mTOR-dependent loss of PON1 secretion and antiphospholipid autoantibody production underlie autoimmunity-mediated cirrhosis in transaldolase deficiency

Transaldolase deficiency predisposes to chronic liver disease progressing from cirrhosis to hepatocellular carcinoma (HCC). Transition from cirrhosis to hepatocarcinogenesis depends on mitochondrial oxidative stress, as controlled by cytosolic aldose metabolism through the pentose phosphate pathway (PPP). Progression to HCC is critically dependent on NADPH depletion and polyol buildup by aldose reductase (AR), while this enzyme protects from carbon trapping in the PPP and growth restriction in TAL deficiency. Although AR inactivation blocked susceptibility to hepatocarcinogenesis, it enhanced growth restriction, carbon trapping in the non-oxidative branch of the PPP and failed to reverse the depletion of glucose 6-phosphate (G6P) and liver cirrhosis. Here, we show that inactivation of the TAL-AR axis results in metabolic stress characterized by reduced mitophagy, enhanced overall autophagy, activation of the mechanistic target of rapamycin (mTOR), diminished glycosylation and secretion of paraoxonase 1 (PON1), production of antiphospholipid autoantibodies (aPL), loss of CD161+ NK cells, and expansion of CD38+ Ito cells, which are responsive to treatment with rapamycin in vivo. The present study thus identifies glycosylation and secretion of PON1 and aPL production as mTOR-dependent regulatory checkpoints of autoimmunity underlying liver cirrhosis in TAL deficiency.

Cytosolic aldose metabolism contributes to progression from cirrhosis to hepatocarcinogenesis

Oxidative stress modulates carcinogenesis in the liver; however, direct evidence for metabolic control of oxidative stress during pathogenesis, particularly, of progression from cirrhosis to hepatocellular carcinoma (HCC), has been lacking. Deficiency of transaldolase (TAL), a rate-limiting enzyme of the non-oxidative branch of the pentose phosphate pathway (PPP), restricts growth and predisposes to cirrhosis and HCC in mice and humans. Here, we show that mitochondrial oxidative stress and progression from cirrhosis to HCC and acetaminophen-induced liver necrosis are critically dependent on NADPH depletion and polyol buildup by aldose reductase (AR), while this enzyme protects from carbon trapping in the PPP and growth restriction in TAL deficiency. Both TAL and AR are confined to the cytosol; however, their inactivation distorts mitochondrial redox homeostasis in opposite directions. The results suggest that AR acts as a rheostat of carbon recycling and NADPH output of the PPP with broad implications for disease progression from cirrhosis to HCC.

Utility of sonographic transcerebellar diameter in the assessment of gestational age in normal and intrauterine growth-retarded fetuses

Background

The fetal cerebellum has been shown to be least affected by external pressures and molding during pregnancy and therefore might provide more accurate estimation of GA.

Aims

To study the utility of transcerebellar diameter (TCD) measured by ultrasound for the detection of GA in normal and intrauterine growth-retarded (IUGR) fetuses.

Subjects and Methods

This cross-sectional study comprised 500 antenatal patients with a GA between 14 and 39 weeks and who were certain of their last menstrual periods. The TCD was measured ultrasonographically and the corresponding GA was determined. The GA was also determined with other customarily used sonographic parameters such as biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL) and compared with TCD. Data of normal pregnancy patients was used to formulate nomograms by taking the 5^th, 50^th, and 95^th percentile measurements. TCD to AC ratio was also calculated in both normal (n = 424) and IUGR pregnancies (n = 76).

Results

TCD showed significant correlation with gestational age (GA) measured by last menstrual period (LMP) as well as with GA calculated with other biometric fetal parameters. TCD also showed significant correlation with GA in normal (R² = 0.979) as well as with IUGR pregnancies (R² = 0.942). TCD to AC ratio remained fairly constant in normal pregnancies while it was increased in IUGR pregnancies.

