Imaging evaluation of CSF shunts

Rare Complications of CSF Diversion: Paradoxical Neuroimaging Findings in a Double, Chiasmic Case Report

Two patients with CSF shunting systems exhibited symptoms of altered intracranial pressure. Initial neuroimaging led to misinterpretation, but integrating clinical history and follow-up imaging revealed the true diagnosis. In the first case, reduced ventricular size was mistaken for CSF overdrainage, while the actual problem was increased intracranial pressure, as seen in slit ventricle syndrome. In the second case, symptoms attributed to intracranial hypertension were due to CSF overdrainage causing tonsillar displacement and hydrocephalus. Adjusting the spinoperitoneal shunt pressure resolved symptoms and imaging abnormalities. These cases highlight the necessity of correlating clinical presentation with a deep understanding of CSF dynamics in shunt assessments.

EEG Correlates of Spikes in Intracranial Pressure Caused by Transient Ventriculoperitoneal Shunt Malfunction

SUMMARY

A 30-year-old man with recurrent headaches and seizure-like activity and a 26-year-old woman with worsening headaches were admitted to the hospital. Both had ventriculoperitoneal shunts and history of several shunt revisions for congenital hydrocephalus. The ventricle size visualized on computed tomography scans was unremarkable, and shunt series were negative in both cases. Both patients began to present with brief periods of unresponsiveness, and video electroencephalography at that time showed periods of diffuse delta slowing. Lumbar punctures revealed increased opening pressures. Despite normal imaging and shunt series, both patients ultimately had increased intracranial pressure caused by shunt malfunction. This series demonstrates the difficulty of diagnosing potential transient increases in intracranial pressure based on standard-of-care diagnostics/examination and the potentially critical role for EEG in the identification of shunt malfunction.

Abdominal pseudocyst complicating ventriculoperitoneal shunt: A rare indication for ventriculopleural shunt conversion

Key Clinical Message

Abdominal pseudocyst is a rare complication of ventriculoperitoneal (VP) shunt placement. Ventriculopleural shunt (VPL) can be an effective treatment option for the recurrent complications of VP shunt failure.

Abstract

Abdominal pseudocyst (APC) is a rare complication of ventriculoperitoneal (VP) shunt placement for the treatment of congenital hydrocephalus. This case report presents a two-and-a-half-year-old male child who underwent VP shunt placement for aqueductal stenosis-related hydrocephalus. The patient subsequently developed recurrent shunt failure and an APC, which was managed initially by surgical excision of the cyst and repositioning of the catheter. However, shunt failure recurred. The patient underwent ventriculopleural (VPL) shunt conversion as a more viable option for recurrent blockage. Postoperatively, the patient developed respiratory distress with massive pleural effusion, which was treated with chest tube insertion. This case highlights the complexity of managing congenital hydrocephalus and its rare complication, APC. Prompt recognition and appropriate management of APC can lead to improved outcomes and minimize the need for invasive procedures. VPL shunt conversion can be considered an alternative treatment option when other treatments have failed. Further research is needed to establish guidelines for the management of APC and determine the long-term effectiveness of VPL shunting.

Right Transcephalic Ventriculo-Subclavian Shunt in the Surgical Treatment of Hydrocephalus-An Original Procedure for Drainage of Cerebrospinal Fluid into the Venous System

The objectives of this article are to present an original surgical procedure for the temporary or definitive resolution of hydrocephalus, in the case of repeated failure of standard treatment techniques, and to present a case that was resolved using this surgical technique.

MATERIALS AND METHODS

We present the case of a 20-year-old male patient with congenital hydrocephalus who underwent a number of 39 shunt revisions, given the repetitive dysfunctions of various techniques (ventriculo-peritoneal shunt, ventriculo-cardiac shunt). The patient was evaluated with the ventricular catheter externalized at the distal end and it was necessary to find an emergency surgical solution, considering the imminent risk of meningitis. The patient was also associated with the diagnosis of acute lithiasic cholecystitis.

RESULTS AND DISCUSSIONS

The final chosen solution, right ventriculo-venous drainage using the cephalic vein, was a temporary surgical solution, but there are signs that this procedure can provide long-term ventricular drainage.

CONCLUSIONS

Transcephalic ventriculo-subclavian drainage represents an alternative technical option, which can be used when established options become ineffective.

