Use of Digital Tomosynthesis in Assessing Accurate Medial Epicondyle Fracture Displacement as Compared With Conventional Radiography and Computed Tomography.

INTRODUCTION: Medial epicondyle fracture displacement is notoriously difficult to determine on conventional radiography, and follow-up computed tomography (CT) is often obtained to measure precise displacement. Another option for fracture characterization is digital tomosynthesis (DT), a technology providing high in-plane resolution of bony anatomy by acquiring multiple low-dose images in a linear arc. Advantages of DT include lower radiation exposure and lower cost than CT, rapid image acquisition, and a similar patient experience to conventional radiography. The digital application of tomosynthesis is relatively new and is integrated as an add-on feature with modern radiography equipment. This study compares DT, CT and conventional radiography for measurement accuracy in medial epicondyle fractures with the goal of determining relative accuracy in measuring medial epicondyle fracture displacement. METHODS: Medial epicondyle fractures were created in 5 cadaveric elbow specimens. Each specimen was imaged with conventional radiography, DT, and CT. True displacement measured by digital calipers was compared with "measured" displacement for each image acquisition. CT images included axial, sagittal, and coronal reformats. DT images of the elbow included anteroposterior (AP) longitudinal and transverse, lateral longitudinal and transverse, and axial longitudinal and transverse. Conventional radiographs included AP, lateral, and axial distal humerus images. Four physicians reviewed all images 3 months later. Each reviewer independently measured maximum apparent fracture displacement to the nearest 0.1 mm. Measurement accuracy was calculated as percent difference [(measured displacement-actual displacement)/actual displacement] for each acquisition. Mean, median, and SD for measurement accuracy were calculated. Two-tailed paired t tests were performed on each acquisition to compare the measurement accuracy. RESULTS: Compared with conventional radiographs, accuracy of DT was superior in AP longitudinal (P=0.03), AP transverse (P=0.01), axial longitudinal (P=0.0001), and axial transverse projections (P=0.001). Accuracy of CT was superior to conventional radiography in the AP projection (P=0.03), but was equivalent in the axial projection (P=0.9). Accuracy of CT was similar to DT in AP longitudinal (P=0.6), AP transverse (P=0.5), and axial longitudinal projections (P=0.07). Accuracy of DT in the axial transverse projection was superior to CT (P=0.03). CONCLUSION: DT is more accurate than conventional radiography (both AP and axial views) and as accurate as CT in assessing millimeters of displacement of medial epicondyle fracture fragments. LEVEL OF EVIDENCE: Level IV-diagnostic study.

Improved diagnostic confidence and accuracy of pediatric elbow fractures with digital tomosynthesis.

BACKGROUND: Pediatric elbow fractures are common but remain challenging to accurately diagnose. Digital tomosynthesis is a technique that has shown promise in difficult adult fracture patterns but has not been formally studied in the pediatric population. OBJECTIVE: To assess the added value of digital tomosynthesis on the detection and diagnostic confidence of pediatric elbow fractures. MATERIALS AND METHODS: A retrospective study was performed between January 2016 and December 2017 in pediatric patients (≤18 years) to assess the ability of conventional elbow radiographs and digital tomosynthesis to detect elbow fractures. One hundred twenty-one pediatric patients with concern for pediatric elbow trauma (64 males, 57 females; mean age: 8.1 years, range: 1 year to 17 years) were imaged with both conventional elbow radiographs and digital tomosynthesis. Two blinded pediatric radiologists identified fractures and indicated their diagnostic confidence. Observer agreement was assessed with Cohen's Kappa coefficient and a nonparametric Wilcoxon rank sum test was used to compare the degree of diagnostic confidence between standard radiographs alone and standard radiographs with digital tomosynthesis. McNemar's test was used to assess the difference in the rate of fracture detection between the two methods and sensitivity, specificity, precision, accuracy and diagnostic odds ratios were calculated. RESULTS: Compared with standard radiographs alone, standard radiographs with digital tomosynthesis improved inter-rater agreement, sensitivity, specificity, accuracy, precision and the diagnostic odds ratio for fracture detection and increased diagnostic confidence (Rater 1: P=0.01, Rater 2: P=0.003). CONCLUSION: The addition of digital tomosynthesis with conventional elbow radiographs improves diagnostic confidence and performance for the detection of pediatric elbow fractures.

