Sphenopalatine artery pseudoaneurysm masquerading as a second primary maxillary carcinoma.

PURPOSE: Maxillary sinus carcinomas usually present as a locally advanced disease at the time of diagnosis and it is extremely unusual to have a second primary maxillary carcinoma on the contralateral side after many years of completion of treatment of the first malignancy. We present here a case report of a sphenopalatine artery (SPA) pseudoaneurysm mimicking the second primary maxillary carcinoma. METHODS: We reviewed the literature for SPA pseudoaneurysm. RESULTS/CASE REPORT: This report describes the case of a 90-year-old man with a background of adenoid cystic carcinoma of the right maxillary sinus, diagnosed and treated with surgery and radiotherapy 14 years ago, who presented with a history of multiple episodes of epistaxis. The radiological evaluation showed a heterogeneously enhancing mass with a central hemorrhagic component and surrounding bony erosions in the left maxillary sinus and the patient was planned for biopsy from the suspicious mass along with SPA ligation. However, on opening the maxillary antrum there was excessive bleeding and it was determined unsafe to proceed further. The patient was subsequently taken to interventional radiology for diagnostic angiography which revealed an SPA pseudoaneurysm that was subsequently embolized successfully. CONCLUSIONS: Sphenopalatine artery pseudoaneurysms should be considered as a differential for recurrent epistaxis in patients with a history of sinonasal malignancy. In such cases, endovascular embolization is a viable management option.

Diffusion-weighted (DW) MRI in lung cancers: ADC test-retest repeatability.

PURPOSE: To determine the test-retest repeatability of Apparent Diffusion Coefficient (ADC) measurements across institutions and MRI vendors, plus investigate the effect of post-processing methodology on measurement precision. METHODS: Thirty malignant lung lesions >2 cm in size (23 patients) were scanned on two occasions, using echo-planar-Diffusion-Weighted (DW)-MRI to derive whole-tumour ADC (b = 100, 500 and 800smm-2). Scanning was performed at 4 institutions (3 MRI vendors). Whole-tumour volumes-of-interest were copied from first visit onto second visit images and from one post-processing platform to an open-source platform, to assess ADC repeatability and cross-platform reproducibility. RESULTS: Whole-tumour ADC values ranged from 0.66-1.94x10-3mm2s-1 (mean = 1.14). Within-patient coefficient-of-variation (wCV) was 7.1% (95% CI 5.7-9.6%), limits-of-agreement (LoA) -18.0 to 21.9%. Lesions >3 cm had improved repeatability: wCV 3.9% (95% CI 2.9-5.9%); and LoA -10.2 to 11.4%. Variability for lesions <3 cm was 2.46 times higher. ADC reproducibility across different post-processing platforms was excellent: Pearson's R2 = 0.99; CoV 2.8% (95% CI 2.3-3.4%); and LoA -7.4 to 8.0%. CONCLUSION: A free-breathing DW-MRI protocol for imaging malignant lung tumours achieved satisfactory within-patient repeatability and was robust to changes in post-processing software, justifying its use in multi-centre trials. For response evaluation in individual patients, a change in ADC >21.9% will reflect treatment-related change. KEY POINTS: • In lung cancer, free-breathing DWI-MRI produces acceptable images with evaluable ADC measurement. • ADC repeatability coefficient-of-variation is 7.1% for lung tumours >2 cm. • ADC repeatability coefficient-of-variation is 3.9% for lung tumours >3 cm. • ADC measurement precision is unaffected by the post-processing software used. • In multicentre trials, 22% increase in ADC indicates positive treatment response.

Rare events in earth history include the LB1 human skeleton from Flores, Indonesia, as a developmental singularity, not a unique taxon.