MRI as a one-stop destination for evaluation of CSF shunt malfunction

Background

Despite the high-frequency rate of cerebrospinal fluid shunt malfunction, radiological evaluation of CSF shunts has remained deficient, focusing mainly on demonstrating secondary signs of shunt failure rather than evaluating the shunt tube itself. We aimed to study the utility of different MR pulse sequences in evaluating the cranial and abdominal ends of CSF shunts in order to identify the potential cause of shunt failure and its impact on patient management.

Results

Twenty-five patients (18 males, 7 females, median age 2.5 years, IQR 0.75–15) were enrolled in the study, having 28 ventriculo-peritoneal shunts and single ventriculo-gallbladder shunt. The catheter lumen and fine intraventricular septae were only demonstrated in 3D-DRIVE sequences (p < 0.001). Except for three patients (having cranial end-related complications), all patients with cranial and/or abdominal end-related complications received surgery (p < 0.001, positive likelihood and negative likelihood ratios = 7.27, 0.3, respectively, sensitivity = 0.7 and specificity = 0.9). MRI findings (luminal occlusion, disconnection, CSF collection, or migration) were consistent with operative data. There is no significant difference between patients who underwent surgery and those with conservative management, or symptomatic and asymptomatic patients in terms of the prevalence of ventricular dilatation or white matter signal abnormality. The results of the abdomino-pelvic fat-suppressed T2-WI showed excellent agreement with ultrasound findings (Cohen’s Kappa 0.9). Quantitative PC could give insights into CSF dynamics, which depend on the site and cause of shunt malfunction.

Conclusions

MRI could be a one-stop destination for evaluating patients with suspected non-acute shunt malfunction. It was found to have clinical relevance in terms of accurately locating the exact site and possible cause of shunt-related complications.

Pitfalls in the interpretation of pediatric head CTs: what the emergency radiologist needs to know

Pediatric radiology studies can be some of the most anxiety-inducing imaging examinations encountered in practice. This can be in part due to the wide range of normal anatomic appearances inherent to the pediatric population that create potential interpretive pitfalls for radiologists. The pediatric head is no exception; for instance, the inherent greater water content within the neonatal brain compared to older patients could easily be mistaken for cerebral edema, and anatomic variant calvarial sutures can be mistaken for skull fractures. This article reviews potential pitfalls emergency radiologists may encounter in practice when interpreting pediatric head CTs, including trauma, extra-axial fluid collections, intra-axial hemorrhage, and ventriculoperitoneal shunt complications.

Improving the detection of ventricular shunt disruption using volume-rendered three-dimensional head computed tomography

Hydrocephalus is the most common neurosurgical disorder in children, and cerebrospinal fluid (CSF) diversion with shunt placement is the most commonly performed pediatric neurosurgical procedure. CT is frequently used to evaluate children with suspected CSF shunt malfunction to assess change in ventricular size. Moreover, careful review of the CT images is important to confirm the integrity of the imaged portions of the shunt system. Subtle shunt disruptions can be missed on multiplanar two-dimensional (2-D) CT images, especially when the disruption lies in the plane of imaging. The use of volume-rendered CT images enables radiologists to view the extracranial shunt tubing within the field of view as a three-dimensional (3-D) object. This allows for a rapid and intuitive method of assessing the integrity of the extracranial shunt tubing. The purpose of this pictorial essay is to discuss how volume-rendered CT images can be generated to evaluate CSF shunts in the pediatric population and to provide several examples of their utility in diagnosing shunt disruption. We also address the potential pitfalls of this technique and ways to avoid them.

Huge subcutaneous extraperitoneal pseudocyst after migration of the ventriculoperitoneal shunt catheter

The formation of an intraperitoneal pseudocyst as a complication of ventriculoperitoneal shunts is well known. However, the formation of a pseudocyst at the subcutaneous extraperitoneal abdominal space is unusual and likely secondary to the migration of the peritoneal catheter. We present a 53-year-old male who had placement of a ventriculoperitoneal shunt for hydrocephalus secondary to a vestibular schwannoma. Five months later, he presented with an enormously distended abdomen. Investigations showed the peritoneal catheter in the extraperitoneal space within a large right lower quadrant abdominal wall pseudocyst. The patient was taken to the operating theatre, and the shunt was externalised at the original abdominal incision. Approximately 3 L of cerebrospinal fluid were aspirated from the distal peritoneal catheter. After negative cultures, a new peritoneal catheter was placed intraperitoneally at the contralateral lower abdominal quadrant. The contralateral quadrant was utilised to prevent fluid accumulation into the old extraperitoneal cavity.

