-
Photodiagnosis and Photodynamic Therapy Mar 2021Photoacoustic tomography (PAT) is an emerging noninvasive imaging technique combining high sensitivity optical absorption contrast, such as melanin, with high-resolution...
BACKGROUND
Photoacoustic tomography (PAT) is an emerging noninvasive imaging technique combining high sensitivity optical absorption contrast, such as melanin, with high-resolution ultrasound for deep tissue imaging. The ability of PAT to provide real-time images of skin structures at depth has been studied for diagnosis of primary and metastatic malignant melanoma (MM).
OBJECTIVE
To provide an overview of the rapidly expanding clinical use of PAT for determination of melanoma thickness and architecture, visualization of metastases in lymph nodes and detection of circulating melanoma cells.
METHODS
Medline, PubMed, EMBASE, Web of Science, Google Scholar, and Cochrane Library were searched for papers using PAT to assess cutaneous malignant melanoma and melanoma metastases in humans or human specimens.
RESULTS
The research resulted in 14 articles which met the search criteria.
CONCLUSIONS
Results from current studies suggest that PAT is a promising tool for assessing both primary and metastatic malignant melanoma in the clinic. The potential of PAT to noninvasively visualize tumour boundaries, as well as assist in the evaluation of metastatic status, could facilitate more effective treatment, resulting in better clearance and reducing the need for additional biopsies. However, larger and methodologically sound studies are warranted.
Topics: Humans; Melanoma; Photochemotherapy; Photosensitizing Agents; Skin Neoplasms; Tomography, X-Ray Computed
PubMed: 33188938
DOI: 10.1016/j.pdpdt.2020.102095 -
European Radiology Mar 2021To determine the diagnostic performance of neuromelanin-sensitive magnetic resonance imaging discriminating between patients with Parkinson's disease and normal healthy... (Meta-Analysis)
Meta-Analysis
Diagnostic performance of neuromelanin-sensitive magnetic resonance imaging for patients with Parkinson's disease and factor analysis for its heterogeneity: a systematic review and meta-analysis.
OBJECTIVE
To determine the diagnostic performance of neuromelanin-sensitive magnetic resonance imaging discriminating between patients with Parkinson's disease and normal healthy controls and to identify factors causing heterogeneity influencing the diagnostic performance.
METHODS
A systematic literature search in the Ovid-MEDLINE and EMBASE databases was performed for studies reporting the relevant topic before February 17, 2020. The pooled sensitivity and specificity values with their 95% confidence intervals were calculated using bivariate random-effects modeling. Subgroup and meta-regression analyses were also performed to determine factors influencing heterogeneity.
RESULTS
Twelve articles including 403 patients with Parkinson's disease and 298 control participants were included in this systematic review and meta-analysis. Neuromelanin-sensitive magnetic resonance imaging showed a pooled sensitivity of 89% (95% confidence interval, 86-92%) and a pooled specificity of 83% (95% confidence interval, 76-88%). In the subgroup and meta-regression analysis, a disease duration longer than 5 and 10 years, comparisons using measured volumes instead of signal intensities, a slice thickness in terms of magnetic resonance imaging parameters of more than 2 mm, and semi-/automated segmentation methods instead of manual segmentation improved the diagnostic performance.
CONCLUSION
Neuromelanin-sensitive magnetic resonance imaging had a favorable diagnostic performance in discriminating patients with Parkinson's disease from healthy controls. To improve diagnostic accuracy, further investigations directly comparing these heterogeneity-affecting factors and optimizing these parameters are necessary.
KEY POINTS
• Neuromelanin-sensitive MRI favorably discriminates patients with Parkinson's disease from healthy controls. • Disease duration, parameters used for comparison, magnetic resonance imaging slice thickness, and segmentation methods affected heterogeneity across the studies.
Topics: Factor Analysis, Statistical; Humans; Magnetic Resonance Imaging; Melanins; Parkinson Disease; Substantia Nigra
PubMed: 32886201
DOI: 10.1007/s00330-020-07240-7 -
Advanced Drug Delivery Reviews Jan 2020Skin pigmentation is a result of melanin produced by melanocytes in the epidermis. Melanocyte activity, along with the type and distribution of melanins, is the main...
Skin pigmentation is a result of melanin produced by melanocytes in the epidermis. Melanocyte activity, along with the type and distribution of melanins, is the main driver for diversity of skin pigmentation. Dark melanin acts to protect against the deleterious effects of ultraviolet (UV) radiation, including photo-aging and skin cancer formation. In turn, UV radiation activates skin melanocytes to induce further pigmentation (i.e., "tanning pathway"). The well-characterized MSH/MC1R-cAMP-MITF pathway regulates UV-induced melanization. Pharmacologic activation of this pathway ("sunless tanning") represents a potential strategy for skin cancer prevention, particularly in those with light skin or the "red hair" phenotype who tan poorly after UV exposure due to MC1R inactivating polymorphisms. Skin hyperpigmentation can also occur as a result of inflammatory processes and dermatological disorders such as melasma. While primarily of cosmetic concern, these conditions can dramatically impact quality of life of affected patients. Several topical agents are utilized to treat skin pigmentation disorders. Here, we review melanogenesis induced by UV exposure and the agents that target this pathway.
Topics: Administration, Cutaneous; Cyclic AMP; Dermatologic Agents; Drug Delivery Systems; Humans; Melanins; Pigmentation Disorders; Protein Kinases; Skin Pigmentation; Ultraviolet Rays
PubMed: 32092380
DOI: 10.1016/j.addr.2020.02.002 -
Neurological Sciences : Official... Dec 2019The main purpose of this study was to systematically evaluate the accuracy of neuromelanin-sensitive magnetic resonance imaging (NM-MRI) in Parkinson's disease (PD)... (Meta-Analysis)
Meta-Analysis
The main purpose of this study was to systematically evaluate the accuracy of neuromelanin-sensitive magnetic resonance imaging (NM-MRI) in Parkinson's disease (PD) diagnosis using a meta-analysis method. In PubMed, Web of Science, Embase, and Google Scholar, the literatures were searched for the diagnostic value of neuromelanin-sensitive magnetic resonance imaging in PD. The literatures were screened in the light of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Data analysis was processed by Stata 12.0 software to obtain meta-analysis, heterogeneity analysis, and publication bias. Meta-analysis results showed by using NM-MRI observed substantia nigra pars compacta (SNpc) on PD, the pooled diagnostic sensitivity and specificity were 0.82 (95% CI, 0.74-0.87) and 0.82 (95% CI, 0.73-0.89), respectively. And the pooled positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 4.58 (95% CI, 3.08-6.82) and 0.22 (95% CI, 0.16-0.31), respectively. Moreover, subgroup analysis according to the measurement criteria of SNpc showed the SNpc volume should be used as good a marker for diagnosing PD. Finally, Fagan test demonstrated that when PLR was equal to 5, the posterior probability is significantly enhanced to 53%, compared with prior probability (20%). As for NLR (0.22), the prior probability is 20%, while the posterior probability remarkably dropped to 5%. In conclusion, SNpc signal detected by NM-MRI exhibited high sensitivity and specificity for diagnosis of PD, which was a high-performance imaging diagnostic method for PD. We recommend NM-MRI imaging technology to be widely used in Parkinson's diagnosis.
Topics: Humans; Magnetic Resonance Imaging; Melanins; Neuroimaging; Parkinson Disease; Substantia Nigra
PubMed: 31392640
DOI: 10.1007/s10072-019-04014-y