Cystic fibrosis: scoring system with thin-section CT

The progression of lung disease in patients with cystic fibrosis (CF) was evaluated with chest radiography. The severity and extent of the various radiographic changes were scored with the Chrispin or the Birmingham method, which involves the use of imprecise and subjective terms, such as line shadows, large pulmonary shadows, and nodular cystic lesions. Although computed tomography (CT) has been shown to be helpful in the evaluation of lung disease in CF, no scoring system or other objective criteria have been developed for the evaluation of the wide range of pulmonary changes in these patients. A CT scoring system was devised that incorporates all of the changes seen in the lungs of patients with CF. Such a scoring system may facilitate objective evaluation of existing and newly developed therapeutic regimens and may be a valuable tool in the preoperative evaluation of patients being considered for lobectomy or bullectomy and in the selection of patients for lung transplantation.

Visual-motor recalibration in geographical slant perception

In 4 experiments, it was shown that hills appear steeper to people who are encumbered by wearing a heavy backpack (Experiment 1), are fatigued (Experiment 2), are of low physical fitness (Experiment 3), or are elderly and/or in declining health (Experiment 4). Visually guided actions are unaffected by these manipulations of physiological potential. Although dissociable, the awareness and action systems were also shown to be interconnected. Recalibration of the transformation relating awareness and actions was found to occur over long-term changes in physiological potential (fitness level, age, and health) but not with transitory changes (fatigue and load). Findings are discussed in terms of a time-dependent coordination between the separate systems that control explicit visual awareness and visually guided action.

Visual-motor recalibration in geographical slant perception

In 4 experiments, it was shown that hills appear steeper to people who are encumbered by wearing a heavy backpack (Experiment 1), are fatigued (Experiment 2), are of low physical fitness (Experiment 3), or are elderly and/or in declining health (Experiment 4). Visually guided actions are unaffected by these manipulations of physiological potential. Although dissociable, the awareness and action systems were also shown to be interconnected. Recalibration of the transformation relating awareness and actions was found to occur over long-term changes in physiological potential (fitness level, age, and health) but not with transitory changes (fatigue and load). Findings are discussed in terms of a time-dependent coordination between the separate systems that control explicit visual awareness and visually guided action.

Diffuse lung disease: assessment with helical CT--preliminary observations of the role of maximum and minimum intensity projection images

PURPOSE

To evaluate assessment of diffuse lung disease with helical computed tomography (CT) and maximum intensity projection (MIP) and minimum intensity projection images.

MATERIALS AND METHODS

Six patients with suspected lung disease (the control group) and 20 patients with documented disease underwent axial helical CT through the upper and lower lung fields. Findings on the MIP and minimum intensity projection images of each helical data set were compared with findings on the thin-section scan obtained at the midplane of the series.

RESULTS

Owing to markedly improved visualization of peripheral pulmonary vessels (n = 26) and improved spatial orientation, MIP images were superior to helical scans to help identify pulmonary nodules and characterize them as peribronchovascular (n = 2) or centrilobular (n = 7). Minimum intensity projection images were more accurate than thin-section scans to help identify lumina of central airways (n = 23) and define abnormal low (n = 15) and high (ground-glass) (n = 8) lung attenuation. Conventional thin-section scans depicted fine linear structures more clearly than either MIP or minimum intensity projection images, including the walls of peripheral, dilated airways (n = 3) and interlobular septa (n = 3). MIP and minimum intensity projection images added additional diagnostic findings to those on thin-section scans in 13 (65%) of 20 cases.

CONCLUSION

MIP and minimum intensity projection images of helical data sets may help diagnosis of a wide spectrum of diffuse lung diseases.

Volumetric (helical/spiral) CT (VCT) of the airways

Volumetric computed tomography (VCT) represents an important improvement over conventional CT for assessing most airway abnormalities. Elimination of misregistration due to variations in respiration coupled with decreased motion artifact and the ability to obtain routine overlapping sections allow a more confident estimation of the presence and extent of disease. Recently, attention has focused on newer reconstruction techniques including: multiplanar reconstructions (MPRs), including curved multiplanar reformations; multiplanar volume reconstructions (MPVRs) using ray projection techniques, such as maximum and minimum projection imaging; external rendering, or 3D-shaded surface displays; and, most recently, internal rendering or so-called "virtual bronchoscopy". Given the often redundant nature of many of these methodologies determining indications for their use remains to be established, especially by comparison to axial imaging. The purpose of this article is to review these various reconstruction techniques and, based on current knowledge, place them in an appropriate clinical context.

