A deep learning approach to detect blood vessels in basal cell carcinoma.

PURPOSE: Blood vessels called telangiectasia are visible in skin lesions with the aid of dermoscopy. Telangiectasia are a pivotal identifying feature of basal cell carcinoma. These vessels appear thready, serpiginous, and may also appear arborizing, that is, wide vessels branch into successively thinner vessels. Due to these intricacies, their detection is not an easy task, neither with manual annotation nor with computerized techniques. In this study, we automate the segmentation of telangiectasia in dermoscopic images with a deep learning U-Net approach. METHODS: We apply a combination of image processing techniques and a deep learning-based U-Net approach to detect telangiectasia in digital basal cell carcinoma skin cancer images. We compare loss functions and optimize the performance by using a combination loss function to manage class imbalance of skin versus vessel pixels. RESULTS: We establish a baseline method for pixel-based telangiectasia detection in skin cancer lesion images. An analysis and comparison for human observer variability in annotation is also presented. CONCLUSION: Our approach yields Jaccard score within the variation of human observers as it addresses a new aspect of the rapidly evolving field of deep learning: automatic identification of cancer-specific structures. Further application of DL techniques to detect dermoscopic structures and handle noisy labels is warranted.

Thresholding methods for lesion segmentation of basal cell carcinoma in dermoscopy images.

PURPOSE: Algorithms employed for pigmented lesion segmentation perform poorly on dermoscopy images of basal cell carcinoma (BCC), the most common skin cancer. The main objective was to develop better methods for BCC segmentation. METHODS: Fifteen thresholding methods were implemented for BCC lesion segmentation. We propose two error metrics that better measure the type II error: Relative XOR Error and Lesion Capture Ratio. RESULTS: On training/test sets of 305 and 34 BCC images, respectively, five new techniques outperform two state-of-the-art methods used in segmentation of melanomas, based on the new error metrics. CONCLUSION: The proposed algorithms, which include solutions for image vignetting correction and border expansion to achieve dermatologist-like borders, provide more inclusive and feature-preserving border detection, favoring better BCC classification accuracy, in future work.

High-sensitivity electronic Stark spectrometer featuring a laser-driven light source.

We report developmental details of a high-sensitivity Stark absorption spectrometer featuring a laser-driven light source. The light source exhibits intensity fluctuations of ∼0.3% over timescales ranging from 1 min to 12 h, minimal drift (≤0.1%/h), and very little 1/f noise at frequencies greater than 200 Hz, which are comparable to or better than an arc-driven light source. Additional features of the spectrometer include balanced detection with multiplex sampling, which yielded lower noise in A, and constant wavelength or wavenumber (energy) spectral bandpass modes. We achieve noise amplitudes of ∼7 × 10-4 and ∼6 × 10-6 in measurements of single A and ΔA spectra (with 92 data points) taking ∼7 and ∼19 min, respectively.

Automatic telangiectasia analysis in dermoscopy images using adaptive critic design.

BACKGROUND: Telangiectasia, tiny skin vessels, are important dermoscopy structures used to discriminate basal cell carcinoma (BCC) from benign skin lesions. This research builds off of previously developed image analysis techniques to identify vessels automatically to discriminate benign lesions from BCCs. METHODS: A biologically inspired reinforcement learning approach is investigated in an adaptive critic design framework to apply action-dependent heuristic dynamic programming (ADHDP) for discrimination based on computed features using different skin lesion contrast variations to promote the discrimination process. Lesion discrimination results for ADHDP are compared with multilayer perception backpropagation artificial neural networks. RESULTS: This study uses a data set of 498 dermoscopy skin lesion images of 263 BCCs and 226 competitive benign images as the input sets. This data set is extended from previous research [Cheng et al., Skin Research and Technology, 2011, 17: 278]. Experimental results yielded a diagnostic accuracy as high as 84.6% using the ADHDP approach, providing an 8.03% improvement over a standard multilayer perception method. CONCLUSION: We have chosen BCC detection rather than vessel detection as the endpoint. Although vessel detection is inherently easier, BCC detection has potential direct clinical applications. Small BCCs are detectable early by dermoscopy and potentially detectable by the automated methods described in this research.

