Quantification of smooth muscle in human airways by polarization-sensitive optical coherence tomography requires correction for perichondrium.

Quantifying airway smooth muscle (ASM) in patients with asthma raises the possibility of improved and personalized disease management. Endobronchial polarization-sensitive optical coherence tomography (PS-OCT) is a promising quantitative imaging approach that is in the early stages of clinical translation. To date, only animal tissues have been used to assess the accuracy of PS-OCT to quantify absolute (rather than relative) ASM in cross sections with directly matched histological cross sections as validation. We report the use of whole fresh human and pig airways to perform a detailed side-by-side qualitative and quantitative validation of PS-OCT against gold-standard histology. We matched and quantified 120 sections from five human and seven pig (small and large) airways and linked PS-OCT signatures of ASM to the tissue structural appearance in histology. Notably, we found that human cartilage perichondrium can share with ASM the properties of birefringence and circumferential alignment of fibers, making it a significant confounder for ASM detection. Measurements not corrected for perichondrium overestimated ASM content several-fold (P < 0.001, paired t test). After careful exclusion of perichondrium, we found a strong positive correlation (r = 0.96, P < 0.00001) of ASM area measured by PS-OCT and histology, supporting the method's application in human subjects. Matching human histology further indicated that PS-OCT allows conclusions on the intralayer composition and in turn potential contractile capacity of ASM bands. Together these results form a reliable basis for future clinical studies.NEW & NOTEWORTHY Polarization-sensitive optical coherence tomography (PS-OCT) may facilitate in vivo measurement of airway smooth muscle (ASM). We present a quantitative validation correlating absolute ASM area from PS-OCT to directly matched histological cross sections using human tissue. A major confounder for ASM quantification was observed and resolved: fibrous perichondrium surrounding hyaline cartilage in human airways presents a PS-OCT signature similar to ASM for birefringence and optic axis orientation. Findings impact the development of automated methods for ASM segmentation.

Requirements and limitations of imaging airway smooth muscle throughout the lung in vivo.

Clinical visualization and quantification of the amount and distribution of airway smooth muscle (ASM) in the lungs of individuals with asthma has major implications for our understanding of airway wall remodeling as well as treatments targeted at the ASM. This paper theoretically investigates the feasibility of quantifying airway wall thickness (focusing on the ASM) throughout the lung in vivo by means of bronchoscopic polarization-sensitive optical coherence tomography (PS-OCT). Using extensive human biobank data from subjects with and without asthma in conjunction with a mathematical model of airway compliance, we define constraints that airways of various sizes pose to any endoscopic imaging technique and how this is impacted by physiologically relevant processes such as constriction, inflation and deflation. We identify critical PS-OCT system parameters and pinpoint parts of the airway tree that are conducive to successful quantification of ASM. We further quantify the impact of breathing and ASM contraction on the measurement error and recommend strategies for standardization and normalization.

X-ray micro-computed tomography in the assessment of penile cavernous fibrosis in a rabbit castration model.

