In vivo visualization of pyloric mucosal hypertrophy in infants with hypertrophic pyloric stenosis: is there an etiologic role?

OBJECTIVE: Infantile hypertrophic pyloric stenosis (IHPS) is a common condition which presents in infants at 2-12 weeks of postnatal life, and whose cause remains obscure. Multiple associated abnormalities have been recognized within the external hypertrophied pyloric muscle layer, but the internal component of the pyloric mucosa has received scant attention in the literature to date. Our purpose in this study was to show that pyloric mucosal redundancy is a constant finding in infants with IHPS, to discuss its possible cause, and to explore the hypothesis of a relationship between pyloric mucosal redundancy and the development of IHPS. MATERIALS AND METHODS: We identified 102 consecutive infants with surgically confirmed IHPS and determined the thickness of the pyloric mucosa compared with the thickness of the surrounding hypertrophied muscle. Fifty-one infants who did not have pyloric stenosis served as controls. RESULTS: Mean mucosal thickness in patients with IHPS approximated mean muscle thickness, with a ratio of 0.89. In infants with IHPS, the pyloric mucosa constitutes approximately one third of the cross-sectional diameter of the pyloric mass and fills and obstructs the pyloric canal. CONCLUSION: Mucosal redundancy is a constant associated finding in IHPS. Although the origin of the redundancy and a cause-and-effect relationship are difficult to establish, our findings support the hypothesis that hypergastrinemia may be implicated in the pathogenesis of IHPS, and suggest that mucosal thickening could be implicated as one of the initiating factors in its development.     

Is there an advantage to using computer aided detection for the early detection of pulmonary nodules within chest X-Ray imaging?

ObjectiveUsing published literature, this research examines whether Computer-aided Detection (CAD) identifies more Pulmonary Nodules (PN) within Chest X-ray (CXR) systems, compared to radiologist diagnosis without CAD.Key FindingsAlthough the primary papers were pointing to CAD being a beneficial system in the diagnosis of PN detection, a regression analysis of the data available within these papers showed no correlation between the higher sensitivity of CAD against the detrimental high False Positives (FP) of CAD. Findings of the studies were deemed inconclusive.ConclusionFurther research is recommended to review the potential of CAD on CXR PN detection.Implications for practiceCAD acting as a second reader could potentially reduce interpreter error rate.     

Colour flow Doppler ultrasound of the carotid bifurcation: can it replace routine angiography before carotid endarterectomy?

The objective of this study was to assess the diagnostic accuracy of colour flow Doppler ultrasound (CFD) and its potential to replace digital subtraction angiography (DSA) before carotid endarterectomy (CEA). All patients undergoing CFD of the carotid bifurcation in our department over a period of 1-1/2 years for whom both CFD and DSA results were available were included in the study. We evaluated the feasibility of CFD, its diagnostic accuracy and its potential to diagnose clinically significant stenosis (50%, 70% and 90% NASCET type diameter stenosis) compared with DSA. 225 carotid bifurcations in 116 patients met the criteria for evaluation (biplane arterial DSA without superimposition). Data analysis yielded the following diagnostic performance of CFD: sensitivity for a 50% stenosis 91.4% (95% confidence interval (CI) 83.3--96.2%), specificity 93.2% (95% CI 87.1--96.8%) and accuracy 92.4% (95% CI 88.4--95.4%); sensitivity for a 70% stenosis 89.2% (95% CI 81.9--94.1%), specificity 96.2% (95% CI 90.5--98.6%) and accuracy 92.4% (95% CI 88.4--95.4%). In 9 of 116 cases, carotid angiography was used to evaluate inconclusive CFD results. DSA disclosed relevant information not suspected by CFD in only 1 of the 116 cases. Thus, 91% (106/116) of the angiographies could have been dispensed with without loss of information. One major stroke occurred during diagnostic DSA. We conclude that DSA of the carotid arteries is unnecessary when CFD is unequivocal. The diagnostic gain of DSA must be counterweighted against its potential risks.     

Risk factors for fatal accidents and suicides in peacekeepers: is there an overlap?

OBJECTIVE: Previous research has indicated that there is an increased risk of fatal accidents in veterans of military operations and that such accidental deaths may be related to mental health problems. This study was conducted to investigate fatal accidents in Norwegian former peacekeepers. METHODS: A subgroup of alcohol-related fatal accidents was identified. Interview data with next of kin, military data and police report data from 17 cases of alcohol-related fatal accidents were compared with data from 28 cases of other accidents and 43 cases of suicide among Norwegian veterans of peacekeeping service. RESULTS: The alcohol-related fatal accidents were found to share many common features with the suicide group, such as depression, alcohol and substance abuse, and various social problems, and were also found to differ significantly from the other fatal accidents. CONCLUSIONS: The findings indicate a need for preventive measures directed at reducing the risk of premature death not only from suicide, but also from accidental death.     

Myocardial perfusion imaging protocols: is there an ideal protocol?

Is there an ideal myocardial perfusion imaging protocol? In order to answer this question and choose a protocol for clinical use, one must understand the characteristics of the available radiopharmaceuticals, the protocol variables, and the advantages and disadvantages of each. After reading this article, the technologist should be able to list the ideal characteristics of a myocardial perfusion imaging agent, describe and compare the characteristics of myocardial perfusion imaging agents, discuss the relationship between coronary blood flow and myocardial uptake of various tracers, describe imaging protocols, and discuss the advantages and disadvantages of each protocol.     

Post-fundoplication contrast studies: is there room for improvement?

