Specificity Of Optical Coherence Tomography Research Articles

Comparing the diagnostic efficacy of optical coherence tomography and frozen section for margin assessment in breast-conserving surgery: a meta-analysis

AimsThis meta-analysis assessed the relative diagnostic accuracy of optical coherence tomography (OCT) versus frozen section (FS) in evaluating surgical margins during breast-conserving procedures.MethodsPubMed and Embase were searched for relevant studies...

Novel image features of optical coherence tomography for pathological classification of lung cancer: Results from a prospective clinical trial.

This study aimed to explore the characteristics of optical coherence tomography (OCT) imaging for differentiating between benign and malignant lesions and different pathological types of lung cancer in bronchial lesions and to preliminarily evaluate the clinical value of OCT. Patients who underwent bronchoscopy biopsy and OCT between February 2019 and December 2019 at the Chinese PLA General Hospital were enrolled in this study. White-light bronchoscopy (WLB), auto-fluorescence bronchoscopy (AFB), and OCT were performed at the lesion location. The main characteristics of OCT imaging for the differentiation between benign and malignant lesions and the prediction of the pathological classification of lung cancer in bronchial lesions were identified, and their clinical value was evaluated. A total of 135 patients were included in this study. The accuracy of OCT imaging for differentiating between benign and malignant bronchial lesions was 94.1%, which was significantly higher than that of AFB (67.4%). For the OCT imaging of SCC, adenocarcinoma, and small-cell lung cancer, the accuracies were 95.6, 94.3, and 92%, respectively. The accuracy, sensitivity, and specificity of OCT were higher than those of WLB. In addition, these main OCT image characteristics are independent influencing factors for predicting the corresponding diseases through logistic regression analysis between the main OCT image characteristics in the study and the general clinical features of patients (p<0.05). As a non-biopsy technique, OCT can be used to improve the diagnosis rate of lung cancer and promote the development of non-invasive histological biopsy.

Latent Diabetic Macular Edema in Chinese Diabetic Retinopathy Patients.

Purpose: To compare the detection rates of optical coherence tomography (OCT) and fluorescein angiography (FA) in a diabetic macular edema (DME) and the severity of diabetic retinopathy in both color fundus images (CFI) and FA, and to investigate the predictive factors in macular leakages in FA.Methods: This was a retrospective study, and a total of 132 eyes of 77 patients with diabetic retinopathy were enrolled. Macular OCT, FA, and CFI were reviewed and measured. Central foveal thickness was also measured.Results: The severity of diabetic retinopathy in FA was significantly higher than that in CFI (p < 0.001). OCT detected 26 eyes with DMEs, which included the following: 13 eyes with cystoid macular edemas; 13 eyes with serous retinal detachments; 11 eyes with diffuse retinal thickening; 4 eyes with vitreomacular interface abnormalities. In contrast, 72 out of 132 eyes (54.5%) showed macular leakages in FA, which was significantly higher than that detected by OCT (p < 0.001). Compared with FA, the sensitivity and the specificity of OCT in detecting DMEs were 30.6 and 93.3%, respectively. However, central foveal thickness was not significantly different between the patients with non-clinically significant macular edema (CSME, 253.1 ± 26.95 μm) and slight CSME (270.9 ± 37.11 μm, p = 0.204). The mean central foveal thickness in diabetic macular edema (FA) eyes was 271.8 ± 66.02 μm, which was significantly higher than that (253. ± 25.21 μm) in non-DME (FA) eyes (p = 0.039). The central foveal thickness in DME (FA) eyes was significantly lower than that in eyes with DME (OCT) (p = 0.014). After adjusting for age and sex, a logistic regression analysis showed that the classification of diabetic retinopathy in FA was positively associated with macular leakage in FA (p < 0.001).Conclusions: The severity of diabetic retinopathy is underestimated in CFI compared with that in FA. FA can detect latent DMEs, which appeared normal on OCT. The central foveal thickness is not a sensitive parameter for detecting latent DMEs.

