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PET/CT imaging is a dual-modality diagnostic technology that merges metabolic and structural imaging. There are several currently available radiotracers, but 18F-FDG is the most commonly utilized due to its widespread availability. 18F-FDG PET/CT is a cornerstone of head and neck squamous cell carcinoma imaging. 68Ga-DOTA-TOC is another widely used radiotracer. It allows for whole-body imaging of cellular somatostatin receptors, commonly expressed by neuroendocrine tumors and is the standard of reference for the characterization and staging of neuroendocrine tumors. The normal biodistribution of these PET radiotracers as well as the technical aspects of image acquisition and inadequate patient preparation affect the quality of PET/CT imaging. In addition, normal variants, artifacts and incidental findings may impede accurate image interpretation and can potentially lead to misdiagnosis. In order to correctly interpret PET/CT imaging, it is necessary to have a comprehensive knowledge of the normal anatomy of the head and neck and to be cognizant of potential imaging pitfalls. The interpreter must be familiar with benign conditions which may accumulate radiotracer potentially mimicking neoplastic processes and also be aware of malignancies which can demonstrate low radiotracer uptake. Appropriate use of structural imaging with either CT, MR or ultrasound can serve a complimentary role in several head and neck pathologies including local tumor staging, detection of bone marrow involvement or perineural spread, and classification of thyroid nodules. It is important to be aware of the role of these complementary modalities to maximize diagnostic accuracy and patient outcomes. The purpose of this article is to outline the basic principles of PET/CT imaging, with a focus on 18F-FDG PET/CT and 68Ga-DOTA PET/CT. Basic physiology, variant imaging appearances and potential pitfalls of image interpretation are presented within the context of common use cases of PET technology in patients with head and neck cancers and other pathologies, benign and malignant.

Posterior Reversible Encephalopathy Syndrome (PRES) is a rare complication of Takayasu's Arteritis. A 54-year-old, right-handed woman presented with Lilliputian visual hallucinations, postprandial abdominal pain, blurred vision and headaches. She then had a tonic-clonic seizure. Neuroimaging revealed characteristic white matter oedema of the occipital lobes, in keeping with PRES. Renal infarcts and abnormalities of the abdominal aorta, subclavian, mesenteric, and internal carotid arteries were demonstrated on further imaging. The combination of hypertension, absent peripheral pulses, postprandial claudication, and imaging abnormalities of the aorta as well as its branches, lead to the diagnosis of PRES secondary to Takayasu's Arteritis. Treatment with oral steroids resulted in complete resolution of the patient's symptoms and abnormalities found on CT and MRI brain imaging. Takayasu's Arteritis is a rare vasculitis, more common in women and PRES is an unusual complication. Symptoms of PRES may include headache, seizures, hallucinations, confusion, and altered consciousness. Risk factors for PRES include; pregnancy, immunosuppression, renal disease, hypertension and rheumatological disorders. Vasogenic oedema in affected lobes, most often occipital, is characteristic of PRES on neuroimaging. Prompt treatment of PRES can avoid catastrophic consequences such as death and can achieve complete resolution of symptoms and imaging abnormalities.

Eagles syndrome, which is due to calcified stylohyoid ligaments or an elongated styloid process, may manifest as chronic throat pain. It is not usually implicated in trauma. This case report is unique in that we describe firstly a complete bony ring extending from bilateral styloids, and secondly, this abnormality being implicated in serious soft tissue injury. Our patient suffered a blow to the neck during a sports game. While initially asymptomatic, he developed severe neck pain, neck stiffness and odynophagia. Clinical examination of the larynx revealed pharyngeal wall oedema and there was evidence of free air in the retro-pharynx on plain film x-rays. Treatment was initiated in the intensive care unit. He made a complete recovery after 5 days and was discharged with no negative sequelae on follow up. This is a rare finding of bilateral styloid elongation and stylohoid complex ossification forming a complete bony ring around the larynx. Upon retropulsion of this tissue ring, puncture and disruption of the retropharyngeal soft tissues lead to the formation of free air. Prompt airway management is essential in cases such as this that have the potential to compromise the airway if not treated. This case represents a rare finding and an even rarer mechanism of injury.