BACKGROUND: Current assessment methods of penile cavernous fibrosis in animal models have limitations due to the inability to provide complex and volume analysis of fibrotic alterations. OBJECTIVE: The aim was to evaluate micro-computed tomography for assessment of cavernous fibrosis and compare it with histological, histochemical, immunohistochemical, and RT-PCR analysis. MATERIALS AND METHODS: A controlled trial was performed involving 25 New Zealand male rabbits with induced testosterone deficiency by orchidectomy. Penile samples were obtained before and after 7, 14, 21, and 84 days from orchidectomy. We consistently performed (a) gray value analysis of corpora cavernosa 3D models reconstructed after micro-computed tomography, (b) morphometry of smooth muscles/connective tissue ratio, collagen type I/III ratio, and area of TGF-beta-1 expression in corpora cavernosa, and (c) RT-PCR of TGF-beta-1 expression. RESULTS: Micro-computed tomography allowed visualization of penile structures at a resolution comparable to light microscopy. Gray values of corpora cavernosa decreased from 1673 (1512-1773) on the initial day to 1184 (1089-1232) on the 21st day (p < 0.005). However, on the 84th day, it increased to 1610 (1551-1768). On 21st and 84th days, there was observed a significant decrease in smooth muscle/connective tissue ratio and a significant increase in collagen type I/III ratio (p < 0.05). TGF-beta1 expression increased on the 84th day according to immunohistochemistry (p < 0.005). RT-PCR was impossible to conduct due to the absence of RNA in obtained samples after micro-CT. DISCUSSION AND CONCLUSIONS: Micro-computed tomography provided 3D visualization of entire corpora cavernosa and assessment of radiodensity alterations by gray value analysis in fibrosis progression. We speculate that gray value changes at early and late fibrosis stages could be related to tissue reorganization. RT-PCR is impossible to conduct on tissue samples studied by micro-CT due to RNA destruction. We also suggest that micro-computed tomography could negatively affect the immunohistochemical outcome, as a significant increase of TGF-beta-1 expression occurs later than histological fibrotic signs.

Appendix muscle bands, a forgotten entity.

INTRODUCTION: Appendix muscle bands (AMB) develop from the appendix muscle layer into the mesoappendix. There are few recent publications on this forgotten entity. The objectives of this study were to assess the morphological features of AMB as detected at microscopy examination of appendectomy specimens. METHODS: Sixty-six cases of AMB as detected on appendectomy specimens were assessed for microscopy features on routine hematoxilin and eosin stained tissue slides. The morphological features were analyzed with regard to the main clinico-pathological parameters. RESULTS: AMBs were multiple in 35 cases. Most AMBs were located between the tip and cecal limit, 7 at the tip, and 1 at the cecal limit of the appendectomy specimen. Associated appendix lesions were: acute appendicitis, neuroma, mesoappendix cyst, muscle hiatus, and diverticulae (60,6,2,45, and 1, respectively). In 24 appendices, the AMB developed from the perihiatus muscle. Two microscopy types of AMBs were detected: muscle-AMB and mesoappendix-AMB. CONCLUSION: AMB may be detected incidentally at microscopy of appendectomy specimens. Acute appendicitis was associated in most cases, independently on the microscopy type of AMB. Appendix abnormalities as neuroma, mesoappendix cyst, muscle hiatus, and diverticulae can be associated to AMBs.

Anterior bladder wall thickness, post-void urine residue, and bladder emptying efficiency as indicators of bladder dysfunction in Nigerian men with benign prostatic hyperplasia.

BACKGROUND: Benign Prostatic Hypertrophy [BPH] is associated with voiding dysfunctions. Urodynamic study is the gold standard for diagnosis of voiding dysfunctions but is invasive. Bladder wall thickness (BWT), post-void urine residue (PVR), and bladder emptying efficiency (BEE) are noninvasive predictors of voiding dysfunction. OBJECTIVE: To study the relationship among BWT, PVR, and BEE in BPH. SUBJECTS AND METHODS: A hospital-based cross-sectional prospective study of new BPH patients at Nnamdi Azikiwe University Teaching Hospital, Nnewi. The participants had abdominal ultrasonography measurement of anterior BWT (at bladder volume ≥200 mls), prostate volume (PV), and PVR using Prosound SSD3500 (Aloka Co Ltd, Tokyo, Japan) with an abdominal probe frequency of 3.5 MHz. Then the BEE was calculated. The anterior BWT was divided into two groups: <5 mm and ≥5 mm. The data were analyzed using SPSS version 20. Pearson's correlation was used to assess correlation and the differences between the means of the two groups of BWT were compared by Mann-Whitney test. A P- Value <0.05 was considered significant. RESULTS: Seventy seven men with a mean age of 66.66 ± 10.74 years were included in the study. Sixty one percent had symptoms lasting >12 months. The average anterior BWT, PBV, PVR, BEE, PV, and PSA were 4.55 ± 1.02 mm, 260.98 ± 57.44 mls, 58.36 ± 52.94 mls, 77.98 ± 17.37%, 66.31 ± 46.38 mls, and 8.04 ± 5.97 ng/ml, respectively. There was a significant positive correlation between BWT and duration of symptoms (P = 0.044) and a significant negative correlation between BWT and BEE (P = 0.005). An insignificant positive correlation was found between BWT and PVR (P = 0.255). Fifty four (70.1%) had BWT <5 mm and 29.9% had BWT ≥5 mm. The mean IPSS (P = 0.000), PV (P = 0.032) and PVR (P = 0.020) were significantly higher in the ≥5 mm group. The ≥5 mm group also had a significantly lower BEE (P = 0.002). CONCLUSION: Voiding dysfunction was more severe in patients with BWT of 5 mm or more. There was a positive, but insignificant, correlation between anterior BWT and PVR and a significant negative correlation between BWT and BEE.