Indian Society of Pediatric Neurosurgery Consensus Guidelines on Preventing and Managing Shunt Infection: Version 2020-21

Background

Shunt infection is the most significant morbidity associated with shunt surgery. Based on the existing literature for the prevention and management of shunt infection, region and resource-specific recommendations are needed.

Methods

In February 2020, a Guidelines Development Group (GDG) was created by the Indian Society of Paediatric Neurosurgery (IndSPN) to formulate guidelines on shunt infections, which would be relevant to our country and LMIC in general. An initial email survey identified existing practices among the membership of the IndSPN, and eight broad issues pertaining to shunt infection were identified. Next, members of the GDG performed a systematic review of the literature on the prevention and management of shunt infection. Then, through a series of virtual meetings of the GDG over 1 year, evidence from the literature was presented to all the members and consensus was built on different aspects of shunt infection. Finally, the guidelines document was drafted and circulated among the GDG for final approval. Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to grade the evidence and strength of recommendation.

Results

The guidelines are divided into eight sections. Level I and Level II evidence was available for only five recommendations and led to a moderate level of recommendations. Most of the available evidence was at Level III and below, and hence the level of recommendation was low or very low. A consensus method was used to provide recommendations for several issues.

Conclusions

Although most of the recommendations for the prevention and management of shunt infections are based on a low level of evidence, we believe that this document will provide a useful reference to neurosurgeons not only in India but also in other low and middle income countries. These guidelines need to be updated as and when new evidence emerges.

Thoracic abscess due to unusual migration of a ventriculoperitoneal shunt and literature review

Background:

Thoracic complications of ventriculoperitoneal (VP) cerebrospinal fluid shunting are rare and the diagnosis is difficult without neurological impairment.

Case Description:

We report a case of a 36-year-old woman who had a VP shunt in the right side when she was 13 years for a posterior fossa ependymoma and hydrocephalus. 23 years after surgery, she developed acute yellowfish cough and sputum, and the computed tomography scan found an intrathoracic cyst. She had a thoracotomy for the cyst and during surgery, we found the peritoneal catheter of the VP shunt, with a collected abscess in the left side. The patient was treated for the abscess and the VP shunt was removed. We also review the literature cases of thoracic complications after VP shunts.

Conclusion:

Thoracic abscess due to VP shunt migration is extremely rare and could happen after a long time delay VP shunt surgery.

"Shunt Pumping Test": role of practice on an experimental model

PURPOSE

To ascertain the benefits of practicing shunt pumping test on a validated experimental model.

METHODS

A validated experimental model of shunt was used and 25 medical professionals were asked to assess the block in the model where artificial blocks were created. The assessment was repeated after the participants had practiced on the same model. The performance of participants before and after practice was compared and statistically evaluated.

RESULTS

The ability to predict the status of shunt showed an improvement in all scenarios after practice. The odds ratio for predicting a blocked shunt before and after practice was 7.25 (95% credible interval: 1.50-21.01). The odds ratio for predicting a functional shunt before and after practice was 8.81 (95% credible interval of 1.64 to 13.65).

CONCLUSION

Practicing on the experimental model significantly improves the ability to predict the status of shunt. Training of primary caregivers on similar shunt models based on the shunts used in respective centers can improve an early detection of shunt block and reduce reliance on more invasive and expensive evaluation modalities.

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41747-021-00222-4.

In vitro testing of explanted shunt valves in hydrocephalic patients with suspected valve malfunction