Chest CT in patients with scleroderma: prevalence of asymptomatic esophageal dilatation and mediastinal lymphadenopathy

OBJECTIVE

The high-resolution CT findings of chronic diffuse interstitial lung disease associated with scleroderma have been reported previously. This study determined the prevalence of esophageal dilatation and mediastinal adenopathy on high-resolution CT scans in patients with this disease.

MATERIALS AND METHODS

We retrospectively reviewed the high-resolution CT scans of 25 patients with scleroderma who had diffuse interstitial lung disease. Esophageal dilatation was diagnosed if the esophagus below the aortic arch had a single, large, nonloculated collection of intraluminal air on four or more consecutive axial images and if the luminal diameter of such an air-filled esophagus exceeded 10 mm in the coronal plane. The presence of fluid or an air-fluid level was also considered abnormal. For mediastinal adenopathy, we used the American Thoracic Society lymph node mapping scheme and the size criteria described previously.

RESULTS

Asymptomatic esophageal dilatation was detected in 20 patients (80%) and mediastinal adenopathy was present in 15 (60%).

CONCLUSION

Our results suggest that CT is useful in the detection of mediastinal adenopathy and asymptomatic esophageal involvement in patients with scleroderma. These findings can be used to narrow the differential diagnosis in patients in whom CT shows diffuse interstitial lung disease. Furthermore, the early detection of esophageal involvement in these patients shows the need for treatment to forestall the complications of esophageal dysmotility and accompanying chronic gastroesophageal reflux.

Lung hernia: radiographic features

Lung hernia is an abnormal protrusion of the lung beyond the confines of the thoracic cage. Hernias are classified as cervical, intercostal, or diaphragmatic. Each of these types can be either congenital or acquired. Acquired hernias can be spontaneous, posttraumatic, or pathologic as a result of a neoplastic or inflammatory process. This report describes five cases of lung hernias. Two were congenital cervical hernias, detected as incidental findings on chest radiographs of infants. One was a posttraumatic intercostal hernia detected on a chest radiograph and confirmed with CT. The remaining two were acquired intercostal hernias at the site of prior chest-tube drainage of tuberculous empyemas. Although both of these were clearly shown on CT scans, only one was visible on chest radiographs.

Acute chest syndrome in sickle cell disease: CT evidence of microvascular occlusion

Patients with sickle cell disease often develop acute chest syndrome (ACS). Signs of ACS include chest pain, fever, prostration, and pulmonary opacities. Pneumonia and infarction have been implicated in the pathogenesis of this syndrome. Infarction as a result of microvascular occlusion and pneumonia are not easily differentiated with chest radiography or ventilation-perfusion scintigraphy. The authors evaluated the ability of thin section (3-mm) chest computed tomography (CT) to help diagnose microvascular occlusion in ACS and thus help differentiate two of its most likely causes. CT scans of the chest of 10 patients with moderate to severe ACS were retrospectively reviewed by two observers, who listed the number of bronchopulmonary segments showing consolidation; areas of ground-glass attenuation due to early hemorrhagic edema; and paucity or absence of small vessels, arterioles, and venules. In all patients, the degree of hypoxia was out of proportion to the extent of consolidation evident at chest radiography. The CT scans showed microvascular occlusion and areas of ground-glass attenuation in nine patients. Infection was ruled out in eight patients. High-resolution CT may play an important role in the initial evaluation and timely selection of an appropriate treatment regimen aimed at improving tissue perfusion, thus forestalling irreversible organ damage and chronic pulmonary arterial hypertension in patients with sickle cell disease.

Unusual lymphoproliferative disorders in nine adults with HIV or AIDS: CT and pathologic findings

PURPOSE

To identify characteristic computed tomographic (CT) findings in unusual pulmonary lymphoproliferative disorders seen in adults with the human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS).

