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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 (18)F-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 (18)F-fluciclovine PET/MRI including multiparametric prostate MRI; 12 underwent (18)F-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 (18)F-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 SUV(mean), SUV(max), and volume of the MRI-defined intraprostatic lesion and SUV(max) of suspicious lymph nodes on PET before and after initiation of ADT. Changes in SUV were analyzed using nonparametric Wilcoxon signed-rank tests. RESULTS. The biopsy-proven lesion in the prostate gland was accurately identified in all 14 patients on both MRI and (18)F-fluciclovine PET/MRI. Suspected nodal metastases were detected in three patients on MRI and seven patients on (18)F-fluciclovine PET/MRI. After ADT, all patients showed decreased activity within the intraprostatic lesion and/or all suspicious lymph nodes. The primary lesion SUV(mean) 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 SUV(max) was 5.5 ± 3.7 (range, 2.8–12.7) and the posttreatment SUV(max) was 2.8 ± 1.4 (range, 1.4–5.5) (p = .03). CONCLUSION. (18)F-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 (18)F-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

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.

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.

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.

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.

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.

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.

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.

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.

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.

Skull base osteomyelitis is a relatively rare condition, generally occurring as a complication of advanced otologic or sinus infection in immunocompromised patients. Skull base osteomyelitis is generally divided into 2 broad categories: typical and atypical. Typical skull base osteomyelitis occurs secondary to uncontrolled infection of the temporal bone region, most often from necrotizing external otitis caused by Pseudomonas aeruginosa in a patient with diabetes. Atypical skull base osteomyelitis occurs in the absence of obvious temporal bone infection or external auditory canal infection. It may be secondary to advanced sinusitis or deep face infection or might occur in the absence of a known local source of infection. Atypical skull base osteomyelitis preferentially affects the central skull base and can be caused by bacterial or fungal infections. Clinically, typical skull base osteomyelitis presents with signs and symptoms of otitis externa or other temporal bone infection. Both typical and atypical forms can produce nonspecific symptoms including headache and fever, and progress to cranial neuropathies and meningitis. Early diagnosis can be difficult both clinically and radiologically, and the diagnosis is often delayed. Radiologic evaluation plays a critical role in the diagnosis of skull base osteomyelitis, with CT and MR imaging serving complementary roles. CT best demonstrates cortical and trabecular destruction of bone. MR imaging is best for determining the overall extent of disease and best demonstrates involvement of marrow space and extraosseous soft tissue. Nuclear medicine studies can also be contributory to diagnosis and follow-up. The goal of this article was to review the basic pathophysiology, clinical findings, and key radiologic features of skull base osteomyelitis.

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

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. Keywords: Persistent hypoglossal artery, Computed tomography

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.

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.

Although central nervous system infections in children are rare, when suspected, urgent diagnosis and treatment are mandated to prevent morbidity and mortality. Inflammation of the meninges alone is termed meningitis; associated involvement of the underlying brain leads to meningoencephalitis. CSF analysis remains the gold standard in identifying the infectious agent. Imaging plays a vital role not only in supporting the diagnosis of meningitis or meningoencephalitis but also in identifying potential complications, monitoring treatment response, and follow-up. The pattern of meningeal and brain involvement can vary depending on the infectious agent; cerebral convexity meninges is commonly involved in acute bacterial infection, basilar meninges in tuberculosis, and meningoencephalitis in viral infection. In this article, we review the characteristic imaging appearances of common bacterial, mycobacterial and viral agents, role of newer imaging technique, and list potential complications.

Infection of the spine and spinal cord are uncommon in children which if not diagnosed and treated early in the course of disease can lead to spinal instability and devastating neurological outcome. The spectrum of spinal infection ranges from discitis/osteomyelitis, spinal epidural abscess, subdural abscess, spinal meningitis, arachnoiditis, neuritis, myelitis, and intramedullary abscess. Inability of the children to express themselves and nonspecific clinical features like abdominal pain, walking/crawling difficulty, and fever can result in difficult and delayed diagnosis. Imaging plays a critical role in diagnosis of spinal infection; its complication and treatment follow-up. Magnetic resonance imaging with gadolinium contrast is considered as the imaging modality of choice for evaluation of spinal and cord infections. Infectious mimics like chronic recurrent multifocal osteomyelitis, pars articular defect with active inflammatory changes, spondyloarthritis, Guillain-Barre syndrome, transverse myelitis, acute disseminated encephalomyelitis, and multiple sclerosis can pose diagnostic challenge on imaging. The aim of this article is to briefly review the imaging appearances of infection involving various spinal compartments, pattern of infection spread, its complications and various mimics.