Dementia with Lewy bodies (DLB) and frontotemporal lobar degeneration (FTLD) are common causes of dementia. Early diagnosis of both conditions is challenging due to clinical and radiological overlap with other forms of dementia, particularly Alzheimer's disease (AD). Structural and functional imaging combined can aid differential diagnosis and help to discriminate DLB or FTLD from other forms of dementia. Imaging of DLB involves the use of 123I-FP-CIT SPECT and 123I-metaiodobenzylguanidine (123I-MIBG), both of which have an established role distinguishing DLB from AD. AD is also characterised by more pronounced atrophy of the medial temporal lobe structures when compared to DLB and these can be assessed at MR using the Medial Temporal Atrophy Scale. 18F-FDG-PET is used as a supportive biomarker for the diagnoses of DLB and can distinguish DLB from AD with high accuracy. Polysomnography and electroencephalography also have established roles in the diagnoses of DLB. FTLD is a heterogenous group of neurodegenerative disorders characterised pathologically by abnormally aggregated proteins. Clinical subtypes include behavioral variant FTD (bvFTD), primary progressive aphasia (PPA), which can be subdivided into semantic variant PPA (svPPA) or nonfluent agrammatic PPA (nfaPPA) and FTD associated with motor neuron disease (FTD-MND). Structural imaging is often the first step in making an image supported diagnoses of FTLD. Regional patterns of atrophy can be assessed on MR and graded according to the global cortical atrophy scale. FTLD is typically associated with atrophy of the frontal and temporal lobes. The patterns of atrophy are associated with the specific clinical subtypes, underlying neuropathology and genetic mutations although there is significant overlap. 18F-FDG-PET is useful for distinguishing FTLD from other forms of dementia and focal areas of hypometabolism can often precede atrophy identified on structural MR imaging. There are currently no biomarkers with which to unambiguously diagnose DLB or FTLD and both conditions demonstrate a wide range of heterogeneity. A combined approach of structural and functional imaging improves diagnostic accuracy in both conditions.

Introduction There has been a recent explosion of research into the field of artificial intelligence as applied to clinical radiology with the advent of highly accurate computer vision technology. These studies, however, vary significantly in design and quality. While recent guidelines have been established to advise on ethics, data management and the potential directions of future research, systematic reviews of the entire field are lacking. We aim to investigate the use of artificial intelligence as applied to radiology, to identify the clinical questions being asked, which methodological approaches are applied to these questions and trends in use over time. Methods and analysis We will follow the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and by the Cochrane Collaboration Handbook. We will perform a literature search through MEDLINE (Pubmed), and EMBASE, a detailed data extraction of trial characteristics and a narrative synthesis of the data. There will be no language restrictions. We will take a task-centred approach rather than focusing on modality or clinical subspecialty. Sub-group analysis will be performed by segmentation tasks, identification tasks, classification tasks, pegression/prediction tasks as well as a sub-analysis for paediatric patients. Ethics and dissemination Ethical approval will not be required for this study, as data will be obtained from publicly available clinical trials. We will disseminate our results in a peer-reviewed publication. Registration number PROSPERO: CRD42020154790

Recurrent painful ophthalmoplegic neuropathy (RPON) replaced the term ‘ophthalmoplegic migraine’ as the condition behaves more like an inflammatory cranial neuropathy than a primary headache disorder. RPON may be associated with cranial nerve thickening on MR imaging and persistent oculomotor paresis. Oculomotor tumours have rarely been described in cases of relapsing painful ophthalmoplegia with and without persistent paresis. Here, we present a case of relapsing painful left ophthalmoplegia that gradually became persistent. MR imaging after 14 years of symptoms revealed an enhancing tumour of the left oculomotor nerve. It is unclear whether the tumour was the cause of the attacks or whether repeated cycles could lead to tumour development. MR imaging is indicated in patients with RPON who develop persistent deficits to screen for associated oculomotor tumour.

The diagnosis of multiple sclerosis (MS) is based on a history consistent with demyelination of the central nervous system and corresponding physical signs on examination. However, this diagnosis is supported radiologically using magnetic resonance imaging (MRI). At present, MRI serves as the most reliable and widely available biomarker for the practising clinician to measure disease activity and treatment response in MS. As MRI remains central to both the diagnosis and management of MS, this paper provides proposed guidelines for its use in routine clinical practice.

Cognitive impairment is a common and disabling feature of Multiple Sclerosis (MS), including early MS, and may even pre-date any physical symptoms. It contributes even more to withdrawal from work than physical disability. Here, we provide an overview of cognitive impairment in MS, particularly in early MS where it is most commonly under-reported and under-treated. We address the presenting features of CI, its impact on quality of life, and its validated assessments (in particular the use of Brief International Cognitive Assessment in MS for use in a clinical setting). We review the insights radiology has given us into the pathogenesis of cognitive impairment in MS, particularly in early CI and in cognitively preserved MS patients. We review current treatments for cognitive impairment, primarily cognitive rehabilitation. We address the evidence for its associated co-morbidities, which may exacerbate or trigger CI, and should therefore be addressed early in the disease course (smoking, alcohol, mood, fatigue and potential co-existing sleep disorders, exercise, and vitamin D). The article supports the importance for early recognition and management of cognitive impairment in MS, before it becomes an established and irreversible entity.

In the context of delayed autoimmune encephalitis antibody results, functional imaging can support the diagnosis of limbic encephalitis associated with anti-voltage-gated potassium channel complex (VGKCC) antibodies. Here we present a typical case of VGKCC encephalitis in a 69-year-old woman whose symptoms responded to plasmapheresis. A cerebral 18F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) scan performed prior to commencing treatment revealed striatal hypermetabolism assessed qualitatively and semi-quantitatively, with normal uptake in the cortex and cerebellum when analysed semi-quantitatively. Repeat FDG-PET imaging performed three months later revealed normalisation of striatal hypermetabolism. Previous case reports have described striatal hypermetabolism and/or cortical hypometabolism in patients with VGKCC encephalitis. However, most of these descriptions were based on qualitative analyses only and may represent the relative change in cortical metabolism compared with striatal metabolism. We recommend semi-quantitative analysis of cerebral FDG-PET, in addition to reporting the qualitative FDG-PET images.