Conclusions

TCD and TCD/AC ratio can be employed as an objective parameter to establish the GA in normal as well as IUGR pregnancy cases.

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.

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.

Skull Base Osteomyelitis: A Comprehensive Imaging Review

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.

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.

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.

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.].

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.

[18F]Fluciclovine-PET/MRI use in monitoring response to androgen deprivation therapy in men with prostate cancer following initial staging

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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-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.

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.

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.

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.

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.

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.

Imaging of Meningitis and Meningoencephalitis in Children

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.

Imaging of Atypical Brain Infections and Infection Mimics in Children

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.

Infections of the Spine and Spinal Cord in Children

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.

A Classification System for the Spread of Polymethyl Methacrylate in Vertebral Bodies Treated with Vertebral Augmentation

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 < .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.

Abstract P3-12-12: Incidence of internal mammary node, sternum, and manubrium failure as detected by FDG-18 PET/CT

Introduction:

Elective radiotherapy to the internal mammary (IM) lymph nodes remains an ongoing subject of debate. While the incidence of occult IM involvement on extended mastectomy ranges from 15-65%, reported rates of IM failure are substantially lower (approximately 1%). Interest in this subject has resurfaced recently as randomized trials have shown a survival benefit to adjuvant regional node irradiation including the IM chain. The mechanism by which extended field radiotherapy leads to improved systemic outcomes has not been clearly demonstrated and the degree of benefit directly attributable to IM irradiation remains to be seen. We hypothesized that the IM lymphatic chain may provide a direct route for tumor cell dissemination into the the sternum or manubrium. As such, sternal metastases may be a manifestation of IM involvement rather than true hematogenous metastases. We sought to better elucidate patterns of failure by evaluating the incidence and timing of IM, sternal, or manubrial involvement identified by PET/CT imaging following diagnosis of metastatic breast cancer.

Patients and Methods:

Between 2007 and 2014, 96 patients with invasive breast cancer were found to have metastatic disease as diagnosed on FDG-18 PET/CT. Site of recurrence was scored as breast/chest wall, axilla/supraclav, IM chain, sternum/manubrium, or distant. IM or sternum/manubrium failure was scored as isolated (occurring without distant metastatic disease), synchronous (involved at initial diagnosis of distant metastatic disease), or metachronous (involved at any time after diagnosis of metastatic disease).

Results:

Isolated IM failures were observed in 3.1% of patients while isolated sternum/manubrium failures were recorded in 7.3% of patients. Isolated involvement of the sternum/manubrium or IM nodes occurred in 11.4%. The rate of synchronous IM failure was 11.4% with the rate of metachronous failure being 13.5%. The rate of synchronous sternum/manubrium failure was 17.7% with the rate of metachronous failure being 23.9%. The incidence of sternum/manubrium or IM involvement at the initial diagnosis of distant metastatic disease was 29.2% with the rate of involvement at any point increasing to 36.5%.

Conclusion:

The rate of internal mammary node failure by PET/CT at the time of metastatic diagnosis is higher than the incidence reported in previous trials. This discrepancy is likely due increased sensitivity of PET/CT and the difficulty of accurately assessing this region once patients have been found to have metastatic disease. Interestingly, sternum and manubrium were more often the first site of recurrence than the IM nodes. This could be due to a tropism of hematogenous metastases for these bones or could represent direct tumor cell dissemination from the internal mammary chain. This is of special interest as this region is incidentally included in the radiotherapy fields when targeting the IM nodes. Overall, our findings suggest that historic patterns of failure studies may underestimate the local benefit of internal mammary node radiotherapy.

Citation Format: Grow JL, Choudhary G, Kuo P, Livingston RB, Gonzalez VJ. Incidence of internal mammary node, sternum, and manubrium failure as detected by FDG-18 PET/CT. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-12-12.

Six-Minute Magnetic Resonance Imaging Protocol for Evaluation of Acute Ischemic Stroke

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.