Advances in flavin and flavoprotein optical spectroscopy.

Flavins and flavoproteins are versatile redox cofactors that can perform both one- and two-electron transfer. Because they are highly colored in all three oxidation states, optical spectroscopy has been exploited for decades to study these redox changes. This review summarizes the application of optical spectroscopies to flavins and flavoproteins since 1990. Special emphasis is placed on new techniques, such as Stark spectroscopy, as well as significant refinements in more well known techniques, such as resonance Raman spectroscopy and ultrafast spectroscopy.

Cholesterol pericarditis terminating as constrictive calcific pericarditis. Follow-up study of patient with 40 year history of disease.

This is a follow-up report of a patient with idiopathic cholesterol pericarditis (previously described in this Journal in 1961). The patient had had recurrent pericardial effusions since 1939, and died with calcific constrictive pericarditis some 40 years later. In the interim, the patient had an extended period (17 years) of symptomatic relief after pericardiotomy in 1958.

Actinic cheilitis: treatment with the carbon dioxide laser.

Actinic cheilitis is a premalignant condition that may be symptomatic; it occurs predominantly on the lower lip and is caused by chronic exposure to sunlight. Many treatment modalities, including vermilionectomy, have been used to destroy or remove the damaged epithelium. A new procedure for the treatment of actinic cheilitis is the use of the carbon dioxide (CO2) laser. This simple and quick method can be performed on an outpatient basis with use of local anesthesia. It is associated with remarkably low morbidity, especially in comparison with vermilionectomy, because vaporization is limited to diseased tissue, the mucosal epithelium, and very superficial dermis. The cosmetic results of CO2 laser treatment of actinic cheilitis are excellent.

Dense liver in a 72-year-old woman with congestive heart failure.

Amiodarone is a cardiac antiarrhythmic agent now undergoing clinical trials in the United States. Its most important side effect is pulmonary toxicity, which may present radiographically in two forms. One is similar to eosinophilic pneumonia with peripheral alveolar opacities but without any of the laboratory or pathologic findings. A second presentation is as a bilateral interstitial pattern resembling interstitial pulmonary edema. This is often mistaken for heart failure in the clinical and radiographic setting. Amiodarone also causes a phospholipidosis of the liver, which is usually asymptomatic but on occasion may present as hepatitis. On abdominal CT the liver will have an abnormally high attenuation (80-140 HU), which appears to be due to accumulation of an amiodarone metabolite in hepatocytes. This appearance is usually distinguishable from the other causes of increased hepatic attenuation by virtue of other CT criteria and clinical history. However, from a radiographic standpoint alone, the combination of acute congestive heart failure and an abnormally dense liver may result in at least an initial misdiagnosis of advanced primary hemochromatosis.

Gated computed tomography of the human heart.

Production of in vivo images of the human heart, with delineation of the individual cardiac chambers and myocardial wall thickness, was accomplished by coupling a relatively simple electrocardiographic gating device to a translate-rotate type of computed body tomographic scanner. Differentiation between the myocardial wall and the intracardiac blood pool was attainable in the patient with a normal hematocrit only when intravenous iodinated contrast media was used.

Allergic reaction to Hulka clips.

Hulka clip sterilization has become a popular method of tubal occlusion. A case is presented in which the gold covering the Hulka clip resulted in an allergic reaction, evidenced by sterile abscess formation and resulting in exploratory laparotomy for removal of the Hulka clips, sterile abscess, and resultant adhesions. To the authors' knowledge, no previous case has been presented of this type of gold allergy. It would appear that careful screening for gold allergy should be undertaken before tubal sterilization with Hulka clips.

Superficial ulcerating necrobiosis in rheumatoid arthritis. A variant of the necrobiosis lipoidica-rheumatoid nodule spectrum?

