Tunneled and routine peripherally inserted central catheters placement in adult and pediatric population: review, technical feasibility, and troubleshooting.

Vascular access procedures are crucial for the management of various critically ill pediatric and adult patients. Venous access is commonly performed in the form routine as well as tunneled peripherally inserted central catheters (PICC). These venous accesses are commonly used in emergency, surgical as well as ICU settings, for various infusions, total parenteral nutrition, long term intravenous antibiotics, frequent blood draws, etc. PICC insertion is guided using ultrasound and fluoroscopic guidance, which decreases the risk of complications that are otherwise seen with central venous accesses like triple lumen catheters, etc. PICC insertion and care is very simple and can be performed by specially trained PICC nurses and that helps in decreasing the overall cost of healthcare. This review article is written with educational intent for the readers to discuss indications, contraindications, procedure techniques, imaging, care of routine as well as tunneled PICC.

Susceptibility-Weighted Imaging in Neurodegenerative Disorders: A Review.

As human life expectancy increases, there is an increased prevalence of neurodegenerative disorders and dementia. There are many ongoing research trials for early diagnosis and management of dementia, and neuroimaging is a critical part of such studies. However, conventional neuroimaging often fails to provide enough diagnostic findings in patients with neurodegenerative disorders. In this context, different MRI sequences are currently under investigation to facilitate the accurate diagnosis of such disorders. Susceptibility-weighted imaging (SWI) is an innovative MRI technique that utilizes "magnitude" and "phase" images to produce an image contrast that is sensitive for the detection of susceptibility differences of the tissues. As many neurodegenerative disorders are associated with accelerated iron deposition and/or microhemorrhages in different parts of the brain, SWI can be applied to detect these diagnostic clues. For instance, in cerebral amyloid angiopathy, SWI can demonstrate cortical microhemorrhages, which are predominantly in the frontal and parietal regions. Or in Parkinson disease, abnormal swallow-tail sign on high-resolution SWI is highly diagnostic. Also, SWI is a useful sequence to detect the low signal intensity of precentral cortices in patients with amyotrophic lateral sclerosis. Being familiar with SWI findings in neurodegenerative disorders is critical for an accurate diagnosis. In this paper, the authors review the technical parameters of SWI, physiologic, and pathologic iron deposition in the brain, and the role of SWI in the evaluation of neurodegenerative disorders in daily practice.

Emerging Applications of Radiomics in Neurological Disorders: A Review.

Radiomics has achieved significant momentum in radiology research and can reveal image information invisible to radiologists' eyes. Radiomics first evolved for oncologic imaging. Oncologic applications (histopathology, tumor grading, gene mutation analysis, patient survival, and treatment response prediction) of radiomics are widespread. However, it is not limited to oncologic analysis, and any digital medical images can benefit from radiomics analysis. This article reviews the current literature on radiomics in non-oncologic, neurological disorders including ischemic strokes, hemorrhagic stroke, cerebral aneurysms, and demyelinating disorders.

Utility of 18F-Fluciclovine PET/MRI for Staging Newly Diagnosed High-Risk Prostate Cancer and Evaluating Response to Initial Androgen Deprivation Therapy: A Prospective Single-Arm Pilot Study.