Digital tomosynthesis of the pediatric elbow.

Imaging pediatric elbow trauma in the acute setting remains diagnostically challenging given difficult patient positioning, multiple ossification centers of the pediatric elbow, overlapping structures, and complex joint anatomy. Digital tomosynthesis is a technique where the X-ray source travels across a limited arc angle, obtaining a series of low-dose exposures that are in turn digitally reconstructed to produce high in-plane resolution at a relatively low overall radiation dose. Digital tomosynthesis is now more commonly integrated into standard radiographic machines and offers a new and exciting way to assess the pediatric elbow. In this review article we discuss the clinical applications of digital tomosynthesis in pediatric elbow trauma along with challenges related to technique, patient positioning and artifacts.

Value of dedicated small-field-of-view sacroiliac versus large-field-of-view pelvic magnetic resonance imaging for evaluating pediatric sacroiliitis.

BACKGROUND: Optimized MRI parameters can be leveraged to improve signal intensity, accelerate imaging acquisition and increase resolution. Higher-resolution imaging with a small field of view (FOV) has been proposed as standard practice for investigating sacroiliac (SI) joints, but the improvement in disease detection and characterization over pelvic imaging with large FOV has not been established. OBJECTIVE: The purpose of this study was to compare dedicated MR images of the SI joints with survey imaging (large-FOV pelvic MRI) for detecting sacroiliitis. MATERIALS AND METHODS: Fifty-eight pediatric patients suspected of having sacroiliitis underwent dedicated sacroiliac joint and survey pelvic imaging at the same imaging session. We independently evaluated the small- and large-FOV image data sets for presence or absence of sacroiliitis, e.g., bone marrow edema, erosions and synovitis. We used nonparametric statistical tests to compare lesion scores for severity of inflammation. We created test characteristics for the survey pelvic images (low-resolution images of the sacroiliac joints) using dedicated sacroiliac images (small-FOV, high-resolution images) as the gold standard. RESULTS: Dedicated sacroiliac small-FOV MRI detected more sacroiliitis compared to survey pelvic imaging with large FOV (χ2=6.125, P=0.013). Readers detected significantly more features of inflammation on small- compared to large-FOV images, e.g., erosions (P=0.039), synovitis (P=0.009), sclerosis (P=0.017) and osteitis (P=0.001). Test characteristics for pelvic large-FOV imaging were sensitivity=0.76, specificity=1.00, positive predictive value = 1.00 and negative predictive value = 0.75. CONCLUSION: This study provides test characteristics for survey pelvic MRI with lower-resolution large-field-of-view images as a screening tool for detecting sacroiliitis. Pelvic screening studies with large FOV have lower sensitivity, and dedicated sacroiliac MRI with small FOV is superior in detecting sacroiliitis when compared to pelvic screening MRI.

Pilot Study of Renal Diffusion Tensor Imaging as a Correlate to Histopathology in Pediatric Renal Allografts.

OBJECTIVE: Fractional anisotropy (FA) is a measure of molecular motion obtained from diffusion tensor imaging (DTI). The objective of this study was to assess the use of FA as a noninvasive correlate of renal allograft histopathology. SUBJECTS AND METHODS: Sixteen pediatric renal allograft recipients were imaged using DTI in a prospective study, between October 2014 and January 2016, before a same-day renal allograft biopsy. The Kendall tau correlation coefficient was used to assess the relationship between cortical and medullary FA values and several clinically important Banff renal allograft histopathology scores. The Mann-Whitney U test was also used to compare cortical and medullary FA values in the region of biopsy in patients whose biopsy results did and in those whose biopsy results did not change clinical management. RESULTS: Medullary FA values had direct inverse correlation with several histopathology scores: tubulitis (designated "t" score in Banff pathologic classification, p < 0.04), interstitial inflammation (i score, p < 0.005), tubular atrophy (ct score, p < 0.002), and interstitial fibrosis (ci score, p < 0.007). Cortical FA values inversely correlated with peritubular capillaritis (ptc score, p < 0.02). Neither medullary nor cortical FA values correlated with glomerulitis (g score). At a b value of 800 s/mm2, medullary FA values of pediatric renal allograft recipients whose renal biopsies prompted a change in clinical management (mean ± SD at a b value of 800 s/mm2 = 0.262 ± 0.07; n = 9) were statistically different compared with the group whose biopsy results did not change clinical management (mean ± SD at a b value of 800 s/mm2 = 0.333 ± 0.06; n = 7) (p < 0.006). CONCLUSION: FA is a noninvasive correlate of several important renal allograft histopathology scores and a potential noninvasive method of assessing renal allograft health in pediatric allograft recipients.

