Intraoperative near infrared functional imaging of rectal cancer using artificial intelligence methods - now and near future state of the art.

Colorectal cancer remains a major cause of cancer death and morbidity worldwide. Surgery is a major treatment modality for primary and, increasingly, secondary curative therapy. However, with more patients being diagnosed with early stage and premalignant disease manifesting as large polyps, greater accuracy in diagnostic and therapeutic precision is needed right from the time of first endoscopic encounter. Rapid advancements in the field of artificial intelligence (AI), coupled with widespread availability of near infrared imaging (currently based around indocyanine green (ICG)) can enable colonoscopic tissue classification and prognostic stratification for significant polyps, in a similar manner to contemporary dynamic radiological perfusion imaging but with the advantage of being able to do so directly within interventional procedural time frames. It can provide an explainable method for immediate digital biopsies that could guide or even replace traditional forceps biopsies and provide guidance re margins (both areas where current practice is only approximately 80% accurate prior to definitive excision). Here, we discuss the concept and practice of AI enhanced ICG perfusion analysis for rectal cancer surgery while highlighting recent and essential near-future advancements. These include breakthrough developments in computer vision and time series analysis that allow for real-time quantification and classification of fluorescent perfusion signals of rectal cancer tissue intraoperatively that accurately distinguish between normal, benign, and malignant tissues in situ endoscopically, which are now undergoing international prospective validation (the Horizon Europe CLASSICA study). Next stage advancements may include detailed digital characterisation of small rectal malignancy based on intraoperative assessment of specific intratumoral fluorescent signal pattern. This could include T staging and intratumoral molecular process profiling (e.g. regarding angiogenesis, differentiation, inflammatory component, and tumour to stroma ratio) with the potential to accurately predict the microscopic local response to nonsurgical treatment enabling personalised therapy via decision support tools. Such advancements are also applicable to the next generation fluorophores and imaging agents currently emerging from clinical trials. In addition, by providing an understandable, applicable method for detailed tissue characterisation visually, such technology paves the way for acceptance of other AI methodology during surgery including, potentially, deep learning methods based on whole screen/video detailing.

Multimodality imaging of the gastrointestinal manifestations of scleroderma.

Scleroderma is a complex multisystem connective tissue disorder. Early visceral disease, such as gastrointestinal (GI) involvement, is associated with significant morbidity and a poorer prognosis. Prompt diagnosis is crucial to allow disease modifying therapies be initiated early in the course of the disease. The primary underlying pathophysiology in the GI tract is dysmotility, muscular atrophy, and fibrosis, and this is reflected in the imaging features. In this paper, we demonstrate the imaging appearances of involvement of the GI tract and describe the use of advanced imaging with magnetic resonance enterography (MRE). A multimodal imaging approach is required to identify both characteristic features of scleroderma and potential complications. Traditional fluoroscopic contrast (barium) studies are still commonly performed for assessment of the oesophagus. More recent advances in cross-sectional imaging allow for thorough three-dimensional assessment of the entire GI tract. MRE is particularly useful for small bowel evaluation while also allowing "pseudodynamic" functional imaging and concomitant assessment of the other abdominal viscera and structures.

National Survey of CT Colonography Practice in Ireland.

CT Colonography was first introduced to Ireland in 1999. Our aim of this study is to review current CT Colonography practices in the Republic of Ireland. A questionnaire on CT Colonography practice was sent to all non-maternity adult radiology departments in the Republic of Ireland with a CT scanner. The results are interpreted in the context of the recommendations on CT Colonography quality standards as published by the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus statement in the journal of European Radiology in 2013. Thirty centres provide CT Colonography; 21 of which responded (70%). Each centre performs median 90 studies per year; the majority follow accepted patient preparation and image acquisition protocols. Seventy-six percent of the centres repsonded that the majority of patients imaged are symptomatic. Of the 51 consultant radiologists reading CT Colonography, 37 (73%) have attended a CT Colonography course. In 17 (81%) of the centres the studies are single read although 81% of the centres have access to a second radiologist's opinion. Fourteen (67%) of the centres reported limited access to CT scanner time as the major limiting factor to expanding their service. CT Colonography is widely available in Ireland and is largely performed in accordance with European recommendations.

