Image quality evaluation of diffusion-weighted imaging in bladder cancer: a comparison between integrated slice-specific dynamic shimming and single-shot echo-planar imaging.

Background: Diffusion-weighted imaging (DWI) image quality will affect how well radiologists detect lesions and judge muscular invasion. This study qualitatively and quantitatively compared the image quality of DWI with integrated slice-specific dynamic shimming (iShim) and single-shot echo-planar imaging (SS-EPI) in the diagnosis of bladder cancer (BC) using 3.0 T magnetic resonance imaging (MRI). We also investigated the application value of iShim DWI in BC. Methods: This retrospective study enrolled 97 patients with BC who underwent a preoperative MRI examination, including iShim and SS-EPI DWI. Two radiologists, blinded to the type of DWI, independently rated DWIs on a 5-point Likert scale regarding image quality features (anatomical details, distortion, lesion conspicuity, artifacts, and overall image quality) and evaluated tumor muscular invasion. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), apparent diffusion coefficient (ADC) values, and tumor numbers were manually recorded by another 2 radiologists. Pathologists recorded tumor numbers and sizes in a standard manner. Results: The inter- and intraobserver consistency of image quality features scoring was good to excellent (κ >0.75; P<0.001). The scores of iShim DWI were higher than those of SS-EPI DWI in terms of distortion, artifacts, and overall image quality (P<0.001). The SNR and CNR of iShim DWI were higher than those of SS-EPI DWI (P<0.001), but there was no significant difference in ADC values between the 2 sequences (P>0.05). Based on pathological findings, the sensitivity of iShim and SS-EPI DWI in diagnosing tumor that diameter less than 1 cm was 100% (79/79) and 93.7% (74/79), respectively. The specificity and accuracy (95.2% and 90.2%, respectively) of iShim DWI in diagnosing tumor muscular invasion were significantly higher than those of SS-EPI DWI (76.2% and 80.4%, respectively). The area under the receiver operating characteristic curve of iShim DWI was significantly higher than that of SS-EPI DWI in diagnosing tumor muscular invasion (P=0.017). Conclusions: Compared with SS-EPI DWI, iShim DWI provided higher image quality. iShim DWI effectively detected BC and better identified muscular invasion. This finding can guide the clinical selection of appropriate treatments for patients with BC.

Multiple directional DWI combined with T2WI in predicting muscle layer and Ki-67 correlation in bladder cancer in 3.0-T MRI.

OBJECTIVE: To investigate the value of 3.0T MRI multi-directional diffusion-weighted imaging (DWI) combined with T2WI morphological features and lesion distribution in preoperative prediction of muscle layer invasion of bladder cancer (BC) and the correlation with postoperative Ki-67. MATERIALS AND METHODS: This retrospective study enrolled patients with BC between 2019 and 2021. Patients with muscular invasive bladder cancer (MIBC) or non-muscular invasive BC (NMIBC) were also analyzed by preoperative 3.0T MRI aFostic efficacy. RESULTS: A total of 186 patients were enrolled. About 27 patients with MIBC (35 lesions in total) and 62 with NMIBC (99 lesions in total). We found the tumor with a larger size, a wide base, and a smaller apparent dispersion coefficient (ADC) value and normalized ADC(nADC) value, without a stalk, presenting a greater risk of muscle invasion. ADC value, nADC value, maximum diameter, and stalk were independently associated with muscle invasion. Lesions located at the bladder fundus or involvement of multiple sites were independently associated with muscle invasion compared to the bladder body. In combination with morphological features, the AUCs of ADC and nADC showed accuracies of 0.925 and 0.947-0.951, respectively. TADC and nTADC showed the best diagnostic efficacy in multiple respects. KI-67 LI was negatively correlated with ADC and nADC values. CONCLUSIONS: This is the first report in which we found Multi-directional DWI combined with T2WI in 3.0T MRI can be used to predict the muscle layer invasion of bladder cancer. ADC values reflect the muscular invasion of bladder cancer and show a moderate negative correlation with Ki-67. It is especially suitable for bladder cancer patients with renal insufficiency or tumor recurrence.