Since its introduction into clinical practice, 2-deoxy-2-[18F]flu-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) has become firmly established in the field of oncological imaging, with a growing body of evidence demonstrating its use in infectious and inflammatory vascular pathologies. This pictorial review illustrates the utility of FDG PET/CT as a diagnostic tool in the investigation of vascular disease and highlights some of the more common incidental vascular findings that PET reporters may encounter on standard oncology FDG PET/CTs, including atherosclerosis, large vessel vasculitis, complications of vascular grafts, infectious aortitis and acute aortic syndromes.

Background Detection of optic neuropathy on MRI has potential implications for the diagnosis and management of Multiple Sclerosis (MS). Objective This study assessed the accuracy of T2 sagittal MRI brain for detection of optic neuropathy, compared to coronal STIR orbit. Methods and materials Retrospective single-center blinded diagnostic accuracy study of 100 consecutive patients who underwent both T2 sagittal brain and coronal STIR orbit MRI. All were performed on 1.5T scanners. T2 sagittal slice thickness was 4 mm for the first 50 patients (group1) and 3 mm for the second 50 (group2). The MRIs were reviewed in a blinded fashion to determine the presence of optic neuropathy. Coronal STIR orbit sequences were considered the diagnostic reference standard. Results The sensitivity of T2 sagittal brain imaging for ON was 44% in group 1 and 85% in group 2 (p = 0.007). The specificities were 98% and 97% respectively (p = 0.9). Sensitivity was poorest for evaluation of the intraorbital nerve segment (56% grp1, 69% grp2, p = 0.4). Conclusion T2 sagittal MRI brain has high specificity for the detection of optic neuropathy when compared to coronal STIR orbit. Sensitivity is increased when slice thickness is reduced, but remains poor for evaluation of the intraorbital segment.

Objective This study examined the use of positron emission tomography (PET) ratios to improve the diagnostic ability of 18F-FDG PET/computed tomography (CT) in the differentiation of enhancing brain metastases, central nervous system lymphomas, and gliomas. Materials and methods Seventy-six patients with malignant brain tumors and available magnetic resonance imaging and PET/CT examinations were included. Results Among standardized uptake value (SUV)-related parameters tested, tumor maximum SUV to ipsilateral cortex maximum SUV ratio (Tmax:WMimax) and maximum SUV (SUVmax) proved to be the two most valuable parameters for differential diagnosis. Conclusion In addition to SUVmax, Tmax:WMimax also seems to provide helpful information for the differential diagnosis of lymphomas from other malignant brain tumors.

The original version of this article unfortunately contained a mistake. The presentation of Table 1 was incorrectly captured. The Publisher regrets that it introduced errors to Table 1 during the typesetting of the article. The original article has been corrected.

BACKGROUND AND PURPOSE: Sialolithiasis is a common benign pathology affecting the salivary glands but it is unclear if contrast-enhanced CT, which is commonly used for investigation of head and neck pathology, can identify calculi as accurately as noncontrast CT. The aim of this study was to assess the diagnostic accuracy of contrast-enhanced CT of the neck in the diagnosis of sialolithiasis compared with noncontrast CT of the neck used as the criterion standard. MATERIALS AND METHODS: This was a retrospective, case-control study of 92 consecutive cases in 90 patients who underwent both noncontrast CT of the neck and contrast-enhanced CT of the neck in 2 tertiary referral centers from January 2011 to December 2015 for investigation of sialolithiasis. Axial 3-mm-section images were assessed by a fellowship-trained diagnostic neuroradiologist and diagnostic neuroradiology fellow in consensus. Blinded assessment of the contrast-enhanced CT of the neck was performed first, followed by noncontrast CT of the neck after a 2-week interval. The presence or absence of a stone and stone location and size were documented. Statistical analysis was undertaken to assess the agreement between CT protocols and calculate the sensitivity and specificity of contrast-enhanced CT of the neck. RESULTS: Fifty calculi were identified on noncontrast CT of the neck in 31 cases; and 48 calculi, in 31 cases on contrast-enhanced CT of the neck. No calculi were identified in the remaining 61 cases. The sensitivity and specificity of contrast-enhanced CT of the neck in the detection of sialolithiasis was 96% (95% CI, 86.3%–99.5%) and 100% (95% CI, 94.1%–100%), respectively. The positive predictive value of contrast-enhanced CT of the neck was 100% (95% CI, 92.6%–100%), and the negative predictive value was 96.8% (95% CI, 89%–99.6%). The accuracy of contrast-enhanced CT of the neck in diagnosing the presence or absence of salivary calculi was 98%. CONCLUSIONS: Contrast-enhanced CT of the neck is accurate in the detection of sialolithiasis, with no difference in diagnostic accuracy compared with noncontrast CT of the neck.