BACKGROUND. Despite advances in prostate cancer treatment, rates of biochemical recurrence remain high, relating to lack of detection of small-volume metastatic disease using conventional imaging for initial staging. OBJECTIVE. The purpose of this study was to assess the potential use of 18F-fluciclovine PET/MRI for initial staging of high-risk prostate cancer and evaluating response to androgen deprivation therapy (ADT). METHODS. This prospective clinical trial enrolled 14 men with newly diagnosed high-risk prostate cancer and negative or equivocal conventional staging imaging for metastatic disease between January 2018 and February 2019. All patients underwent pretreatment 18F-fluciclovine PET/MRI including multiparametric prostate MRI; 12 underwent 18F-fluciclovine PET/MRI after surgery or between ADT and radiotherapy. Confidence in identification of the primary intraprostatic lesion and nodal metastases was independently rated on a 0-3 Likert scale by three readers with nuclear medicine experience for 18F-fluciclovine PET/MRI and three readers with abdominal imaging experience for MRI alone. Findings scored as 2 or 3 by at least two readers of a given modality were considered positive. A single reader measured SUVmean, SUVmax, and volume of the MRI-defined intraprostatic lesion and SUVmax of suspicious lymph nodes on PET before and after initiation of ADT. Changes in SUV were analyzed using nonparametric Wilcox-on signed-rank tests. RESULTS. The biopsy-proven lesion in the prostate gland was accurately identified in all 14 patients on both MRI and 18F-fluciclovine PET/MRI. Suspected nodal metastases were detected in three patients on MRI and seven patients on 18F-fluciclovine PET/MRI. After ADT, all patients showed decreased activity within the intraprostatic lesion and/or all suspicious lymph nodes. The primary lesion SUVmean was 4.5 ± 1.1 (range, 2.7-6.5) before treatment and 2.4 ± 1.1 (range, 0.0-3.6) after initiation of ADT (p = .008). For suspicious lymph nodes, the pretreatment SUVmax was 5.5 ± 3.7 (range, 2.8-12.7) and the post-treatment SUVmax was 2.8 ± 1.4 (range, 1.4-5.5) (p = .03). CONCLUSION.18F-labeled fluciclovine PET/MRI shows potential utility in initial staging of high-risk prostate cancer and in evaluating response to ADT. CLINICAL IMPACT. Given the FDA approval and widespread availability of 18F-fluciclovine, the findings could have an impact in the immediate future in guiding initial management of patients with prostate cancer. TRIAL REGISTRATION. ClinicalTrials.gov NCT03264456.

Brainstem Encephalitis. The Role of Imaging in Diagnosis.

Encephalitis is a relatively challenging rare condition caused by a diverse group of etiologies. Brainstem encephalitis/Rhombencephalitis (BE), which affects the cerebellum, pons, and medulla, is even less common and more challenging for diagnosis and treatment. At this time, there is scattered data about BE in the literature, mainly in the form of case reports and case series. In this manuscript, the imaging presentation of BE is reviewed with the help of case examples. Many imaging presentations are not pathognomonic for BE; however, in many cases, clinical presentation, the spatial distribution of lesions, and other associated radiological lesions can provide the radiologists and clinician the clues to an accurate diagnosis.

High-resolution computed tomography (HRCT) in pediatric and adult patients with unsafe chronic suppurative otitis media (CSOM) and its surgical correlation.

BACKGROUND AND AIM: Atticoantral, alias unsafe type of CSOM affects the posterosuperior part of the middle ear cleft and is frequently coupled with complications and bony erosions. This study aimed to correlate the high-resolution computed tomography (HRCT) temporal bone and intraoperative findings in the patients with the unsafe type of CSOM. METHODS: This prospective study included 50 patients (28 males: 22 females; mean age 24 ± 14 years) who presented with clinically suspected unsafe CSOM. All patients underwent HRCT of the temporal bone and subsequent surgical procedure. The intraoperative and histopathological findings were compared with HRCT findings. Descriptive statistics, sensitivity, specificity, and positive and negative predictive value for HRCT were calculated. Student's t-test and Chi-square test were performed. RESULTS: Out of 50 patients, left, right, and bilateral ear involvement were seen in 42% (21/50), 38% (19/50), and 20% (10/50) patients, respectively. Ear discharge was the most common symptom (100%) followed by earache (66%), vertigo (16%), and tinnitus (14%), respectively. Cholesteatoma was reported in 82% (49/60) of ears on HRCT while histopathological and intraoperative evaluation confirmed the diagnosis in 40 out of 49 ears. In 18% (11/60) ears, the cholesteatoma was not diagnosed on HRCT evaluation; however, the intraoperative and histopathological assessment revealed cholesteatoma in six patients while the rest had granulation tissue. For detection of ossicular erosions, tegmen erosions, erosions of facial nerve canal, erosions of sigmoid sinus plate, and erosions of lateral/posterior semicircular canals; HRCT had high sensitivity (86.44%-100%) and specificity (93.33%-100%). CONCLUSION: HRCT has a superb correlation with intraoperative findings and is a valuable tool for preoperative assessment of temporal bone pathologies.