Low compliance to guidelines in nonmuscle-invasive bladder carcinoma: A systematic review.

PURPOSE: This systematic review assessed compliance to guidelines for the management of nonmuscle-invasive bladder carcinoma (NMIBC). METHODS: The PUBMED, Web of Science, Cochrane Library, and Scopus databases were searched in November 2019 in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis statement. RESULTS: Fifteen studies incorporating a collective total of 10,575 NMIBC patients were eligible for inclusion in this systematic review. We found that the rates of compliance were 53.0% with a single immediate intravesical instillation in patients with presumed low or intermediate risk, 37.1% with intravesical bacillus Calmette-Guerin or chemotherapy in those with intermediate risk, 43.4% with performance of a second transurethral resection in high-risk patients, 32.5% with administration of adjuvant intravesical bacillus Calmette-Guerin in high-risk patients, 36.1% with radical cystectomy in highest-risk patients, and 82.2% with cystoscopy for follow-up. CONCLUSIONS: Compliance with NMIBC guidelines remains low. Better guideline education and understanding holds the key to achieving high compliance. Strategies to improve guideline compliance at the physician level are urgently required.

Review of the application of the open-source software CilOCT for semi-automatic segmentation and analysis of the ciliary muscle in OCT images.

Presbyopia and myopia research shows a growing interest in ciliary muscle biometry using optical coherence tomography (OCT). Until now, segmentation of the ciliary muscle is often performed manually using either custom-developed programs or image processing software. Here we present a novel software for semi-automatic segmentation of the ciliary muscle. It provides direct import of OCT images in DICOM format, a standardized procedure for segmentation, image distortion correction, the export of anatomical ciliary muscle landmarks, like ciliary muscle apex and scleral spur, as well as a continuous thickness profile of the ciliary muscle as a novel way of analysis. All processing steps are stored as XML files, fostering documentation and reproducibility of research through the possibility of replicating the analysis. Additionally, CilOCT supports batch processing for the automated analysis of large numbers of images and the respective data export to tabulated text files based on the stored XML files. CilOCT was successfully applied in several studies and their results will be summarized in this paper.

Cutting-edge Management of Muscle-invasive Bladder Cancer in 2020 and a Glimpse into the Future.

This case-based discussion describes the clinical course of a 63-yr-old patient who presented with gross hematuria and was diagnosed with a muscle-invasive bladder cancer at transurethral resection. Computed tomography revealed a locally advanced tumor, and the patient underwent neoadjuvant chemotherapy followed by open radical cystectomy with standard pelvic lymph node dissection. In a step-by-step fashion, we elaborate on diagnostic and therapeutic treatment options from two different vantage points: (1) guideline-adherent treatment with the state-of-the-art standard of care, and (2) a glimpse into the future discussing the evidence of potential additional or alternative approaches based on recent scientific advances. PATIENT SUMMARY: In this case-based discussion, we follow the clinical course of a patient with advanced bladder cancer and elaborate how the state-of-the-art treatment looks like in 2020, based on the best available evidence. This is compared with potential future treatment strategies, which may change and alternate our understanding of optimal bladder cancer care.

