Reduce Patient Radiation Exposure Research Articles

Adult Gamma Camera Myocardial Perfusion Imaging: Diagnostic Reference Levels and Achievable Administered Activities Derived From ACR Accreditation Data

PurposeThe aim of this study was to glean from accreditation surveys of US nuclear medicine facilities the in-practice radiopharmaceutical diagnostic reference levels (DRLs) and achievable administered activities (AAAs) for adult gamma camera myocardial perfusion imaging (MPI). MethodsData were collected from the ACR Nuclear Medicine Accreditation Program during one three-year accreditation cycle from May 1, 2012, to April 30, 2015. Data elements included radiopharmaceutical, administered activity, examination protocol, interpreting physician specialty, practice type, and facility annual examination volume. Facility demographics, DRLs, and AAAs were tabulated for analysis. ResultsThe calculated DRLs and AAAs are consistent with previously published surveys, and they adhere to national societal guidelines. Facilities seeking ACR accreditation are nearly evenly split between hospital based with multiple gamma cameras and office based with single gamma cameras. The majority of facilities use single-day, low-dosage/high-dosage 99mTc-based protocols; a small minority use 201TlCl protocols. Administered activities show a consistency across facilities, likely reflecting adoption of standard MPI protocols. ConclusionsThis practice-based analysis provides DRL and AAA benchmarks that nuclear medicine facilities may use to refine gamma camera MPI protocols. In general, the protocols submitted for ACR accreditation are consistent with national societal guidelines. The results suggest that there may be opportunities to further reduce patient radiation exposure by using modified examination protocols and newer gamma camera software and hardware technologies.

Fluoroscopy pulse rate reduction during diagnostic and therapeutic imaging in the cardiac catheterization laboratory: An evaluation of radiation dose, procedure complications and outcomes.

To evaluate radiation reduction by reducing fluoroscopy pulse rate in diagnostic cardiac catheterizations and percutaneous coronary interventions (PCI) as well as outcomes at 30 days and six months. Radiation exposure to the public at large has increased dramatically over the past three decades, and the cardiac catheterization laboratory is a large contributor. Fluoroscopy pulse rate is one way to decrease radiation exposure. Fluoroscopy pulse rate was reduced from 10 pulses/sec (p/s) to 7.5 p/s as part of an internal quality improvement project. A retrospective analysis of all cardiac catheterizations was performed, evaluating Air KERMA at the interventional reference point (Ka, r ), Air KERMA area product (PKA ), procedural complications and major adverse cardiac events at 30 days and 6 months. In diagnostic catheterization median PKA (µGy·m2 ) and Ka,r (mGy) were significantly reduced (PKA - 5,613.3 vs. 4,400, P < 0.001; Ka,r - 703.0 vs. 621.0, P = 0.041). In PCI, median PKA and Ka,r were further reduced (PKA - 13,481.6 vs. 10,648.0, P < 0.001; Ka,r - 1787.0 vs. 1,459.0, P = 0.002). There was no difference in complications, fluoroscopy time or number of stents placed. There was no difference in MACE after adjustment for number of STEMIs. Reducing fluoroscopy pulse rates to 7.5 from 10 is an effective way to reduce patient radiation exposure across meaningful dose indices. A pulse rate of 7.5 p/s is safe, with no difference in complications or outcomes. A fluoroscopy pulse rate of 7.5 p/s should be given strong consideration for a new standard. © 2016 Wiley Periodicals, Inc.

Reducing Patient Radiation Exposure From CT Fluoroscopy-Guided Lumbar Spine Pain Injections by Targeting the Planning CT.

CT fluoroscopy-guided lumbar spine pain injections typically include a preprocedural planning CT that contributes considerably to patient dose. The purpose of this study was to quantify the degree of radiation exposure reduction achieved by modifying only the planning CT component of the examination. A retrospective review was performed of 80 CT fluoroscopy-guided lumbar spine injections. Forty patients were scanned with a standard protocol using automatic tube current modulation (method A). Another 40 patients were scanned using a new technique that fixed the tube current of the planning CT to either 50 or 100 mA on the basis of the patient's anteroposterior diameter and that reduced the z-axis coverage (method B). Dose-length products (DLPs) were compared for the two methods. The mean maximal tube current for the planning CT was 435.0 mA for method A and 67.5 mA for method B. The mean z-axis was shorter for method B at 6.5 cm than for method A at 9.6 cm (p < 0.0001). The mean DLP for the planning CT was 11 times lower for method B than for method A: 27.9 versus 313.1 mGy × cm, respectively (p < 0.0001). When method B was used, the mean DLP for the total procedure (i.e., planning CT plus CT fluoroscopy components) was reduced by 78%. There was no significant difference between methods A and B in CT fluoroscopy time (p = 0.37). All procedures were technically successful. A nearly fivefold reduction in radiation exposure can be achieved in CT fluoroscopy-guided lumbar spine pain injections through modifications to the planning CT alone.