Optical coherence tomography‐based determination of ischaemia onset – the temporal dynamics of retinal thickness increase in acute central retinal artery occlusion

Acute central retinal artery occlusion (CRAO) induces ischaemic retinal oedema. The purpose of this study was to define sensitivity and specificity of optical coherence tomography (OCT) based retinal thickness analysis in determining ischaemia onset in CRAO. The relative retinal thickness increase (RRTI) in comparison with the fellow eye was analysed retrospectively in OCT scans of 66 patients diagnosed with CRAO between January 2010 and December 2019 within 48hr of ischaemia onset. The natural course of RRTI and the sensitivity and specificity of OCT-based determination of ischaemia onset in identifying CRAO within 4.5hr using the RRTI were evaluated. Relative retinal thickness increase (RRTI) in acute CRAO follows a hyperbolic curve with a steep incline within the early phase after which it reaches a plateau. Optical coherence tomography (OCT)-based retinal thickness analysis in CRAO allows to differentiate patients with ischaemia onset within the past 4.5hr or thereafter with a sensitivity of 100% and a specificity of 94.3%. Relative retinal thickness increase (RRTI) allows to identify CRAO patients that are eligible for a potentially beneficial reperfusion therapy within a therapeutic window of 4.5hr with a high accuracy. Especially in patients with unknown ischaemia onset, this diagnostic tool could be of major importance in the future clinical management.

Detection of intracranial hypertension in children using optical coherence tomography: a systematic review protocol

IntroductionIntracranial hypertension (ICH) in children can have deleterious effects on the brain and vision. It is notoriously difficult to estimate intracranial pressure (ICP) in children and existing methods deliver suboptimal...

P3576Histopathological validation of optical coherence tomography assessment for cholesterol crystals

Abstract Background Cholesterol crystals (CCs) are well recognized as one of important components of advanced atherosclerotic plaques. Whilethe consensus document for intravascular optical coherence tomography (OCT) has proposed that CCs are appeared as thin, linear regions of high-signal intensity within a plaque, no study has validated CCs assessment by OCT in comparison with histopathology. Purpose Thepurpose of this study was to validate OCT assessments of CCs with histopathology. Methods A total of 27 diseased coronary artery samples (10–20 mm length) were resected from 7 randomly selected cadavers. OCT imaging was performed for the samples. Then, arterial samples were fixed in 10% formalin for ≥48 hours, decalcified and processed for standard paraffin embedding. Sections 5μm thick were sliced at the ink-marked imaging sites and stained with hematoxylin and eosin, and Masson's Trichrome. An independent pathologist blinded to the OCT results diagnosed all of the plaques. Subsequently, the OCT images were interpreted by an observer blinded to the histological results. In the OCT assessment, CCs were defined as thin, linear regions of high-signal intensity within a plaque. Results We obtained 27 pairs of OCT/ histopathology. CCs were diagnosed by histology in 10 (37%) of the 27 pairs. The sensitivity and specificity of OCT for detecting CCs were 60% and 94%, respectively. Conclusion OCT has a high specificity but modest sensitivity for detection of CCs in comparison with histopathology. CCs diagnosed with OCT would help the identification of advanced atherosclerotic plaques. Acknowledgement/Funding JSPS KAKENHI 17K09557

Sensitivity and specificity of optical coherence tomography in diagnosing polypoidal choroidal vasculopathy

To establish the diagnostic criteria for polypoidal choroidal vasculopathy (PCV) based on spectral-domain optical coherence tomography (SD OCT) by evaluating the sensitivity and specificity of SD OCT in differentiating PCV from wet age-related macular degeneration (wAMD). The clinical data were reviewed for 62 patients (63 eyes) with the initial diagnosis of PCV or wAMD between August, 2012 and June, 2016. Twenty-four patients (25 eyes) were diagnosed to have PCV and 38 (38 eyes) had wAMD based on findings by fundus photography, fluorescein angiography (FFA) and indocyanine green angiography (ICGA). Among the 6 features of SD OCT, namely a sharp RPED peak, double-layer sign, multiple RPED, an RPED notch, a hyporeflective lumen representing polyps, and hyperreflective intraretinal hard exudates, findings of the first two features and at least one of the other features sufficed the diagnosis of PCV; in the absence of the first two features, the diagnosis of PCV was also made when at least 3 of the other features were present simultaneously. The sensitivity and specificity of SD OCT-based diagnosis were estimated by comparison with the gold standard ICGA-based diagnosis. In the 25 eyes with an established diagnosis of PCV, 23 eyes (92.0%) met the diagnostic criteria based on SD OCT findings; in the 38 eyes with the diagnosis of wAMD, only 4 eyes (10.5%) met the criteria. The sensitivity and specificity of SD OCT-based diagnosis of PCV was 92.0% and 89.5%, respectively. s We established the diagnostic criteria for PCV based on SD OCT findings with a high sensitivity and specificity. SD OCT shows a strong capacity for differentiating PCV from wAMD.