Atypical brain infections in the pediatric age group are uncommon and different from the adult population; however, when present, they pose a diagnostic challenge and can result in serious and potentially fatal complications if not recognized and treated early in the course of the disease. Imaging plays a vital role because of relative inaccessibility to tissue sampling. This review article regroups the atypical pediatric brain infections (parasitic, fungal, viral, and bacterial) by age group (prenatal, perinatal, and post-neonatal period) and elucidates their characteristic imaging appearance, as well as focuses on their complications, in an aim to help clinicians (pediatricians/pediatric neuroradiologists/radiologists) better characterize, diagnose, and guide patient treatment. In addition, this review article also emphasizes on infection mimics of the central nervous system in order to empower our differential diagnosis, improve our diagnostic accuracy, and avoid unindicated patient management and treatment.

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.

Similar to various gastroenteropancreatic (GEP) neuroendocrine tumors (NETs), somatostatin receptors (SSTRs) are overexpressed in a wide array of malignant and benign conditions. Using somatostatin positron emission tomography (PET) analogs ([68Ga]DOTA-peptides) this overexpression of SSTRs can be exploited for clinical management in terms of diagnosis, therapy, and for peptide receptor radionuclide therapy (PRRT). Recent reports suggest that [68Ga]DOTA-peptide PET tracers have an emerging role in the management of wide array of non-GEP-NETs due to overexpression of SSTRs. The potential role of SSTR-PET imaging in the management of medullary thyroid cancer, paraganglioma, Merkel cell carcinoma, phosphaturic mesenchymal tumors, and inflammation will be discussed. The emerging role of theranostic and personalized medicine with PRRT using peptides labeled with yttrium-90 (90Y) or lutetium-177 (177Lu) beta emitters will also be discussed. SSTR-PET imaging with [68Ga]DOTA-peptides has utility in malignant and benign conditions other than GEP-NETs. Combining SSTR-PET with other anatomic and functional imaging modalities has demonstrated superior diagnostic accuracy. The presence of SSTRs in these conditions opens up new possibilities in the management of these conditions in terms of imaging and therapeutics.

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.

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.

In this study, we develop a classification system for describing polymethyl methacrylate (PMMA) spread in vertebral bodies after kyphoplasty or vertebroplasty for vertebral compression fractures (VCFs) and for assessing whether PMMA spread varies between operators, VCF etiology, or vertebral level. Intraoperative fluoroscopic images of 198 vertebral levels were reviewed in 137 patients (women, 84, men, 53, mean age, 75.8 ± 12.5, and those with a diagnosis of osteoporosis, 63%) treated with kyphoplasty between January 01, 2015 and May 31, 2015 at a single center to create a 5-class descriptive system. PMMA spread patterns in the same images were then classified by 2 board-certified radiologists, and a third board-certified radiologist resolved conflicts. A total of 2 primary PMMA spread patterns were identified, namely, acinar and globular, with subtypes of localized acinar, diffuse globular, and mixed, to describe an equal combination of patterns. Interrater reliability using the system was moderate (κ = 0.47). After resolving conflicts, the most common spread class was globular (n = 63), followed by mixed (n = 58), diffuse globular (n = 30), acinar (n = 27), and localized acinar (n = 20). The spread class after treatment by the 2 most frequent operators differed significantly (n1 = 63, n2 = 70, P &lt, 0001). There was no difference in the spread class between VCF etiologies or vertebral levels. PMMA spread may, therefore, be a modifiable parameter that affects kyphoplasty and vertebroplasty efficacy and adverse events.