Imaging for urolithiasis: standards, trends, and radiation exposure.

To discuss current trends in imaging for urolithiasis and review the recent scientific literature surrounding this topic. Specifically, to address the efforts urologist should be making to reduce the use of ionizing radiation and to examine alternatives to computerized tomography (CT) scan in diagnosing and managing patients with stones. Although CT remains the gold standard for diagnosing urolithiasis, low-dose and ultralow-dose CT scans should be utilized more frequently. Imaging with ultrasound and digital tomosynthesis, especially in follow-up for urolithiasis, offers the dual benefit of reduced patient radiation exposure and acceptable diagnostic ability. Urolithiasis is a prevalent and recurrent condition and patient radiation exposure throughout diagnosis and management of this disease needs to be considered. Imaging modalities that limit radiation and preserve diagnostic accuracy must be utilized.

Accuracy of Low Dose Computed Tomography Scanogram for Measurement of Femoral Version after Locked Intramedullary Nailing.

This prospective study was performed to compare the accuracy of femoral version measurements following repair of femoral shaft fractures using computed tomography (CT) scanograms with 10% of the standard dose of ionizing radiation versus standard-dose scanograms. CT scanogram protocols that used 90 and 10% of the usual dose of ionizing radiation were developed. Ten patients with comminuted femoral shaft fractures repaired with either an intramedullary (IM) nail or plate were imaged with both high- and low-dose CT scanograms. Postoperative version of both femurs was measured and compared between the two dose scans using the Bonesetter application. This was a prospective blinded controlled study at a level 1 trauma centre. Statistical analysis was performed, including standard deviation (SD) and paired t test. Significance was set at p < 0.05. Comparison of femoral version measurements between the 90 and 10% dose scanograms on the native and repaired sides were insignificant (p = 0.870 and p = 0.737, respectively). The difference between native and repaired femurs had an average error of 2.0 ± 1.1° for both the high- and low-dose scans and was insignificant (p = 0.742). Reducing the dose of ionizing radiation in a CT scanogram by 90% has no significant effect on the accuracy of femoral version measurement. This simple change can significantly reduce patient radiation exposure while accurately measuring femoral version and length.

Dose Optimization of the Administered Activity in Pediatric Bone Scintigraphy: Validation of the North American Consensus Guidelines.

The 2010 North American Consensus Guidelines (NACG) for pediatric administered doses and the European Association of Nuclear Medicine (EANM) Dosage Card guidelines recommend lower activities than those administered at our institution. We compared the quality of the lower-activity images with the higher-activity images to determine whether the reduction in counts affects overall image quality. Twenty patients presenting to our pediatric radiology department for bone scintigraphy were evaluated. Their mean weight was 20 kg. The patients were referred for oncologic (n = 10), infectious/inflammatory (n = 5), and pain (n = 5) evaluation. Dynamic anterior and posterior images were acquired for 5 min for each patient. Data were subsampled to represent different administered activities corresponding to the activities recommended by the NACG and the EANM Dosage Card. Images were evaluated twice, first for diagnostic quality and then for acceptability for daily clinical use. There was no statistically significant difference in the diagnostic quality of the images from any of the 3 protocols. Pathologic uptake was correctly identified independent of the administered activity, although there was a single false-positive result for an EANM image. When images were subjectively evaluated as acceptable for daily clinical use, there was a slight preference for the higher-activity images over the NACG (P = 0.04). The recommended administered activities of the NACG produce images of diagnostic quality while reducing patient radiation exposure.

Electronic Apex Locators May Be Better at Determining Endodontic Working Length Than Radiographs and Could Reduce Patient Radiation Exposure

Clinical efficacy of electronic apex locators: Systematic review. Martins JNR, Marques M, Mata A, Carames J.J Endod 2014;40(6):759-77. Nicholas Chandler, BDS, MSc, PhD, LDSRCS, MRACDS (Endo), FDSRCPS, FDSRCSEd, FFDRCSI PURPOSE/QUESTION: The authors conducted a systematic review to compare radiographic and electronic methods of determining endodontic working length. The authors reported no external funding sources. Systematic review Level 2: Limited-quality patient-oriented evidence STRENGTH OF THE RECOMMENDATION GRADE: Grade B: Limited-quality patient-oriented evidence.