MATERIALS AND METHODS

The authors retrospectively reviewed the CT scans and pathologic specimens from nine patients with pulmonary lymphoproliferative disorders. CT scans were evaluated for nodules, reticulation, areas of ground-glass attenuation, consolidation, and bronchial disease. Changes seen in pathologic specimens were classified as consistent with classic lymphocytic interstitial pneumonitis (LIP), mucosa-associated lymphoid tissue lymphoma (MALTOMA), or atypical lymphoproliferative disorder (ALD). Immunopathologic results were reviewed when available.

RESULTS

Eight patients had AIDS. Five patients had classic LIP. One patient had MALTOMA, and three patients had ALD. Altogether, 2-4-mm-diameter nodules were the predominant CT finding in eight patients; these were peribronchovascular in four patients. The presence of interstitial nodules correlated with the pathologic finding of nodular disease in seven patients.

CONCLUSION

Familiarity with these AIDS-related disorders and their CT appearance should assist in the differential diagnosis.

Needle localization of peripheral lung nodules for video-assisted thoracoscopic surgery

Video-assisted thoracoscopic surgery provides an alternative to conventional thoracotomy for resection of peripheral lung nodules. To localize small peripheral lung nodules that may not be visible or palpable by the surgeon, we have placed a Kopans hook wire percutaneously into the lung as a guide. The indications for localization included previous nondiagnostic percutaneous needle aspiration biopsy (PNAB) (n = 4), nodules too small for PNAB (n = 2), nodules inaccessible to PNAB (n = 3), and planned resection of a known peripheral tumor less than 1 cm (n = 1). The localization procedure was performed with computed tomographic guidance in all patients. The nodules ranged in size from 2 to 15 mm and were located immediately subpleural to 2-cm deep the pleura. A 20-gauge Greene biopsy needle was used as an introducer for a 35-cm-long Kopans hook wire. Patients were sent directly to the operating room in a dependent position. All ten nodules were successfully resected, including hamartoma (n = 1), carcinoid tumors (n = 2), granulomas (n = 3), adenocarcinoma (n = 1), fibrosis (n = 1), benign metastasizing leiomyoma (n = 1), and lymphoma (n = 1). In two patients, the wire slipped out of the lung. Small focal pneumothoraces developed in five patients. There were no major complications. This procedure can safely and effectively localize nonvisible or nonpalpable pulmonary nodules for thoracoscopic surgery for diagnostic purposes or for resection of small peripheral tumors in patients who cannot tolerate a lobectomy or pneumonectomy.

AIDS-related airway disease

To our knowledge, the importance of airway disease in HIV-positive patients has been infrequently noted. This deficit likely reflects a combination of factors including lack of familiarity with recent changes in clinical and epidemiologic patterns of pulmonary manifestations of HIV infection and documented limitations of chest radiography for identifying and differentiating airway disease from other causes of pulmonary disease in HIV-positive patients. Familiarity with the imaging findings for these various entities should facilitate prompt diagnosis and treatment. The accuracy of CT in detecting airway disease [55-59] is well established and should be of value in excluding more common diseases that may be initially confused with airway abnormalities [60, 61]. Small airways disease, in particular, which may be occult or mimic an interstitial infiltrate on chest radiography, can be recognized with CT as likely representing infectious bronchitis or bronchiolitis. Patients with findings suggesting bacterial infections may benefit from empiric antibiotic therapy. CT also may be valuable for differentiating between various noninfectious pulmonary diseases, allowing a presumptive diagnosis of parenchymal Kaposi's sarcoma in the appropriate clinical context. In distinction, by detecting localized endobronchial or parenchymal abnormalities in patients with mycobacterial or fungal infections or lymphoma, CT may be valuable for deciding between various invasive methods of obtaining either histologic or bacteriologic diagnoses.

