Evaluation of 4 three-dimensional representation algorithms in capsule endoscopy images

AIM:To evaluate the three-dimensional(3-D)representation performance of 4 publicly available Shapefrom-Shading(SfS)algorithms in small-bowel capsule endoscopy(SBCE).METHODS:SfS techniques recover the shape of objects using the gradual variation of shading.There are4 publicly available SfS algorithms.To the best of our knowledge,no comparative study with images obtained during clinical SBCE has been performed to date.Three experienced reviewers were asked to evaluate 54 twodimensional(2-D)images(categories:protrusion/inflammation/vascular)transformed to 3-D by the aforementioned SfS 3-D algorithms.The best algorithm was selected and inter-rater agreement was calculated.RESULTS:Four publicly available SfS algorithms were compared.Tsai’s SfS algorithm outperformed the rest(selected as best performing in 45/54 SBCE images),followed by Ciuti’s algorithm(best performing in 7/54images)and Torre o’s(in 1/54 images).In 26/54 images;Tsai’s algorithm was unanimously selected as the best performing 3-D representation SfS software.Tsai’s 3-D algorithm superiority was independent of lesion category(protrusion/inflammatory/vascular;P=0.678)and/or CE system used to obtain the 2-D images(MiroCam/PillCam;P=0.558).Lastly,the interobserver agreement was good(kappa=0.55).CONCLUSION:3-D representation software offers a plausible alternative for 3-D representation of conventional capsule endoscopy images(until optics technology matures enough to allow hardware enabled-"real"3-D reconstruction of the gastrointestinal tract).

Distinct colonoscopy findings of microscopic colitis:Not so microscopic after all?

Microscopic colitis(MC) is considered an "umbrella term",comprising two subtypes,i.e.,collagenous colitis(CC) and lymphocytic colitis(LC).They are classically associated with normal or unremarkable colonoscopy.In the last few years,reports have been published revealing findings that are thought to be characteristic or pathognomonic of MC,especially CC.A systematic electronic and manual search of PubMed and EMBASE(to December 2010),for publications on distinct endoscopic findings in MC,resulted in 42 relevant reports for inclusion in this review.Eighty eight patients with collagenous colitis were presented.Only one publication describing a distinct endoscopic pattern in LC was found.Typical findings in CC are alteration of the vascular mucosal pattern,mucosal nodularity,a sequence of change from mucosal defects to mucosal cicatricial lesions,and perhaps(although of doubtful relevance) mucosal pseudomembranes.A causal connection of mucosal defects with the use of lansoprazole seems to exist.Adoption of the proposed lesion description herein is recommended in order to improve homogeneity of future reports.

Use of enhancement algorithm to suppress reflections in 3-D reconstructed capsule endoscopy images

In capsule endoscopy(CE), there is research to develop hardware that enables ‘‘real'' three-dimensional(3-D) video. However, it should not be forgotten that ‘‘true'' 3-D requires dual video images. Inclusion of two cameras within the shell of a capsule endoscope though might be unwieldy at present. Therefore, in an attempt to approximate a 3-D reconstruction of the digestive tract surface, a software that recovers information-using gradual variation of shading-from monocular two-dimensional CE images has been proposed. Light reflections on the surface of the digestive tract are still a significant problem. Therefore, a phantom model and simulator has been constructed in an attempt to check the validity of a highlight suppression algorithm. Our results confirm that 3-D representation software performs better with simultaneous application of a highlight reduction algorithm. Furthermore, 3-D representation follows a good approximation of the real distance to the lumen surface.

Diabetic cardiomyopathy:Pathophysiology,diagnostic evaluation and management

Diabetes affects every organ in the body and cardiovascular disease accounts for two-thirds of the mortality in the diabetic population.Diabetes-related heart disease occurs in the form of coronary artery disease(CAD),cardiac autonomic neuropathy or diabetic cardiomyopathy(DbCM).The prevalence of cardiac failure is high in the diabetic population and DbCM is a common but underestimated cause of heart failure in diabetes.The pathogenesis of diabetic cardiomyopathy is yet to be clearly defined.Hyperglycemia,dyslipidemia and inflammation are thought to play key roles in the generation of reactive oxygen or nitrogen species which are in turn implicated.The myocardial interstitium undergoes alterations resulting in abnormal contractile function noted in DbCM.In the early stages of the disease diastolic dysfunction is the only abnormality,but systolic dysfunction supervenes in the later stages with impaired left ventricular ejection fraction.Transmitral Doppler echocardiography is usually used to assess diastolic dysfunction,but tissue Doppler Imaging and Cardiac Magnetic Resonance Imaging are being increasingly used recently for early detection of DbCM.The management of DbCM involves improvement in lifestyle,control of glucose and lipid abnormalities,and treatment of hypertension and CAD,if present.The role of vasoactive drugs and antioxidants is being explored.This review discusses the pathophysiology,diagnostic evaluation and management options of DbCM.