Percutaneous Needle Based Optical Coherence Tomography for the Differentiation of Renal Masses: a Pilot Cohort

We determine the ability of percutaneous needle based optical coherence tomography to differentiate renal masses by using the attenuation coefficient (μOCT, mm(-1)) as a quantitative measure. Percutaneous needle based optical coherence tomography of the kidney was performed in patients presenting with a solid renal mass. A pathology specimen was acquired in the form of biopsies and/or a resection specimen. Optical coherence tomography results of 40 patients were correlated to pathology results of the resected specimens in order to derive μOCT values corresponding with oncocytoma and renal cell carcinoma, and with the 3 main subgroups of renal cell carcinoma. The sensitivity and specificity of optical coherence tomography in differentiating between oncocytoma and renal cell carcinoma were assessed through ROC analysis. The median μOCT of oncocytoma (3.38 mm(-1)) was significantly lower (p=0.043) than the median μOCT of renal cell carcinoma (4.37 mm(-1)). ROC analysis showed a μOCT cutoff value of greater than 3.8 mm(-1) to yield a sensitivity, specificity, positive predictive value and negative predictive value of 86%, 75%, 97% and 37%, respectively, to differentiate between oncocytoma and renal cell carcinoma. The area under the ROC curve was 0.81. Median μOCT was significantly lower for oncocytoma vs clear cell renal cell carcinoma (3.38 vs 4.36mm(-1), p=0.049) and for oncocytoma vs papillary renal cell carcinoma (3.38vs 4.79 mm(-1), p=0.027). We demonstrated that the μOCT is significantly higher in renal cell carcinoma vs oncocytoma, with ROC analysis showing promising results for their differentiation. This demonstrates the potential of percutaneous needle based optical coherence tomography to help in the differentiation of renal masses, thus warranting ongoing research.

Optical coherence tomography as a method to identify parathyroid glands

The identification of parathyroid glands can be a major problem in parathyroid surgery. The purpose of this study was to evaluate the feasibility of optical coherence tomography (OCT) in distinguishing between parathyroid tissue, thyroid tissue, lymph nodes, and adipose tissue. Ex vivo OCT images as well as histological sections were generated from parathyroid glands, thyroid tissue, lymph nodes and fat in order to define significant morphologic differences between these entities. As a second step all OCT images were separately evaluated by two blinded investigators and later compared to the corresponding histology. Sensitivity and specificity of OCT in distinguishing between the different tissues were determined. To assess the interobserver agreement, κ coefficients were calculated from the ratings of each investigator for each OCT image seen. A total of 320 OCT images from 32 patients undergoing thyroid surgery, parathyroidectomy or lymphadenectomy were compared with the corresponding histology. The sensitivity and specificity in distinguishing parathyroid tissue from the other entities was 84% (second investigator: 82%) and 94% (93%) respectively. Unweighted κ using four diagnostic categories was 0.97 (95% CI, 0.94-0.99) showing substantial agreement between both investigators. OCT is highly sensitive in distinguishing between parathyroid tissue, thyroid tissue, lymph nodes and adipose tissue. These ex vivo results should be confirmed by using OCT imaging intraoperatively.

Optical coherence tomography in the assessment of suspicious oral lesions: An immediate ex vivo study