Mixed evidence for the potential of non-invasive transcutaneous vagal nerve stimulation to improve the extinction and retention of fear.

Extinction memories are fragile and their formation has been proposed to partially rely on vagus nerve activity. We tested whether stimulating the auricular branch of the vagus (transcutaneous VNS; tVNS) accelerates extinction and reduces spontaneous recovery of fear. Forty-two healthy students participated in a 3-day fear conditioning study, where we tested fear acquisition (day 1), fear extinction (day 2) and the retention of the extinction memory (day 3). During extinction, participants were randomly allocated to receive tVNS or sham stimulation concurrently with each CS presentation. During the acquisition and retention phases, all participants received sham stimulation. Indexes of fear included US-expectancy, startle blink EMG and skin conductance responses. Results showed successful acquisition and extinction of fear in all measures. tVNS facilitated the extinction of declarative fear (US expectancy ratings), but did not promote a stronger retention of the declarative extinction memory. No clear effects of tVNS on extinction and retention of extinction were found for the psychophysiological indexes. The present findings provide tentative indications that tVNS could be a promising tool to improve fear extinction and call for larger scale studies to replicate these effects.

Giant solitary non-parasitic cyst of the liver.

BACKGROUND: Cystic diseases of the liver and intrahepatic biliary tree are uncommon. The majority of cases are detected only when patients become symptomatic, or as an incidental finding on radiological imaging. METHODS: We discuss the case of a 25-yr-old female with a centrally located giant liver cyst causing obstructive jaundice, and briefly discuss the management options in the treatment of this uncommon problem. RESULTS AND CONCLUSIONS: Intervention is recommended in patients with symptomatic simple cysts of the liver. Surgical cystectomy is the treatment of choice for large deep seated cysts.

Tracheobronchial amyloidosis. The Boston University experience from 1984 to 1999.

Tracheobronchial amyloidosis (TBA), an idiopathic disorder characterized by deposition of fibrillar proteins in the tracheobronchial tree, occurred in 10 patients referred to the Amyloid Program at Boston University over the past 15 years. Fewer than 100 cases of TBA have been described; only 1 series encompassed more than 3 patients. We analyzed our experience with biopsy-proven TBA to define better its natural history. Follow-up averaged approximately 8 years and was obtained in all cases, making this outcome reporting the largest and most complete to date. Three of these patients were prospectively studied for up to 24 months to examine the utility of bronchoscopy, computerized tomography (CT) imaging, and pulmonary function tests (PFTs) in monitoring disease progression. No patient with TBA developed signs or symptoms of systemic amyloidosis during the period reviewed. Conversely, tracheobronchial disease was not diagnosed in 685 patients with primary systemic (AL) amyloidosis during the 15-year study period at Boston University. Bronchoscopy proved most useful in establishing the diagnosis by biopsy. Narrowing of major airways limited its inspection of the tracheobronchial tree, however. In contrast, CT imaging provided quantitative assessment of airway narrowing and mural thickening--2 major consequences of amyloid infiltration. These CT features, in the presence of mural calcifications sparing the posterior tracheal membrane, have been reported in few disorders other than TBA. The ability of CT to map airway involvement and identify extraluminal manifestations of TBA made it the study of choice for establishing disease extent. Three patterns of disease were evident by CT imaging and bronchoscopic examination: proximal, mid, and distal airways involvement. Those with severe proximal disease had significantly decreased air flows, air trapping, and fixed upper airway obstruction on PFTs. Patients with distal disease had normal airflows. PFTs could not clearly distinguish proximal from severe mid airways disease. Thirty percent of patients died within 7-12 years after diagnosis, all having proximal or severe mid airways disease. Repeated rigid bronchoscopic debridement and laser treatments did not prevent progressive airways narrowing in patients dying from TBA. Most patients with mid airways involvement, and all distal airway cases, had either stagnant disease or slowly increasing amyloid deposits when followed for up to 14 years. In a small subset of patients followed prospectively, serial PFTs were most sensitive to disease progression. CT-derived measures of airway lumen diameter and wall thickness did not change significantly despite marked improvements in airflow after rigid bronchoscopy. Our experience suggests that serial PFTs and CT imaging together offer the best assessment of airway involvement and disease progression in patients with TBA. In the future, radiation therapy may provide more definitive treatment of TBA than debulking procedure have to date.