Diagnosis of symptomatic valve malfunction in hydrocephalic patients treated with VP-Shunt (VPS) might be difficult. Clinical symptoms such as headache or nausea are nonspecific, hence cerebrospinal fluid (CSF) over- or underdrainage can only be suspected but not proven. Knowledge concerning valve malfunction is still limited. We aim to provide data on the flow characteristics of explanted shunt valves in patients with suspected valve malfunction. An in vitro shunt laboratory setup was used to analyze the explanted valves under conditions similar to those in an implanted VPS. The differential pressure (DP) of the valve was adjusted stepwise to 20, 10, 6, and 4 cmH₂O. The flow rate of the explanted and the regular flow rate of an identical reference valve were evaluated at the respective DPs. Twelve valves of different types (Codman CertasPlus valve n = 3, Miethke Shuntassistant valve n = 4, Codman Hakim programmable valve n = 3, DP component of Miethke proGAV 2.0 valve n = 2) from eight hydrocephalic patients (four male), in whom valve malfunction was assumed between 2016 and 2017, were replaced with a new valve. Four patients suffered from idiopathic normal pressure (iNPH), three patients from malresorptive and one patient from obstructive hydrocephalus. Post-hoc analysis revealed a significant difference (p < 0.001) of the flow rate between each explanted valve and their corresponding reference valve, at each DP. In all patients, significant alterations of flow rates were demonstrated, verifying a valve malfunction, which could not be objectified by the diagnostic tools used in the clinical routine. In cases with obscure clinical VPS insufficiency, valve deficiency should be considered.

Abdominal and pelvic radiographs of medical devices and materials- part 2: neurologic and genitourinary devices and materials

Radiographs of the abdomen and pelvis are routinely obtained as a standard part of clinical care for the abdomen and pelvis. Brisk advances in technology over the last few decades have resulted in a multitude of medical devices and materials. Recognizing and evaluating these devices on abdominal and pelvic radiographs are critical, yet increasingly a difficult endeavor. In addition, multiple devices serving different purposes may have a similar radiographic appearance and position causing confusion for the interpreting radiologist. The role of the radiologist is to not only identify accurately these medical objects, but also to confirm for their accurate placement and to recognize any complications that could affect patient care, management or even be potentially life threatening. An extensive online search of literature showed our review article to be the most comprehensive work on medical devices and materials of the abdomen and pelvis, and in this second part of our two-part series, we discuss in depth about the neurologic and genitourinary devices seen on abdominal and pelvic radiographs.

A Rare Case of a CSF Pseudocyst Mimicking a Complex Hepatic Cyst

Cerebrospinal fluid (CSF) peritoneal pseudocysts are a rare complication of ventriculoperitoneal shunts. They can manifest with symptoms of shunt malfunction or, more commonly, vague symptoms of abdominal discomfort such as pain or distention. The imaging features of peritoneal CSF pseudocysts may be nonspecific. In this case, we report a peritoneal CSF pseudocyst, which was initially mistaken for a complex hepatic cyst on both ultrasonography and MRI. The correct diagnosis was confirmed with a shuntogram and CT of the abdomen.

Management of Hydrocephalus in Children: Anatomic Imaging Appearances of CSF Shunts and Their Complications

OBJECTIVE. This article addresses the management of hydrocephalus and the CSF shunts used to treat this entity. CONCLUSION. CSF shunts have a high failure rate. Imaging plays a pivotal role in assessing CSF shunt failure and determining the need for surgical revision. An in-depth knowledge of CSF shunt components, their failure modes, and the corresponding findings on anatomic imaging studies is necessary to ensure timely diagnosis and prevent permanent neurologic damage.

United States emergency department visits for children with cerebrospinal fluid shunts

OBJECTIVE

CSF shunt placement is the primary therapy for hydrocephalus; however, shunt malfunctions remain common and lead to neurological deficits if missed. There is a lack of literature characterizing the epidemiology of children with possible shunt malfunctions presenting to United States emergency departments (EDs).

METHODS

A retrospective study was conducted of the 2006-2017 National Emergency Department Sample. The data were queried using an exhaustive list of Current Procedural Terminology and International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision codes representing children with hydrocephalus diagnoses, diagnostic imaging for shunt malfunctions, and shunt-related surgical revision procedures.

RESULTS

In 2017, there were an estimated 16,376 ED visits for suspected shunt malfunction. Children were more commonly male (57.9%), ages 0-4 years (42.2%), and publicly insured (55.8%). Many did not undergo diagnostic imaging (37.2%), and of those who did, most underwent head CT scans (43.7%). Between 2006 and 2017, pediatric ED visits for suspected shunt malfunction increased 18% (95% CI 12.1-23.8). The use of MRI increased substantially (178.0%, 95% CI 176.9-179.2). Visits resulting in discharge home from the ED increased by 76.3% (95% CI 73.1-79.4), and those involving no surgical intervention increased by 32.9% (95% CI 29.2-36.6).

