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Computers in Biology and Medicine Jun 2023Automatic vertebra recognition from magnetic resonance imaging (MRI) is of significance in disease diagnosis and surgical treatment of spinal patients. Although modern...
Automatic vertebra recognition from magnetic resonance imaging (MRI) is of significance in disease diagnosis and surgical treatment of spinal patients. Although modern methods have achieved remarkable progress, vertebra recognition still faces two challenges in practice: (1) Vertebral appearance challenge: The vertebral repetitive nature causes similar appearance among different vertebrae, while pathological variation causes different appearance among the same vertebrae; (2) Field of view (FOV) challenge: The FOVs of the input MRI images are unpredictable, which exacerbates the appearance challenge because there may be no specific-appearing vertebrae to assist recognition. In this paper, we propose a Feature-cOrrelation-aware history-pReserving-sparse-Coding framEwork (FORCE) to extract highly discriminative features and alleviate these challenges. FORCE is a recognition framework with two elaborated modules: (1) A feature similarity regularization (FSR) module to constrain the features of the vertebrae with the same label (but potentially with different appearances) to be closer in the latent feature space in an Eigenmap-based regularization manner. (2) A cumulative sparse representation (CSR) module to achieve feed-forward sparse coding while preventing historical features from being erased, which leverages both the intrinsic advantages of sparse codes and the historical features for obtaining more discriminative sparse codes encoding each vertebra. These two modules are embedded into the vertebra recognition framework in a plug-and-play manner to improve feature discrimination. FORCE is trained and evaluated on a challenging dataset containing 600 MRI images. The evaluation results show that FORCE achieves high performance in vertebra recognition and outperforms other state-of-the-art methods.
Topics: Humans; Algorithms; Spine; Magnetic Resonance Imaging
PubMed: 37163964
DOI: 10.1016/j.compbiomed.2023.106977 -
AJR. American Journal of Roentgenology Nov 2014Temporomandibular joint (TMJ) dysfunction is a common condition, affecting up to 28% of the population. The TMJ can be affected by abnormal dynamics of the disk-condyle... (Review)
Review
OBJECTIVE
Temporomandibular joint (TMJ) dysfunction is a common condition, affecting up to 28% of the population. The TMJ can be affected by abnormal dynamics of the disk-condyle complex, degenerative arthritis, inflammatory arthritis, and crystal arthropathy. Less commonly, neoplasms and abnormal morphologic features of the condyle are causes of TMJ symptoms. Cross-sectional imaging is frequently used for diagnosis.
CONCLUSION
Knowledge of the normal imaging appearance of the TMJ, its appearance on radiological examination, and interventional techniques are useful for providing a meaningful radiologic contribution. This article will review normal TMJ anatomy; describe the normal ultrasound, CT, and MRI appearances of TMJ; provide imaging examples of abnormal TMJs; and illustrate imaging-guided therapeutic TMJ injection.
Topics: Adolescent; Adult; Diagnostic Imaging; Humans; Male; Radiography; Surgery, Computer-Assisted; Temporomandibular Joint; Temporomandibular Joint Disorders; Young Adult
PubMed: 25341144
DOI: 10.2214/AJR.13.12177 -
Abdominal Radiology (New York) Jun 2024Pancreatic cystic neoplasms are lesions comprised of cystic components that show different biological behaviors, epidemiology, clinical manifestations, imaging features,... (Review)
Review
Pancreatic cystic neoplasms are lesions comprised of cystic components that show different biological behaviors, epidemiology, clinical manifestations, imaging features, and malignant potential and management. Benign cystic neoplasms include serous cystic neoplasms (SCAs). Other pancreatic cystic lesions have malignant potential, such as intraductal papillary mucinous neoplasms and mucinous cystic neoplasms. SCAs can be divided into microcystic (classic appearance), honeycomb, oligocystic/macrocystic, and solid patterns based on imaging appearance. They are usually solitary but may be multiple in von Hippel-Lindau disease, which may depict disseminated involvement. The variable appearances of SCAs can mimic other types of pancreatic cystic lesions, and cross-sectional imaging plays an important role in their differential diagnosis. Endoscopic ultrasonography has helped in improving diagnostic accuracy of pancreatic cystic lesions by guiding tissue sampling (biopsy) or cyst fluid analysis. Immunohistochemistry and newer techniques such as radiomics have shown improved performance for preoperatively discriminating SCAs and their mimickers.