Optical coherence tomography (OCT) is an evolving optical technology that is capable of delivering real-time, high-resolution signatures of tissue. The purpose of this immediate ex vivo prospective clinical study was: (1) to assess the sensitivity and specificity of OCT on biopsy material in identifying potentially malignant and malignant oral lesions, (2) to determine the inter-observer agreement in the analysis of specific image parameters, and (3) to find out the oral epithelial thickness for different pathology groups. This prospective study involved 125 suspicious oral lesions from 125 patients. The lesions were surgically biopsied and subjected to OCT in the immediate ex vivo phase. Two independent readers (surgeon and pathologist) examined the OCT images and assessed several cellular features including keratin layer, epithelial layer, basement membrane and lamina propria, and recorded their findings using special OCT reading score. The sensitivity, specificity and accuracy of OCT to predict "the future need for surgical biopsy in case of any similar lesion" were calculated. The epithelial thickness was also measured. The degree of agreement between the two readers was recorded. The pathological diagnosis revealed that the majority of lesions demonstrated microinvasive carcinomas (n=43). Forty-one had different degree of dysplasia. Benign oral lesions were less common and included 22 keratosis, 11 non-specific lesions, 6 mucocels and 2 papillomas. Optical coherence tomography achieved a sensitivity of 85% and a specificity of 78% in the assessment of oral potentially malignant and malignant disorders. The positive and negative predictive values were 86.5% and 77.5%, respectively. The accuracy was 82% and the kappa coefficient of inter-observer agreement was 0.72 on "the need for biopsy". OCT imaging of oral lesions provided valuable information on the oral epithelial thickness. This study proposes that OCT can accurately identify wide spectrum of oral tissue pathologies. Further studies can assess the role of OCT in evaluating and guiding surgical biopsies and monitoring disease.

Fizyolojik optik sinir başı çukurlaşması olan olgularda optik sinir başının heidelberg retina tomografisi ve optik koherens tomografi ile değerlendirilmesi: karşılaştırmalı çalışma

amaclandi. Gerec ve Yontem: Daha once glokom tanisi almamis ve rutin muayenede cup/disk orani (C/D) ≥ 0.6 olan fizyolojik cukurlasmali 57 olgunun 57 gozu ile C/D ≤ 0.4 olan 55 olgunun 55 gozu (normal grup) ve glokom birimimizde takipli erken glokomatoz hasari olan 56 hastanin 56 gozu calismaya alindi. Tum olgulara tam oftalmolojik muayene, gun ici intraokuler basinc takibi, gonyoskopi, santral kornea kalinligi (SKK), OKT ile RSLT kalinlik analizleri, HRT ile OSB parametreleri olcumleri ve GA testleri yapildi. Tum olgularin birer gozleri randomize olarak secildi. Bulgular: OKT ve HRT ile yapilan olcumlerde uc grup arasinda anlami farklilik oldugu goruldu (p<0.001). FC'li olgularin disk alaninin her iki gruptan anlamli olarak daha buyuk oldugu goruldu (p<0.001). FC'li olgularin cukurluk alani EG'lu olgularin cukurluk alanina benzer (p=0.085) bulunurken NK grubundaki olgulardan anlamli olarak yuksek bulunmustur (p<0.001). Rim alaninda beklendigi gibi FC'li ve NK' lu olgular arasinda fark yoktu (p=0.355) ve her iki grubun rim alani EG'lu olgulardan daha kalin olarak olculdu (p=0.002). FC, EG olgulari birbirinden ayirdedebilen en onemli OKT parametresinin ortalama RSLT kalinligi oldugu goruldu. OKT ve HRT ile yapilan olcumlerin FC'li olgulari ayirt etmedeki duyarliligi ve ozgunlugu karsilastirildiginda OKT'nin daha ustun oldugu goruldu. Sonuc: Optik koherens tomografi ve Heidelberg retina tomografisi genis optik sinir basi cukurlugu olan olgularin glokomdan ayriminda faydali olabilirler. Anahtar kelimeler: Fizyolojik cukurlasma, OKT, HRT, RSLT ABSTRACT Optic nerve head evaluation with heidelberg retinal tomography and optical coherence tomography in cases with physiologic large cups: a comperative study Objective: In this study we evaluated the optic nerve head (ONH) cupping parameters and thickness of retinal nerve fibre layers (RNFL) with Heidelberg retinal tomography (HRT) and optical coherence tomography (OCT) in patients with the diagnosis of physiological cupping whose intraocular pressure (IOP) and visual fields (VF) are normal but ONH cupping is more than 0.6. We then compared them with early glaucomatous (EG) patients and normal cases as control (NK). Material and Methods: The study enclosed 57 eyes of 57 patients having no previous diagnosis of glaucoma but with physiological cupping C/D≥0.6 on routine ophthalomological evaluation and 56 eyes of 56 early glaucomatous patients followed in our glaucoma unit. Control group (NK) consisted of 55 eyes of 55 cases with C/D≤0.4. All the patients were evaluated with whole ophthalmologic examination, intraocular pressure measurements, with gonioscopy and tests for thickness of central cornea (TCC), OCT, RNFL analyses, HRT, ONH parameters and VF tests. Only one eyes of each patient were randomly chosen. Results: All of the three groups were comparable with regards to TCC and refraction values (p=0.437 and p=0.478). But there was significant differences regarding OCT and HRT evaluations (p<0.001). Disc areas of PC cases were greater than those of other groups (p<0.001). The cupping area of PC cases was similar to those of EG cases (p=0.085) whereas it was significantly greater than those in control group (p<0.001). There was no difference in Rim area of PC and C groups as was expected (p=0.355) and Rim area of both groups was measured thicker than that of EG cases (p=0.002). It was seen that the most important OCT parameter differentiating PC and EG cases from each other was mean RNFL thickness. When the sensitivity and specificity of OCT and HRT measurements in differentiating PC cases were compared it was seen that OCT was superior. Conclusion: Optic coherence tomography and Heidelberg retinal tomography might be valuable in differentiating between large optic nerve head