CONCLUSIONS

Between 2006 and 2017, ED visits for children to rule out shunt malfunction increased, yet there was a decline in surgical intervention and an increase in discharges home from the ED. Possible contributing factors include improved clinical criteria for shunt evaluation, alternative CSF diversion techniques, changing indications for shunt placement, and increased use of advanced imaging in the ED.

ABBREVIATIONS

CPT = Current Procedural Terminology; ED = emergency department; ETV = endoscopic third ventriculostomy; ICD-9 = International Classification of Diseases, Ninth Revision; ICD-10 = International Classification of Diseases, Tenth Revision; NEDS = National Emergency Department Sample.

The contribution of SPECT/CT in patients with radionuclide shuntography through shunt dysfunction

OBJECTIVE

Radionuclide CSF study is a simple, effective, and low-radiation-dose procedure for the assessment of shunt patency. With the help of CT image of single-photon emission computed tomography/computed tomography (SPECT/CT), the interpretation becomes more accurate and easier.The aim of this study was to compare the classical methods and 2D planar scintigraphic images with radionuclide shuntography fused SPECT/CT.

METHODS

Between 2015-2019 all hydrocephalic patients who underwent radionuclide shuntography and classical methods (cranial CT, USG and/or direct X-rays), for suspected VP shunt malfunction at our hospital were retrospectively enrolled in the study. Fusion with SPECT/CT is provided in all radionuclide shuntographies. Approximately 0.5-1 mCi diethylene-triaminepentaaceticacid (DTPA) was intrathecally injected. Images were collected as 5-second frames for the first minute, and 1-min frames for the second to the 30th min. Static whole body images were obtained as early (30 min) and delayed (120 min) images. SPECT/CT was performed in 120 min.

RESULTS

When the classical methods were evaluated in the operated patients, according to the direct radiographic findings, in only 17 patients had shunt dysfunction due to disconnection-kinking or laceration, was obtained.On the other hand,while67 shuntography were evaluated,65 of these patients (97%) whose intraoperative and shuntography findings were found to be compatible with each other.

CONCLUSION

The 3D SPECT images combined with the two-dimensional planar images added to the CT provide more accurate information and also provide detailed anatomical information. The patient's operation was performed successfully in one session in cooperation with the other surgical branches when needed.

Medical Devices of the Abdomen and Pelvis and Their Complications: A Radiologic Atlas

의료기구들이 발달하면서 복부 및 골반 내에 이식되거나 거치되는 의료기구들이 다양해졌다. 흔하게 사용되는 기구들의 영상의학 소견은 영상의학과 의사들에게 매우 익숙하지만, 상대적으로 사용 빈도가 낮거나 새로운 형태의 기구들의 영상의학 소견은 잘 알려져 있지 않다. 또한 환자에 대한 임상정보가 제한적일 경우 이런 새로운 형태의 의료기구들은 잘못 해석되거나 놓치기 쉽다. 그러므로 복부 및 골반 내 의료기구들의 영상의학 소견을 인지하는 것은 기구들의 올바른 위치를 평가하고, 이와 관련된 합병증을 평가하는데 있어 매우 중요하다. 본 논문에서는 다양한 복부 및 골반 내 의료기구들과 이와 관련된 합병증의 영상의학 소견을 소개하고자 한다.

Utility of Shunt Series in the Evaluation of Ventriculoperitoneal Shunt Dysfunction in Adults

BACKGROUND

When patients present to emergency departments (EDs) with symptoms suspicious for ventriculoperitoneal shunt malfunction, evaluation often includes imaging of the shunt with both computed tomography (CT) of the head without contrast and a plain radiograph "shunt series" (SS). Recent literature has called into question the diagnostic value of the SS for the detection of ventriculoperitoneal shunt complications, suggesting that the plain radiographs provide redundant information and unnecessary exposure to radiation.

OBJECTIVE

The aim of our study was to assess the frequency of abnormal SS plain radiography and head CT in the evaluation of shunt malfunction in all adult ED patients and to measure the association of abnormalities on CT and SS with surgical intervention.

METHODS

We performed a retrospective chart review of all emergency department encounters at an urban level I trauma center between August 1, 2013 and October 3, 2018 in which an SS and head CT examination were performed within 24 h of each other. We described the results of imaging studies qualitatively and descriptive statistics were performed.