A pictorial review of gall stones and its associated complications.

Gallstone disease is the term commonly used to refer to gallstones that cause symptoms. There is a myriad of complications that can arise from gallstones: acute cholecystitis, xanthogranulomatous cholecystitis, emphysematous cholecystitis, gallbladder wall perforations, pericholecystic abscesses, Mirizzi syndrome, cholecystoenteric fistulas, choledocholithiasis, gallstone pancreatitis, porcelain gallbladder, gallbladder malignancies, and many more. The aim of this pictorial review is to revisit how multimodality imaging can help with the diagnosis of gallstone disease. We review the classic imaging findings on different imaging modalities for gallstone disease and its associated complications and how it is useful in early diagnosis for timely management of complications as well as surgical planning.

Pseudohypoxic Brain Swelling: Report of 2 Cases and Introduction of the Lentiform Rim Sign as Potential MRI Marker.

BACKGROUND: A rare but important complication related to otherwise uneventful brain and spine surgery is becoming more recognized and more frequently reported in the medical literature. This has been variably labeled as pseudohypoxic brain swelling or postoperative hypotension-associated venous congestion. This poorly understood condition occurs in the setting of surgical intervention and is thought to be related to cerebrospinal fluid leak or evacuation, decreased intracranial pressure, and subsequent development of deep venous congestion affecting the basal ganglia, thalami, and cerebellum. Clinically, patients may have global neurologic deficit and outcomes range from full recovery to vegetative state or death. The imaging correlate includes atypical edema, infarction, or hemorrhage and can overlap the appearance of diffuse hypoxic injury, for which this condition can be mistaken both clinically and radiologically. Although this deep brain tissue edema can be associated with other signs of cerebrospinal fluid hypotension such as dural thickening, brain sagging, and cerebellar herniation, it can be isolated, making the diagnosis challenging. CASE DESCRIPTION: We present 2 cases of unexpected clinical deterioration occurring in patients with otherwise uncomplicated neurosurgery, 1 with craniotomy and the other with lumbar spine intervention. Both patients exhibit similar appearing edema in the deep gray structures on postoperative magnetic resonance imaging scans. In addition to reviewing the prior literature and imaging findings, we evaluate the imaging findings to determine if there are unique features or signatures that might allow differentiation of PHBS from hypoxic-ischemic encephalopathy. CONCLUSIONS: The lentiform rim sign can be helpful for differentiation of pseudohypoxic brain swelling versus hypoxic-ischemic encephalopathy.

Construction of a Machine Learning Dataset through Collaboration: The RSNA 2019 Brain CT Hemorrhage Challenge.

This dataset is composed of annotations of the five hemorrhage subtypes (subarachnoid, intraventricular, subdural, epidural, and intraparenchymal hemorrhage) typically encountered at brain CT.

Erratum: Construction of a Machine Learning Dataset through Collaboration: The RSNA 2019 Brain CT Hemorrhage Challenge.

[This corrects the article DOI: 10.1148/ryai.2020190211.].

18F-Sodium Fluoride PET: History, Technical Feasibility, Mechanism of Action, Normal Biodistribution, and Diagnostic Performance in Bone Metastasis Detection Compared with Other Imaging Modalities.

The skeleton is the third most common site for metastasis overall, after the lungs and liver. Accurate diagnosis of osseous metastasis is critical for initial staging, treatment planning, restaging, treatment monitoring, and survival prediction. Currently, 99mTc-methylene diphosphonate whole-body scanning is the cornerstone of imaging to detect osseous metastasis. Although 18F-sodium fluoride (18F-NaF) was one of the oldest medical tracers for this purpose, it was replaced by other tracers because of their better physical properties, until recently. Continued development of PET scanners has opened a new era for 18F-NaF, and given its higher sensitivity, there have been increasing applications in imaging. In this review, we will discuss the history, technical aspects, radiobiology, and biodistribution of this tracer. Finally, we compare the accuracy of 18F-NaF PET with other conventional imaging methods for detection of osseous metastasis.