Intravoxel incoherent motion analysis of renal allograft diffusion with clinical and histopathological correlation in pediatric kidney transplant patients: A preliminary cross-sectional observational study.

The purpose of this study was to compare IVIM values in pediatric renal transplants with histopathology and clinical management change. Fifteen pediatric renal transplant recipients (mean 15.7±2.9 years) were prospectively scanned on a 3T MR scanner with multi-b DTI, prior to same-day transplant biopsy. IVIM maps from 14 subjects were analyzed (one excluded due to motion). Mean values were computed from cortical ROIs and medullary ROIs corresponding to the biopsy site. Subjects were also grouped according to whether or not the biopsy resulted in a change in clinical management. Cortico-medullary IVIM estimates and histopathologic Banff scores were correlated with KT. Cortico-medullary IVIM differences between the "change" and "no change" groups was compared with Mann-Whitney U test. Cortical Dp showed significant moderate negative correlation with Banff t and ci scores (KT=-0.497, P=.035 and KT=-0.46, P=.046) and moderate positive correlation with Banff i score (KT=0.527, P=.028). Cortical Pf showed significant moderate correlation with ci and ct scores (KT=0.489, P=.035 and KT=0.457, P=.043). Tissue diffusivity, Dt , estimated with IVIM was significantly different between the "change" and "no change" groups in medullary ROIs (U=6, P=.021). IVIM analysis has potential as a noninvasive biomarker in assessment of pediatric renal allograft pathology.

Intussusception: past, present and future.

Intussusception is a common etiology of acute abdominal pain in children. Over the last 70 years, there have been significant changes in how we diagnose and treat intussusception, with a more recent focus on the role of ultrasound. In this article we discuss historical and current approaches to intussusception, with an emphasis on ultrasound as a diagnostic and therapeutic modality.

Pediatric renal transplant biopsy with ultrasound guidance: the 'core' essentials.

This review provides a comprehensive and practical approach to pediatric percutaneous renal transplant biopsies, highlighting techniques and strategies to optimize adequate sample yield and ensure patient safety. In children with end-stage renal disease, transplantation is the preferred choice of therapy, providing for overall lower long-term morbidity and mortality compared with dialysis. In the ongoing management of renal transplant patients, core tissue sampling via a percutaneous renal biopsy remains the gold standard when transplant dysfunction is suspected. Indications for renal transplant biopsy and techniques/tools for adequate sample yield are discussed. Strategies for common challenges such as poor visualization and renal transplant mobility are addressed. We discuss the clinical signs, techniques and imaging findings for common complications including hematomas, arteriovenous fistulas and pseudoaneurysms. Although the percutaneous renal transplant biopsy procedure is generally safe with rare complications, care must be taken to ensure major complications are promptly recognized and treated. Adequate tissue samples obtained via renal biopsy are imperative to promptly identify transplant rejection to provide valuable information for patient diagnosis, treatment and outcomes. Radiologist and nephrologist attention to proper ultrasound techniques and optimal biopsy tools are critical to ensure tissue adequacy and minimize complications.

Pediatric chest CT at chest radiograph doses: when is the ultralow-dose chest CT clinically appropriate?