Quantitative assessment of field strength, total intracranial volume, sex, and age effects on the goodness of harmonization for volumetric analysis on the ADNI database

When analyzing large multicenter databases, the effects of multiple confounding covariates increase the variability in the data and may reduce the ability to detect changes due to the actual effect of interest, for example, changes due to disease. Efficient ways to evaluate the effect of covariates toward the data harmonization are therefore important. In this article, we showcase techniques to assess the "goodness of harmonization" of covariates. We analyze 7,656 MR images in the multisite, multiscanner Alzheimer's Disease Neuroimaging Initiative (ADNI) database. We present a comparison of three methods for estimating total intracranial volume to assess their robustness and correct the brain structure volumes using the residual method and the proportional (normalization by division) method. We then evaluated the distribution of brain structure volumes over the entire ADNI database before and after accounting for multiple covariates such as total intracranial volume, scanner field strength, sex, and age using two techniques: (a) Zscapes, a panoramic visualization technique to analyze the entire database and (b) empirical cumulative distributions functions. The results from this study highlight the importance of assessing the goodness of data harmonization as a necessary preprocessing step when pooling large data set with multiple covariates, prior to further statistical data analysis.

Development and validation of a novel dementia of Alzheimer's type (DAT) score based on metabolism FDG-PET imaging

Fluorodeoxyglucose positron emission tomography (FDG-PET) imaging based 3D topographic brain glucose metabolism patterns from normal controls (NC) and individuals with dementia of Alzheimer's type (DAT) are used to train a novel multi-scale ensemble classification model. This ensemble model outputs a FDG-PET DAT score (FPDS) between 0 and 1 denoting the probability of a subject to be clinically diagnosed with DAT based on their metabolism profile. A novel 7 group image stratification scheme is devised that groups images not only based on their associated clinical diagnosis but also on past and future trajectories of the clinical diagnoses, yielding a more continuous representation of the different stages of DAT spectrum that mimics a real-world clinical setting. The potential for using FPDS as a DAT biomarker was validated on a large number of FDG-PET images (N=2984) obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database taken across the proposed stratification, and a good classification AUC (area under the curve) of 0.78 was achieved in distinguishing between images belonging to subjects on a DAT trajectory and those images taken from subjects not progressing to a DAT diagnosis. Further, the FPDS biomarker achieved state-of-the-art performance on the mild cognitive impairment (MCI) to DAT conversion prediction task with an AUC of 0.81, 0.80, 0.77 for the 2, 3, 5 years to conversion windows respectively.

Early detection of multi-drug resistance and common mutations in Mycobacterium tuberculosis isolates from Delhi using GenoType MTBDRplus assay

PURPOSE

There is scarcity of prevalence data of multi-drug-resistant tuberculosis (MDR-TB) data and common mutations responsible in North India. This study aimed to detect MDR-TB among MDR-TB suspects from Delhi and mutation patterns using GenoType MTBDRplus assay.

MATERIALS AND METHODS

All MDR suspects in five districts of New Delhi were referred to the laboratory from 1 st October 2011 to 31 st December 2012 as per criterion defined by Programmatic Management of Drug Resistant Tuberculosis (PMDT). GenoType MTBDRplus assay was performed on 2182 samples or cultures and mutations in the rpoB gene for rifampicin (RIF) and katG and inhA genes for isoniazid (INH) were analyzed.

RESULTS

A total of 366 (16.8%) MDR-TB cases were diagnosed. MDR rate was found to be 32%, 16.6% and 10.2% during criterion A, B and C respectively. The most common mutation detected for RIF was S531L (59.0%) and for INH was S315T1 (88.3%). Mutations S531L and S315T1 occurred significantly higher in MDR strains as compared to RIF mono-resistant and INH mono-resistant strains, respectively. Average laboratory turn-around time (TAT) for dispatch of result to districts for test conducted on samples was 4.4 days.

CONCLUSION

GenoType MTBDRplus is a useful assay for rapid detection of MDR-TB. The common mutations for RIF and INH were similar to those seen in other regions. However, mutations determining MDR strains and mono-resistant strains differed significantly for both RIF and INH.