Reducing patient radiation exposure during paediatric SVT ablations: use of CARTO® 3 in concert with "ALARA" principles profoundly lowers total dose.

"ALARA--As Low As Reasonably Achievable" protocols reduce patient radiation dose. Addition of electroanatomical mapping may further reduce dose. From 6/11 to 4/12, a novel ALARA protocol was utilised for all patients undergoing supraventricular tachycardia ablation, including low frame rates (2-3 frames/second), low fluoro dose/frame (6-18 nGy/frame), and other techniques to reduce fluoroscopy (ALARA). From 6/12 to 3/13, use of CARTO® 3 (C3) with "fast anatomical mapping" (ALARA+C3) was added to the ALARA protocol. Intravascular echo was not utilised. Demographics, procedural, and radiation data were analysed and compared between the two protocols. A total of 75 patients were included: 42 ALARA patients, and 33 ALARA+C3 patients. Patient demographics were similar between the two groups. The acute success rate in ALARA was 95%, and 100% in ALARA+C3; no catheterisation-related complications were observed. Procedural time was 125.7 minutes in the ALARA group versus 131.4 in ALARA+C3 (p=0.36). Radiation doses were significantly lower in the ALARA+C3 group with a mean air Kerma in ALARA+C3 of 13.1±28.3 mGy (SD) compared with 93.8±112 mGy in ALARA (p<0.001). Mean dose area product was 92.2±179 uGym2 in ALARA+C3 compared with 584±687 uGym2 in ALARA (p<0.001). Of the 33 subjects (42%) in the ALARA+C3 group, 14 received ⩽1 mGy exposure. The ALARA+C3 dosages are the lowest reported for a combined electroanatomical-fluoroscopy technique. Addition of CARTO® 3 to ALARA protocols markedly reduced radiation exposure to young people undergoing supraventricular tachycardia ablation while allowing for equivalent procedural efficacy and safety.

A Retrospective Study of Chest Tomosynthesis as a Tool for Optimizing the use of Computed Tomography Resources and Reducing Patient Radiation Exposure

To investigate potential benefits and drawbacks of the clinical use of chest tomosynthesis (CTS), to what extent CTS obviates the need for chest computed tomography (CT), and what reduction in radiation dose thereby can be achieved. The Regional Ethical Review Board approved the follow-up study of patients examined with CTS as part of clinical routine. For each case, two radiologists in consensus determined whether CT would have been performed, had CTS not been an option, and whether CTS was an adequate examination. Thereafter, it was determined whether the use of CTS instead of CT in retrospect was beneficial, neutral, or detrimental for the radiological work-up. The radiation dose to the patient population was determined both for the actual clinical situation and for the alternative scenario that would result, had CTS not been available. During 1 month 3.5 years before the survey, 149 patients (74 women, age 18-91 years) had undergone CTS for clinical purposes. It was judged that CT would have been performed in 100 cases, had CTS not been available, and that CTS obviated the need for CT in 80 cases. CTS was judged as beneficial, neutral, and detrimental for the radiological work-up in 85, 13, and two cases, respectively. For the entire study population, the use of CTS decreased the average effective dose from 2.7 to 0.7 mSv. The present study indicates that CTS may have benefits for the radiological work-up as it has the potential to both optimize the use of CT resources and reduce the effective dose to the patient population. A drawback is that CTS examinations may fail to reveal pathology visible with CT and in clinically doubtful cases further investigations including other imaging procedures should be considered.