Severe arthritis and tenosynovitis caused by immune checkpoint blockade therapy with pembrolizumab (anti-PD-1 antibody).

Pembrolizumab, a monoclonal antibody against the immune checkpoint receptor-programmed cell death protein 1, has proven clinical efficacy in melanoma and other solid tumors. It increases the body's immune response against the tumor cells. However, because of an uninhibited immune system, immune-mediated adverse effects can arise. Though most adverse effects from pembrolizumab involve the gastrointestinal tract, skin, and endocrine system, rheumatologic manifestations are not very well defined. We describe two cases of severe inflammatory arthritis and tenosynovitis, which are rare adverse effects of pembrolizumab. Increased awareness of this manifestation is imperative to establish the diagnosis and initiate timely treatment.

PHACES syndrome with ectopia cordis and hemihypertrophy.

PHACES is the acronym describing the phenotypic association of posterior fossa anomalies, facial hemangioma, cardiac and eye anomalies, and sternal defects. To date, more than 300 cases of PHACE(S) have been reported. We present the case of a newborn girl who was born with a variant of the PHACES syndrome. Although the sternal cleft and the small facial hemangioma were evident clinically at birth, magnetic resonance imaging of the brain provided additional information to establish the diagnosis. In addition, the patient manifested later with hemihypertrophy, an association that has not been described previously.

Type 2 persistent primitive proatlantal intersegmental artery, a rare variant of persistent carotid-vertebrobasilar anastomoses.

We describe a 48-year-old man with type 2 persistent primitive proatlantal intersegmental artery found incidentally on imaging. It is one of the rare persistent carotid-vertebrobasilar anastomoses in which the anomalous vessel arises from the external carotid artery and enters the skull through the foramen magnum.

A systematic approach in the diagnosis of paediatric skull lesions: what radiologists need to know.

Paediatric skull lesions are commonly identified on imaging. They can be challenging to image, given their location and size, and often require several imaging modalities to narrow down the differential diagnosis. Accurate diagnosis of these lesions is paramount because the clinical therapy can vary tremendously. In this review, we provide a simple and systematic approach to clinical-radiological features of primary skull lesions. We highlight the imaging characteristics and differentiate pathologies based on imaging appearances. We also accentuate the role of cross-sectional imaging in lesion identification and management implications.

Utility of Scintigraphy in Assessment of Noninfectious Complications of Peritoneal Dialysis.

Dialysis is an artificial process to remove waste products and excess water from the body in patients with kidney failure. Two main types of dialysis are available. Hemodialysis, which uses an artificial filtration apparatus, is usually done at specialized centers but can be done in a patient's home. Peritoneal dialysis functions by placing dialysis fluid, also called dialysate, into the peritoneal cavity, allowing for solute to be removed from the peritoneal capillaries through diffusion across a chemical gradient into the dialysate and removal of water through an osmotic gradient created by hypertonic dextrose. Peritoneal dialysis can be either automated, which is done with the help of a machine called a cycler, or continuous ambulatory, which is a process involving multiple exchanges a day and is performed using only gravity to infuse and drain the solution from the peritoneal cavity. For many reasons, the number of people using home dialysis has recently started to rise, with the largest increase in the United States occurring after the implementation of the prospective bundled payment system for end-stage renal disease. With the increased use of home dialysis, potential complications will increase as well. It is imperative that our health-care system be poised not only to increase the number of home dialysis patients but also to diagnose and manage any complications. Nuclear imaging is a commonly available modality to detect various complications related to peritoneal dialysis. In this review article, we discuss the role of peritoneal scintigraphy in detecting some noninfectious peritoneal dialysis complications, with emphasis on scintigraphy technique; imaging time points; the role of planar, SPECT, and SPECT/CT imaging; and the clinical indications, with illustrative case examples.