The original centrally defining features of "Homo floresiensis" are based on bones represented only in the single specimen LB1. Initial published values of 380-mL endocranial volume and 1.06-m stature are markedly lower than later attempts to confirm them, and facial asymmetry originally unreported, then denied, has been established by our group and later confirmed independently. Of nearly 200 syndromes in which microcephaly is one sign, more than half include asymmetry as another sign and more than one-fourth also explicitly include short stature. The original diagnosis of the putative new species noted and dismissed just three developmental abnormalities. Subsequent independent attempts at diagnosis (Laron Syndrome, Majewski osteodysplastic primordial dwarfism type II, cretinism) have been hampered a priori by selectively restricted access to specimens, and disparaged a posteriori using data previously unpublished, without acknowledging that all of the independent diagnoses corroborate the patent abnormal singularity of LB1. In this report we establish in detail that even in the absence of a particular syndromic diagnosis, the originally defining features of LB1 do not establish either the uniqueness or normality necessary to meet the formal criteria for a type specimen of a new species. In a companion paper we present a new syndromic diagnosis for LB1.

Dual-energy CT for imaging of pulmonary hypertension: challenges and opportunities.

Computed tomography (CT) is routinely used in the evaluation of patients with pulmonary hypertension (PH) to assess vascular anatomy and parenchymal morphology. The introduction of dual-energy CT (DECT) enables additional qualitative and quantitative insights into pulmonary hemodynamics and the extent and variability of parenchymal enhancement. Lung perfusion assessed at pulmonary blood volume imaging correlates well with findings at scintigraphy, and pulmonary blood volume defects seen in pulmonary embolism studies infer occlusive disease with increased risk of right heart dysfunction. Similarly, perfusion inhomogeneities seen in patients with PH closely reflect mosaic lung changes and may be useful for severity assessment and prognostication. The use of DECT may increase detection of peripheral thromboembolic disease, which is of particular prognostic importance in patients with chronic thromboembolic PH with microvascular involvement. Other DECT applications for imaging of PH include low-kilovoltage images with greater inherent iodine conspicuity and iodine-selective color-coded maps of vascular perfusion (both of which can improve visualization of vascular enhancement), virtual nonenhanced imaging (which better depicts vascular calcification), and, potentially, ventricular perfusion maps (to assess myocardial ischemia). In addition, quantitative assessment of central vascular and parenchymal enhancement can be used to evaluate pulmonary hemodynamics in patients with PH. The current status and potential advantages and limitations of DECT for imaging of PH are reviewed, and current evidence is supplemented with data from a tertiary referral center for PH.

Gadolinium and nephrogenic systemic fibrosis: an update.

Nephrogenic systemic fibrosis (NSF) is a multisystem disease seen exclusively in patients with renal impairment. It can be severely debilitating and sometimes fatal. There is a strong association with gadolinium-based contrast agents used in magnetic resonance imaging (MRI). Risk factors include renal impairment and proinflammatory conditions, e.g. major surgery and vascular events. Although there is no single effective treatment for NSF, the most successful outcomes are seen following restoration of renal function, either following recovery from acute kidney injury or following renal transplantation. There have been ten biopsy-proved pediatric cases of NSF, with no convincing evidence that children have a significantly altered risk compared with the adult population. After implementation of guidelines restricting the use of gadolinium-based contrast agents in at-risk patients, there has been a sharp reduction in new cases and no new reports in children. Continued vigilance is recommended: screening for renal impairment, use of more stable gadolinium chelates, consideration of non-contrast-enhanced MRI or alternative imaging modalities where appropriate.

Intraoperative Positioning in Maxillofacial Trauma Patients With Cervical Spine Injury - Is It Safe? Radiological Simulation in a Healthy Volunteer.

Study Design: Observational. Objective: To investigate the effects on the cervical spine of positioning patients for maxillofacial procedures by simulating intraoperative positions for common maxillofacial procedures. Methods: Magnetic resonance imaging was used to assess the effects of head position in common intraoperative configurations - neutral (anterior mandible position), extended (tracheostomy position) and laterally rotated (mandibular condyle position) on the C-spine of a healthy volunteer. Results: In the tracheostomy position, maximal movement occurred in the sagittal plane between the cervico-occipital junction and C4-C5, as well as at the cervico-thoracic junction. Minimal movement occurred at C2 (on C3), C5 (on C6) and C6 (on C7). In the mandibular condyle position, C-spine movements occurred in both rotational and sagittal planes. Maximal movement occurred above the level of C4, concentrated at atlanto-occipital and atlanto-axial (C1-2) joints. Conclusions: Neck extension is likely to be relatively safe in injuries that are stable in flexion and extension, such as odontoid peg fracture and fractures between C5 and C7. Head rotation is likely to be relatively safe in fractures below C4, as well as vertebral body fractures, and laminar fractures without disc disruption. Early dialogue with the neurosurgical team remains a central tenet of safe management of patients with combined maxillofacial and C-spine injuries.