Impact of Reduced-radiation Dual-energy Protocols Using 320-Detector Row Computed Tomography for Analyzing Urinary Calculus Components: Initial In Vitro Evaluation

To evaluate the impact of reduced-radiation dual-energy (DE) protocols using 320-detector row computed tomography on the differentiation of urinary calculus components. A total of 58 urinary calculi were placed into the same phantom and underwent DE scanning with 320-detector row computed tomography. Each calculus was scanned 4 times with the DE protocols using 135 kV and 80 kV tube voltage and different tube current combinations, including 100 mA and 570 mA (group A), 50 mA and 290 mA (group B), 30 mA and 170 mA (group C), and 10 mA and 60 mA (group D). The acquisition data of all 4 groups were then analyzed by stone DE analysis software, and the results were compared with x-ray diffraction analysis. Noise, contrast-to-noise ratio, and radiation dose were compared. Calculi were correctly identified in 56 of 58 stones (96.6%) using group A and B protocols. However, only 35 stones (60.3%) and 16 stones (27.6%) were correctly diagnosed using group C and D protocols, respectively. Mean noise increased significantly and mean contrast-to-noise ratio decreased significantly from groups A to D (P <.05). In addition, the effective dose decreased markedly from groups A to D at 3.78, 1.81, 1.07, and 0.37 mSv, respectively. Decreasing the DE tube currents from 100 mA and 570 mA to 50 mA and 290 mA resulted in 96.6% accuracy for urinary calculus component analysis while reducing patient radiation exposure to 1.81 mSv. Further reduction of tube currents may compromise diagnostic accuracy.

E-045 Separating the Wheat from the Chaff: Completion Angiography Following Complex Aneurysm Repair Using Low-Dose Volume of Interest Plus Metal Artefact Reduction Imaging

IntroductionFollowing complex endovascular or microsurgical treatment of aneurysms, volumetric assessment of the surgical outcome in the angiography suite can be challenging due to device resolution and metallic artefact. We investigated...

Simultaneous Tc-99m/I-123 dual-radionuclide myocardial perfusion/innervation imaging using Siemens IQ-SPECT with SMARTZOOM collimator

Simultaneous dual-radionuclide myocardial perfusion/innervation SPECT imaging can provide important information about the mismatch between scar tissue and denervated regions. The Siemens IQ-SPECT system developed for cardiac imaging uses a multifocal SMARTZOOM collimator to achieve a four-fold sensitivity for the cardiac region, compared to a typical parallel-hole low-energy high-resolution collimator, but without the data truncation that can result with conventional converging-beam collimators. The increased sensitivity allows shorter image acquisition times or reduced patient dose, making IQ-SPECT ideal for simultaneous dual-radionuclide SPECT, where reduced administrated activity is desirable in order to reduce patient radiation exposure. However, crosstalk is a major factor affecting the image quality in dual-radionuclide imaging. In this work we developed a model-based method that can estimate and compensate for the crosstalk in IQ-SPECT data. The crosstalk model takes into account interactions in the object and collimator-detector system. Scatter in the object was modeled using the effective source scatter estimation technique (ESSE), previously developed to model scatter with parallel-hole collimators. The geometric collimator-detector response was analytically modeled in the IQ-SPECT projector. The estimated crosstalk was then compensated for in an iterative reconstruction process. The new method was validated with data from both Monte Carlo simulations and physical phantom experiments. The results showed that the estimated crosstalk was in good agreement with simulated and measured results. After model-based compensation the images from simultaneous dual-radionuclide acquisitions were similar in quality to those from single-radionuclide acquisitions that did not have crosstalk contamination. The proposed model-based method can be used to improve simultaneous dual-radionuclide images acquired using IQ-SPECT. This work also demonstrates that ESSE scatter modeling can be applied to non-parallel-beam projection geometries.

607 Delivery of Monthly Patient Radiation Exposure Report Cards to Endoscopists Significantly Reduces Patient Radiation Exposure During ERCP: a Prospective Quality Improvement Study

Patients exposure to radiation during ERCP may increase their lifetime risk of developing cancer. In prior studies we demonstrated that low volume endoscopists (LVE) exposed patients to significantly higher amounts of radiation compared to high volume endoscopists (HVE) and that educating endoscopists in fluoroscopy best practices significantly reduced patient radiation exposure during ERCP for both LVE and HVE.

Personalized Technologist Dose Audit Feedback for Reducing Patient Radiation Exposure From CT

The aim of this study was to determine whether providing radiologic technologists with audit feedback on doses from CT examinations they conduct and education on dose-reduction strategies reduces patients' radiation exposure. This prospective, controlled pilot study was conducted within an integrated health care system from November 2010 to October 2011. Ten technologists at 2 facilities received personalized dose audit reports and education on dose-reduction strategies; 9 technologists at a control facility received no intervention. Radiation exposure was measured by the dose-length product (DLP) from CT scans performed before (n = 1,630) and after (n = 1,499) the intervention and compared using quantile regression. Technologists were surveyed before and after the intervention. For abdominal CT, DLPs decreased by 3% to 12% at intervention facilities but not at the control facility. For brain CT, DLPs significantly decreased by 7% to 12% at one intervention facility; did not change at the second intervention facility, which had the lowest preintervention DLPs; and increased at the control facility. Technologists were more likely to report always thinking about radiation exposure and associated cancer risk and optimizing settings to reduce exposure after the intervention. Personalized audit feedback and education can change technologists' attitudes about, and awareness of, radiation and can lower patient radiation exposure from CT imaging.