Variability in adherence to guidelines based management of nonmuscle invasive bladder cancer among Society of Urologic Oncology (SUO) members.

PURPOSE: The American Urological Association (AUA) introduced evidence-based guidelines for the management of nonmuscle invasive bladder cancer (NMIBC) in 2016. We sought to assess the implementation of these guidelines among members of the Society of Urologic Oncology (SUO) with an aim to identifying addressable gaps. METHODS AND MATERIALS: An SUO approved survey was distributed to 747 members from December 28, 2018 to February 2, 2019. This 14-question online survey (Qualtrics, SAP SE, Germany) consisted of 38 individual items addressing specific statements from the AUA NMIBC guidelines within 3 broad categories - initial diagnosis, surveillance, and imaging/biomarkers. Adherence to guidelines was assessed by dichotomizing responses to each item that was related to recommended action statement within the guidelines. Statistical analysis was applied using Pearson's chi-squared test, where a P-value of <0.05 was considered statistically significant. RESULTS: A total of 121 (16.2%) members completed the survey. Members reported a mean of 71% guidelines adherence; adherence was higher for the intermediate- and high-risk subgroups (82% and 76%, respectively) compared to low-risk (58%). Specifically, adherence to guideline recommended cystoscopic surveillance intervals for low-risk disease differed based on clinical experience (60.9% [<10 years] vs. 36.8% [≥10 years], P = 0.01) and type of fellowship training (55.2% [urologic oncology] vs. 28.0% [none/other], P = 0.02). CONCLUSION: Adherence to guidelines across risk-categories was higher for intermediate- and high-risk patients. Decreased adherence observed for low-risk patients resulted in higher than recommended use of cytology, imaging, and surveillance cystoscopy. These results identify addressable gaps and provide impetus for targeted interventions to support high-value care, especially for low-risk patients.

High-resolution iris and retinal imaging in multisystemic smooth muscle dysfunction syndrome due to a novel Asn117Lys substitution in ACTA2: a case report.

BACKGROUND: Congenital mydriasis and retinal arteriolar tortuosity are associated with the life-threatening multisystemic smooth muscle dysfunction syndrome (MSMDS) due to mutations in the gene, ACTA2, which encodes alpha-smooth muscle actin (α-SMA). Previous reports attributed MSMDS-related congenital mydriasis to the absence of iris sphincter muscle. Similarly, it has been hypothesized that abnormal proliferation of the vascular smooth muscle cells causes the marked tortuosity of retinal arterioles in MSMDS. In this report, high-resolution ocular imaging reveals unexpected findings that reject previous hypotheses. CASE PRESENTATION: The proband is a 37-year-old female with a history of neonatal patent ductus arteriosus (PDA) ligation, left-sided choreiform movements at the age of 11 and a transient aphasia with right-sided weakness at the age of 30. Her older sister also had PDA ligation and congenital mydriasis but no neurological deficit up to age 41. Magnetic resonance angiogram demonstrated cerebrovascular lesions resembling but distinct from Moyamoya disease, characterised by internal carotid artery dilatation, terminal segment stenosis and absent basal collaterals. Their mother had poorly reactive pupils with asymptomatic cerebral arteriopathy resembling her daughters. All three had prominent retinal arteriolar tortuosity. The daughters were heterozygous and the mother was a somatic mosaic for a novel c.351C > G (p.Asn117Lys) transversion in ACTA2. Iris optical coherence tomography (OCT) showed a hyporeflective band anterior to the pigment epithelium indicating the presence of dysfunctional sphincter muscle. Adaptive optics retinal imaging showed no thickening of the arteriolar vessel wall whilst OCT angiography showed extreme corkscrew course of arterioles suggesting vessel elongation. CONCLUSIONS: In addition to the known association between Met46, Arg179 and Arg258 substitutions and ACTA2-related arteriopathy, this case illustrates the possibility that Asn117 also plays an important role in α-SMA function within the cerebrovascular smooth muscle cell. MSMDS-related congenital mydriasis is due to reduced iris sphincter contractility rather than its absence. Retinal arteriolar tortuosity might be due to longitudinal proliferation of arteriolar smooth muscle cells. The described cerebrovascular and ocular signs are consistent with predicted effects of the novel Asn117Lys substitution in ACTA2.