Objective

Since the mid-1990s, laparoscopic fundoplication for gastro-oesophageal reflux disease has become the surgical procedure of choice. Several surgical groups perform routine post-operative contrast studies to exclude any (asymptomatic) anatomical abnormality and to expedite discharge from hospital. The purpose of this study was to determine the accuracy and interobserver reliability for surgeons and radiologists in contrast study interpretation.

Methods

11 surgeons and 13 radiologists (all blinded to outcome) retrospectively reviewed the contrast studies of 20 patients who had undergone a laparoscopic fundoplication. Each observer reported on fundal wrap position, leak or extravasation of contrast and contrast hold-up at the gastro-oesophageal junction (on a scale of 0–4). A κ coefficient was used to evaluate interobserver reliability.

Results

Surgeons were more accurate than radiologists in identifying normal studies (specificity=91.6% vs 78.9%), whereas both groups had similar accuracy in identifying abnormal studies (sensitivity=82.3% vs 85.2%). There was higher agreement amongst surgeons than amongst radiologists when determining wrap position (κ=0.65 vs 0.54). Both groups had low agreement when classifying a wrap migration as partial or total (κ=0.33 vs 0.06). Radiologists were more likely to interpret the position of the wrap as abnormal (relative risk=1.25) while surgeons reported a greater degree of hold-up of contrast at the gastro-oesophageal junction (mean score=1.17 vs 0.86).

Conclusion

Radiologists would benefit from more information about the technical details of laparoscopic anti-reflux surgery. Standardised protocols for performing post-fundoplication contrast studies are needed.Gastro-oesophageal reflux disease is a common problem within the community. 10–20% of the population experience symptoms of reflux or heartburn on a regular basis [1]. First-line treatment for most patients involves medical management alone, usually with proton pump inhibitors. However, a proportion of patients remain symptomatic despite maximal medical therapy and some are averse to taking medication on a long-term basis [2]. For these patients, surgical management with a laparoscopic fundoplication is an effective means of controlling symptoms [3].A total fundoplication is a 360° wrap using the fundus of the stomach to recreate a competent lower oesophageal sphincter or valve. Whilst a total fundoplication has been shown to be very effective in controlling reflux of acid into the distal oesophagus, many patients experience increased dysphagia, bloating and flatulence after the procedure. Various forms of partial fundoplication have been developed to minimise these adverse effects, in particular a 180° anterior wrap and a 270° posterior wrap [4-6].Early post-operative complications after laparoscopic antireflux surgery may include acute intrathoracic migration of the wrap [7-9], complete obstruction at the gastro-oesophageal junction (GOJ) [10] and perforation of the oesophagus or stomach [11]. Patients with a perforation or a complete obstruction are generally symptomatic and the decision to re-operate is made on the basis of their clinical symptoms and signs [12]. However, a recent study in our institution found that 15 out of 1894 (0.8%) patients who had undergone a laparoscopic fundoplication had an asymptomatic acute intrathoracic wrap migration and benefited from a routine early post-operative contrast study [12]. Prompt diagnosis of an asymptomatic wrap migration allows early laparoscopic re-intervention to repair the anatomical defect and prevents what would almost certainly be a more difficult revisional procedure if the diagnosis were delayed [10,13].Routine early contrast studies are therefore advocated in our institution for all patients undergoing laparoscopic fundoplication for gastro-oesophageal reflux disease. However, there is very little in the literature addressing the quality and accuracy of post-operative contrast swallows. One prior publication [14] found that agreement between two radiologists in differentiating partial (Type I) and total (Type II) wrap migrations was good (κ=0.84), but no mention was made of the accuracy of diagnosis nor of the interobserver reliability within and between upper gastrointestinal surgeons and radiologists. The aim of this study was to determine the accuracy and interobserver reliability of surgeons and radiologists in interpreting post-operative contrast studies following laparoscopic fundoplication.     

MDCT of abdominal wall hernias: is there a role for valsalva's maneuver?

OBJECTIVE: Our objective was to evaluate the role of Valsalva's maneuver during MDCT for the diagnosis and characterization of abdominal wall hernias. SUBJECTS AND METHODS: From September 2002 to May 2003, 100 consecutive patients (37 men and 63 women; mean age, 53 years) with suspected anterior abdominal wall hernias underwent 4-, 8-, or 16-MDCT with and without Valsalva's maneuver. Patients received both oral and IV contrast material. On a workstation, three independent reviewers evaluated each scan obtained during rest and during Valsalva's maneuver for the following parameters: anteroposterior (AP) diameter of the abdomen; presence, location, and contents of the hernia; and transverse diameter of the fascial defect. The scans were compared to assess for changes in hernia size and contents and to determine whether the hernia would have been overlooked without Valsalva's maneuver. Fisher's exact test, the McNemar test, and Cohen's kappa coefficient were used to assess for significant differences. RESULTS: The three reviewers identified a mean of 72 abdominal wall hernias (72%). The reviewers agreed (kappa = 0.723) with respect to the presence of a hernia. AP diameters increased an average of 1.33 cm during Valsalva's maneuver (p < 0.001). The transverse diameter of the fascial defect increased an average of 0.66 cm and the AP diameter of the hernia sac increased an average of 0.79 cm during Valsalva's maneuver (p < 0.001). Fifty percent of the hernias became more apparent with Valsalva's maneuver. Ten percent of the hernias could be detected only on the scan obtained during Valsalva's maneuver. Conversely, in no patients was the hernia detected only on the rest scan. CONCLUSION: As opposed to scans obtained at rest, scans obtained during Valsalva's maneuver aid in the detection and characterization of suspected abdominal wall hernias. A single scan obtained during Valsalva's maneuver is sufficient to detect 100% of anterior abdominal wall hernias identified on CT.