Optical coherence tomography for the diagnosis of cervical intraepithelial neoplasia

Optical coherence tomography (OCT) permits high-resolution imaging of tissue subsurfaces up to 2 mm in depth. The purpose of this study was to evaluate the accuracy and reproducibility of OCT in the characterization of cervical intraepithelial neoplasia (CIN) and to distinguish between different CIN grades. Colposcopy-guided OCT images were taken from unsuspicious and suspicious areas in women with suspected CIN. Each woman then underwent directed biopsies. All OCT images were separately evaluated by two blinded investigators and later compared to the corresponding histology based on a 6-grade classification (normal, inflammation, CIN 1, CIN 2, CIN 3, squamous carcinoma). Sensitivity and specificity of OCT in detecting CIN were determined. To assess the interobserver agreement, kappa coefficients were calculated from the ratings of each investigator for each OCT image seen. A total of 210 OCT images were compared with the corresponding histology in 120 women undergoing colposcopy for suspected CIN. Sensitivity calculated for both investigators was 98% and 96% respectively with the threshold at CIN1 and 86% and 84% respectively with the threshold at CIN2. Thirty nine (38) false positive results reduced the specificity to 39% and 41% respectively with the threshold at CIN1. Defining the threshold at CIN2 the specificity increased to 64% and 60% respectively. Unweighted kappa from a dichotomous classification with the threshold at CIN1 was 0.69 (95% CI, 0.54-0.84) and 0.62 (95% CI, 0.51-0.73) with the threshold at CIN2. OCT is highly sensitive in identifying pre-invasive and invasive cancer of the uterine cervix. Improvements in resolution and the development of new light sources and optics may improve the specificity as well as the differentiation of cervical dysplasia. The interobserver agreement was substantial.

Study of the Diagnostic Efficacy of Real-Time Optical Coherence Tomography as an Adjunct to Unaided Visual Inspection With Acetic Acid for the Diagnosis of Preinvasive and Invasive Neoplasia of the Uterine Cervix

To determine the sensitivity and specificity of optical coherence tomography (OCT) as an adjunct to unaided visual inspection using acetic acid (VIA) in the detection of cervical intraepithelial neoplasia 2 (CIN 2) in a real-time clinical evaluation. This clinical study was a prospective cross-sectional comparative trial that screened 1000 patients (aged 30-50 years) in a low-resource setting. Women with abnormal cervical cytology or positive human papillomavirus (HPV) tests were referred for further evaluation including VIA, OCT imaging, colposcopy, and cervical biopsies. The VIA diagnoses were coded by quadrant. The OCT was then performed in all VIA-positive areas and at the squamocolumnar junction in all 4 quadrants. All patients were colposcoped; assessed by quadrant with biopsies at 2, 4, 8, and 10 o'clock; all abnormal areas were biopsied; and endocervical curettage was performed. Data were analyzed using generalized estimating equations and logistic regression. Of the 1000 patients, 175 (17.5%) were HPV positive, 93 (9.3%) had abnormal cervical cytology greater than or equal to atypical squamous cells of undetermined significance, and 211 (21.1%) were either HPV positive or had abnormal cytology. The VIA, OCT, colposcopy, and biopsies were completed on 183 (86.7%) of 211 women. For VIA alone, the sensitivity and specificity in detecting lesions greater than or equal to CIN 2 was 43% and 96%. With the addition of OCT, the sensitivity increases to 62% with a specificity of 80%. With the addition of OCT, the sensitivity of VIA increased in all analyses for the detection of greater than or equal to CIN II, with a loss in specificity. We hope that the potential of this technology will be realized when a computer algorithm is generated to aid in image interpretation.