Validation of vesical imaging reporting and data system for assessing muscle invasion in bladder tumor.

PURPOSE: To retrospectively determine the diagnostic values of vesical imaging reporting and data system (VI-RADS) score for detecting muscle-invasive bladder tumors. METHODS: This study included 297 consecutive patients with 339 tumors who previously diagnosed and subsequently underwent multiparametric MR imaging between January 2015 and March 2019. Two radiologists assessed the scores of muscle-invasive tumors using cutoff values of ≥ 4 and ≥ 3. Cutoff values for VI-RADS scores were estimated from the best operating points of the areas under the receiver operating characteristic curve analyses using the Youden J statistic. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated to assess the utility of VI-RADS for diagnosing muscle-invasive tumors. RESULTS: Inter-observer agreement was excellent for three different MR imaging type at lesion level (k = 0.89 for T2W, k = 0.82 for DW, and k = 0.85 for DCE). At a cutoff value of 4, T2W and DW imaging had a diagnostic accuracy of 79.3% (269/339) for tumor lesions with muscle invasion, which was similar to an overall score of 80.2% (272/339). The overall VI-RAD score showed 80.2% accuracy (272/339), with a cutoff value of ≥ 4, yielding 91.3% sensitivity (85/93), 76.0% specificity (187/246), 83.3% PPV (85/102), and 78.9% NPV (187/237). When we considered an arbitrary overall score of ≥ 3 as the cutoff value, the accuracy was 63.7% (216/339); sensitivity, 94.6% (125/132); specificity, 43.9% (91/207); PPV, 51.6% (125/242); and NPV, 63.7% (91/97). CONCLUSION: VI-RADS has an overall good performance in the diagnosis of muscle-invasive tumors.

Cavernous smooth muscles: innovative potential therapies are promising for an unrevealed clinical diagnosis.

While erectile dysfunction (ED) is highly prevalent worldwide, unrevealed cavernous smooth muscles (CSM) defects can confound the diagnosis of vascular ED and lead to failure of treatments. Currently, the first-line oral treatment for ED is phosphodiesterase type 5 inhibitors (PDE5Is). Patients with diabetes mellitus (DM), those who have undergone a radical prostatectomy (RP), and the elderly population are difficult to treat by the PDE5Is; unrevealed CSM defects can result in corporo veno-occlusive dysfunction (CVOD); and penile veno-ligation surgeries are currently abandoned due to high failure rates. It has been found that gene and stem cell therapies, among others, reduce cavernous tissue apoptosis and fibrosis and can specifically target CSM defects such as the nitric oxide (NO)-mediated signaling pathway, Rho-ROCK system, and transformation growth factor (TGF)-ß1/angiotensin II (Ang II) pathway, in several laboratory animals. Current data clarify the need of diagnostic techniques that can provide an initial assessment of CSM. This assessment should be essential before giving a diagnosis of vascular ED and before applying several tests searching for a specific CSM defect to guide the specific therapy. Moreover, while patients with corporal fibrosis would fail the current medical therapies, these patients can benefit from the stem cell-based therapies that induce the internal mechanisms of tissue repair. However, penile elastography can determine the stiffness of tissues and corpus cavernosum electromyography (CC-EMG) can assess the integrated activity of CSM bulk, further refinements are required for these techniques before being considered in the evaluation of patients with ED. In conclusion, on the basis of the current scientific research, it may be possible to formulate new therapies and achieve the appropriate selection of patients who can benefit from these therapies.