Although necrobiosis is not a precise term, it primarily refers to collagen changes found in association with the palisading granulomas seen in granuloma annulare, necrobiosis lipoidica diabeticorum (NLD), and rheumatoid nodules. While the pathogenesis of each of these conditions remains unknown, immune complex vasculitis and delayed hypersensitivity mechanisms have been postulated. Two patients are described, having "classic" rheumatoid arthritis with chronic, superficial, ulcerating, discrete lesions on their lower legs that histologically were interpreted as NLD. While the argument for a chance association of NLD and rheumatoid arthritis could be advanced, the occurrence of identical lesions in two patients with high-titer rheumatoid factor, rheumatoid nodules, and some clinical and microscopic evidence of a low-grade rheumatoid vasculitis suggests a new subset of patients with necrobiotic palisading granulomas.

Sensory radicular neuropathy.

A patient had sensory radicular neuropathy. The patient demonstrated features characteristic of this entity: (1) recurrent trophic ulcerations of the hands and feet, (2) onset in early adulthood, (3) distal, dissociated loss of pain and temperature sensation far out of proportion to the loss of other sensory perceptions, and (4) complete sparing of motor function.

Two-photon excitation of 4'-hydroxymethyl-4,5',8-trimethylpsoralen.

Psoralens are a class of pharmaceutical agents commonly used to treat several cutaneous disorders. When irradiated with a mode-locked titanium: sapphire (Ti:sapphire) laser tuned to 730 nm, an aqueous solution of 4'-hydroxymethyl-4,5',8-trimethylpsoralen (HMT) emits blue light. The emission spectrum is centered at 452 nm and is identical to that obtained by one-photon excitation with UVA excitation, and its magnitude depends quadratically on the intensity of laser excitation. These results suggest that two-photon excitation occurs to a potentially photochemically active state. To estimate the two-photon absorption cross section, it was first necessary to measure the emission quantum yield of HMT using 365 nm excitation at room temperature that resulted in a value of 0.045 +/- 0.007. The two-photon absorption cross section of HMT at 730 nm is therefore estimated to be 20 x 10(-50) cm4 s (20 Göppert-Mayer). The excited-state photophysics and photochemistry of psoralens suggest potential applications to cutaneous phototherapy in diseases such as psoriasis and dystrophic epidermolysis bullosa.

Data-driven homologue matching for chromosome identification.

Karyotyping involves the visualization and classification of chromosomes into standard classes. In "normal" human metaphase spreads, chromosomes occur in homologous pairs for the autosomal classes 1-22, and X chromosome for females. Many existing approaches for performing automated human chromosome image analysis presuppose cell normalcy, containing 46 chromosomes within a metaphase spread with two chromosomes per class. This is an acceptable assumption for routine automated chromosome image analysis. However, many genetic abnormalities are directly linked to structural or numerical aberrations of chromosomes within the metaphase spread. Thus, two chromosomes per class cannot be assumed for anomaly analysis. This paper presents the development of image analysis techniques which are extendible to detecting numerical aberrations evolving from structural abnormalities. Specifically, an approach to identifying "normal" chromosomes from selected class(es) within a metaphase spread is presented. Chromosome assignment to a specific class is initially based on neural networks, followed by banding pattern and centromeric index criteria checking, and concluding with homologue matching. Experimental results are presented comparing neural networks as the sole classifier to our homologue matcher for identifying class 17 within normal and abnormal metaphase spreads.

Cholecystosonography: accuracy, pitfalls and unusual findings.

Gray scale cholecystosonograms in 200 patients were reviewed. The findings in 133 of the patients were proved correct at surgery or autopsy. The overall accuracy for the detection of gallstones was 92 percent, with a false-negative rate of 4 percent. A false-positive diagnosis of cholelithiasis was made in three patients, two of whom proved to have extensive cholesterolosis. Causes of false-negative studies were the presence of a single small calculus, obseity and a large distended gallbladder. Ultrasound was specific but insensitive in the detection of a thickened gallbladder wall. The significance of a nonvisualized gallbladder by ultrasound and the role of ultrasound in the diagnosis of gallbladder disease are discussed.