Incidence of adrenal masses in patients referred for renal artery stenosis screening MR.

RATIONALE AND OBJECTIVES: Prior work has shown the efficacy of magnetic resonance (MR) in renal artery stenosis evaluation. The increasing role of renal artery stenosis in the differential diagnostic evaluation of hypertension raises the question of whether MR should be used as a screening modality. This project evaluated the additional potential benefits of MR by determining the incidence of adrenal masses in this selected population. METHODS: A 2-year retrospective study analysis of patients who failed to respond to antihypertensive medical management and were referred for renal MR for hypertension amassed 77 subjects ranging in age from 18 to 88 years. A masked analysis for adrenal masses was performed on this data set. Magnetic resonance techniques included T2-weighted turbo spin-echo (repetition time [TR] 2000-4000 ms, echo time [TE] 80-100 ms, turbo factor 2-16), T1-weighted spin-echo (TR 200-500 ms, TE 10-30 ms), gradient-echo time-of-flight (TR 26 ms, TE 6.9 ms, 40 degrees flip angle, 2 excitations), and dynamic gadopentetate dimeglumine-enhanced MR angiography (three-dimensional gradient recalled echo, TR 10 ms, TE 3 ms, 40 degrees flip angle, 1 excitation). RESULTS: Thirty-three patients had renal artery disease, 44 had normal renal arteries, and 7 had adrenal masses. Forty-three percent of patients who underwent renal MR had disease of the renal arteries detected, and 9% of patients referred for MR had adrenal masses that would have been missed with scintigraphy and/or angiography, of which 57% were responsible for hypertension. CONCLUSIONS: The ability to evaluate renal artery and adrenal anatomy globally can be useful, as exemplified in the current series, and the adrenals should be examined carefully in any renal MR in a hypertensive patient.

Thin-section helical computed tomography of the bladder: initial clinical experience with virtual reality imaging.

OBJECTIVES: To evaluate the application of virtual reality imaging of the bladder (virtual cystoscopy) in the detection of bladder masses. METHODS: Six patients (mean age 61 years, range 43 to 75) with hematuria and positive findings on conventional cystoscopy were studied by means of thin-section helical computed tomography of the air-distended bladder. Using volume-rendering algorithms, interactive intraluminal views of the bladder mucosa were generated (virtual cystoscopy). Results of virtual cystoscopy were compared with those of conventional cystoscopy in each case. RESULTS: Twenty-six (100%) of 26 masses (mean size 1.7 cm, range 0.3 to 6), detected on conventional cystoscopy, were visualized on virtual cystoscopy. Twelve of 26 masses measured less than 1 cm in maximum diameter. All masses were pathologically proven transitional cell carcinomas. Virtual cystoscopy was well tolerated by all patients, and no complications occurred. CONCLUSIONS: Our results indicate that virtual cystoscopy is an accurate technique for detection of intrinsic bladder masses. It may represent a radiologic adjunct to conventional cystoscopy for initial evaluation of patients with hematuria and for surveillance of patients after bladder tumor resection.

Primary hepatic lymphoma in a man with chronic hepatitis C.