Coexistence of Dense and Sparse Areas in the Longitudinal Smooth Muscle of the Anal Canal: Anatomical and Histological Analyses Inspired by Magnetic Resonance Images.

Magnetic resonance images of the anal canal show small, circular, low-intensity areas arranged in a row and a high-intensity area surrounding them internally and externally in the longitudinal muscle layer that cannot be explained by current anatomical findings. The purpose of this study was to elucidate the detailed structure of the longitudinal smooth muscle of the anal canal and to interpret the magnetic resonance image of the longitudinal muscle. Specimens for macroscopic anatomy and histology were obtained from six and seven cadavers, respectively. The histological nature of the longitudinal muscle was examined by staining serial transverse and coronal sections of the lateral wall of the anal canal with Masson's trichrome stain and using immunohistochemistry for smooth and skeletal muscle fibers. Dense and sparse areas of smooth muscle fibers coexisted in the longitudinal muscle layer. The dense areas formed columnar muscle bundles approximately 1.0-1.5 mm in diameter, and they continued from the longitudinal muscle bundles of the rectum. The columnar muscle bundles of the longitudinal anal muscle were internally and externally surrounded by sparsely arranged smooth muscle fibers that ran longitudinally. The coexistence of dense and sparse areas of smooth muscle fibers suggests that the structure of the smooth muscle is optimized for its function. This histological nature is probably reflected in the magnetic resonance image of the longitudinal muscle as the coexistence of low- and high-intensity areas. Clin. Anat. 33:619-626, 2020. © 2019 Wiley Periodicals, Inc.

Smooth muscle of the male pelvic floor: An anatomic study.

Knowledge of the anatomy of the male pelvic floor is important to avoid damaging the pelvic floor muscles during surgery. We set out to explore the structure and innervation of the smooth muscle (SM) of the whole pelvic floor using male fetuses. We removed en-bloc the entire pelvis of three male fetuses. The specimens were serially sectioned before being stained with Masson's trichrome and hematoxylin and eosin, and immunostained for SMs, and somatic, adrenergic, sensory and nitrergic nerve fibers. Slides were digitized for three-dimensional reconstruction. We individualized a middle compartment that contains SM cells. This compartment is in close relation with the levator ani muscle (LAM), rectum, and urethra. We describe a posterior part of the middle compartment posterior to the rectal wall and an anterior part anterior to the rectal wall. The anterior part is split into (1) a centro-levator area of SM cells localized between the right and left LAM, (2) an endo-levator area that upholsters the internal aspect of the LAM, and (3) an infra-levator area below the LAM. All these areas are innervated by autonomic nerves coming from the inferior hypogastric plexus. The core and the infra-levator area receive the cavernous nerve and nerves supplying the urethra. We thus demonstrate that these muscular structures are smooth and under autonomic influence. These findings are relevant for the pelvic surgeon, and especially the urologist, during radical prostatectomy, abdominoperineal resection and intersphincteric resection. Clin. Anat., 2019. © 2019 Wiley Periodicals, Inc.

Quantitative Ultrasound Detects Smooth Muscle Activity at the Cervical Internal Os in Vitro.

The cervix has two biomechanical functions: to remain closed while the fetus develops throughout pregnancy, and to open for delivery of the fetus at full term. This dual function is principally attributed to collagen within the extracellular matrix (ECM). However, recent evidence suggests that other ECM, and non-ECM, components play a role as well. One component is smooth muscle cells arranged circumferentially near the internal os. In this study, we investigate correlations between cervical smooth muscle cell force generation and the effective scatterer diameter (ESD), a quantitative ultrasound parameter directly related to the acoustic impedance distribution and, therefore, a potential biomarker of muscle contractility. Using whole cervical slices (N = 5), we determined significant positive correlations (quantified with Pearson's r) between muscle force generation and ESD immediately after administration of oxytocin (median r = 0.90). In summary, the ESD may prove a useful biomarker for studying structure and function of cervical smooth muscle in vivo.

