safety and assessment of cutaneous discomfort by the subject.Results: Both calcitriol and calcipotriol were significantly effective (p <0.001) in reduction of DSS but the difference between the two groups was not statistically significant. Mean score of global improvement assessed clinically was 2.20 for calcitriol and 2.16 for calcipotriol (p >0.05) and by the subject was 1.92 for calcitriol and 1.84 for calcipotriol (p >0.05). The difference between the two groups was not statistically significant. The mean worst score for cutaneous safety was higher in calcipotriol group compared to calcitriol group (0.28 vs 0.04 and 0.36 vs 0.04 by clinically and by the subject, respectively). Statistically significant better safety profile (p <0.05) was seen for calcitriol, only when assessed by the subject. 24% treatment related adverse events were reported with calcipotriol against only 4% with calcitriol.Conclusions: Topical calcitriol and calcipotriol showed similar efficacy in the treatment of chronic plaque psoriasis while calcitriol showed better safety profile in comparison with calcipotriol, in terms of local tolerance and induced less treatment related adverse events.

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Quantitative Evaluation of Encrustations in Double-J Ureteral Stents With Micro-computed Tomography and Semantic Segmentation

10.21203/rs.3.rs-763507/v1 ◽

2021 ◽

Author(s):

Shaokai Zheng ◽

Pedro Amado ◽

Bernhard Kiss ◽

Fabian Stangl ◽

Andreas Haeberlin ◽

...

Keyword(s):

Computed Tomography ◽

Network Models ◽

Semantic Segmentation ◽

Stone Disease ◽

Volume Distribution ◽

Ureteral Stents ◽

Micro Computed Tomography ◽

Neural Network Models ◽

Ureterovesical Junction ◽

Patient Groups

Abstract Accurate evaluations of stent encrustation patterns, such as volume distribution, from different patient groups are valuable for clinical management and the development of better stents. This study compared stent encrustation patterns from stone and kidney transplant patients. Twenty-three double-J ureteral stents were collected at a single center from patients with stone disease or underwent kidney transplantation. Encrustations on stent samples were quantified by means of micro‑computed tomography and semantic segmentation using Convolutional Neural Network models. Luminal encrustation volume per stent unit was derived to represent encrustation level, which did not differ between patient groups in the first six weeks. However, stone patients showed higher encrustation levels over prolonged indwelling times (p = 0.036). Along the stent shaft body, the stone group showed higher encrustation levels near the ureteropelvic junction compared to the ureterovesical junction (p = 0.013), whereas the transplant group showed no such difference. Possible explanations were discussed regarding vesicoureteral refluxes. In both patient groups, stent pigtails were more susceptible to encrustations, and no difference between renal and bladder pigtail was identified. Our results suggest that excessively long stents with superfluous pigtails should be avoided.

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