Abstract 117: A Six Minute MRI Protocol for Evaluation of Acute Ischemic Stroke: Pushing the Boundaries

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.

Multifocal skeletal tuberculosis involving the lumbar spine and iliac bone, mimicking a malignant bone tumour: a case report

ABSTRACT

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.

Carvedilol titration in patients with congestive heart failure receiving inotropic therapy

BACKGROUND

Carvedilol has been shown to improve morbidity and mortality in patients with congestive heart failure (CHF). There are limited data of carvedilol use in patients on inotrope therapy. We present our experience with carvedilol titration in New York Heart Association (NYHA) class IIIb/IV patients stabilized on milrinone therapy, as a nonrandomized study with a parallel control group of patients never on inotropes. These patients achieved volume control and stabilization of their symptoms during the course of milrinone therapy.

METHODS AND RESULTS

Seventeen patients in class IIIb/IV CHF (group 1) on intermittent intravenous milrinone therapy and 15 patients in class II/IIIa compensated CHF (group 2) on standard triple heart failure therapy were titrated on carvedilol. Success and adverse events during titration were compared between the 2 groups. Fifteen (88%) patients in group 1 and 14 (93%) patients in group 2 were successfully titrated on carvedilol over 8.1 +/- 1.8 weeks and 6.7 +/- 2.8 weeks, respectively. The target dose of carvedilol (25 or 50 mg twice daily) was achieved in 13 (87%) patients (group 1) and 14 (93%) patients (group 2). Seven (47%) patients in group 1 and 4 (28%) patients in group 2 had adverse events during carvedilol titration. Eight (53%) patients in group 1 were weaned off milrinone over a period of 8.4 weeks after carvedilol titration, whereas the rest of the patients had reduction in the frequency of infusion. Ten (63%) patients in group 1 improved by one or more functional classes.

CONCLUSIONS

Patients in NYHA class IIIb/IV who are treated with inotropic therapy can be titrated on carvedilol after reaching a stable state while on milrinone and standard oral drugs. Most of these patients can be successfully weaned off of milrinone or have decreased frequency of infusions and demonstrate improved functional status. Prospective randomized trials are required to evaluate these observations made in a limited number of patients in class IIIb and IV CHF because the combination of milrinone and beta-blockers has never been adequately evaluated.

Apoptosis of lung epithelial cells in response to TNF-alpha requires angiotensin II generation de novo

Recent work from this laboratory demonstrated that apoptosis of pulmonary alveolar epithelial cells (AEC) in response to Fas requires angiotensin II (ANGII) generation de novo and binding to its receptor (Wang et al., 1999b, Am J Physiol Lung Cell Mol Physiol 277:L1245-L1250). These findings led us to hypothesize that a similar mechanism might be involved in the induction of AEC apoptosis by TNF-alpha. Apoptosis was detected by assessment of nuclear and chromatin morphology, increased activity of caspase 3, binding of annexin V, and by net cell loss inhibitable by the caspase inhibitor ZVAD-fmk. Purified human TNF-alpha induced dose-dependent apoptosis in primary type II pneumocytes isolated from rats or in the AEC-derived human lung carcinoma cell line A549. Apoptosis in response to TNF-alpha was inhibited in a dose-dependent manner by the nonselective ANGII receptor antagonist saralasin or by the nonthiol ACE inhibitor lisinopril; the inhibition of TNF-induced apoptosis was maximal at 50 microgram/ml saralasin (101% inhibition) and at 0.5 microgram/ml lisinopril (86% inhibition). In both cell culture models, purified TNF-alpha caused a significant increase in the mRNA for angiotensinogen (ANGEN), which was not expressed in unactivated cells. Transfection of primary cultures of rat AEC with antisense oligonucleotides against ANGEN mRNA inhibited the subsequent induction of TNF-stimulated apoptosis by 72% (P < 0.01). Exposure to TNF-alpha increased the concentration of ANGII in the serum-free extracellular medium by fivefold in A549 cell cultures and by 40-fold in primary AEC preparations; further, exposure to TNF-alpha for 40 h caused a net cell loss of 70%, which was completely abrogated by either the caspase inhibitor ZVAD-fmk, lisinopril, or saralasin. Apoptosis in response to TNF-alpha was also completely inhibited by neutralizing antibodies specific for ANGII (P < 0.01), but isotype-matched nonimmune immunoglobulins had no significant effect. These data indicate that the induction of AEC apoptosis by TNF-alpha requires a functional renin/angiotensin system (RAS) in the target cell. They also suggest that therapeutic control of AEC apoptosis in response to TNF-alpha is feasible through pharmacologic manipulation of the local RAS.