Multiparametric MRI in differentiation between muscle invasive and non-muscle invasive urinary bladder cancer with vesical imaging reporting and data system (VI-RADS) application.

OBJECTIVE: To evaluate role of multiparametric MRI (mp-MRI) in differentiation between invasive and non-invasive bladder cancer and accuracy of vesical imaging reporting and data system (VI-RADS) score. METHODS AND MATERIALS: 50 patients diagnosed as cancer bladder were enrolled in this study, mp-MRI including conventional (T1 weighted imaging and high resolution T2 weighted imaging) and functional sequences (diffusion-weighted imaging and dynamic contrast enhanced-MRI) were done, all data were regrouped to evaluate the accuracy of each separate sequence and mp-MRI in distinguishing non-muscle invasive from muscle-invasive tumors, with VI-RADS score application and comparison with pathological findings, then interobserver agreement for detection of muscle invasion according to mp-MRI and VI-RADS scoring system findings was calculated. RESULTS: Diagnostic accuracy of mp-MRI in differentiation between muscle invasive and non-muscle invasive bladder cancer was (84%) with highest sensitivity (78%), very good agreement between mp-MRI and histopathological data (k = 0.87), and highest area under curve (AUC) reaching 0.83, dynamic contrast enhanced-MRI sequence showed the highest accuracy in muscle invasion detection by (88%), with highest AUC 0.83. Diagnostic accuracy of VI-RADS score in detection of muscle invasion was 84%, with specificity and negative predictive value of 88% and AUC was 0.83. Interobserver agreement was strong as regard diagnostic performance of mp-MRI and VI-RADS scoring for detection of muscle invasion reaching (K = 0.82, p < 0.001) and (K = 0.87, p < 0.001) respectively. CONCLUSION: mp-MRI is considered as comprehensive and effective tool for determination of muscle invasion in cases of urinary bladder cancer. Also VI-RADS scoring system can accurately differentiate between invasive and non-invasive bladder cancer. ADVANCES IN KNOWLEDGE: The VI-RADS system was recently suggested for the uniform evaluation of muscle invasion in cancer bladder by mp-MRI. In this paper, we applied this system to 50 cases to evaluate its ease and compared the results with the histopathological findings for evaluation of its accuracy.

Use of Micro X-ray Computed Tomography with Phosphotungstic Acid Preparation to Visualize Human Fibromuscular Tissue.

Manual dissection and histological observation are common methods used to investigate human tissues. However, manual dissection can damage delicate structures while processing and histological observation provide limited information through cross-sectional imaging. Micro X-ray computed tomography (microCT) is an effective tool for obtaining three-dimensional information without damaging specimens. However, it shows limited efficiency in differentiating soft tissue parts. Use of contrast-enhancing agents, like phosphotungstic acid (PTA), can solve this problem by improving soft tissue contrast. We implemented microCT with PTA to investigate the human orbicularis retaining ligament (ORL), which is a delicate structure in the orbit area. In this method, harvested specimens are fixed in formalin, dehydrated in serial ethanol solutions, and stained with a PTA solution. After staining, microCT scanning, 3D reconstruction, and analysis are performed. Skin, ligaments, and muscles can be clearly visualized using this method. The specimen size and duration of staining are essential features of the method. The suitable specimen thickness was about 5-7 mm, above which the process was slowed, and the optimum duration was 5-7 days, below which an empty hole in the central area occasionally occurred. To maintain the location and direction of small pieces during cutting, sewing on the same region of each part is recommended. Furthermore, preliminary analyses of the anatomical structure are needed to correctly identify each piece. Parafilm can be used to prevent drying, but care should be taken to prevent specimen distortion. Our multidirectional observation showed that the ORL is composed of a multilayered meshwork of continuous plates, rather than thread-like fibers, as reported previously. These results suggest that microCT scanning with PTA is useful for examining specific compartments within complex structures of human tissue. It may be helpful in the analyses of cancer tissues, nerve tissues, and various organs, like the heart and liver.