Diagnostic Efficacy of Real-Time Optical Coherence Tomography in the Management of Preinvasive and Invasive Neoplasia of the Uterine Cervix

Determine the sensitivity and specificity of optical coherence tomography (OCT) as an adjunct to colposcopy in the detection of cervical intraepithelial neoplasia (CIN) grade 2 or higher in a real-time clinical evaluation. Optical coherence tomography (OCT) uses infrared light similar to ultrasound pulse-echo imaging. Image resolution is optimal in the 1-to-3-mm range. This study is the third in our series of OCT investigations and our first real-time clinical trial. The study was conducted at the Peking University Shenzhen Hospital, Shenzhen, China. Nonpregnant women 18 years or older with abnormal cervical cytologic findings or a positive high-risk human papillomavirus test result were recruited. Women were assessed; and diagnoses, recorded by cervical quadrant first with colposcopy, followed by colposcopic directed OCT. A biopsy of the abnormal areas was performed. In normal quadrants, biopsy specimens were obtained at the 2-, 4-, 8-, and 10-o'clock positions at the squamocolumnar junction depending on the quadrant. An endocervical curettage was also done. Individual OCT diagnoses were paired with colposcopic impressions and biopsy specimens to assess its role as a paired secondary screen. Data were analyzed using generalized estimating equations to control for correlation within a woman. One thousand two hundred thirty-seven paired diagnoses from 299 women were analyzed. Median age was 36 years. Ninety-six women (8%) had a diagnosis of CIN 2 or higher. Evaluation by quadrant showed that the sensitivity for CIN 2 or higher decreased by adding OCT to colposcopy, but the specificity increased from 83% to 93%. We continue to try to improve sensitivity by improving the near-infrared light source, decreasing the scan time to 8 frames per second, and using a larger diameter (5 mm) fiberoptic probe with a newly designed application specific probe sheath.

Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration Compared to Fluorescein Angiography and Visual Acuity

To assess the sensitivity and specificity of optical coherence tomography (OCT) for monitoring patients with choroidal neovascularization (CNV) after photodynamic therapy (PDT) in comparison to fluorescein angiography (FA). Prospective study of 14 patients with CNV secondary to age-related macular degeneration receiving PDT. Best-corrected visual acuity (BCVA), fluorescein angiography, and OCT (Zeiss Stratus OCT3) were performed before and at 2, 6, 12, and 24 weeks after treatment. FA images were assessed for leakage and presence of subretinal or intraretinal fluid was assessed on OCT images. Retinal thickness was measured automatically. OCT sensitivity and specificity levels for detecting leaking CNV were calculated. Retinal thickness was correlated with visual acuity. Mean follow-up time was 14.1 weeks. Sixty-one OCT/FA examinations were analyzed. Thirty-one examinations presented leakage (51%). OCT showed intraretinal fluid in 46 (75%) and subretinal fluid in 30 cases (49%). In 49 cases (80%), either intraretinal or subretinal fluid was present. Sensitivity for detecting intraretinal fluid in OCT was 90% (specificity 40%) and 71% (specificity 73%) for subretinal fluid. Combined sensitivity for intraretinal or subretinal fluid was 97% (specificity 37%). Increased central foveal thickness correlated with decreased BCVA. Correlations were significant (p<0.05). OCT showed good sensitivity in detecting active CNV. Specificity was only moderate. Central foveal thickness correlated negatively with visual acuity. Owing to different aspects of active CNV shown by FA and OCT, OCT should be combined with other examinations, and may not substitute FA for indication/reindication of PDT but can be a valuable addition in difficult cases.