Feasibility of Early Evaluation for the Recurrence of Bladder Cancer after Trans-Urethral Resection: A Comparison between Magnetic Resonance Imaging and Multidetector Computed Tomography.

(1) Background: This study investigates the early evaluation value of magnetic resonance imaging (MRI) and multidetector computed tomography (MDCT) in diagnosing the recurrence of bladder cancer (BC) after trans-urethral resection (TUR) alone or combined with intravesical perfusion chemotherapy. (2) Methods: This retrospective study enrolled 92 patients with BC who underwent MRI and MDCT after TUR. The time interval between MRI and MDCT was no more than 1 week. Tumor recurrence was recorded by two experienced radiologists who were double-blind. Recurrent patients were divided into nodular masses, irregular wall thickening and smooth wall thickening groups according to tumor morphology in cystoscopy and resected gross specimens. Inter- and intra-observer agreement was evaluated using the Kappa test. Imaging diagnostic performance was assessed using receiver operating characteristic (ROC) analysis and McNemar's test based on pathology. (3) Results: There were 56 relapsed and 36 non-relapsed patients. The intra-observer agreement for the imaging diagnosis was excellent (κ = 0.96 for MRI and κ = 0.91 for MDCT, both p < 0.001). The area under the ROC curve of MRI was higher than that for MDCT (0.91 vs. 0.74, p < 0.001) in identifying tumor recurrence and benign treatment-related changes. The sensitivity, specificity and accuracy of MRI (87.5%, 94.4% and 90.2%, respectively) were higher than those of MDCT (67.9%, 80.6% and 72.8%, respectively) in diagnosing tumor recurrence. Two observers missed 10 cases of small lesions (<1 cm) on MDCT. The accuracy of MRI (100%, 90.0% and 25.0%, respectively) was higher than that of MDCT (92.1%, 30.0% and 0%, respectively) in diagnosing nodular masses, irregular wall thickening and smooth wall thickening recurrence patterns. (4) Conclusions: Compared with MDCT, MRI had a higher accuracy in detecting BC recurrence early, especially for nodular masses and irregular wall thickening, and could better differentiate tumor recurrence from benign treatment-related changes.

A Preliminary Study on the Feasibility of the Quantitative Parameters of Dual-Energy Computed Tomography Enterography in the Assessment of the Activity of Intestinal Crohn's Disease.

OBJECTIVE: To investigate the value of dual energy CT enterography (DECTE) in evaluating the activity of Crohn's disease (CD). METHODS: The endoscopy and imaging data of 29 patients with CD confirmed by clinic and pathology were analyzed retrospectively. The clinical CD activity index (CDAI) was used as the disease activity grouping standard, 29 patients with CD were grouped into activity groups, 18 patients in the active group (CDAI ≥ 150) with 36 intestinal segments, and 11 patients in the remission group (CDAI < 150) with 20 intestinal segments.The virtual single energy CT value, slope of energy spectrum curve and iodine content were analyzed to evaluate the evaluation of intestinal CD activity by DECTE. RESULTS: There were statistically significant differences in virtual single energy CT value (except 90 keV and 100 keV virtual single energy CT value), curve slope and iodine content between remission group and active group (P < 0.05), and has more diagnostic value for active phase (AUC > 0.5). ① Virtual single energy CT value: the AUC of 60 keV in arterial phase was the highest (0.924). The specificity of diagnosing CD in active stage was high (95%). ② Curve slope: the AUC of portal vein phase was the largest (0.731). The specificity of diagnosing CD in active stage was higher (85%). ③ Iodine content: the AUC of arterial phase was the highest (0.885). The specificity of diagnosing CD lesions in the active stage was 100%. CONCLUSION: The virtual single energy CT value, energy spectrum curve slope and iodine content can provide reference for clinical accurate diagnosis of CD activity.

Influence of Different Marginal Forms on Endodontically Treated Posterior Teeth Restored with Lithium Disilicate Glass-Ceramic Onlays: Two-Year Follow-up.