Effectiveness of Fluorography Versus Cineangiography at Reducing Radiation Exposure During Diagnostic Coronary Angiography

Coronary angiography is the gold standard for defining obstructive coronary disease. However, radiation exposure remains an unwanted hazard. Patients referred for coronary angiography with abdominal circumference<45 inches and glomerular filtration rate>60 ml/min were randomized to the fluorography (n=25) or cineangiography (n=25) group. Patients in the fluorography group underwent coronary angiography using retrospectively stored fluorography with repeat injection under cineangiography only when needed for better resolution per operator's discretion. Patients in the cineangiography group underwent coronary angiography using routine cineangiography. The primary end point was patient radiation exposure measured by radiochromic film. Secondary end points included the radiation output measurement of kerma-area product and air kerma at the interventional reference point (Ka,r) and operator radiation exposure measured by a dosimeter. Patient radiation exposure (158.2 mGy [76.5 to 210.2] vs 272.5 mGy [163.3 to 314.0], p=0.001), kerma-area product (1,323 μGy·m2 [826 to 1,765] vs 3,451 μGy·m2 [2,464 to 4,818], p<0.001), and Ka,r (175 mGy [112 to 252] vs 558 mGy [313 to 621], p<0.001) were significantly lower in the fluorography compared with cineangiography group (42%, 62%, and 69% relative reduction, respectively). Operator radiation exposure trended in the same direction, although statistically nonsignificant (fluorography 2.35 μGy [1.24 to 6.30] vs cineangiography 5.03 μGy [2.48 to 7.80], p=0.059). In conclusion, the use of fluorography in a select group of patients during coronary angiography, with repeat injection under cineangiography only when needed, was efficacious at reducing patient radiation exposure.

CardioPulse Articles

# Cardiologists urged to reduce inappropriate radiation exposure {#article-title-2} Radiation from cardiology procedures equals more than 50 chest X-rays per person each year Cardiologists have been urged to reduce patient radiation exposure in a European Society of Cardiology (ESC) position paper that outlines doses and risks of common cardiology examinations for the first time. ![Graphic][1] ![Graphic][2] The full paper, entitled ‘The appropriate and justified use of medical radiation in cardiovascular imaging: a position document of the ESC Associations of Cardiovascular Imaging and Percutaneous Cardiovascular Interventions’, was published in European Heart Journal (EHJ) .1 ![Graphic][3] The lead author, Dr Eugenio Picano (Pisa, Italy), said: ‘Cardiologists today are the true contemporary radiologists. Cardiology accounts for 40% of patient radiology exposure and equals more than 50 chest X-rays per person per year’. He added: ‘Unfortunately, radiation risks are not widely known to all cardiologists and patients and this creates a potential for unwanted damage that will appear as cancers, decades later. We need the entire cardiology community to be proactive in minimising the radiological friendly fire in our imaging labs’. The paper lists doses and risks of the most common cardiology examinations for the first time. CT, PCI, cardiac electrophysiology, and nuclear cardiology deliver a dose equivalent to 750 chest X-rays (with wide variation from 100 to 2000 chest X-rays) per procedure. PCI for dilation of coronary artery stenosis totals almost 1 million procedures per year in Europe. The additional lifetime risk of fatal and non-fatal cancer for one PCI ranges from 1 in 1000, to 1 in 100 for a healthy 50-year- old man. Risks are 1.38 times higher in women and 4 times higher in children. Dr Picano said: ‘Even in the best centres, and even when the income of doctors is not related to number of examinations performed, 30 to 50% of examinations are totally or partially inappropriate according to specialty … [1]: /embed/inline-graphic-1.gif [2]: /embed/inline-graphic-2.gif [3]: /embed/inline-graphic-3.gif