Should the definition of preeclampsia include a rise in diastolic blood pressure of >/=15 mm Hg to a level <90 mm Hg in association with proteinuria?

OBJECTIVE

This study was undertaken to compare baseline characteristics and pregnancy outcomes between normotensive women who did and those who did not have a rise in diastolic blood pressure of >/=15 mm Hg in association with proteinuria.

STUDY DESIGN

We studied 4302 healthy nulliparous women from the Calcium for Preeclampsia Prevention trial who were delivered at >/=20 weeks' gestation. We selected as the study group normotensive women who developed proteinuria within 7 days of a rise in diastolic blood pressure of >/=15 mm Hg with respect to baseline on 2 occasions 4 to 168 hours apart. Baseline blood pressure was the mean of measurements at 2 clinic visits before 22 weeks' gestation. Other normotensive women used for comparison were those who did not develop gestational hypertension or a rise in diastolic blood pressure of >/=15 mm Hg in association with proteinuria.

RESULTS

Except for greater weight (P <.001), body mass index (P <.001), and systolic blood pressure (P =.05) the baseline characteristics of the 82 women with a rise in diastolic blood pressure of >/=15 mm Hg in association with proteinuria did not differ significantly from those of the other normotensive women. Although they had a greater rate of weight gain (P <.005), larger babies (P =.06), and a 2-fold increase in abdominal delivery (P <.001), there was little other evidence of adverse pregnancy outcomes among these women.

CONCLUSION

During normotensive pregnancy a rise in diastolic blood pressure of >/=15 mm Hg in association with proteinuria appears to be benign and is not a useful clinical construct.

Use of on-line mass spectrometric detection in capillary electrochromatography

Capillary electrochromatography (CEC) is a liquid phase analytical separation technique that is generally carried out with packed capillary columns by electroosmotically driven mobile phase at high electric field strength. The analytes are separated by virtue of the differences in their distribution between the mobile and stationary phases and, if charged in their electrophoretic mobilities as well. It is thus considered a hybrid of liquid chromatography and capillary electrophoresis and is expected to combine the high peak efficiency of capillary zone electrophoresis (CZE) with the versatility and loading capacity of HPLC. This review explores the potential use of on-line mass spectrometric detection for CEC. It discusses key design issues that focus on the physical and electrical arrangement of the CEC column with respect to the electrospray orifice inlet. The salient features of the sheathless, sheath flow and liquid junction interfaces that are frequently employed while coupling a CEC column to an electrospray ionization mass spectrometry system are also highlighted. Possible configurations of the CEC column outlet that would obviate the need for pressurizing the capillary column are also presented. While coupling CEC with MS both the nature of the interface and the configuration of the column outlet will determine the optimal arrangement. The review also discusses bandspreading that occurs when a connecting tube is employed to transfer mobile phase from the column outlet to the atmospheric region of the electrospray source with a concomitant loss in sensitivity. Selected examples that highlight the potential of this technique for a wide range of applications are also presented.

Integrated approach to the multidimensional analysis of complex biological samples by microseparation techniques. Analysis of glycoprotein factor associated with cancer cachexia

Microanalytical separation techniques including capillary liquid chromatography, capillary electrophoresis and capillary electrochromatography are suitable for detection of diagnostically important changes in the metabolic profiles of biological fluids. A prototype instrument was employed to serve as an integrated platform for the analysis of urine sample from patients suffering from cancer cachexia. The instrument provides for convenient, rapid and efficient multidimensional approach towards method development which would facilitate simultaneous analysis of complex biological mixtures by the above techniques.