PURPOSE: To evaluate the clinical performance of endodontically treated (ET) teeth restored with two different marginal forms of lithium disilicate glass-ceramic (LDG ceramic) onlays. MATERIALS AND METHODS: A total of 120 posterior teeth were prepared for onlays after ET. The occlusal surfaces of the teeth were removed 1.5 to 2 mm anatomically. Different marginal forms were employed depending on the thickness of the residual axis wall of each tooth: In Group S, a 1-mm shoulder was prepared when the remaining axis wall was > 2 mm (n = 50), and in Group B, a 20- to 30-degree bevel was prepared when the remaining axis wall was ≤ 2 mm (n = 70). The access of the pulp chamber was filled with resin, and 1.5 to 2 mm of the box morphology of the pulp chamber was preserved. The pressed LDG ceramic was applied to the fabricated onlays. The teeth and restorations were checked after 6, 12, and 24 months. All available restored teeth were assessed using modified United States Public Health Service criteria. RESULTS: During the observation period, no tooth fracture occurred. Neither tooth cracks nor secondary caries were observed in Group S or Group B. The 2-year survival rate of the teeth was 100%. Five fractured onlays were observed in Group S in the molar region, while all onlays in Group B were intact (P < .05). The survival rate of the onlays was 95.83%. CONCLUSION: The results demonstrate that LDG ceramic onlays can preserve ET posterior teeth with a highly satisfactory outcome, though the marginal form may affect the survival rate of the onlay.

Different performances of CXCR4, integrin-1ß and CCR-2 in bone marrow stromal cells (BMSCs) migration by low-intensity pulsed ultrasound stimulation.

Low-intensity pulsed ultrasound (LIPUS) is an established therapy for fracture healing where bone marrow stromal cells (BMSCs) migration is crucial to bone regeneration. This work focused on different performances of C-X-C-receptor 4 (CXCR4), integrin-1ß and chemokine-chemokine receptor2 (CCR-2) in BMSCs migration by LIPUS stimulation. Single 20-min LIPUS treatment was applied to BMSCs during wound healing assay with or without the inhibitor AMD3100. The migration rate of BMSCs with LIPUS stimulation exhibited a higher closure rate than that of BMSCs without LIPUS stimulation, which was 1.89 µm/h and 1.38 µm/h, respectively. After LIPUS stimulation, significant elevation of the expression of CXCR4, integrin-1ß and CCR-2 was observed. When AMD3100 was added, the migration rate of the BMSCs was obviously declined with or without LIPUS treatment. Furthermore, the expression of CXCR4 was significantly down-regulated by AMD3100, while integrin-1ß and CCR-2 were less affected. It suggested that the enhancement of the migration of the BMSCs by LIPUS was inhibited by AMD3100. The results confirmed that LIPUS stimulation was able to activate and improve migration of BMSCs. Nevertheless, CXCR4 and both integrin-1ß and CCR-2 had different roles in BMSCs migration after LIPUS treatment.

Effects of Low-Intensity Pulsed Ultrasound on Implant Osseointegration in Ovariectomized Rats.

OBJECTIVES: To investigate the effect of low-intensity pulsed ultrasound (US) on peri-implant bone healing and osseointegration under osteoporotic conditions. METHODS: Seventy-two 12-week-old female Sprague Dawley rats received bilateral ovariectomies. Twelve weeks later, titanium implants were bilaterally placed in the proximal tibial metaphysis. The right tibia was exposed to low-intensity pulsed US (40 mW/cm2 , spatial and temporal average) for 20 min/d starting the 2nd day after implantation, and the left tibia served as a control without stimulation. The rats were randomly assigned to 6 groups of 12 each according to the US duration (group 1: weeks 0-2, 280 minutes; group 2: weeks 0-4, 560 minutes; group 3: weeks 0-6, 840 minutes; group 4: weeks 0-8, 1120 minutes; group 5: weeks 0-10, 1400 minutes; group 6: weeks 0-12, 1680 minutes). At the end of the 2nd, 4th, 6th, 8th, 10th, and 12th weeks, the rats were euthanized, and bilateral tibias were harvested. Peri-implant bone volume and bone-implant contact were assessed by micro-computed tomography; the implant-bone interface was assessed histologically; and implant fixation strength was determined by a removal torque test. RESULTS: Low-intensity pulsed US increased bone-implant contact at the 4th, 6th, 8th, 10th, and 12th weeks (P = .019, .017, <.001, <.001, and <.001, respectively) and peri-implant bone volume at all times (P = <.001, .002, .012, .007, .005, and .010). Removal torque on the US side was improved at the 6th, 8th, 10th, and 12th weeks (P= .012, <.001, .006, and .009). Ultrasound evoked a favorable bone response in the histologic study. CONCLUSIONS: Low-intensity pulsed US might enhance new bone formation, especially at an early stage, and improve osseointegration in osteoporotic bone as an auxiliary method. However, further studies are needed to elucidate the mechanisms underlying its action.