Lymphoepithelioma (undifferentiated carcinoma) of the laryngohypopharynx.

Lymphoepithelioma (World Health Organization type 3, undifferentiated carcinoma of the nasopharyngeal type) is an extremely rare cancer in the laryngohypopharyngeal regions. We found reports of only 6 such tumors in the English language medical literature; 1 of the 6 was from our institution. We report four additional cases seen at the Mayo Clinic. Radiotherapy controlled disease at the primary site in three of the four cases. The neoplasm has a propensity for early, widespread dissemination. Three of our four patients died of extensive visceral and nodal metastases. One patient has survived eight years without a recurrence.

High resolution computed tomography in the staging of carcinoma of the larynx.

The normal anatomy of the larynx as displayed on computed tomography is illustrated. Pathological alterations in patients with carcinoma of the larynx are depicted and discussed. Computed tomography (CT) is recommended as the initial radiological procedure when additional diagnostic information is required to supplement the findings of laryngoscopy. CT provides information regarding deep penetration of tumor, including cartilaginous invasion, and about the inferior extension of neoplasm, including the subglottic area. This knowledge helps to determine whether conservative surgery as opposed to total laryngectomy is possible.

Space-occupying orbital lesions: can critical increases in intraorbital pressure be predicted clinically?

Thirteen cadaver orbits were studied to determine whether noninvasive clinical measurements of globe excursion could be used to predict intraorbital pressure. Intraorbital pressure measurements, exophthalmometry, and orbitonometry (which measures resistance to globe retrodisplacement) were performed at 1-ml increments to 12 ml of added orbital volume. Orbitonometry, performed with forces of 100, 200, and 300 g, yielded both E (global position) and Y (retrodisplacement) values. Plots of orbital pressure against percentage of excursion, a function of orbital retrodisplacement (that is, orbital pressure versus [(E0 - E300)/E0] x 100), for 131 paired values over all orbits yielded a function with low percentage of excursion values associated with high intraorbital pressures. This relationship reflected both the proptosis and the increased orbital tension produced by added volumes. Comparison of clinical orbitonometry data with such experimental data may allow predictions about which patients are threatened by critical intraorbital pressure levels and may benefit from orbital decompression surgery to preserve vision.

Rhinectomy for malignant disease. A 20-year experience.

In a 20-year experience with total rhinectomy for malignant disease, 27 of 51 patients had prior irradiation. In five patients, the tumor masqueraded as a dermatosis. Basal or squamous cell carcinomas were the usual histologic types (86%). There had been previous unsuccessful surgical therapy in 31 patients and radiation therapy in 17 patients. Twenty-two tumors recurred at a mean of 9.4 months after rhinectomy; 50% of these patients died. Despite rhinectomy, almost 25% (and 40% of patients with squamous cell carcinoma) died, usually of uncontrolled local disease. Results of surgical reconstruction after total rhinectomy were not satisfactory. In eight of 12 cases, attempts failed primarily or recurrent disease developed. Reconstruction should not be attempted before one year after rhinectomy, and use of a nasal prosthesis is the cornerstone of rehabilitation. Total rhinectomy is an oncologically sound operation for extensive nasal carcinoma.

Oncocytic and oncocytoid carcinoid tumors (well-differentiated neuroendocrine carcinomas) of the larynx.

Carcinoid tumors of the larynx are exceedingly rare neoplasms. With the inclusion of the five neoplasms we report herein, the total number reported in the English-language literature is 16. These five neoplasms all showed light microscopic features of oncocytic (or oncocytoid) cells. Ultrastructurally, all lesions contained dense-core granules of the neurosecretory type. One case further met the ultrastructural criteria for true oncocytoma (that is, an oncocytic carcinoid). The lesion did not metastasize, and the patient was successfully treated surgically. In the other four cases, the lesions were considered to be oncocytoid carcinoids, since they failed to meet the ultrastructural requirements of a true oncocytoma. Each of these four lesions metastasized, although one patient did have a long, indolent course.