PubMed: 38825609
DOI: 10.1007/s00261-024-04337-1 -
Abdominal Imaging Oct 2015Hemangiomas are common lesions, best known for their appearance in the liver. Their appearance in less common locations, such as the gastrointestinal and genitourinary... (Review)
Review
Hemangiomas are common lesions, best known for their appearance in the liver. Their appearance in less common locations, such as the gastrointestinal and genitourinary tracts, is less well known. We will review the typical and atypical appearance of hemangiomas in these locations on sonography, CT, and MRI.
Topics: Gastrointestinal Neoplasms; Hemangioma; Humans; Liver Neoplasms; Magnetic Resonance Imaging; Tomography, X-Ray Computed; Ultrasonography; Urogenital Neoplasms
PubMed: 26239397
DOI: 10.1007/s00261-015-0515-8 -
Current Opinion in Behavioral Sciences Dec 2019Materials with complex appearances, like textiles and foodstuffs, pose challenges for conventional theories of vision. But recent advances in unsupervised deep learning... (Review)
Review
Materials with complex appearances, like textiles and foodstuffs, pose challenges for conventional theories of vision. But recent advances in unsupervised deep learning provide a framework for explaining how we learn to see them. We suggest that perception does not involve estimating physical quantities like reflectance or lighting. Instead, representations emerge from learning to encode and predict the visual input as efficiently and accurately as possible. Neural networks can be trained to compress natural images or to predict frames in movies without 'ground truth' data about the outside world. Yet, to succeed, such systems may automatically discover how to disentangle distal causal factors. Such 'statistical appearance models' potentially provide a coherent explanation of both failures and successes in perception.
PubMed: 31886321
DOI: 10.1016/j.cobeha.2019.07.004 -
Acta Neurologica Scandinavica May 2021Minor hallucinations (MHs), including sense of presence, passage hallucinations, and visual illusions, have been reported in Parkinson's disease (PD). Here, we...
OBJECTIVES
Minor hallucinations (MHs), including sense of presence, passage hallucinations, and visual illusions, have been reported in Parkinson's disease (PD). Here, we investigated the prevalence and associated risk factors for MHs according to appearance time.
METHODS
Data on the clinical characteristics and the appearance time of MHs for 100 PD patients were collected using a questionnaire and analyzed. MHs were classified into two groups according to the time when MHs appeared: MHs appearing while awake during the daytime (dMHs) and MHs appearing at arousal from sleep during the night or early morning (aMHs).
RESULTS
Thirty-eight patients (38%) experienced MHs. dMHs and aMHs were present in 21 (21%) and 28 patients (28%), respectively. Compared to patients without MHs, patients with dMHs had more severe motor symptoms, longer disease duration, higher levodopa equivalent daily dose (LEDD), and higher rates of cognitive impairment and visual hallucinations during the daytime, whereas patients with aMHs had a higher rate of rapid eye movement sleep behavior disorder (RBD), longer disease duration, higher LEDD, and higher dopamine agonist dosage. Logistic regression analysis showed that cognitive impairment was significantly associated with dMHs (odds ratio (OR) 7.292, p = .001), and that RBD (OR 8.306, p < .001) and LEDD (OR 1.002, p = .049) were significantly associated with aMHs.
CONCLUSIONS
Patients with MHs have different clinical characteristics according to the time when MHs appear. These findings have important clinical and prognostic implications and suggest appropriate therapeutic options for psychotic symptoms.