RESULTS

Positive findings on CT were significantly associated with the decision to proceed to surgery. Positive findings on SS, however, were not significantly associated with the decision to proceed to surgery.

CONCLUSIONS

The potential information gained from SS and convenience of ordering simultaneously with head CT does not appear to outweigh the risk of increased radiation exposure to the patient, the additional costs of the study, and the potential delay in time to head CT. These findings support the initial use of head CT in evaluation of shunt malfunction.

Chest radiographs of cardiac devices (Part 1): Lines, tubes, non-cardiac medical devices and materials

Chest radiographs (CXRs) are the most common imaging investigations undertaken because of their value in evaluating the cardiorespiratory system. They play a vital role in intensive care units for evaluating the critically ill. It is therefore very common for the radiologist to encounter tubes, lines, medical devices and materials on a daily basis. It is important for the interpreting radiologist not only to identify these iatrogenic objects, but also to look for their accurate placement as well as for any complications related to their placement, which may be seen either on the immediate post-procedural CXR or on a follow-up CXR. In this article, we discussed and illustrated the routinely encountered tubes and lines that one may see on a CXR as well as some of their complications. In addition, we also provide a brief overview of other important non-cardiac medical devices and materials that may be seen on CXRs.

Neuroimaging of Patients in the Intensive Care Unit: Pearls and Pitfalls

A brief introduction is provided of the different imaging modalities encountered in the intensive care unit (ICU). The spectrum of intracranial pathology as well as potential postsurgical complications is reviewed, with a focus on pearls and pitfalls. A brief overview also is provided of imaging of the spine in an ICU patient.

Epidermal electronics for noninvasive, wireless, quantitative assessment of ventricular shunt function in patients with hydrocephalus

Hydrocephalus is a common and costly neurological condition caused by the overproduction and/or impaired resorption of cerebrospinal fluid (CSF). The current standard of care, ventricular catheters (shunts), is prone to failure, which can result in nonspecific symptoms such as headaches, dizziness, and nausea. Current diagnostic tools for shunt failure such as computed tomography (CT), magnetic resonance imaging (MRI), radionuclide shunt patency studies (RSPSs), and ice pack-mediated thermodilution have disadvantages including high cost, poor accuracy, inconvenience, and safety concerns. Here, we developed and tested a noninvasive, skin-mounted, wearable measurement platform that incorporates arrays of thermal sensors and actuators for precise, continuous, or intermittent measurements of flow through subdermal shunts, without the drawbacks of other methods. Systematic theoretical and experimental benchtop studies demonstrate high performance across a range of practical operating conditions. Advanced electronics designs serve as the basis of a wireless embodiment for continuous monitoring based on rechargeable batteries and data transmission using Bluetooth protocols. Clinical studies involving five patients validate the sensor's ability to detect the presence of CSF flow (P = 0.012) and further distinguish between baseline flow, diminished flow, and distal shunt failure. Last, we demonstrate processing algorithms to translate measured data into quantitative flow rate. The sensor designs, fabrication schemes, wireless architectures, and patient trials reported here represent an advance in hydrocephalus diagnostics with ability to visualize flow in a simple, user-friendly mode, accessible to the physician and patient alike.

Comparing the Efficiency of Two Treatment Methods of Hydrocephalus: Shunt Implantation and Endoscopic Third Ventriculostomy

Introduction:

Hydrocephalus is one of the most common diseases in children, and its treatment requires brain operation. However, the pathophysiology of the disease is very complicated and still unknown.

Methods:

Endoscopic Third Ventriculostomy (ETV) and Ventriculoperitoneal Shunt (VPS) implantation are among the common treatments of hydrocephalus. In this study, Cerebrospinal Fluid (CSF) hydrodynamic parameters and efficiency of the treatment methods were compared with numerical simulation and clinical follow-up of the treated patients.