Magnetic resonance imaging (MRI) plays an integral role in the management of multiple sclerosis (MS), from both diagnostic and therapeutic perspectives. This 2-part review aims to detail the evolving and expanding role of MRI for both radiologists and neurologists. In this article, we discuss the diagnostic criteria for MS relevant to radiologists, as well as its varying imaging manifestations. The role of MRI in therapeutic modification and complications are discussed.

Cervical dystonia is a common neurological movement disorder characterised by muscle contractions causing abnormal movements and postures affecting the head and neck. The neural networks underpinning this condition are incompletely understood. While animal models suggest a role for the superior colliculus in its pathophysiology, this link has yet to be established in humans. The present experiment was designed to test the hypothesis that disrupted superior collicular processing is evident in affected patients and in relatives harbouring a disease-specific endophenotype (abnormal temporal discrimination). The study participants were 16 cervical dystonia patients, 16 unaffected first-degree relatives with abnormal temporal discrimination, 16 unaffected first-degree relatives with normal temporal discrimination and 16 healthy controls. The response of participant’s superior colliculi to looming stimuli was assessed by functional magnetic resonance imaging. Cervical dystonia patients and relatives with abnormal temporal discrimination demonstrated (i) significantly reduced superior collicular activation for whole brain and region of interest analysis; (ii) a statistically significant negative correlation between temporal discrimination threshold and superior collicular peak values. Our results support the hypothesis that disrupted superior collicular processing is involved in the pathogenesis of cervical dystonia. These findings, which align with animal models of cervical dystonia, shed new light on pathomechanisms in humans.

We read with interest the recent article entitled “Distinguishing Neuroimaging Features in Patients Presenting with Visual Hallucinations” by Winton-Brown et al.[1][1] They described the features of dementia with Lewy bodies (DLB) on multiplanar T1-weighted MR imaging.[1][1] In our practice, we

The clinical manifestations of neurosarcoidosis are highly variable and it should be considered as a potential differential diagnosis in any neurological presentation. This study was designed to describe the clinical, diagnostic, and treatment patterns and functional outcome in a Caucasian neurosarcoidosis population. A retrospective analysis was performed on prospectively recorded data in patients attending our neurology clinic between 2008 and 2014 with a diagnosis of definite or probable neurosarcoidosis according to Zajiek criteria. Detailed clinical features, baseline demographic data, results of investigations, treatment type and duration, and clinical outcomes were collated. Eleven patients were identified (55% men) with mean age 39 years (range 21–63). Four had a prior history of systemic sarcoidosis leading to earlier diagnosis (6.7 vs 13.1 months). Six were found to have evidence of systemic sarcoidosis on further investigation and one was biopsy proven isolated neurosarcoidosis. The commonest site of CNS involvement was the cranial nerves (64%), and headache (45%) was the most frequent presenting symptom. MRI abnormalities included leptomeningeal enhancement, white matter lesions, acute arteritis, spinal cord lesion, and cauda equina enhancement. The commonest CSF finding was raised protein (n = 6) and a lymphocytic pleocytosis (n = 7). Serum ACE was only elevated in three cases. Ten patients were treated with both corticosteroids and steroid-sparing agents 8 of whom went into remission. This series highlights the diverse nature of neurosarcoidosis. Early introduction of aggressive therapy with corticosteroids and steroid-sparing agents appears to improve clinical outcome.

Recent technologic advances in cardiac magnetic resonance (MR) imaging have resulted in images with high spatial and temporal resolution and excellent myocardial tissue characterization. Cardiac MR is a valuable imaging technique for detection and assessment of the morphology and functional characteristics of the nonischemic cardiomyopathy. It has gained acceptance as a standalone imaging modality that can provide further information beyond the capabilities of traditional modalities such as echocardiography and angiography. Black-blood fast spin-echo MR images allow morphologic assessment of the heart with high spatial resolution, while T2-weighted MR images can depict acute myocardial edema. Contrast material-enhanced images can depict and be used to quantify myocardial edema, infiltration, and fibrosis. This review presents recommended cardiac MR protocols for and the spectrum of imaging appearances of the nonischemic cardiomyopathies.