216 Background: [18F]Fluciclovine PET is clinically approved for detection of biochemically recurrent prostate cancer (PCa). However, its use for initial staging and treatment monitoring remains uncertain. No published data exists evaluating the use of fluciclovine-PET for monitoring response to androgen deprivation therapy. Thus, the purpose of this study is to evaluate the potential use of fluciclovine-PET in monitoring response to androgen deprivation therapy (ADT) during initial treatment of patients with newly diagnosed high risk PCa. Methods: A prospective study enrolled patients with high-risk PCa who had no imaging evidence of metastatic disease. All patients underwent a pretreatment fluciclovine-PET/MRI for primary staging, 6 weeks of ADT, and had a follow-up PET/MRI. All exams were interpreted by 3 nuclear medicine physicians. Identification of the primary intraprostatic lesion and nodal metastatic disease was performed with mean and maximum SUV of the MRI-defined primary prostatic lesions and lymph node metastases measured before and after ADT. Results: A total of 10 patients were enrolled. Gleason scores of their primary tumor were 3+4 (n = 2), 4+3 (n=2), 8 (n = 3), and 9 (n = 3). The average pretreatment serum PSA value was 33.04 ng/mL (range 2.83–76.5). The average serum PSA 6 weeks following initiation of ADT was 2.13 ng/mL (range 0.29–5.66). The primary intraprostatic lesion was accurately identified in all 10 patients and 7/10 patients demonstrated suspicious lymph nodes on the pretreatment PET/MRI. Following ADT, all 10 patients demonstrated a decrease in tracer activity both within the primary intraprostatic lesion and suspicious lymph nodes. The primary lesion mean SUV prior to treatment was 4.46±1.14 and 2.37±1.07 following initiation of ADT (p=0.0007). The primary lesion maximum SUV prior to treatment was 7.13±1.70 and 3.54±2.04 following initiation of ADT (p=0.0006). Conclusions: Fluciclovine-PET tracer activity in patients with PCa undergoing ADT appears to correlate with decrease in serum PSA. Fluciclovine-PET imaging may be useful in monitoring response to ADT, particularly if there is a failure of appropriate PSA response. Clinical trial information: NCT03264456.

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.

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

OBJECTIVE Nuclear imaging can confirm pleuroperitoneal shunt as the cause of pleural effusion. No society guidelines exist for scintigraphic pleuroperitoneal shunt detection. Our institutional protocol was evaluated to determine optimal imaging time points for shunt detection. METHODS Pleuroperitoneal shunt studies over 4 years were blindly reviewed by 2 nuclear radiologists. Data from blinded review included presence or absence of pleuroperitoneal shunt, laterality of shunt and time points for shunt detection. RESULTS Chart review yielded 30 studies. Three cases were excluded because of improper injection. Imaging was positive for pleuroperitoneal shunt in 81% (22/27) of cases. In positive cases, activity was identified in the right hemithorax in 82% (18/22), left hemithorax in 9% (2/22), and bilaterally in 9% (2/22). One-hour imaging demonstrated 91% (20/22) of positive cases. The remaining 2 positive cases were negative at 1 hour but positive after 4 hours. No study was negative at 1 and 4 hours and positive at 24 hours. All negative cases (5/27) were confirmed on 24-hour imaging. CONCLUSIONS The majority of positive pleuroperitoneal shunt examinations will demonstrate activity in the right hemithorax on 1-hour imaging. Although no case was negative at 1 and 4 hours and positive at 24 hours, imaging at 24 hours may still be necessary to confirm absence of shunt. Therefore, optimal imaging time points consist of early 1-hour and delayed 24-hour images if the 1-hour time point was negative. The 4-hour time point may be considered optional, thereby potentially optimizing patient safety and resource utilization.

Ascites can cause pleural effusions when the peritoneal fluid crosses the diaphragm through a pleuroperitoneal shunt in the setting of hepatic cirrhosis (hepatic hydrothorax) or malignant ascites. Scintigraphic imaging for pleuroperitoneal shunt requires intraperitoneal injection of Tc-SC or Tc-macroaggregated albumin followed by planar imaging of the chest and abdomen. Pleuroperitoneal shunt is confirmed by identifying radiotracer crossing the diaphragm from the peritoneal to pleural space. An atlas of pleuroperitoneal shunt imaging pitfalls is presented to facilitate optimal performance and interpretation of nuclear pleuroperitoneal shunt examinations. Examples include cases of nondiagnostic radiotracer injections, processing errors, and nontarget uptake.

Multifocal osteoarticular tuberculosis is uncommon and accounts for approximately10% of all cases of osteoarticular tuberculosis. Concomitant vertebral and iliac bone tuberculosis has not been reported in the literature to date. We report one such case for its unusual clinical and radiological presentation, which had presentation more similar to a malignant bone tumour than an infection. Key words Skeletal tuberculosis, multifocal osteoarticular tuberculosis.