Results:

Studies have shown that in patients under 19 years of age suffering from hydrocephalus related to a Posterior Fossa Brain Tumor (PFBT), the cumulative failure rate was 21% and 29% in ETV and VPS operation, respectively. At first, the ETV survival curve shows a sharp decrease and after two months it gets fixed while VPS curve makes a gradual decrease and reaches to a level lower than ETV curve after 5.7 months. Post-operative complications in ETV and VPS methods are 17% and 31%, respectively. In infants younger than 12 months with hydrocephalus due to congenital Aqueduct Stenosis (AS), and also in the elderly patients suffering from Normal Pressure Hydrocephalus (NPH), ETV is a better treatment option. Computer simulations show that the maximum CSF pressure is the most reliable hydrodynamic index for the evaluation of the treatment efficacy in these patients. After treatment by ETV and shunt methods, CSF pressure decreases about 9 and 5.3 times, respectively and 2.5 years after shunt implantation, this number returns to normal range.

Conclusion:

In infants with hydrocephalus, initial treatment by ETV was more reasonable than implanting the shunt. In adult with hydrocephalus, the initial failure in ETV occurred sooner compared to shunt therapy; however, ETV was more efficient.

Progressive Hydrocephalus Due to Ventriculoperitoneal Shunt Infection: Detection With FDG PET CT

Ventriculoperitoneal shunt malfunction is common in patients after shunt surgery. Imaging is done to reveal the underlying cause and confirm the diagnosis. Shunt infection is one of the common causes of shunt malfunction. FDG PET CT is an accepted infection imaging tool and can be used to diagnose shunt infection accurately in a patient with high clinical suspicion.

Tales from the Night:: Emergency MR Imaging in Pediatric Patients after Hours

Overnight in-house radiology has rapidly become an important part of contemporary practice models, and is increasingly the norm in pediatric radiology. MR imaging is an indispensable first-line and problem-solving tool in the pediatric population. This has led to increasingly complex MR imaging being performed "after hours" on pediatric patients. This article reviews the factors that have led to widespread overnight subspecialty radiology and the associated challenges for overnight radiologists, and provides an overview of up-to-date imaging techniques and imaging findings of the most common indications for emergent MR imaging in the pediatric population.

Shunt Devices for Neurointensivists: Complications and Management

Cerebrospinal fluid diversion has become the mainstay treatment in hydrocephalus for over 50 years. As the number of patients with ventricular shunt systems increases, neurointensivists are becoming the first-line physicians for many of these patients. When symptoms of a shunt malfunction are suspected and access to a neurosurgeon is limited or delayed, workup and temporizing measures must be initiated. The article highlights the functional nuances, complications, and management of current programmable shunt valves and their MRI sensitivity.

Two signs indicative of successful access in nuclear medicine cerebrospinal fluid diversionary shunt studies

BACKGROUND

Successful shunt access is the first step in a properly performed nuclear medicine cerebrospinal fluid (CSF) shunt study.

OBJECTIVE

To determine the significance of the radiotracer configuration at the injection site during initial nuclear medicine CSF shunt imaging and the lack of early systemic radiotracer activity as predictors of successful shunt access.

MATERIALS AND METHODS

With Institutional Review Board approval, three nuclear medicine physicians performed a retrospective review of all consecutive CSF shunt studies performed in children at our institution in 2015. Antecedent nuclear medicine CSF shunt studies in these patients were also assessed and included in the review. The appearance of the reservoir site immediately after radiotracer injection was classified as either figure-of-eight or round/ovoid configuration. The presence or absence of early systemic distribution of the tracer on the 5-min static images was noted and separately evaluated.

RESULTS

A total of 98 nuclear medicine ventriculoperitoneal CSF shunt studies were evaluated. Figure-of-eight configuration was identified in 87% of studies and, when present, had 93% sensitivity, 78% specificity, 92% accuracy, 98% positive predictive value (PPV) and 54% negative predictive value (NPV) as a predictor of successful shunt access. Early systemic activity was absent in 89 of 98 studies. Lack of early systemic distribution of the radiotracer had 98% sensitivity, 78% specificity, 96% accuracy, 98% PPV and 78% NPV as a predictor of successful shunt access. Figure-of-eight configuration in conjunction with the absence of early systemic tracer activity had 99% PPV for successful shunt access.

CONCLUSION

Figure-of-eight configuration at the injection site or lack of early systemic radiotracer activity had moderate specificity for successful shunt access. Specificity and PPV significantly improved when both signs were combined in assessment.