Optical coherence tomography in pediatric patients: A feasible technique for diagnosing celiac disease in children with villous atrophy

Celiac disease is a common condition with many atypical manifestations, where histology serves as the "gold standard" for diagnosis. A useful new technique, optical coherence tomography, can depict villous morphology in detail, using light waves. This study examined the correlation between the sensitivity and specificity of optical coherence tomography in pediatric patients undergoing esophago-gastro-duodenoscopy for the diagnosis of celiac disease. A total of 134 children were prospectively enrolled, 67 with a serological suspicion of celiac disease (group 1) and 67 with negative histology for celiac disease (group 2). During a diagnostic esophago-gastro-duodenoscopy we acquired multiple images and films in the four quadrants of the second part of the duodenum, and biopsies were taken in the area where optical coherence tomography had been done. Three patterns of villous morphology were considered: pattern 1=no atrophy (types 0, 1 or 2 of the Marsh classification); pattern 2=mild atrophy (type 3a or 3b); pattern 3=marked atrophy (type 3c). The diagnosis of celiac disease was histologically confirmed in all 67 children with positive antiendomysium and/or antitransglutaminase antibodies. Optical coherence tomography correlated with pattern 1 histology in 11/11 cases, pattern 2 in 30/32 (93.8%) and pattern 3 in 22/24 (91.6%). Sensitivity and specificity were 82% and 100%. In the control group there was 100% concordance between optical coherence tomography and histology. The overall concordance between optical coherence tomography and histology in determining patchy lesions was 75%. Optical coherence tomography could be a helpful diagnostic tool in children with mild or marked villous atrophy for diagnosing celiac disease during upper gastrointestinal (GI) endoscopy, avoiding biopsies. However, duodenal biopsies are mandatory if the optical coherence tomography shows normal villous morphology in patients with positive antibodies.

Optical Coherence Tomography versus Stereoscopic Fundus Photography or Biomicroscopy for Diagnosing Diabetic Macular Edema: A Systematic Review

To review systematically the sensitivity and specificity of optical coherence tomography (OCT) for diagnosing macular edema attributable to diabetic retinopathy compared with well-established gold standard tests such as fundus stereophotography or contact and noncontact fundus biomicroscopy. Medline and Embase were searched electronically and six major ophthalmic journals from 1998 to 2006 were hand searched. Two reviewers independently assessed trial searches, studied quality with the QUADAS (Quality Assessment of Diagnostic Accuracy Studies) checklist, and extracted data. The target disease was clinically significant macular edema (CSME) according to Early Treatment of Diabetic Retinopathy Study (ETDRS) criteria. A bivariate model was used to obtain summary estimates of sensitivity and specificity and fit a summary receiver operating characteristic (ROC) curve. Fifteen studies were considered eligible. These studies were of good quality for most items of the QUADAS checklist, but most studies did not report masking of examiners and did not describe how withdrawals and undetermined results were treated. Seven studies included healthy control subjects, which could have artificially enhanced OCT diagnostic performance. All but one study included both eyes of the patients without taking into account the within-subject correlation in statistical analyses. Sensitivity and specificity data could be extracted from only 6 of 15 studies, because appropriate cross tabulations of index and reference tests were not reported by the others. In five of these studies, central retinal thickness cutoffs between 230 and 300 microm were adopted to define abnormal OCT results and considered the central type of CSME only, whereas in one study a complex algorithm accounting for extrafoveal CSME was used. The design of one study was case-control and was excluded from the meta-analysis. The expected operating point on the summary ROC, a pooled estimate of all studies, corresponded to a sensitivity of 0.79 (95% CI: 0.71-0.86), a specificity of 0.88 (95% CI: 0.80-0.93), a positive likelihood ratio of 6.5 (95% CI: 4.0-10.7), and a negative likelihood ratio of 0.24 (95% CI: 0.17-0.32). These values suggest a good overall performance of OCT for diagnosing CSME. OCT performs well compared with fundus stereophotography or biomicroscopy to diagnose diabetic macular edema. The quality of reporting of such studies should be improved, and authors should present cross tabulations of index and reference test results. Data adjusted for within-subject correlation should also be provided, although this issue represents a challenge for systematic reviewers.