PURPOSE: Computed tomography (CT) use in emergency departments represents a significant contribution to pediatric patients' exposure to ionizing radiation. Here, we evaluate whether ultralow-dose chest CT can be diagnostically adequate for other diagnoses and whether model-based iterative reconstruction (MBIR) can improve diagnostic adequacy compared to adaptive statistical iterative reconstruction (ASIR) at ultralow doses. METHODS: Twenty children underwent chest CTs: 10 standard-dose reconstructed with ASIR and 10 ultralow-dose reconstructed with ASIR and MBIR. Four radiologists assessed images for their adequacy to exclude five hypothetical diagnoses: foreign body, fracture, lung metastasis, pulmonary infection, and interstitial lung disease. Additionally, pairwise comparison for subjective image quality was used to compare ultralow-dose chest CT with ASIR and MBIR. Radiation dose and objective image noise measures were obtained. RESULTS: For exclusion of an airway foreign body, the adequacy of ultralow-dose CT was comparable to standard-dose (p = 0.6). For the remaining diagnoses, ultralow-dose CT was inferior to standard-dose (p = 0.03-<0.001). MBIR partially recovered the adequacy of ultralow-dose CT to exclude pulmonary infection (p = 0.017), but was suboptimal for the other diagnoses. Image noise was significantly lower with MBIR compared to ASIR in ultralow-dose CT (p < 0.001), although subjective preference showed only a slight advantage of MBIR (58 versus 42%). CONCLUSIONS: Ultralow-dose chest CT may be adequate for airway assessment, but suboptimal for the evaluation parenchymal lung disease. Although MBIR improves objective and subjective image quality, it does not completely restore the diagnostic adequacy of ultralow-dose CT when compared to standard-dose CT.

Image quality and dose optimisation for infant CT using a paediatric phantom.

OBJECTIVE: To optimise image quality and reduce radiation exposure for infant body CT imaging. METHODS: An image quality CT phantom was created to model the infant body habitus. Image noise, spatial resolution, low contrast detectability and tube current modulation (TCM) were measured after adjusting CT protocol parameters. Reconstruction method (FBP, hybrid iterative and model-based iterative), image quality reference parameter, helical pitch and beam collimation were systematically investigated for their influence on image quality and radiation output. RESULTS: Both spatial and low contrast resolution were significantly improved with model-based iterative reconstruction (p < 0.05). A change in the helical pitch from 0.969 to 1.375 resulted in a 23% reduction in total TCM, while a change in collimation from 20 to 40 mm resulted in a 46% TCM reduction. Image noise and radiation output were both unaffected by changes in collimation, while an increase in pitch enabled a dose length product reduction of ~6% at equivalent noise. An optimised protocol with ~30% dose reduction was identified using model-based iterative reconstruction. CONCLUSIONS: CT technology continues to evolve and require protocol redesign. This work provides an example of how an infant-specific phantom is essential for leveraging this technology to maintain image quality while reducing radiation exposure. KEY POINTS: • A size-specific phantom is critical in protocol development for infant CT. • New reconstruction technology enables ~30% dose reduction at equivalent image quality. • A consistent performance is observed for this scanner system across protocol changes. • A tradeoff exists between reducing exposure time and enabling tube current modulation.

Premature physeal closure following 13-cis-retinoic acid and prolonged fenretinide administration in neuroblastoma.

Retinoid therapy has contributed to improved outcomes in neuroblastoma. Clinical trials of fenretinide report favorable toxicity and disease stabilization in patients with high risk (HR) neuroblastoma. Skeletal effects have been described with other retinoids, but not with fenretinide to date. Two patients with HR, metastatic, refractory neuroblastoma received protracted courses of oral fenretinide for more than 5 years' duration. Both developed premature long bone physeal closure, causing limb length discrepancies; their neuroblastoma remains in remission. The radiographic and clinical findings reported suggest these skeletal abnormalities may be a consequence of treatment with 13-cis-retinoic acid (13cisRA) followed by prolonged oral fenretinide exposure.

Magnetic resonance imaging of Müllerian duct anomalies in children.

Müllerian duct anomalies encompass a wide variety of disorders resulting from abnormalities in the embryological development of the Müllerian ducts. In the prepubertal pediatric population, Müllerian duct anomalies are often incidental findings on studies obtained for other reasons. The onset of menses can prompt more clinical symptoms. Proper characterization of Müllerian duct anomalies is important because these anomalies can affect the development of gynecological disorders as well as fertility. Müllerian duct anomalies also carry a high association with other congenital anomalies, particularly renal abnormalities. MRI is widely considered the best modality for assessing Müllerian duct anomalies; it provides multiplanar capability, clear anatomical detail and tissue characterization without ionizing radiation. MRI allows for careful description of Müllerian duct anomalies, often leading to classification into the most widely accepted classification system for Müllerian duct anomalies. This system, developed by the American Society of Reproductive Medicine, includes seven subtypes: uterine agenesis/hypoplasia, unicornuate, didelphys, bicornuate, septate, arcuate, and diethylstilbestrol (DES) drug-related uterus. In cases of complex anomalies that defy classification, MRI allows detailed depiction of all components of the anatomical abnormality, allowing for proper management and surgical planning.