Bilateral persistent primitive hypoglossal artery presenting with hemiplegia✰.

The manuscript describes an unusual vascular anomaly. Persistence of carotid-vertebrobasilar anastomosis is a rare occurrence with presence of bilateral hypoglossal arteries (HAs) rarer still. We present a case of bilateral persistent HAs with hypoplastic vertebral arteries which end into posterior inferior cerebellar arteries. The computed tomography and magnetic resonance imaging appearance, course, and other associations are discussed. A review of 6 cases of bilateral HA published in the world literature is also discussed.

Regional Changes in Brain 18F-FDG Uptake After Prophylactic Cranial Irradiation and Chemotherapy in Small Cell Lung Cancer May Reflect Functional Changes.

Chemotherapy followed by prophylactic cranial irradiation (PCI) is associated with increased survival in patients with small cell lung cancer but is associated with fatigue and cognitive impairment. This retrospective study evaluated regional differences in 18F-FDG uptake by the brain before and after PCI. The null hypothesis was that direct toxic effects on the brain from PCI and chemotherapy are symmetric; thus, asymmetric deviations may reflect functional changes due to therapy. Methods: Electronic medical records from 2013 to 2016 were reviewed for patients with small cell lung cancer, MRI of brain negative for metastasis, and 18F-FDG PET/CT scans before and after PCI. As the standard of care, patients received first-line chemotherapy or chemoradiation to the thorax followed by PCI. The 18F-FDG PET/CT scans nearest the PCI were selected. Sixteen patients met these initial criteria. Commercially available PET software was used to register and subtract the PET scans before and after PCI to obtain difference maps. Occipital and cerebellar regions were excluded from the final statistical analysis given the known high variability and misregistration. The χ2 test was used to analyze the data. Results: Two patients had 18F-FDG uptake differences only in the occipital and cerebellar regions. The software registration failed on 1 patient's scans. Therefore, 13 patients were included in the final analysis. Nine of 13 patients demonstrated significant unilateral changes in only 1 region of the brain, and 3 of 13 showed significant changes unilaterally in 2 regions. The χ2 test revealed a significant unilateral regional difference on a patient level (χ2 = 6.24, P = 0.025). The most commonly affected brain region was the frontal lobe. Conclusion: Significantly more patients had unilateral than bilateral regional differences (both increases and decreases) in 18F-FDG uptake in the brain before and after PCI. This finding suggests that differences in unilateral distribution are related to functional changes, since direct toxicity alone from PCI and chemotherapy would be symmetric. The frontal region was the most commonly affected, suggesting a potential contributing etiology for cognitive impairment and decreased executive function after therapy.

Investigational PET tracers for high-grade gliomas.

High-grade gliomas (HGGs) are the most common primary malignant tumors of the brain, with glioblastoma (GBM) constituting over 50% of all the gliomas in adults. The disease carries very high mortality, and even with optimal treatment, the median survival is 2-5 years for anaplastic tumors and 1-2 years for GBMs. Neuroimaging is critical to managing patients with HGG for diagnosis, treatment planning, response assessment, and detecting recurrent disease. Magnetic resonance imaging (MRI) is the cornerstone of imaging in neuro-oncology, but molecular imaging with positron emission tomography (PET) can overcome some of the inherent limitations of MRI. Additionally, PET has the potential to target metabolic and molecular alterations in HGGs relevant to prognosis and therapy that cannot be assessed with anatomic imaging. Many classes of PET tracers have been evaluated in HGG including agents that target cell membrane biosynthesis, protein synthesis, amino acid transport, DNA synthesis, the tricarboxylic acid (TCA) cycle, hypoxic environments, cell surface receptors, blood flow, vascular endothelial growth factor (VEGF), epidermal growth factor (EGFR), and the 18-kDa translocator protein (TSPO), among others. This chapter will provide an overview of PET tracers for HGG that have been evaluated in human subjects with a focus on tracers that are not yet in widespread use for neuro-oncology.