Optical Coherence Tomography Evaluation of Ulcerative Colitis: The Patterns and the Comparison with Histology

The optical coherence tomography (OCT) is an imaging modality based on infrared light backscattering properties of tissues. OCT studies documented the disappearance of crypts and the alteration in light backscattering as features of ulcerative colitis (UC) in human colon. This technique should be more and more able to identify tissue microstructures with a resolution that is nearly that of histology (optical biopsy). To evaluate whether there are OCT patterns specific for UC and to compare the overall technique performance with the histology. A total of 27 patients (20-76 yr) with UC underwent OCT imaging during a total colonoscopy. The OCT images were collected both from affected and normal sites in active UC or disease in remission. Two biopsies of the same sites were acquired. The OCT images were separately scored. Two pathologists blinded to the endoscopic and OCT patterns scored the samples. Three OCT patterns were identified: the mucosal backscattering alteration (MBA), the delimited dark areas (DDA), and the layered colonic wall (LCW). In colon affected segments of active and UC in remission, these patterns showed a good correspondence with the histology. Moreover, in 14/25 (56%) normal sites above the affected segment, the OCT documented the pathological features, confirmed only in 10/14 by the histology. Thus, the assessed sensitivity and specificity of OCT in normal segments of UC patients have been 100% and 69%, respectively. The in vivo OCT correctly detected disease features in endoscopically affected colon segments, but even in apparently normal segments of UC patients.

Optical coherence tomography as a diagnostic aid to visual inspection and colposcopy for preinvasive and invasive cancer of the uterine cervix

The purpose of this study was to determine the sensitivity and specificity of optical coherence tomography (OCT) under two well-defined clinical settings. First, as an aid to cervical cancer screening, using visual inspection with acetic acid (VIA) in low-resource settings, and the second, as an adjunct to the traditional management of abnormal cervical cytology with colposcopy and biopsy. Patients referred for colposcopy with > or = atypical squamous cells of undetermined significance were accrued for the study. Each subject underwent VIA and colposcopy. OCT was performed in all VIA- and colposcopy-positive areas and at the squamocolumnar junction in all four quadrants. The sensitivity of VIA for > or = cervical intraepithelial neoplasia 2 was 76% (95% CI 58-88). When OCT was applied to VIA as a secondary screen, the specificity improved from 34% (95% CI 27-41) to 61% (95% CI 60-74). With liberal diagnostic criteria for the majority of the colposcopy examinations, OCT showed an even greater relative improvement in specificity. OCT proved to be a fair diagnostic modality (receiver operating characteristic curve 0.73) adjunctive to VIA and colposcopy. On the basis of the above findings, we believe that this technology could potentially show greatest utility in the management of cervical dysplasia in low-resource settings where a single episode of care is most desirable.

Diagnostic Accuracy of Optical Coherence Tomography and Integrated Backscatter Intravascular Ultrasound Images for Tissue Characterization of Human Coronary Plaques

The purpose of the present study was to validate the diagnostic accuracy of optical coherence tomography (OCT), integrated backscatter intravascular ultrasound (IB-IVUS), and conventional intravascular ultrasound (C-IVUS) for tissue characterization of coronary plaques and to evaluate the advantages and limitations of each of these modalities. The diagnostic accuracy of OCT for characterizing tissue types is well established. However, comparisons among OCT, C-IVUS, and IB-IVUS have not been done. We examined 128 coronary arterial sites (42 coronary arteries) from 17 cadavers; IVUS and OCT images were acquired on the same slice as histology. Ultrasound signals were obtained using an IVUS system with a 40-MHz catheter and digitized at 1 GHz with 8-bit resolution. The IB values of the ultrasound signals were calculated with a fast Fourier transform. Using histological images as a gold standard, the sensitivity of OCT for characterizing calcification, fibrosis, and lipid pool was 100%, 98%, and 95%, respectively. The specificity of OCT was 100%, 94%, and 98%, respectively (Cohen's kappa = 0.92). The sensitivity of IB-IVUS was 100%, 94%, and 84%, respectively. The specificity of IB-IVUS was 99%, 84%, and 97%, respectively (Cohen's kappa = 0.80). The sensitivity of C-IVUS was 100%, 93%, and 67%, respectively. The specificity of C-IVUS was 99%, 61%, and 95%, respectively (Cohen's kappa = 0.59). Within the penetration depth of OCT, OCT has a best potential for tissue characterization of coronary plaques. Integrated backscatter IVUS has a better potential for characterizing fibrous lesions and lipid pools than C-IVUS.