A seeding-searching-ensemble method for gland segmentation in H&E-stained images.

BACKGROUND: Glands are vital structures found throughout the human body and their structure and function are affected by many diseases. The ability to segment and detect glands among other types of tissues is important for the study of normal and disease processes and helps their analysis and visualization by pathologists in microscopic detail. METHODS: In this paper, we develop a new approach for segmenting and detecting intestinal glands in H&E-stained histology images, which utilizes a set of advanced image processing techniques: graph search, ensemble, feature extraction, and classification. Our method is computationally fast, preserves gland boundaries robustly and detects glands accurately. RESULTS: We tested the performance of our gland detection and segmentation method by analyzing a dataset of over 1700 glands in digitized high resolution clinical histology images obtained from normal and diseased human intestines. The experimental results show that our method outperforms considerably the state-of-the-art methods for gland segmentation and detection. CONCLUSIONS: Our method can produce high-quality segmentation and detection of non-overlapped glands that obey the natural property of glands in histology tissue images. With accurately detected and segmented glands, quantitative measurement and analysis can be developed for further studies of glands and computer-aided diagnosis.

Pairwise comparison versus Likert scale for biomedical image assessment.

OBJECTIVE: Biomedical imaging research relies heavily on the subjective and semi-quantitative reader analysis of images. Current methods are limited by interreader variability and fixed upper and lower limits. The purpose of this study was to compare the performance of two assessment methods, pairwise comparison and Likert scale, for improved analysis of biomedical images. MATERIALS AND METHODS: A set of 10 images with varying degrees of image sharpness was created by digitally blurring a normal clinical chest radiograph. Readers assessed the degree of image sharpness using two different methods: pairwise comparison and a 10-point Likert scale. Reader agreement with actual chest radiograph sharpness was calculated for each method by use of the Lin concordance correlation coefficient (CCC). RESULTS: Reader accuracy was highest for pairwise comparison (CCC, 1.0) and ranked Likert (CCC, 0.99) scores and lowest for nonranked Likert scores (CCC, 0.83). Accuracy improved slightly when readers repeated their assessments (CCC, 0.87) or had reference images available (CCC, 0.91). CONCLUSION: Pairwise comparison and ranked Likert scores yield more accurate reader assessments than nonranked Likert scores.

Nonanesthesia magnetic resonance enterography in young children: feasibility, technique, and performance.

OBJECTIVES: The aim of the present study was to demonstrate the effectiveness and cost savings of a nonanesthesia approach to magnetic resonance enterography (MRE) in 14 young pediatric patients (age 4-7 years) with clinically suspected early-onset inflammatory bowel disease using an MRE protocol. METHODS: MRE was performed using a combination of an abbreviated imaging protocol, magnetic resonance imaging video goggles, and Child Life Services support. MRE results were correlated with both colonoscopy and pathology results using Pearson correlation coefficient. Sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: MRE was performed successfully in 13 of 14 patients (age range 4 years 0 months to 7 years 6 months). MRE findings matched with results in 12 of 13 patients in whom colonoscopy was successfully performed. Both MRE and colonoscopy demonstrated a high specificity (100%) and a positive predictive value (100%), but a low sensitivity (43%) and a negative predictive value (50%). CONCLUSIONS: MRE can be successfully performed in children ages 4 to 7 years using this approach. In addition to decreased risks to the child, the lack of anesthesia also offers a potential overall cost reduction.

Scrotal swelling in the neonate.

Discovery of scrotal swelling in a neonate can be a source of anxiety for parents, clinicians, and sonologists alike. This pictorial essay provides a focused review of commonly encountered scrotal masses and mimics specific to the neonatal setting. Although malignancy is a concern, it is very uncommon, as most neonatal scrotal masses are benign. Key discriminating features and management options are highlighted to improve the radiologist's ability to diagnose neonatal scrotal conditions and guide treatment decisions. Neonatal scrotal processes ranging from common to uncommon will be discussed.

Computed tomography depiction of small pediatric vessels with model-based iterative reconstruction.