PURPOSE To assess whether cardiac computed tomographic angiography (CCTA) can quantify the severity of chronic mitral regurgitation (MR) compared to qualitative and quantitative echocardiographic parameters. MATERIALS AND METHODS Cardiac computed tomographic angiography was performed in 23 patients (mean ± SD age, 63 ± 16 years; range, 24-86 years) with MR and 20 patients without MR (controls) as determined by transthoracic echocardiography. Multiphasic reconstructions (20 data sets reconstructed at 5% increments of the electrocardiographic gated R-R interval) were used to analyze the mitral valve. Using CCTA planimetry, 2 readers measured the regurgitant mitral orifice area (CCTA ROA) during systole. A qualitative echocardiographic assessment of severity of MR was made by visual assessment of the length of the regurgitant jet. Quantitative echocardiographic measurements included the vena contracta, proximal isovelocity surface area, regurgitant volume, and estimated regurgitant orifice (ERO). Comparisons were performed using the independent t test, and correlations were assessed using the Spearman rank test. RESULTS All controls and the patients with MR were correctly identified by CCTA. For patients with mild, moderate, or severe MR, mean ± SD EROs were 0.16 ± 0.03, 0.31 ± 0.08, and 0.52 ± 0.03 cm² (P < 0.0001) compared with mean ± SD CCTA ROAs 0.09 ± 0.05, 0.30 ± 0.04, and 0.97 ± 0.26 cm² (P < 0.0001), respectively. When echocardiographic measurements were graded qualitatively as mild, moderate, or severe, strong correlations were seen with CCTA ROA (R = 0.89; P < 0.001). When echocardiographic measurements were graded quantitatively, the vena contracta and the ERO showed modest correlations with CCTA ROA (0.48 and 0.50; P < 0.05 for both). Neither the proximal isovelocity surface area nor the regurgitant volume demonstrated significant correlations with CCTA ROA. CONCLUSIONS Single-source 64-slice CCTA provides a strong agreement with qualitative echocardiographic parameters but only a moderate correlation with quantitative echocardiographic parameters of chronic MR. Cardiac computed tomographic angiography slightly overestimates mild MR while slightly underestimating severe MR.

Sudden athlete death (SAD) is a widely publicized and increasingly reported phenomenon. For many, the athlete population epitomize human physical endeavour and achievement and their unexpected death comes with a significant emotional impact on the public. Sudden deaths within this group are often without prior warning. Preceding symptoms of exertional syncope and chest pain do, however, occur and warrant investigation. Similarly, a positive family history of sudden death in a young person or a known family history of a condition associated with SAD necessitates further tests. Screening programmes aimed at detecting those at risk individuals also exist with the aim of reducing fatalities. In this paper we review the topic of SAD and discuss the epidemiology, aetiology, and clinical presentations. We then proceed to discuss each underlying cause, in turn discussing the pathophysiology of each condition. This is followed by a discussion of useful imaging methods with an emphasis on cardiac magnetic resonance and cardiac computed tomography and how these address the various issues raised by the pathophysiology of each entity. We conclude by proposing imaging algorithms for the investigation of patients considered at risk for these conditions and discuss the various issues raised in screening.

To determine whether cardiac computed tomography (MDCT) can differentiate between functional and valvular aetiologies of chronic mitral regurgitation (MR) compared with echocardiography (TTE).Twenty-seven patients with functional or valvular MR diagnosed by TTE and 19 controls prospectively underwent cardiac MDCT. The morphological appearance of the mitral valve (MV) leaflets, MV geometry, MV leaflet angle, left ventricular (LV) sphericity and global/regional wall motion were analysed. The coronary arteries were evaluated for obstructive atherosclerosis.All control and MR cases were correctly identified by MDCT. Significant differences were detected between valvular and control groups for anterior leaflet length (30 +/- 7 mm vs. 22 +/- 4 mm, P0.02) and thickness (3.0 +/- 1 mm vs. 2.2 +/- 1 mm, P0.01). High-grade coronary stenosis was detected in all patients with functional MR compared with no controls (P0.001). Significant differences in those with/without MV prolapse were detected in MV tent area (-1.0 +/- 0.6 mm vs. 1.3 +/- 0.9 mm, P0.0001) and MV tent height (-0.7 +/- 0.3 mm vs. 0.8 +/- 0.8 mm, P0.0001). Posterior leaflet angle was significantly greater for functional MR (37.9 +/- 19.1 degrees vs. 22.9 +/- 14 degrees , P0.018) and less for valvular MR (0.6 +/- 35.5 degrees vs. 22.9 +/- 14 degrees, P0.017). Sensitivity, specificity, and positive and negative predictive values of MDCT were 100%, 95%, 96% and 100%.Cardiac MDCT allows the differentiation between functional and valvular causes of MR.

Diffuse large B cell lymphomas (DLBCL) are an aggressive group of non-Hodgkin lymphoid malignancies which have diverse presentation and can have high mortality. Central nervous system relapse is rare but has poor survival. We present the diagnosis of primary mandibular DLBCL and a unique minimally invasive diagnosis of secondary intracranial recurrence. This case highlights the manifold radiological contributions to the diagnosis and management of lymphoma.

The purpose of this study is to evaluate recently reported outcomes for treatment options for proximal cholangiocarcinoma (CCA). Standard evidence based practice techniques were used to formulate a question, search, appraise and evaluate the retrieved literature. Our question was “In patients with CCA, how do stenting alone, stenting in addition to brachytherapy (BT) or photodynamic therapy (PDT), resection and orthotopic liver transplantation with neoadjuvant chemoradiation (OLT) compare for long-term survival? Level 1b survival data was available for stenting alone (179 days), BT and metal stenting (388 days) and PDT with plastic stenting (493 days) and no survival difference was evident with metal vs. plastic stenting or unilateral vs. bilateral stenting. Five year survival data (level 3) was available for OLT (80%), formally curative trisegmentectomy with or without portal vein resection (72% and 52%) and hepatectomy (18%–23%). All patients with proximal CCA should be reviewed by a multidisciplinary team to determine appropriate treatment. For unresectable CCA, patients should be assessed for OLT with neoadjuvant chemoradiation, while those who are unsuitable would appear to have the longest survival with PDT. Extended resection in operable candidates may improve survival over right or left hepatectomy but increased perioperative mortality is a consideration.