Investigation of the potential of capillary electrophoresis with off-line matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for clinical analysis: examination of a glycoprotein factor associated with cancer cachexia

The potential of capillary electrophoresis (CE) with offline matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry has been demonstrated for the examination of a glycoprotein factor associated with cancer cachexia. A comparison of CE profiles of a healthy volunteer and a cancer patient shows the presence of additional peaks in the electropherogram of the cancer patient that could be associated with cachexia. Micropreparative CE was performed with 180-micron fused silica capillary columns with tapered ends to collect CE fractions for further identification by MALDI-TOF-MS. The analysis of crude urine samples of cancer patients exhibiting cachexia, as well as CE fractions, with MALDI-TOF-MS using ferulic acid as the matrix shows a number of characteristic ions at m/z values of approximately 24 and approximately 67 kDa. The 24-kDa peak may be identified as the cachectic factor, a glycoprotein, whereas the peak at 67 kDa is identified as albumin, which is present in urine of most patients, and to which the cachectic factor is noncovalently bound. The combined use of CE and MALDI-TOF-MS was successful in detecting cachexia in all of the patients in this study, including one patient that was in an early phase of the disease.

Capillary electrochromatography of biomolecules with on-line electrospray ionization and time-of-flight mass spectrometry

Capillary electrochromatography (CEC) is considered a hybrid of liquid chromatography and capillary electrophoresis. It is expected to combine the high peak efficiency of capillary zone electrophoresis with the versatility and loading capacity of HPLC to bring about another high-performance MS-compatible chromatographic system. This paper explores the potential of CEC coupled with the electrospray ionization and time-of-flight mass spectrometry in biochemical analysis. The packed columns used in this study were tapered at the outlet to retain the packing material, thereby obviating the need for an outlet frit. Electrosmotically driven solvent gradients were employed for the separation of phenylthiohydantoin (PTH)-amino acids by reversed-phase chromatography, and a time-of-flight (TOF) mass spectrometer was employed as the detector for the CEC column effluent. The effect of CEC operating parameters, such as gradient shape, column length, and electric field, on the analytical results from the separation and MS detection of a standard mixture of PTH-amino acids was investigated. Particular attention was paid to the effect of sheath flow-rate, sheath composition and mass spectra acquisition rate on the performance of the electrospray TOF-MS.

Human health perspective on environmental exposure to hydrazines: a review

Hydrazines are colorless liquid compounds that have been found at various Department of Defense hazardous waste sites. They are designated as environmental contaminants causing adverse effects to public health and have been identified at many National Priorities List (NPL) hazardous waste sites and federal facilities sites in the United States. Three chemically similar hydrazines-hydrazine, 1,1-dimethylhydrazine, and 1,2-dimethylhydrazine--occur in the environment and cause adverse health effects to persons living near hazardous waste sites. Humans are exposed to hydrazines by drinking contaminated, water, by inhaling contaminated air, or by swallowing or touching contaminated dust. Human occupational data and studies in laboratory animals suggest that people exposed to hydrazines may develop adverse systemic health effects or cancer. Hydrazines have caused cancer in animals following acute- or intermediate- duration exposure by the oral and inhalation routes. The U.S. Environmental Protection Agency, the U.S. Department of Health and Human Services, the International Agency for Research on Cancer, and the World Health Organization have classified hydrazines as possible cancer-causing environmental contaminants.