Gray matter changes in asymptomatic C9orf72 and GRN mutation carriers

Frontotemporal dementia (FTD) is a neurodegenerative disease with a strong genetic basis. Understanding the structural brain changes during pre-symptomatic stages may allow for earlier diagnosis of patients suffering from FTD; therefore, we investigated asymptomatic members of FTD families with mutations in C9orf72 and granulin (GRN) genes. Clinically asymptomatic subjects from families with C9orf72 mutation (15 mutation carriers, C9orf72+; and 23 non-carriers, C9orf72-) and GRN mutations (9 mutation carriers, GRN+; and 15 non-carriers, GRN-) underwent structural neuroimaging (MRI). Cortical thickness and subcortical gray matter volumes were calculated using FreeSurfer. Group differences were evaluated, correcting for age, sex and years to mean age of disease onset within the subject's family. Mean age of C9orf72+ and C9orf72- were 42.6 ± 11.3 and 49.7 ± 15.5 years, respectively; while GRN+ and GRN- groups were 50.1 ± 8.7 and 53.2 ± 11.2 years respectively. The C9orf72+ group exhibited cortical thinning in the temporal, parietal and frontal regions, as well as reduced volumes of bilateral thalamus and left caudate compared to the entire group of mutation non-carriers (NC: C9orf72- and GRN- combined). In contrast, the GRN+ group did not show any significant differences compared to NC. C9orf72 mutation carriers demonstrate a pattern of reduced gray matter on MRI prior to symptom onset compared to GRN mutation carriers. These findings suggest that the preclinical course of FTD differs depending on the genetic basis and that the choice of neuroimaging biomarkers for FTD may need to take into account the specific genes involved in causing the disease.

Adenosquamous carcinoma of the lung: radiologic appearance

OBJECTIVE

To our knowledge, the imaging features of pulmonary adenosquamous carcinoma, a form of bronchogenic carcinoma with a greater propensity for metastases at the time of diagnosis and a poorer prognosis than other forms of bronchogenic carcinoma, have not been reported. Accordingly, we studied the radiologic appearance of this tumor to describe the findings and discern if there are features that distinguish it from other bronchogenic carcinomas.

MATERIALS AND METHODS

Clinical and radiologic features of 30 cases of adenosquamous carcinoma were reviewed. Chest radiographs were available in all cases and CT scans were available in 23. In cases without CT scans, planar tomograms were reviewed in five cases and MR images were reviewed in one. Tumors were defined by location, morphology, and TNM classification.

RESULTS

The tumors measured 0.6-6.5 cm in diameter (mean, 2.8 cm) on CT scans or chest radiographs. One tumor not seen even in retrospect on CT scans or chest radiographs was found at autopsy. Twenty-five tumors were solid and four were cavitary. Five tumors were central and 25 were peripheral, including one tumor of the superior sulcus of the lung and the tumor not seen at imaging. Tumor margins were poorly defined in 19 and spiculated in 10. Four large masses had heterogeneous attenuation on CT scans; one had punctate calcification. Fifty-three percent of tumors were peripheral nodules 1-3 cm in diameter. Results of fine-needle aspiration of 18 masses indicated malignant tumors in 16 cases, but adenosquamous carcinoma in only two. Evidence of previous lung injury, including tumor in or next to scar, pneumoconiosis, radiation fibrosis, and interstitial fibrosis, was found on CT scans, chest radiographs, and/or pathology in half the patients.

CONCLUSION

The radiologic findings of adenosquamous lung carcinoma are a spectrum, typically a peripheral solitary nodule, less commonly a central hilar mass or tumor of the superior sulcus. Scar or fibrosis within the lungs suggests that adenosquamous carcinoma, just as adenocarcinoma, may arise in scarred lung parenchyma.

Dual kV CT to detect calcification in solitary pulmonary nodule

OBJECTIVE

At the high kVp values used in CT scanning, almost all interactions in soft tissues occur by Compton scattering. By lowering the kVp close to the k-edge of calcium, beam attenuation by calcium will be greater and will be reflected as an increase in density reading (DR). The presence of calcification in solitary pulmonary nodules (SPNs), and thus an implied benign etiology, is currently being diagnosed on CT by using reference phantoms. We explored the possibility of utilizing low kVp (i.e., 80 kVp) to detect the presence of such calcification in SPNs, thus obviating the need for expensive and cumbersome reference phantoms.

MATERIALS AND METHODS

We first tested this phenomenon of photoelectric interaction by CT and its effect on DRs by scanning various dilutions of calcium bicarbonate solution at the standard 140 kVp and at a lower, 80 kVp, setting. After confirming the hypothesis, we conducted a prospective clinical study of 27 consecutive SPNs and scanned them at 140 and 80 kVp to detect the presence of calcification by measuring their DRs at both kVp values.