BACKGROUND: Computed tomography (CT) is extremely important in characterizing blood vessel anatomy and vascular lesions in children. Recent advances in CT reconstruction technology hold promise for improved image quality and also reductions in radiation dose. This report evaluates potential improvements in image quality for the depiction of small pediatric vessels with model-based iterative reconstruction (Veo™), a technique developed to improve image quality and reduce noise. OBJECTIVE: To evaluate Veo™ as an improved method when compared to adaptive statistical iterative reconstruction (ASIR™) for the depiction of small vessels on pediatric CT. MATERIALS AND METHODS: Seventeen patients (mean age: 3.4 years, range: 2 days to 10.0 years; 6 girls, 11 boys) underwent contrast-enhanced CT examinations of the chest and abdomen in this HIPAA compliant and institutional review board approved study. Raw data were reconstructed into separate image datasets using Veo™ and ASIR™ algorithms (GE Medical Systems, Milwaukee, WI). Four blinded radiologists subjectively evaluated image quality. The pulmonary, hepatic, splenic and renal arteries were evaluated for the length and number of branches depicted. Datasets were compared with parametric and non-parametric statistical tests. RESULTS: Readers stated a preference for Veo™ over ASIR™ images when subjectively evaluating image quality criteria for vessel definition, image noise and resolution of small anatomical structures. The mean image noise in the aorta and fat was significantly less for Veo™ vs. ASIR™ reconstructed images. Quantitative measurements of mean vessel lengths and number of branches vessels delineated were significantly different for Veo™ and ASIR™ images. Veo™ consistently showed more of the vessel anatomy: longer vessel length and more branching vessels. CONCLUSION: When compared to the more established adaptive statistical iterative reconstruction algorithm, model-based iterative reconstruction appears to produce superior images for depiction of small pediatric vessels on computed tomography.

Intra-abdominal inverted umblical cord in gastroschisis: a unique ultrasound finding.

A relatively new surgical technique allows for sutureless closure of a gastroschisis defect. Immediately after birth, a long umbilical cord stump is temporarily inverted into the abdominal cavity and later retracted and used to close the abdominal wall defect. Knowledge of this entity is important since the inverted umbilical cord simulates an intra-abdominal mass on cross-sectional imaging. While this procedure is well described in the surgical literature, the imaging features of inverted umbilical cord have yet to be reported. The case presented here highlights the sonographic imaging findings of the umbilical cord during the intestinal decompression phase of sutureless repair of gastroschisis.

Shooting a moving target: use of real-time cine magnetic resonance imaging in assessment of the small bowel.

The chronic nature of inflammatory bowel disease (IBD) creates a lifelong effect on the morbidity of children affected by the disease. The ability to confidently identify and characterize complications resulting from IBD in the pediatric patient is of critical importance. Magnetic resonance enterography (MRE) is especially valuable in the diagnostic assessment of IBD; however, precise elucidation of complications including strictures can be difficult with standard MRE sequences. The recent development of faster MRI pulse sequences provides rapid, real-time imaging of the intestinal tract. In this review, we describe how the addition of cine MRE confidently pinpoints areas of stricture, aids in lesion detection and diagnosis, and provides valuable information on intestinal motility.

Radiation dose reduction in pediatric CT-guided musculoskeletal procedures.

BACKGROUND: Computed-tomography-guided interventions are attractive for tissue sampling of pediatric bone lesions; however, it comes with exposure to ionizing radiation, inherent to CT and magnified by multiple passes during needle localization. OBJECTIVE: We evaluate a method of CT-guided bone biopsy that minimizes ionizing radiation exposure by lowering CT scanner tube current (mAs) and voltage (kVp) during each localization scan. MATERIALS AND METHODS: We retrospectively reviewed all CT-guided bone biopsies (n = 13) over a 1-year period in 12 children. Three blinded readers identified the needle tip on the reduced-dose CT images (mAs = 50, kVp = 80) during the final localization scan at biopsy and rated the image quality as high, moderate or low. RESULTS: The image quality of the reduced-dose scans during biopsy was rated as either high or moderate, with needle tip visualized in 12 out of 13 biopsies. Twelve of 13 biopsies also returned sufficient sample for a pathological diagnosis. The average savings in exposure using the dose-reduction technique was 87%. CONCLUSION: Our results suggest that a low mAs and kVp strategy for needle localization during CT-guided bone biopsy yields a large dose reduction and produces acceptable image quality without sacrificing yield for biopsy diagnosis.