Topics: Aged; Female; Hallucinations; Humans; Male; Middle Aged; Parkinson Disease; Prevalence; Risk Factors
PubMed: 33222164
DOI: 10.1111/ane.13380 -
Orvosi Hetilap Jan 2018Besides the genetic research, increasing number of scientific studies focus on epigenetic phenomena - such as DNA methylation - regulating the expression of genes behind... (Review)
Review
Besides the genetic research, increasing number of scientific studies focus on epigenetic phenomena - such as DNA methylation - regulating the expression of genes behind the phenotype, thus can be related to the pathomechanism of several diseases. In this review, we aim to summarize the current knowledge about the evolutionary appearance and functional diversity of DNA methylation as one of the epigenetic mechanisms and to demonstrate its role in aging and cancerous diseases. DNA methylation is also characteristic/also appear to prokaryotes, eukaryotes and viruses. In prokaryotes and viruses, it provides defence mechanisms against extragenous DNA. DNA methylation in prokaryotes plays a significant role in the regulation of transcription, the initiation of replication and in Dam-directed mismatch repair. In viruses, it participates not only in defence mechanisms, but in the assembly of capsids as well which is necessary for spreading. In eukaryotes, DNA methylation is involved in recombination, replication, X chromosome inactivation, transposon control, regulation of chromatin structure and transcription, and it also contributes to the imprinting phenomenon. Besides the above-mentioned aspects, DNA methylation also has an evolutionary role as it can change DNA mutation rate. Global hypomethylation appearing during aging and in cancerous diseases can lead to genetic instablility and spontaneous mutations through its role in the regulation of transposable elements. Local hypermethylated alterations such as hypermethylation of SFRP1, SFRP2, DKK1 and APC gene promoters can cause protein expression changes, thus contribute to development of cancer phenotype. DNA methylation alterations during aging in cancerous diseases support the importance of epigenetic research focusing on disease diagnostics and prognostics. Orv Hetil. 2018; 159(1): 3-15.
Topics: Aged; Aged, 80 and over; Aging; Biomarkers, Tumor; DNA Methylation; Epigenesis, Genetic; Humans; Neoplasms
PubMed: 29291647
DOI: 10.1556/650.2018.30927 -
Orbit (Amsterdam, Netherlands) Feb 2024Acquired melanocytic nevi are common eyelid lesions; however, their clinical presentation is not well documented.
PURPOSE
Acquired melanocytic nevi are common eyelid lesions; however, their clinical presentation is not well documented.
METHODS
In this retrospective study, clinical records were reviewed in patients evaluated between 2005 and 2022.
RESULTS
Eyelid margin nevi ( = 150) were more commonly excised in female (78%) and Caucasian (86%) patients. Change in appearance/size were frequent presenting complaints, and 17% experienced ocular symptoms. Referring diagnosis included other benign lesions (11.3%), and concern for malignancy (16.7%). Many individuals (38.7%) noted their lesion for ≤5 years. Nevi were distributed across the 4 margins (9% peripunctal), and 88% had a regular base. Visible pigmentation was more common in non-Caucasians (95.2%) than Caucasians (41.1%). Lashes grew through 60.7% of nevi and were often misdirected.Nevi were treated with superficial excision and cauterization. Histologic subtypes included: dermal (86.6%), compound (9.4%), blue (2.7%), junctional (0.7%), lentiginous dysplastic (0.7%). An irregular base (=0.042) and pigmentation (=0.056) were more common in compound than dermal nevi. Lash line quality and appearance were improved in the majority of patients returning for follow-up, although postoperative trichiasis, marginal erythema, and residual pigmentation were observed.
CONCLUSIONS
Melanocytic nevi commonly involve the eyelid margins and have a variety of presentations and appearances. Existing nevi can change, and new lesions appear throughout adulthood. Stable, benign appearing nevi can be observed. Shave excision provides a diagnosis and improved appearance for symptomatic or suspicious lesions, with few serious complications. Malignant transformation is rare, although evidence for recurrence warrants further evaluation.