RESULTS

All calcium solutions showed an increase in DR on the 80 kVp scan. Of the 27 nodules, 11 (41%) showed an increase in DR, suggesting the presence of calcification: 10 (91%) were benign, and 1 (9%) was malignant.

CONCLUSION

Our study demonstrates that dual kVp CT could be reliably used to identify calcifications in SPNs, very similar to the use of the reference phantoms currently being applied for the purpose.

Surgical flaps in the chest: anatomic considerations, applications, and radiologic appearance

PURPOSE

To determine the frequency of use of surgical flaps--tissue that is transposed from its normal location to promote healing and prevent complications--in noncardiac thoracic surgery and to demonstrate the typical radiologic appearances of such flaps.

MATERIALS AND METHODS

The surgical records of 200 patients who underwent thoracotomy or median sternotomy for noncardiac thoracic surgery were reviewed. Postoperative radiologic studies of randomly selected cases were also reviewed.

RESULTS

A total of 213 surgical flaps were used in these patients, including 80 pericardial fat pad flaps (37.6%), 78 greater omental flaps (36.6%), 21 intercostal muscle flaps (9.9%), 16 anterior serratus muscle flaps (7.5%), and 18 greater pectoral muscle, latissimus dorsi muscle, pleural, thymic, or mediastinal fat flaps (8.5%). The flaps produced unusual opacity or attenuation and/or contour of the mediastinum, hilum, or chest wall.

CONCLUSION

Knowledge of common thoracic surgical flaps is helpful in interpretation of postoperative radiologic studies.

Idiopathic laryngotracheal stenosis: radiologic findings

OBJECTIVE

Acquired nonneoplastic laryngotracheal stenosis can be either focal or diffuse. Diffuse tracheal stenosis is caused by sarcoidosis, tuberculosis, histoplasmosis, relapsing polychondritis, tracheopathia osteoplastica, and Wegener's granulomatosis. Focal tracheal stenosis, on the other hand, usually results from placement of an endotracheal or tracheostomy tube or from previous neck trauma. At our institution, since 1971, we have seen 49 cases of focal laryngotracheal stenosis that could not be attributed clinically or histologically to any one of the aforementioned causes. The purpose of this study was to study the radiologic features of these idiopathic laryngotracheal stenoses.

MATERIALS AND METHODS

A retrospective review of records showed that radiologic studies were still available in only 15 of the 49 patients with idiopathic laryngotracheal stenoses. All 15 patients had radiographs and plain tomograms, and one patient had a CT scan of the neck. Three radiologists reviewed all the images.

RESULTS

The radiologic appearance was variable: the stenoses were from 2 to 4 cm long with a lumen between 3 and 5 mm in diameter at the narrowest portion. The narrowing was concentric and shaped like an hourglass in eight patients (53%) and was eccentric in the other seven (47%). The margins of the stenosis were smooth in nine patients (60%) and irregular and lobulated in six patients (40%). A dominant mass measuring approximately 1 cm in diameter was present in two patients (13%). No evidence of calcification or ossification was seen.

CONCLUSION

Idiopathic laryngotracheal stenosis produces focal stenosis of the cervical part of the trachea, 2 to 4 cm long. The lumen is severely compromised, measuring no more than 5 mm in diameter at its narrowest portion. The stenosis can be concentric or eccentric and can have either smooth or lobulated margins. Special attention should be paid to the airways when chest radiographs of patients with a history of prolonged dyspnea and wheezing are reviewed. The prevalence of focal stenosis of the larynx and the upper part of the trachea due to tracheal intubation has declined since the introduction of low-pressure, high-volume retention cuffs. Therefore, idiopathic laryngotracheal stenosis should be considered in the differential diagnosis in patients with focal narrowing of the airway.