Ventriculopleural Shunt Dysfunction Due to a Loculated Pleural Collection Demonstrated on SPECT/CT Imaging

A 35-year-old woman presented with increasing drowsiness on a background of childhood meningitis and hydrocephalus managed with a ventriculopleural shunt. Her cerebral CT and chest radiograph were unchanged from previous imaging and did not identify significant pathology. Because of clinical suspicion of cerebrospinal fluid shunt dysfunction, she was referred for a cerebrospinal fluid shunt study, which demonstrated tracer accumulation within a loculated pleural collection in the left costophrenic recess.

Common and Uncommon Causes of Ventriculoperitoneal Shunt Malfunction Diagnosed on Plain Radiographs

Thousands of patients with hydrocephalus are treated successfully with ventriculoperitoneal shunts. Ventriculoperitoneal shunts are known to have high malfunction rates, most of which are owing to mechanical causes. When shunt malfunction is suspected, shunt series are often performed to evaluate the mechanical causes of malfunction. These initial radiographs have proven critical in guiding subsequent management. This article is designed to review the various causes of shunt malfunction that can be diagnosed with radiographs.

Intracranial Perishunt Catheter Fluid Collections with Edema, a Sign of Shunt Malfunction: Correlation of CT/MRI and Nuclear Medicine Findings

Fluid collections with edema along the intracranial tract of ventriculoperitoneal shunt catheters in adults are rare and are more frequently seen in children. The imaging appearance of these fluid collections is frequently confusing and presents a diagnostic dilemma. We present 6 cases of adult patients noted to have collections with edema along the tract of ventriculoperitoneal shunt catheters. To our knowledge, there are no previous studies correlating the CT/MR imaging findings with nuclear medicine scans in this entity. We hypothesized that when seen in adults, the imaging findings of a CSF-like fluid collection around the intracranial ventriculoperitoneal shunt catheter on CT/MR imaging may suggest areas of CSF accumulation with interstitial edema. It is important to recognize this rare ventriculoperitoneal shunt complication in adults to prevent misdiagnosis of an abscess or cystic tumor.

Diagnosis and Treatment of Central Nervous System Infections in the Emergency Department

Central nervous system (CNS) infections, including meningitis, encephalitis, and brain abscess, are rare but time-sensitive emergency department (ED) diagnoses. Patients with CNS infection can present to the ED with nonspecific signs and symptoms, including headache, fever, altered mental status, and behavioral changes. Neuroimaging and CSF fluid analysis can appear benign early in the course of disease. Delaying therapy negatively impacts outcomes, particularly with bacterial meningitis and herpes simplex virus encephalitis. Therefore, diagnosis of CNS infection requires vigilance and a high index of suspicion based on the history and physical examination, which must be confirmed with appropriate imaging and laboratory evaluation.

Cross-sectional imaging of thoracic and abdominal complications of cerebrospinal fluid shunt catheters

This study aims to review the imaging findings of distal (thoracic and abdominal) complications related to ventriculo-peritoneal (VP), ventriculo-pleural (VPL), and ventriculo-atrial (VA) cerebrospinal fluid (CSF) shunt catheter placement. Institution review board-approved single-center study of patients with thoracic and abdominal CSF catheter-related complications on cross-sectional imaging examinations over a 14-year period was performed. Clinical presentation, patient demographics, prior medical history, and subsequent surgical treatment were recorded. The presence or absence of CSF catheter-related infection and/or acute hydrocephalus on cross-sectional imaging was also recorded. There were 81 distal CSF catheter-related complications identified on 47 thoracic or abdominal imaging examinations in 30 patients (age 5-80 years, mean 39.3 years), most often on CT (CT = 42, MRI = 1, US = 4). Complications included 38 intraperitoneal and 11 extraperitoneal fluid collections. Extraperitoneal collections included nine abdominal wall subcutaneous (SC) pseudocysts associated with shunt migration and obesity, an intrapleural pseudocyst, and a breast pseudocyst. There were also two large VPL-related pleural effusions, a fractured catheter in the SC tissues, and a large VA shunt thrombus within the right atrium. Ten patients (33.3 %) had culture-positive infection from CSF or shunt catheter samples. Ten patients (33.3 %) had features of temporally related acute or worsening hydrocephalus on neuroimaging. In four of these patients, the detection of thoracic and abdominal complications on CT preceded and predicted the findings of acute hydrocephalus on cranial imaging. Thoracic and abdominal complications of CSF shunts, as can be identified on CT, include shunt infection and/or obstruction, may be both multiple and recurrent, and may be predictive of concurrent acute intracranial problems.