We present the case of a subclinical seizure identified during positron emission tomography with 18-fluorodeoxyglucose in a patient with cavernous malformations.

Background Lowserum vitamin D levels are associated with susceptibility to, and severity of, multiple sclerosis. High dose vitamin D has been proposed as a potential immunomodulator in multiple sclerosis. Objectives We performed a single centre, investigator-led, exploratory, double-blind, randomised, placebo controlled, trial of vitamin D3 in clinically isolated syndrome and healthy control participants to assess its immunological effects. Secondary end-points included clinical and magnetic resonance imaging outcomes and safety. Methods Clinically isolated syndrome patients and healthy control participants were randomised to: placebo, 5000 IU or 10,000 IU vitamin D3/day (Vigantol oil). Study duration was 24 weeks. Results The trial did not meet its primary end point, with no difference in the frequency of pro-inflammatory CD4+ T cells (interleukin (IL)-17+/interferon (IFN)-γ+) seen. A higher level of disease freedom (67% versus 50%) was seen in those with serum 1,25 (OH) vitamin D levels>100 nmol/l but this did not reach significance. High dose vitamin D3 was well tolerated with no safety signal. Conclusions High dose vitamin D3 over 24 weeks was well tolerated but without immunological, magnetic resonance imaging or clinical evidence of benefit. The hypothesised therapeutic effects in clinically isolated syndrome or multiple sclerosis patients may require longer periods of administration or may only be seen in patients treated with vitamin D3 as an adjunct to established disease modifying therapies.

Reported is a case of a man aged 55 years who presented with progressive spastic paraparesis. Examination demonstrated multiple cutaneous telangiectases. Subsequent development of upper limb weakness, acute urinary retention and eventual respiratory compromise resulted in the requirement for intensive care unit admission and mechanical ventilation. MRI spine revealed diffuse T2 hyperintensity in the cervical cord with enhancement and cord expansion. Immunomodulatory therapy for a presumed diagnosis of transverse myelitis yielded no response, so a vascular aetiology was suspected. Spinal angiography demonstrated an arteriovenous fistula involving the upper cervical cord. Endovascular embolisation was successfully performed and a marked clinical improvement was achieved. Cervical arteriovenous fistulas can cause progressive myelopathy, subarachnoid haemorrhage and brainstem dysfunction. Management typically comprises endovascular embolisation or surgical interruption. A clinical diagnosis of hereditary haemorrhagic telangiectasia was also made in this case, and spinal arteriovenous fistula formation has been associated with this condition.

BACKGROUND AND PURPOSE: In recent years CTP has been used as a complementary diagnostic tool in the evaluation of delayed cerebral ischemia and vasospasm. Our aim was to determine the test characteristics of CTP for detecting delayed cerebral ischemia and vasospasm in SAH, and then to apply Bayesian analysis to identify subgroups for its appropriate use. MATERIALS AND METHODS: Our retrospective cohort comprised consecutive patients with SAH and CTP performed between days 6 and 8 following aneurysm rupture. Delayed cerebral ischemia was determined according to primary outcome measures of infarction and/or permanent neurologic deficits. Vasospasm was determined by using DSA. The test characteristics of CTP and its 95% CIs were calculated. Graphs of conditional probabilities were constructed by using Bayesian techniques. Local treatment thresholds (posttest probability of delayed cerebral ischemia needed to initiate induced hypertension, hypervolemia, and hemodilution or intra-arterial therapy) were determined via a survey of 6 independent neurologists. RESULTS: Ninety-seven patients with SAH were included in the study; 39% (38/97) developed delayed cerebral ischemia. Qualitative CTP deficits were seen in 49% (48/97), occurring in 84% (32/38) with delayed cerebral ischemia and 27% (16/59) without. The sensitivity, specificity, and positive and negative predictive values (95% CI) for CTP were 0.84 (0.73–0.96), 0.73 (0.62–0.84), 0.67 (0.51–0.79), and 0.88 (0.74–0.94), respectively. A subgroup of 57 patients underwent DSA; 63% (36/57) developed vasospasm. Qualitative CTP deficits were seen in 70% (40/57), occurring in 97% (35/36) with vasospasm and 23% (5/21) without. The sensitivity, specificity, and positive and negative predictive values (95% CI) for CTP were 0.97 (0.92–1.0), 0.76 (0.58–0.94), 0.88 (0.72–0.95), and 0.94 (0.69–0.99), respectively. Treatment thresholds were determined as 30% for induced hypertension, hypervolemia, and hemodilution and 70% for intra-arterial therapy. CONCLUSIONS: Positive CTP findings identify patients who should be carefully considered for induced hypertension, hypervolemia, and hemodilution and/or intra-arterial therapy while negative CTP findings are useful in guiding a no-treatment decision.