Spect perfusion imaging versus CT for predicting radiation injury to normal lung in lung cancer patients.

OBJECTIVES: In non-small cell lung cancer (NSCLC) patients, to establish whether the fractional volumes of irradiated anatomic or perfused lung differed between those with and without deteriorating lung function or radiation associated lung injury (RALI). METHODS: 48 patients undergoing radical radiotherapy for NSCLC had a radiotherapy-planning CT scan and single photon emission CT lung perfusion imaging (99mTc-labelled macroaggregate albumin). CT defined the anatomic and the single photon emission CT scan (co-registered with CT) identified the perfused (threshold 20 % of maximum) lung volumes. Fractional volumes of anatomic and perfused lung receiving more than 5, 10, 13, 20, 30, 40, 50 Gy were compared between patients with deteriorating (>median decline) vs stable (30, 40, 50 Gy). Fractional volumes of anatomic and perfused lung receiving > 10 Gy best predicted decline in FEV1 (Area under receiver operating characteristic curve (Az = 0.77 and 0.76 respectively); sensitivity/specificity 75%/81 and 80%/71%) for a 32.7% anatomic and 33.5% perfused volume cut-off. Irradiating an anatomic fractional volume of 4.7% to > 50 Gy had a sensitivity/specificity of 83%/89 % for indicating RALI (Az = 0.83). CONCLUSION: A 10-20 Gy radiation dose to anatomic or perfused lung results in decline in FEV1. A fractional anatomic volume of >5% receiving >50 Gy influences development of RALI. ADVANCES IN KNOWLEDGE: Extent of low-dose radiation to normal lung influences functional respiratory decline.

Are complication rates lower with 4-Fr versus 6-Fr transfemoral arterial access - prospective audit at a single interventional radiology centre.

BACKGROUND: Femoral arterial access constitutes the first step in a significant proportion of interventional endovascular procedures. Whilst existing reports describe sheath size as an independent risk factor for bleeding complications in radial arterial access for coronary intervention, the influence of sheath size on overall complication rates and morbidity following femoral arterial access is not well described. This prospective single centre study reports our experience of vascular sheath size, patient and procedural factors in influencing complication rates following femoral arterial access. From April 2010 to May 2013, data was collected prospectively for all femoral arterial access procedures performed in the Interventional Radiology department of a tertiary hospital. For vascular sheath size <6-Fr, haemostasis was achieved by manual compression. For 6-Fr sheath size, a closure device was used in the absence of any contraindication. RESULTS: Of the 320 femoral access cases with eligible inclusion criteria, 52.5% had 4-Fr whilst 47.5% had 6-Fr vascular sheaths inserted. Overall post procedure complications rates were significantly higher following 6-Fr sheath (17/152 (11.2%)) versus 4-Fr systems (3/168 (1.8%)) (p=0.0007) mostly comprising self-limiting hematoma. There was no significant difference in major complications that required escalation of treatment. CONCLUSION: No significant difference has been demonstrated between the use of either sheath systems for major complications. The practical limitations of a smaller system, combined with existing body of evidence, may not justify the routine use of 4-Fr sheath systems as the primary sheath size for all endovascular procedures.

DCE-MRI, DW-MRI, and MRS in Cancer: Challenges and Advantages of Implementing Qualitative and Quantitative Multi-parametric Imaging in the Clinic.

Multi-parametric magnetic resonance imaging (mpMRI) offers a unique insight into tumor biology by combining functional MRI techniques that inform on cellularity (diffusion-weighted MRI), vascular properties (dynamic contrast-enhanced MRI), and metabolites (magnetic resonance spectroscopy) and has scope to provide valuable information for prognostication and response assessment. Challenges in the application of mpMRI in the clinic include the technical considerations in acquiring good quality functional MRI data, development of robust techniques for analysis, and clinical interpretation of the results. This article summarizes the technical challenges in acquisition and analysis of multi-parametric MRI data before reviewing the key applications of multi-parametric MRI in clinical research and practice.