Effects of Low-Intensity Pulsed Ultrasound on Implant Osseointegration in Ovariectomized Rats.

OBJECTIVES: To investigate the effect of low-intensity pulsed ultrasound (US) on periimplant bone healing and osseointegration under osteoporotic conditions. METHODS: Seventy-two 12-week-old female Sprague Dawley rats received bilateral ovariectomies. Twelve weeks later, titanium implants were bilaterally placed in the proximal tibial metaphysis. The right tibia was exposed to low-intensity pulsed US (40 mW/cm2, spatial and temporal average) for 20 min/d starting the 2nd day after implantation, and the left tibia served as a control without stimulation. The rats were randomly assigned to 6 groups of 12 each according to the US duration (group 1: weeks 0­2, 280 minutes; group 2: weeks 0­4, 560 minutes; group 3: weeks 0­6, 840 minutes; group 4: weeks 0­8, 1120 minutes; group 5: weeks 0­10, 1400 minutes; group 6: weeks 0­12, 1680 minutes). At the end of the 2nd, 4th, 6th, 8th, 10th, and 12th weeks, the rats were euthanized, and bilateral tibias were harvested. Peri-implant bone volume and bone-implant contact were assessed by micro­computed tomography; the implantbone interface was assessed histologically; and implant fixation strength was determined by a removal torque test. RESULTS: Low-intensity pulsed US increased bone-implant contact at the 4th, 6th, 8th, 10th, and 12th weeks (P = .019, .017, <.001, <.001, and <.001, respectively) and periimplant bone volume at all times (P = <.001, .002, .012, .007, .005, and .010). Removal torque on the US side was improved at the 6th, 8th, 10th, and 12th weeks (P= .012, <.001, .006, and .009). Ultrasound evoked a favorable bone response in the histologic study. CONCLUSIONS: Low-intensity pulsed US might enhance new bone formation, especially at an early stage, and improve osseointegration in osteoporotic bone as an auxiliary method. However, further studies are needed to elucidate the mechanisms underlying its action.

Multi-walled carbon nanotubes promote cementoblast differentiation and mineralization through the TGF-ß/Smad signaling pathway.

Excretion of cementum by cementoblasts on the root surface is a process indispensable for the formation of a functional periodontal ligament. This study investigated whether carboxyl group-functionalized multi-walled carbon nanotubes (MWCNT-COOH) could enhance differentiation and mineralization of mammalian cementoblasts (OCCM-30) and the possible signaling pathway involved in this process. Cementoblasts were incubated with various doses of MWCNT-COOH suspension. Cell viability was detected, and a scanning electron microscopy (SEM) observed both the nanomaterials and the growth of cells cultured with the materials. Alizarin red staining was used to investigate the formation of calcium deposits. Real-time PCR and western blot were used to detect cementoblast differentiation and the underlying mechanisms through the expression of the osteogenic genes and the downstream effectors of the TGF-ß/Smad signaling. The results showed that 5 µg/mL MWCNT-COOH had the most obvious effects on promoting differentiation without significant toxicity. Alp, Ocn, Bsp, Opn, Col1 and Runx2 gene expression was up-regulated. Smad2 and Smad3 mRNA was up-regulated, while Smad7 was first down-regulated on Day 3 and later up-regulated on Day 7. The elevated levels of phospho-Smad2/3 were also confirmed by western blot. In sum, the MWCNT-COOH promoted cementoblast differentiation and mineralization, at least partially, through interactions with the TGF-ß/Smad pathway.