Background and Purpose— If magnetic resonance imaging (MRI) is to compete with computed tomography for evaluation of patients with acute ischemic stroke, there is a need for further improvements in acquisition speed. Methods— Inclusion criteria for this prospective, single institutional study were symptoms of acute ischemic stroke within 24 hours onset, National Institutes of Health Stroke Scale ≥3, and absence of MRI contraindications. A combination of echo-planar imaging (EPI) and a parallel acquisition technique were used on a 3T magnetic resonance (MR) scanner to accelerate the acquisition time. Image analysis was performed independently by 2 neuroradiologists. Results— A total of 62 patients met inclusion criteria. A repeat MRI scan was performed in 22 patients resulting in a total of 84 MRIs available for analysis. Diagnostic image quality was achieved in 100% of diffusion-weighted imaging, 100% EPI-fluid attenuation inversion recovery imaging, 98% EPI-gradient recalled echo, 90% neck MR angiography and 96% of brain MR angiography, and 94% of dynamic susceptibility contrast perfusion scans with interobserver agreements ( k ) ranging from 0.64 to 0.84. Fifty-nine patients (95%) had acute infarction. There was good interobserver agreement for EPI-fluid attenuation inversion recovery imaging findings ( k =0.78; 95% confidence interval, 0.66–0.87) and for detection of mismatch classification using dynamic susceptibility contrast-Tmax ( k =0.92; 95% confidence interval, 0.87–0.94). Thirteen acute intracranial hemorrhages were detected on EPI-gradient recalled echo by both observers. A total of 68 and 72 segmental arterial stenoses were detected on contrast-enhanced MR angiography of the neck and brain with k =0.93, 95% confidence interval, 0.84 to 0.96 and 0.87, 95% confidence interval, 0.80 to 0.90, respectively. Conclusions— A 6-minute multimodal MR protocol with good diagnostic quality is feasible for the evaluation of patients with acute ischemic stroke and can result in significant reduction in scan time rivaling that of the multimodal computed tomographic protocol.

Purpose: Multimodal cerebrovascular CT and MR can now provide information about tissue viability, site of occlusion, and collateral status in patients with acute ischemic stroke (AIS). If MRI is to compete with CT for evaluation of AIS, there is need for further improvements in acquisition speed. The purpose of this study was to establish the feasibility of a fast MR protocol with a 6 minute acquisition time for evaluation of AIS. Methods: Patients with suspicion of AIS and absence of MRI contraindications were prospectively enrolled. A combination of echo-planar imaging (EPI) and parallel acquisition technique were used on a 3T MR scanner to accelerate the acquisition time. The imaging protocol included: DWI (1 min), EPI-FLAIR (52 sec), EPI-GRE (50 sec), contrast-enhanced MR angiography (CE-MRA) of the entire supra-aortic arteries (20 sec), and DSC perfusion (2 min). Using a modified 2-phase contrast injection scheme, high spatial resolution CE-MRA of the supra-aortic arteries was performed just before DSC perfusion without the need for additional contrast. Image analysis was performed independently by two neuroradiologists and interobserver agreement was calculated using Kappa test. Results: A total of 50 patients were included. Diagnostic image quality was achieved in 100% of DWI, 96% EPI-FLAIR, 98% EPI-GRE, 90% neck MRA, 96% of brain MRA, and 94% of DSC perfusion scans. Thirty eight patients (76%) had acute infarction. Using Tmax perfusion maps and applying DEFUSE criteria, 42% of patients had perfusion-diffusion mismatch with interobserver agreement of k=0.90. The mean of the signal-intensity-ratio values of the infarction on EPI-FLAIR was 1.08 for patients presenting < 4.5 hours (n=16) and 1.35 for patients presenting > 4.5 hours (n=22) from the time of imaging. Three patients had evidence of intracranial hemorrhage detected on EPI-GRE and confirmed by non-contrast CT. CE-MRA showed 27 segmental stenoses of the extra-cranial arteries and 24 segmental stenoses of the intracranial arteries with interobserver agreement of k= 0.82 and 0.74 respectively. Conclusion: Described multimodal MR protocol is feasible for evaluation of patients with AIS and can result in significant reduction in scan time rivaling that of the multimodal CT protocol.