Small-bowel capsule endoscopy: A ten-point contemporary review

The introduction of capsule endoscopy (CE) in clinical practice increased the interest for the study of the small-bowel. Consequently, in about 10 years, an impressive quantity of literature on indications, diagnostic yield (DY), safety profile and technical evolution of CE has been published as well as several reviews. At present time, there are 5 small-bowel capsule enteroscopy (SBCE) models in the worldwide market. Head-to-head trials have showed in the great majority of studies comparable results in terms of DY, image quality and completion rate. CE meta-analyses formed the basis of national/international guidelines; these guidelines place CE in a prime position for the diagnostic work-up of patients with obscure gastrointestinal bleeding, known and/or suspected Crohn's disease and possible small-bowel neoplasia. A 2-L polyethylene glycol-based purge, administered the day before the procedure,is the most widely practiced preparation regimen. Whether this regimen can be further improved (i.e. , by further decreasing its volume, changing the timing of administration, coupling it with prokinetics and/or other factors) or if it can really affect the DY, is still under discussion. Faecal calprotectin has been used in SBCE studies in two settings: in patients taking non-steroidal anti-inflammatory drugs, to evaluate the type and extent of mucosal damage and, more importantly from a clinical point of view, in patients with known or suspected Crohn's disease for assessment of inflam-mation activity. Although there is still a lot of debate around the exact reasons of SBCE poor performance in various small-bowel segments, it is worth to remember that the capsule progress is non-steerable, hence more rapid in the proximal than in lower segments of the small-bowel. Capsule aspiration, a relatively unexpected complication, has been reported with increasing frequency. This is probably related with the increase in the mean age of patients undergoing CE. CE video review is a time-consuming procedure. Therefore, several attempts have been made to develop technical software features, in order to make CE video analysis easier and shorter (without jeopardizing its accuracy). Suspected Blood Indicator, QuickView and Fujinon Intelligent Chromo Endoscopy are some of the software tools that have been checked in various clinical studies to date.

Wireless endoscopy in 2020:Will it still be a capsule?

Currently,the major problem of all existing commercial capsule devices is the lack of control of movement.In the future,with an interface application,the clinician will be able to stop and direct the device into points of interest for detailed inspection/diagnosis,and therapy delivery.This editorial presents current commerciallyavailable new designs,European projects and delivery capsule and gives an overview of the progress required and progress that will be achieved-according to the opinion of the authors- in the next 5 year leading to 2020.

Capsule-odometer: A concept to improve accurate lesion localisation

In order to improve lesion localisation in small-bowel capsule endoscopy,a modified capsule design has been proposed incorporating localisation and-in theorystabilization capabilities.The proposed design consists of a capsule fitted with protruding wheels attached to a spring-mechanism.This would act as a miniature odometer,leading to more accurate lesion localization information in relation to the onset of the investigation(spring expansion e.g.,pyloric opening).Furthermore,this capsule could allow stabilization of the recorded video as any erratic,non-forward movement through the gut is minimised.Three-dimensional(3-D)printing technology was used to build a capsule prototype.Thereafter,miniature wheels were also 3-D printed and mounted on a spring which was attached to conventional capsule endoscopes for the purpose of this proof-of-concept experiment.In vitro and ex vivo experiments with porcine small-bowel are presented herein.Further experiments have been scheduled.

Upper oesophageal images and Z-line detection with 2 different small-bowel capsule systems

Transmission of oesophageal images may vary between different small-bowel capsule endoscopy models. A retrospective review of 100 examinations performed with 2 different Small-bowel capsule endoscopy （SBCE） sys- tems （PillCam and MiroCam） was performed. The oral cavity/aero-digestive tract （i.e., tongue, uvula and/or epiglottis） was captured/identified in almost all （99%） of PillCam videos but in none of MiroCam cases, P 〈 0.0001. Furthermore, oesophageal images （i.e., from the upper oesophageal sphincter to the Z-line were cap- tured in 99% of PillCam videos （mean =1= SD, 60.5 ± 334.1 frames, range： 0-3329 frames） and in 66% of Mi- roCam cases （mean ± SD, 11.1 ± 46.5 frames, range： 0-382 frames）, P 〈 0.0001. The Z-line was identified in 42% of PilICam videos and 17% of MiroCam, P = 0.0002. This information might be useful when perform- ing SBCE in patients with high risks for aspiration.

Three-dimensional image reconstruction in capsule endoscopy

To date,limited research has been carried out in developing methods and materials that offer three-dimensional(3-D) representation of the digestive tract.In the field of capsule endoscopy(CE),hardware approaches have been developed that provide real time both 3-D information and texture using an infrared projector and a complementary metal oxide semiconductor camera.The major drawbacks of this system are its size,power consumption and packaging issues.A software approach to approximate a 3-D representation of digestive tract surface utilising current CE technology has been proposed.The algorithm utilizes the Shape from Shading technique and seem to provide promising results for polypoid structures and angioectasias.Further clinical evaluation is currently under way.

Microsurgical repair of severed thoracic spinal cord and clinical outcome:technical case report

Background:This report describes a case of successful repair of severed thoracic spine in a young man who presented with a penetrating stab injury to spine resulting in Brown-Séquard syndrome.Surgical technique and postoperative management is discussed.Case presentation:A 34-year-old fit and well healthy man was admitted with a history of stab injury to the thoracic spine at thoracic T2/3 level with ASIA impairment score(AIS)score D with an incomplete spinal cord affecting his left lower limb with complete paralysis and right lower limb paresis with impaired sensation below T6 level to L5.Neuroimaging confirmed a penetrating knife injury traversing the T2/3 level causing hemi-section of the spinal cord confirmed intraoperatively.He underwent an urgent exploratory surgery of his spine and a T2/3 laminectomy was performed to aid removal of the knife.The dura was noted to be contused and severed spinal cord was noted to be severed with associated cord oedema.A microsurgical repair of the severed cord was performed with duroplasty followed by intense neuro-rehabilitation.On a 3 month follow up his AIS score is E with lower limb power is 5/5 bilaterally and he is able to mobilise independently up to 8-10 steps without any supportive aid and with crutches he is independently functional and mobile.Conclusion:This is the first documented case of microsurgical repair of severed thoracic spinal cord secondary to traumatic knife injury.In the management of such scenario,apart from the removal of foreign body,repair of the cord with duroplasty should be carefully considered.The role of spinal neuroplasticity in healing following timely repair of the spinal cord along with intense rehabilitation remains the key.This had resulted in a good clinical and functional outcome with in a 18-month follow up.