Semi-supervised deep learning based 3D analysis of the peripapillary region

Optical coherence tomography (OCT) has become an essential tool in the evaluation of glaucoma, typically through analyzing retinal nerve fiber layer changes in circumpapillary scans. Three-dimensional OCT volumes enable a much more thorough analysis of the optic nerve head (ONH) region, which may be the site of initial glaucomatous optic nerve damage. Automated analysis of this region is of great interest, though large anatomical variations and the termination of layers make the requisite peripapillary layer and Bruch's membrane opening (BMO) segmentation a challenging task. Several machine learning-based segmentation methods have been proposed for retinal layer segmentation, and a few for the ONH region, but they typically depend on either heavily averaged or pre-processed B-scans or a large amount of annotated data, which is a tedious task and resource-intensive. We evaluated a semi-supervised adversarial deep learning method for segmenting peripapillary retinal layers in OCT B-scans to take advantage of unlabeled data. We show that the use of a generative adversarial network and unlabeled data can improve the performance of segmentation. Additionally, we use a Faster R-CNN architecture to automatically segment the BMO. The proposed methods are then used for the 3D morphometric analysis of both control and glaucomatous ONH volumes to demonstrate the potential for clinical utility.

Primary extraosseous pulmonary osteogenic sarcoma: CT findings

This is a report of a primary extraosseous osteogenic sarcoma of the lung. The patient presented with fever and productive cough. Chest radiography and CT showed a cavitary lesion with an air-fluid level. The lesion was treated as an abscess. Despite aggressive antibiotic therapy and drainage, the patient continued to deteriorate rapidly. At autopsy the lesion was found to be a primary extraosseous pulmonary osteogenic sarcoma.

Automated identification of cone photoreceptors in adaptive optics optical coherence tomography images using transfer learning

Automated measurements of the human cone mosaic requires the identification of individual cone photoreceptors. The current gold standard, manual labeling, is a tedious process and can not be done in a clinically useful timeframe. As such, we present an automated algorithm for identifying cone photoreceptors in adaptive optics optical coherence tomography (AO-OCT) images. Our approach fine-tunes a pre-trained convolutional neural network originally trained on AO scanning laser ophthalmoscope (AO-SLO) images, to work on previously unseen data from a different imaging modality. On average, the automated method correctly identified 94% of manually labeled cones when compared to manual raters, from twenty different AO-OCT images acquired from five normal subjects. Voronoi analysis confirmed the general hexagonal-packing structure of the cone mosaic as well as the general cone density variability across portions of the retina. The consistency of our measurements demonstrates the high reliability and practical utility of having an automated solution to this problem.

Investigation of the Peripapillary Choriocapillaris in Normal Tension Glaucoma, Primary Open-angle Glaucoma, and Control Eyes

PRECIS

The peripapillary choriocapillaris (CC) was observed to be significantly impaired in normal tension glaucoma (NTG) subjects compared with normal controls using optical coherence tomography angiography (OCTA).

PURPOSE

The aim was to quantitatively evaluate the peripapillary CC in NTG, primary open-angle glaucoma (POAG), and control eyes using OCTA.

MATERIALS AND METHODS

Ninety eyes (30 controls, 30 NTG, and 30 POAG) from 73 patients were imaged using the Zeiss Plex Elite 9000. Five repeat 3×3 mm OCTA scans were acquired both nasally and temporally to the optic disc and subsequently averaged. Four CC flow deficit (FD) measures were calculated using the fuzzy C-means approach: FD density (FDD), mean FD size (MFDS), FD number (FDN), and FD area (FDA).

RESULTS

Temporal NTG CC parameters were associated with visual field index and mean deviation (P<0.05). The control group showed a significantly lower nasal FDD (nasal: 3.79±1.26%, temporal: 4.48±1.73%, P=0.03), FDN (nasal: 156.43±38.44, temporal: 178.40±45.68, P=0.02), and FDA (nasal: 0.22±0.08, temporal: 0.26±0.10, P=0.03) when compared with temporal optic disc. The NTG group showed a significantly higher FDD (NTG: 5.04±2.38%, control: 3.79±1.26%, P=0.03), FDN (NTG: 185.90±56.66, control: 156.43±38.44, P=0.04), and FDA (NTG: 0.30±0.14 mm2, control: 0.22±0.08 mm2, P=0.03) nasal to the optic disc compared with controls.

CONCLUSIONS

Association between CC parameters and glaucoma severity in NTG, but not POAG subjects, suggests vascular abnormalities may be a potential factor in the multifactorial process of glaucoma damage in NTG patients.