We report the case of a middle-aged man who presented de novo with abdominal pain and hepatomegaly and was found to have positive serology for hepatitis C and subsequently a primary hepatic lymphoma. An increased incidence of primary hepatocellular cancer is well characterized in both cirrhotic and non-cirrhotic cases of chronic hepatitis C. The relationship between chronic hepatitis C and primary hepatic lymphoma remains obscure. It has been established that hepatitis C can sustain the clonal B-cell expansion that occurs in associated cryoglobulinaemia, and hepatitis C RNA has been detected within extrahepatic lymphoma tissue. Viral aetiologies for lymphoma are well characterized, such as Epstein-Barr virus (EBV) and human T-cell leukaemia virus (HTLV) I and II. Existing models of chronic infection causing lymphoma within the gastrointestinal tract include that of Helicobacter pylori and mucosa-associated lymphoid tumour of the stomach. Given the relatively low frequency of occurrence it may be prudent to perform a retrospective analysis on past cases of primary hepatic lymphoma in order to determine whether or not hepatitis C was present.

Advances in abdominal, aortic, and peripheral contrast-enhanced MR angiography.

This article reviews the basic principles of contrast-enhanced MR angiography, including methods used for sequence optimization and bolus timing, and describes clinical applications of contrast-enhanced MR angiography in the aortic, abdominal, and peripheral arteries. Novel MR angiography imaging techniques also are described, including moving table-top MR angiography, MR fluoroscopy, and time-resolved MR angiography.

Coronary artery fistula; coronary computed topography--the diagnostic modality of choice.

Coronary artery fistulae (CAF) are rare anomalies. They are vascular communications between the coronary arteries and other cardiac structures, either cardiac chambers or great vessels. There can be considerable variation in the course of a coronary artery fistula. We report a case of a coronary artery fistula between the left circumflex coronary artery and the right and left atria. CAF are often diagnosed by coronary angiogram, however with the advent of new technologies such as Coronary Computed Tomography Angiography (Coronary CTA) the course and communications of these fistulae can be delineated non-invasively and with greater accuracy.

CT colonography: pitfalls and interpretation.

A knowledge of normal colonic anatomy and its variants as demonstrated on CT colonography is essential to limit false positive results and ensure a high sensitivity for polyp detection. Interpretive and perceptual errors undoubtedly decrease with increasing operator experience. To provide a confident and accurate report, radiologists must be familiar with common pitfalls and pseudolesions on CT colonography.

Transrectal US in male infertility: spectrum of findings and role in patient care.

PURPOSE: To determine the findings at transrectal ultrasound (US) in infertile men with low-volume azoospermia and to evaluate its role in patient care. MATERIALS AND METHODS: Transrectal US was performed on 276 infertile men with a mean age of 34 years (range, 24-52 years) who had documented low ejaculate volumes and azoospermia. RESULTS: Of the 276 men, 70 (25.4%) had no anatomic abnormalities. In the remaining patients, abnormalities included congenital bilateral absence of the vas deferens in 94 (34.1%) patients; bilateral occlusion of the vas deferens, seminal vesicles, and ejaculatory ducts by calcification or fibrosis in 43 (15.6%) patients; unilateral absence of the vas deferens in 31 (11.2%) patients; obstructing cysts of the seminal vesicles, vas deferens, ejaculatory ducts, or prostate in 26 (9.4%) patients; and ductal obstruction secondary to calculi in 12 (4.4%) patients. CONCLUSION: Transrectal US is a safe and accurate method for evaluating the distal male reproductive tract that helps identify patients with potentially correctable causes of infertility.

Ileal loop conduit volvulus: a rare but reversible cause of bilateral ureteric obstruction.

Conduit volvulus is a very rare complication of ileal loop diversion. To date it has not been described in association with parastomal herniae. We report two such cases. Antegrade nephrostogram established the diagnosis and nephrostomy drainage facilitated spontaneous resolution of the volvulus with return to baseline renal function in both patients. Percutaneous drainage was the only intervention required in one case. For the second patient, percutaneous decompression permitted elective surgical refashioning of the conduit following clinical stabilization. Conduit volvulus in association with a parastomal hernia is a potentially reversible cause of renal impairment in patients with urinary diversions. The diagnosis depends on accurate radiological evaluation. The initial treatment of choice is percutaneous drainage with elective surgery when the patient's clinical status has improved.