Capillary electrochromatography with gradient elution

A capillary electrochromatograph incorporating a gradient-forming system generally employed in HPLC is described, and the use of gradient elution in reversed phase electrochromatography is demonstrated by the separation of PTH-amino acids and steroid hormones. The gradient former employs two reciprocating displacement pumps to control the composition of the eluent in the reservoir at the column inlet with time in a controlled manner. Thus, the composition of the mobile phase flowing through the column and driven by electrosmotic forces can be changed with time in a controlled fashion as customary in HPLC with gradient elution. The design of the system allows also for isocratic elution by pumping the eluent of constant composition through the cavity at the column inlet and thus continuously supplying fresh buffer. The eluent gradient is generated by the two pumps and a 10 microL mixer. From there the liquid passes at a flow rate of 0.1-0.2 mL/min through the 17 microL cavity housing the column inlet and an electrode. The flow of the mobile phase was electrosmotic at an effective overall electric field strength of 500-1500 V/cm through a 50 microns x 20/12 cm capillary column packed with 3.5 microns octadecylated silica particles. Gradient profiles generated in this manner were highly reproducible. The same-day and day-today reproducibilities of the electrosmotic flow were found to be better than 3%. The use of the capillary electrochromatographic system was demonstrated with isocratic and gradient elution for the separation of complex mixtures of biologically interesting substances. The influence of the column temperature on the electrosmotic flow velocity and retention of PTH-amino acids was also investigated.

Dynamics of capillary electrochromatography experimental study on the electrosmotic flow and conductance in open and packed capillaries

For capillary electrochromatography (CEC) to become an analytical separation technique of high speed and resolution the factors determining the conductivity of the column as well as the generation and control of electrosmotic flow (EOF) in porous media have to be understood. In the present study the conductance of capillaries packed with a variety of stationary phases was evaluated with respect to the conductance of the open capillary and the data were interpreted in the light of the Tobias equation. However, the consistently observed reduction of the EOF when a capillary having a charged inner wall is packed with particles having charges of the same sign and the dependence of the EOF velocity on the particle size needs further explanation. The data suggests that, due to the employment of relatively long columns packed with small particles, CEC may offer peak capacities much higher than HPLC or micro-HPLC. The CEC columns are unique as they consist of a packed and an open capillary segment having different conductances and consequently different voltage gradients and electrical field strengths. Therefore, any sufficiently detailed study on CEC systems requires also the characterization of the individual column segments. EOF velocities of 6-7 mm/s could be realized at 60 kV applied voltage with a 23/32 cm x 50 microns raw fused-silica capillary packed with 6-micron Zorbax ODS particles. The current was a linear function of the field strength up to 1.8 kV/cm, but at high field strengths the EOF increased with squared field strength. Data on band spreading indicate that with a given column the plate height at high EOF velocities is smaller in CEC than in micro-HPLC and it is weakly dependent on the velocity.

Human health perspectives on environmental exposure to benzidine: a review

Benzidine, an odorless, white to slightly reddish-white crystalline organic compound, is an environmental contaminant that has been identified at about 30 National Priorities List (NPL) hazardous waste sites in the United States. In the environment, it is usually found attached to suspended particles either in its "free" state or as chloride or sulfate salts. In the past, U.S. industries used large quantities of benzidine to produce dyes for paper, clothes, and leather. Since the ban on its production and use in the United States in the 1970s, this compound is imported for specialty uses. People living near hazardous waste sites might be exposed to benzidine by drinking contaminated water, by inhaling contaminated air, or by swallowing or touching contaminated dust. People can also be exposed by using benzidine dyes on paper, clothes, and other materials. Human occupational data and studies of laboratory animals suggest that people exposed to benzidine may develop adverse systemic health effects or cancer. The U.S. Environmental Protection Agency (EPA), the U.S. Department of Health and Human Services, the International Agency for Research on Cancer (IARC), and the World Health Organization (WHO) have classified benzidine as a carcinogen. Urinary bladder cancer is the most common form of cancer caused by exposure to benzidine. The stomach, kidneys, brain, mouth, esophagus, liver, and gallbladder might also be targets. The information presented in the article may help public health officials, physicians, and toxicologists evaluate and develop the health information materials on the nature of benzidine in the environment and its potential impact on public health.