Development and implementation of an ultralow-dose CT protocol for the assessment of cerebrospinal shunts in adult hydrocephalus

Background Cerebrospinal fluid shunts in the treatment of hydrocephalus, although associated with clinical benefit, have a high failure rate with repeat computed tomography (CT) imaging resulting in a substantial cumulative radiation dose. Therefore, we sought to develop a whole-body ultralow-dose (ULD) CT protocol for the investigation of shunt malfunction and compare it with the reference standard, plain radiographic shunt series (PRSS). Methods Following ethical approval, using an anthropomorphic phantom and a human cadaveric ventriculoperitoneal shunt model, a whole-body ULD-CT protocol incorporating two iterative reconstruction (IR) algorithms, pure IR and hybrid IR, including 60% filtered back projection and 40% IR was evaluated in 18 adult patients post new shunt implantation or where shunt malfunction was suspected. Effective dose (ED) and image quality were analysed. Results ULD-CT permitted a 36% radiation dose reduction (median ED 0.16 mSv, range 0.07–0.17, versus 0.25 mSv (0.06–1.69 mSv) for PRSS (p = 0.002). Shunt visualisation in the thoracoabdominal cavities was improved with ULD-CT with pure IR (p = 0.004 and p = 0.031, respectively) and, in contrast to PRSS, permitted visualisation of the entire shunt course (p < 0.001), the distal shunt entry point and location of the shunt tip in all cases. For shunt complications, ULD-CT had a perfect specificity. False positives (3/22, 13.6%) were observed with PRSS. Conclusions At a significantly reduced radiation dose, whole body ULD-CT with pure IR demonstrated diagnostic superiority over PRSS in the evaluation of cerebrospinal fluid shunt malfunction.

High output heart failure as a result of an ilio-caval fistula with a negative shunt series

Congestive heart failure (CHF) with high cardiac output is an uncommon, yet attributable result of non-hemodialysis arteriovenous malformations. While the prevalence of high output heart failure has yet to be determined, it is observably low - specifically when looking at cases of high output heart failure as a result of ruptured abdominal aortic aneurysms (AAA) with fistula formation, an entity that carries a reported incidence of <1% of all complications of AAA. In this report, we present a 64-year-old male with high output heart failure secondary to a ruptured right common iliac aneurysm causing right ilio-iliac and ilio-caval fistulas.

Migration of Ventriculoperitoneal Shunt to Scrotum via Patent Processus Vaginalis

Hydrocephalus in children is either treated by ventriculoperitoneal shunt or Endoscopic third ventriculostomy (ETV) dependingupon specific factors pertaining to clinical and radiological diagnosis. There are many complications of ventriculoperitoneal shuntand migration of peritoneal to scrotum, anal canal, urinarry bladder has been reported. The intra abdominal complications aremanaged by a combined team work of neurosurgeon and Pediatric surgeon.We have reported a case in which patient was diagnosed as congenital hydrocephalus with a lumbar myelomeningocele one yearback, Right sided ventriculoperitoneal shunt was passed initially followed by lumbar myelomeningocele repair. Now patient waspresented by parents with scrotal swelling, clinical examination and shunt series X-rays showed migration of lower end ofventriculoperitoneal shunt to scrotum, pediatric surgeon was consulted in same institution, a single incision at right inguinalligament was used to replace the migrated catheter into abdomen and hernia repair.Key Words: Ventriculoperitoneal shunt, Scrotal migration, Post-operative shunt complications

Power flow management analysis using compensating techniques for managing congestion within electrical energy network

In a deregulated electrical energy system with increasing penetration of renewable energy sources, rescheduling of the power generation(s) is required, and it is going to congest some of the power lines in the complex power system. The power flow can be managed using different compensating techniques. This study presents power flow management analysis using selected compensation technologies (i.e. series, shunt, series-shunt, and D-FACTS) for congestion alleviation. In this work, an IEEE 6 bus distributed network is used and the mentioned compensating techniques are evaluated for congestion management considering a case of power line outage. It is observed some of the power lines are overloaded by 10%. To reduce the overloading; the series, shunt, series-shunt, D-FACTS compensation technologies are used and found that they can reduce the active power overloading of the congested line by 27%, 9.5%, 12%, and 27% respectively. But the apparent power congestions can be reduced using series and D-FACTS techniques by 14% compare to shunt and series-shunt techniques. It is affirmed that the D-FACTS can effectively manage the power flow compare to other compensation techniques and can offer other benefits (e.g. voltage quality, line power flows, injection of power at the buses, reduction in power losses, etc.).

The Role of 3D Reconstruction of the Skull in Patients with Suspected Shunt Malfunction

Background: Mechanical shunt malfunction may lead to significant morbidity and mortality. Shunt series assessments help evaluate shunt integrity; however, they are of limited value in the area of the skull due to skull curvature, thickness, and air sinuses. We describe the role of 3D bone reconstruction CT (3DCT) in demonstrating the shunt integrity over the skull, comparing this technique to skull X-rays (SXR). Methods: Data were collected retrospectively for shunted patients with concurrent SXR and 3DCT and for patients presenting with shunt failures at the region of the skull, including clinical course and radiological findings. We compared the SXR and 3DCT findings. The 3DCT was reconstructed from standard diagnostic CT protocols performed during evaluation of suspected shunt malfunction and not thin-slice CT protocols. Results: Forty-eight patients with 57 shunts underwent SXR and 3DCT. Interobserver agreement was high for most variables. Both SXR and 3DCT had a high sensitivity, specificity, and accuracy identifying tubing disconnections (between 0.83 and 1). Full valve type and setting were significantly more accurate based on SXR versus 3DCT (>90 vs. <20%), and valve integrity was significantly more readily verified on 3DCT versus SXR (100 vs. 52%). Conclusions: 3DCT and SXR complement each other in diagnosing mechanical shunt malfunctions over the skull. The main limitation of 3DCT is identification of valve type and settings, which are clearer on SXR, while the main limitation of SXR is a less ability to evaluate valve integrity. 3DCT also enables an intuitive 3D understanding of the shunt tubing over the skull.