Improved cone-beam computed tomography in supine and prone breast radiotherapy

Cone-beam computerized tomography (CBCT) enables three-dimensional information of the scanned region and provides soft tissue images with good spatial resolution. Our aim was to optimize image acquisition settings for prone and supine breast radiotherapy with respect to contour accuracy, clinical practicalities, and radiation dose. CBCT images were acquired for both prone and supine anthropomorphic phantoms and a female cadaver in supine and prone set-up. CBCT protocols were investigated by altering the tube current, exposure time, range of projection views, field of view (FOV), and starting angle. For clinical practicalities, the frequency of the use of an offset CBCT isocenter was evaluated at 558 205°-CBCTs (37 patients; 13 prone and 24 supine) and 1272 360°-CBCTs (102 patients; 13 prone and 89 supine). Prone and supine breast CBCT images acquired with a bowtie filter, a small FOV, a range of projection views equaling 180°, a tube current of 20mA and an exposure time of 32ms, demonstrated adequate contour accuracy and an elimination of the offset CBCT isocenter procedure, while this occurred in 40.7 % for the old full-rotation protocol. Furthermore a 4.3-fold dose reduction was observed for the Computed Tomography Dose Index (CTDIw) compared to the preset Chest M20 protocol. The established 180° protocol demonstrated acceptable contour accuracy, eliminated the CBCT isocenter offset procedure and reduced patient radiation exposure.

The Use of Point of Care Ultrasound in the Medical Intensive Care Unit Reduces Healthcare Cost and Patient Radiation Exposure

The Use of Point of Care Ultrasound in the Medical Intensive Care Unit Reduces Healthcare Cost and Patient Radiation Exposure

Removal of Comfort Pads underneath Babies: A Method of Reducing Radiation Exposure to Neonates

The recent increasing utilization of imaging has increased the population exposure to ionizing radiation. With increasing knowledge of the potential harm of radiation exposure, efforts should be made to minimize patient radiation whenever possible, especially in young children. The purpose of this study was to use the exposure index (EI) standard to assess the potential for reducing radiation dose to babies by removing a soft comfort pad, often placed underneath the baby. The pad is located between the baby and the image detector plate. As such it absorbs x-rays that have already passed through the baby but have not yet reached the imaging detector plate. Using a thoracic infant phantom and fixed exposure factors, we measured the percentage of the radiation exiting a neonatal chest phantom that was absorbed/attenuated by the comfort pad, before it hit the detector to create the image. We studied comfort pads of 4 different thicknesses, ranging from 0.5″ to 8″. Radiation beam attenuation, ranging from 12% to 72.1%, was found with all comfort pads, with increased x-ray beam attenuation occurring with increasing pad thickness. The study shows that comfort pads cause a high attenuation of the radiation beam, after it exits the chest phantom. As such, removal of the pads prior to radiographic exposure of babies is a method of potentially reducing patient radiation exposure in the newborn nursery.

FDG PET of the Brain in Pediatric Patients: Imaging Spectrum with MR Imaging Correlation

Positron emission tomography (PET) of the brain is an important problem-solving tool in pediatric neuroimaging, neurology, and neurosurgery. Fluorine 18 fluorodeoxyglucose (FDG) PET or dual-modality PET and computed tomographic (CT) imaging (PET/CT), with magnetic resonance (MR) imaging correlation, can be used to evaluate childhood epilepsy and pediatric brain tumors, areas in which PET adds value in patient management. FDG PET has been widely used in pediatric temporal lobe epilepsy, most commonly manifesting as mesial temporal sclerosis, which demonstrates hypometabolism at interictal PET and hypermetabolism during seizures. Recently, FDG PET has shown added value for patients with extratemporal epilepsy, in whom FDG PET can help identify cortical foci of interictal hypometabolism that are undetectable or difficult to detect with MR imaging. These findings can then guide additional investigations and surgery. FDG PET also enhances medical decision making in children with brain tumors, in whom FDG PET can be used to (a) improve the diagnostic yield of stereotactic biopsies by detecting metabolically active areas of tumor, (b) help guide the surgeon in achieving total tumor resection, and (c) increase detection of residual or recurrent tumor. Technologic advances in the past decade have allowed fusion of PET and MR images, combining the high resolution of MR imaging with the low-resolution functional capability of PET. As dual-modality integrated PET/MR imaging systems become available, CT coregistration for PET can be eliminated, thus reducing patient radiation exposure. Increasing familiarity with normal and abnormal appearances of FDG PET brain images correlated with MR images can enhance diagnostic yield and improve the care of children with epilepsy and brain tumors.