Topics: Humans; Female; Adult; Retrospective Studies; Nevus; Nevus, Pigmented; Eyelid Neoplasms; Eyelids; Skin Neoplasms
PubMed: 36688501
DOI: 10.1080/01676830.2023.2169717 -
Journal of Oncology 2022The study was conducted to investigate the correlation between the ultrasonographic appearance of a thyroid nodule and the BRAF V600E mutation. Patients with thyroid...
The study was conducted to investigate the correlation between the ultrasonographic appearance of a thyroid nodule and the BRAF V600E mutation. Patients with thyroid nodules ( = 186), for which BRAF V600E testing and cytopathology analysis were performed, and who underwent subsequent surgery for nodule resection were enrolled in this study. For each patient, color Doppler ultrasonography was performed to observe the variables of the nodules. The nodules were then characterized using the thyroid imaging reporting and data system classification TI-RADS. Furthermore, the ultrasonographic appearance of the control group, encompassing patients with nodular thyroid goiters, and the case group, encompassing patients with papillary thyroid microcarcinoma (PTMC), was statically analyzed. Similarly, a statistical analysis of the ultrasonographic appearance of the BRAF V600E-positive and BRAF V600E-negative subgroups was also performed. The accuracy was significantly different for the corresponding values when color Doppler ultrasonography, BRAF V600E testing, or cytopathology alone was used for diagnosis. There were significant differences in the ultrasonographic appearance variables between the control and case groups. Comparing with the BRAF V600E-negative subgroup of the case group, the ultrasonographic appearances of the BRAF V600E-positive subgroup showed less circumscribed and more irregularly shaped nodules, with significantly different aspect ratios of >1. The combination of BRAF V600E testing and color Doppler ultrasonography or cytopathology improved the accuracy of the PTMC diagnose. We found that the ultrasonographic appearance of thyroid nodules was related to PTMC.
PubMed: 35356255
DOI: 10.1155/2022/5916379 -
Acta Veterinaria Scandinavica Jan 2021The ultrasonographic examination technique is a well-established, non-invasive diagnostic tool for diverse conditions in humans and different animal species. The purpose...
BACKGROUND
The ultrasonographic examination technique is a well-established, non-invasive diagnostic tool for diverse conditions in humans and different animal species. The purpose of our study was to describe ultrasonographic localisation, sonographic appearance and dimensions of the kidneys and spleen of clinically healthy llamas and alpacas. Differences between llamas and alpacas and the influence of sex and ages were investigated. Results of this study may aid veterinarians performing ultrasonography in diseased animals and the technique can be used for routine protocol screening.
RESULTS
Ultrasonography was performed in 135 clinically healthy, non-sedated llamas and alpacas. Screening was performed with a 6.6 MHz curve linear transducer with only alcohol as contact medium between the probe and unclipped skin. The kidneys could be imaged from the paralumbar region. The right kidney only was visualized when scanning from the right and the left kidney only from the left. While the left kidney appeared in sagittal view as an oval shape in most llamas and alpacas, in one third of animals the left kidney had a triangular shape. The L-shaped base of the spleen, with its homogeneous, echoic pattern, could be seen craniolateral to the left kidney. Anechoic areas displaying vessels inside the spleen and a thin echoic capsule surrounding the splenic tissue could be differentiated. While sonographic appearances of the examined organs showed no differences between llamas and alpacas, selected dimensions of both of kidney and spleen showed significant differences between species. In terms of age and sex, significant differences in respect of kidney size could be found only in alpacas. Sex seemed to have no influence on kidney and spleen sizes in llamas.
CONCLUSIONS
The present study provides species-specific information on ultrasonographic appearance and reference values for kidney and spleen dimensions of clinically healthy llamas and alpacas. Results show differences in organ sizes between llamas and alpacas and in alpacas of different sex and age. The results of this study can be used as references for veterinarians performing ultrasound examinations in diseased animals.
Topics: Animals; Camelids, New World; Female; Kidney; Male; Reference Values; Species Specificity; Spleen; Ultrasonography
PubMed: 33478520
DOI: 10.1186/s13028-021-00571-5