Room tilt illusion (RTI) describes the perception of ‘tilting’ of the surrounding environment. We present 2 cases in the setting of acute vertebrobasilar territory ischaemia. Case 1: A 56-year old man was admitted with acute dyspnoea and new atrial fibrillation. On day two while lying in bed, he developed vomiting and suddenly perceived the curtain to his left was lying horizontal along the floor and felt he was sliding towards the left. MRI brain revealed acute multiterritory infarction (Figure 1). He was commenced on therapeutic anticoagulation and was well on follow-up. Case 2: A 47-year old man awoke with acute vertigo, vomiting and ataxia, exacerbated by head movement with dysarthria and diplopia. The world appeared ‘sideways’: objects appeared tilted at 90° when lying on his left side with his head tilted to the left. This resolved when he looked ahead or to the right. MRI brain did not show acute ischaemia but MRA revealed acute vertebral dissection. The patient received short-term heparin, with continuation of aspirin and clopidogrel, due to recent coronary angioplasty. Subsequent similar symptoms prompted introduction of warfarin. Discussion These unusual symptoms are thought to involve vestibular-otolith disconnection. These cases highlight the importance of recognising symptoms of RTI in the setting of acute cerebral ischaemia.

Background Adenoid cystic carcinoma is an uncommon malignant neoplasm of salivary glands. We present a case of sublingual gland adenoid cystic carcinoma presenting with trigeminal and hypoglossal neuropathies in a patient with probable benign multiple sclerosis. Case description This 75-year-old woman was referred by her dentist with a six-month history of lower facial numbness (right V3 distribution). Initial MRI brain scan demonstrated multiple periventricular white matter hyperintensities suggestive of demyelination, prompting neurological referral. She reported a remote history of optic neuritis. On examination, she had left optic atrophy, right V3 sensory loss and a right hypoglossal palsy. Repeat MRI showed subtle high signal and abnormal enhancement of right CN V at the foramen ovale and an enhancing lesion in right sublingual space. Oral examination revealed a small, palpable mass in the floor of the mouth. Biopsy confirmed an adenoid cystic carcinoma of the right sublingual gland with perineural invasion. She was referred for surgical resection and adjuvant radiotherapy. Discussion This case illustrates: the risk of incorrectly ascribing new neurological symptoms to a known chronic neurological disorder; the value of careful clinical examination in such cases; and the importance of ‘thinking peripherally’ when assessing a patient with cranial neuropathies.

Introduction Chorea describes abnormal involuntary movements of the limbs and can be a manifestation of a variety of conditions associated with dysfunction of the basal ganglia and their connections. Chorea, hyperglycaemia, basal ganglia syndrome is a rare cause of the disorder. Case History: 74 year old woman with type 2 diabetes, presented with sudden involuntary movements affecting her right arm and leg. Investigations revealed nonketotic hyperglycaemia; blood glucose 21 mmol/L and HbA1C, 119 mmoL/L. MRI scan of brain showed hyperintensities on T1-weighted imaging within the left lentiform nucleus with corresponding low signal on T2-weighted imaging, no infarcts were seen. The appearances were suggestive of chorea, hyperglycaemia, basal ganglia syndrome. Symptoms resolved within one week of achieving adequate glycaemic control. Following an eighteen month period of stability the patient represented with recurrence of choreiform movements. Blood glucose was 33,2 mmol/L and HbA1C, 142 mmoL/L. Clinical improvement once again followed optimisation of glycaemic control, but over a more prolonged period. Repeat imaging showed similar changes. Conclusion Chorea is a rare complication of hyperglycaemia in diabetic patients. The exact mechanism for the syndrome is unknown. Recurrent episodes may aid our understanding of the condition suggesting a possible underlying vascular vulnerability.

History: Patient presented with dysphonia, dysphagia, hoarseness, weight loss, and bilateral cervical adenopathy. On fiber-optic exam, he was found to have a large left true vocal cord lesion extending into the false vocal cord. There was obstruction of approximately 75% of the lumen of the airway. CT scan showed a large mass in the left vocal cord region.

History: Seventy-three-year-old woman presented 7 months earlier was diagnosed at that time with a malignant tumor of the left parotid gland [same patient as Chap. 4, as Case 2]. Tumor was removed surgically with resection of involved lymph nodes, followed by radiation therapy. Patient was referred for FDG PET/CT as follow-up; detection of residual tumor, metastases.

History: Eighty-four-year-old male with a remote history of bladder cancer (status post cystectomy 1998, left nephroureterectomy, radical prostatectomy) and recent history of colon cancer (diagnosed by FDG PET/CT); status post right hemicolectomy in 2008. Now, patient presents with left lower extremity pain and edema.

Rationale and Objectives Delayed cerebral ischemia (DCI) is a devastating condition that occurs secondary to aneurysmal subarachnoid hemorrhage (A-SAH). The purpose is to compare computed tomography perfusion (CTP) and digital subtraction angiography (DSA) for determining DCI in A-SAH. Materials and Methods A retrospective study of A-SAH patients admitted at our institution between December 2004 and December 2008 was performed. CTP and DSA were obtained at days 6–8 after aneurysm rupture. Both qualitative and quantitative analyses of CT perfusion deficits were performed. DSA was categorized as presence or absence of vasospasm. The reference standard for determining DCI was based on clinical deterioration or infarction on CT or MRI. The test characteristics of CTP and DSA were calculated and their graphs of conditional probabilities were constructed using Bayesian analysis. Results Fifty-seven patients were included; 79% (45/57) had DCI. Seventy percent (40/57) had CTP perfusion deficits; 80% (36/45) of the DCI and 33% (4/12) of no DCI patients. Sixty-three percent (36/57) had DSA demonstrating vasospasm; 73% (33/45) of the DCI and 25% (3/12) of no DCI patients. Quantitative analysis of the CTP data revealed a significant difference in cerebral blood flow values for the DCI (29.4 mL/100 g/minute) and no DCI groups (40.5 mL/100 g/minute, P = .0213). The sensitivity, specificity, and positive and negative predictive values for CTP were 0.80 (95% CI 0.68–0.92), 0.67 (95% CI 0.40–0.93), 0.90 (95% CI 0.82–0.96), 0.47 (95% CI 0.27–0.62), and for DSA were 0.73 (95% CI 0.60–0.86), 0.75 (95% CI 0.50–0.99), 0.92 (95% CI 0.82–0.98), and 0.43 (95% CI 0.26–0.53), respectively. Conclusion CTP and DSA have similar test characteristics and Bayesian analysis for determining DCI in A-SAH patients.

One of the most common problems associated with radiopharmaceuticals is an unanticipated or altered biodistribution, which can have a significant clinical impact on safety, scan interpretation, and diagnostic imaging accuracy. In their most extreme manifestations, unanticipated imaging results may even compromise the utility and or accuracy of nuclear medicine studies. We present here an overall summary of altered biodistribution of radiopharmaceuticals with a special emphasis on the molecular mechanisms involved. Important factors affecting the biodistribution of radiopharmaceuticals can be described in 5 major categories and include (1) radiopharmaceutical preparation and formulation problems; (2) problems caused by radiopharmaceutical administration techniques and procedures; (3) by changes in biochemical and pathophysiology; (4) previous medical procedures, such as surgery, radiation therapy and dialysis; and finally (5) by drug interactions. The altered biodistribution of 99m Tc radiopharmaceuticals are generally associated with increased amounts of 99m Tc radiochemical impurities, such as free 99m TcO 4 − and particulate impurities, such as 99m Tc colloids or 99m Tc-reduced hydrolyzed species. Faulty injection, such as dose infiltration or contamination with antiseptics and aluminum during dose administration, may cause significant artifacts. The patient's own medical problems, such as abnormalities in the regulation of hormone levels; failure in the function of excretory organs and systems, such as hepatobiliary and genitourinary systems; and even simple conditions, such as excessive talking may contribute to altered biodistribution of radiopharmaceuticals. Previous medical procedures (chemotherapy, radiation therapy, dialysis) and drug interaction are the some of the nontechnical factors responsible for unanticipated biodistribution of radiotracers. This review provides a comprehensive summary of various factors and specific examples to illustrate the significance of altered biodistribution of radiopharmaceuticals.

Congenital cystic adenomatoid malformation is a rare pulmonary developmental anomaly, which typically manifests in neonates and infants. Presentation in adulthood is uncommon, with

A 65-year-old man with symptomatic atrial fibrillation refractory to medical therapy was referred for repeat pulmonary vein (PV) isolation. Clinical symptoms included paroxysmal palpitations once to twice per week with associated light-headedness and chest pain. Initial PV isolation had been performed 6 months earlier without cessation of atrial fibrillation despite combined medical therapy with oral flecainide and bisoprolol. His past medical history was significant for hypertension, and in his family history, 1 brother had experienced a stroke at the age of 57 years. Physical examination, ECG, chest radiography, and coronary angiography were normal. Holter 24-hour ECG recordings revealed occasional atrial premature beats and paroxysmal atrial tachycardia. A magnetic resonance imaging study of the patient’s PVs and left atrium (LA) was performed before the repeat radiofrequency ablation. Images were acquired with a 1.5-T whole-body magnetic resonance system (Siemens Avanti, Siemens Medical Solutions, Forcheim, Germany) with an 8-element cardiac synergy coil for radiofrequency signal reception. First-pass breath-hold 3-dimensional contrast-enhanced magnetic resonance angiography of the PV was obtained after pump injection (3 mL/s) of 15 mmol of …

OBJECTIVE. This article reviews the optimal cardiac MRI sequences for and the spectrum of imaging appearances of cardiac tumors.CONCLUSION. Recent technologic advances in cardiac MRI have resulted in the rapid acquisition of images of the heart with high spatial and temporal resolution and excellent myocardial tissue characterization. Cardiac MRI provides optimal assessment of the location, functional characteristics, and soft-tissue features of cardiac tumors, allowing accurate differentiation of benign and malignant lesions.