Need For Radiation Exposure Research Articles

Deep learning-based pseudo-CT synthesis from zero echo time MR sequences of the pelvis

ObjectivesTo generate pseudo-CT (pCT) images of the pelvis from zero echo time (ZTE) MR sequences and compare them to conventional CT.MethodsNinety-one patients were prospectively scanned with CT and MRI including ZTE sequences of the pelvis. Eleven ZTE image volumes were excluded due to implants and severe B1 field inhomogeneity. Out of the 80 data sets, 60 were used to train and update a deep learning (DL) model for pCT image synthesis from ZTE sequences while the remaining 20 cases were selected as an evaluation cohort. CT and pCT images were assessed qualitatively and quantitatively by two readers.ResultsMean pCT ratings of qualitative parameters were good to perfect (2–3 on a 4-point scale). Overall intermodality agreement between CT and pCT was good (ICC = 0.88 (95% CI: 0.85–0.90); p < 0.001) with excellent interreader agreements for pCT (ICC = 0.91 (95% CI: 0.88–0.93); p < 0.001). Most geometrical measurements did not show any significant difference between CT and pCT measurements (p > 0.05) with the exception of transverse pelvic diameter measurements and lateral center-edge angle measurements (p = 0.001 and p = 0.002, respectively). Image quality and tissue differentiation in CT and pCT were similar without significant differences between CT and pCT CNRs (all p > 0.05).ConclusionsUsing a DL-based algorithm, it is possible to synthesize pCT images of the pelvis from ZTE sequences. The pCT images showed high bone depiction quality and accurate geometrical measurements compared to conventional CT.Critical relevance statementpCT images generated from MR sequences allow for high accuracy in evaluating bone without the need for radiation exposure. Radiological applications are broad and include assessment of inflammatory and degenerative bone disease or preoperative planning studies.Key PointspCT, based on DL-reconstructed ZTE MR images, may be comparable with true CT images.Overall, the intermodality agreement between CT and pCT was good with excellent interreader agreements for pCT.Geometrical measurements and tissue differentiation were similar in CT and pCT images.Graphical

Ultrasound supports clinical decision-making in determining the Sanders’ skeletal maturity score of the hand

PurposeThe Sanders Scoring System has revolutionized the way we assess the remaining growth potential of the skeleton. However, because it involves radiation exposure, it must be used with caution in children. The purpose of the study was to evaluate whether the Sanders skeletal maturity score (SMS) could be accurately determined using ultrasound (U).MethodsWe took radiographs (R) of the hand and performed U of the thumb and index finger in 115 patients between six and 19 years of age who were undergoing treatment for scoliosis or limb deformities. Paediatric orthopaedic surgeons, a paediatrician, and a paediatric radiologist were evaluated the blinded images. Those classified images are based on the SMS and the Thumb Ossification Composite Index (TOCI).ResultsIntrarater reliability was high for SMS and slightly weaker for TOCI, but still significant. Interrater reliability was clear for R and weaker for U in both staging systems. Ultimately, SMS 3 and 7 achieved the highest percentage of concordance (P) of 71.7% and 66.0%, respectively, when U was performed. Combining the clinically relevant groups of SMS 3&4 and SMS 7&8 also significantly increased peak scores (SMS 3 and 4 P = 76.7%; SMS 7 and 8 P = 79.7%). The probabilities of peak scores were significantly weaker when the TOCI score was examined.ConclusionOur study shows that U can be used effectively especially to measure stages 3 and 4 and stages 7 and 8 of SMS. The U method is easy to use and therefore may offer advantages in clinical practice without the need for radiation exposure.

Results of ultrasonic examination of patients with internal bleeding and multiple injury at the prehospital stage: a literature review

Purpose: review and systematisation of publications in scientific medical literature devoted to ultrasound examination of trauma patients at the prehospital stage. Materials and methods: a search in scientific databases SCOPUS, Cochrane, PubMed, Russian Science Citation Index (RSCI) by key words: polytrauma, haemorrhage, evacuation of victims, ultrasound examination (US) was carried out. We analysed 46 literature sources — 2 domestic and 44 foreign, including data of meta ‑ analyses and systematic reviews; 23 studied articles were published in the last 5 years. Results: according to a number of scientific studies, ultrasound examination can be successfully used in patients with polytrauma at the prehospital stage, including during air ambulance evacuation on board a helicopter. Ultrasound examination according to the FAST protocol reduces the time to surgical intervention by 64–76%, reduces the need for radiation exposure, the incidence of complications after injury and the duration of the patient’s hospital stay. According to some authors, the sensitivity, specificity, positive and negative predictive value of the method in detecting intra–abdominal injuries and haemorrhage are 28–76%, 83–97%, 87–96% and 37–94%, respectively, which makes it an important tool for examination of an urgent patient, especially with unstable haemodynamics, influencing the treatment tactics. For the paediatric population in the diagnosis of haemoperitoneum, according to a meta‑analysis, the specificity of US leaves 95%, sensitivity — 66%. The method can be successfully applied in the work of aeromedical teams on board an air ambulance helicopter: according to a systematic review and meta‑analysis, the overall sensitivity of ultrasound in the diagnosis of pneumothorax during air ambulance evacuation is 61%, specificity — 99%. Conclusion: considering the analysed data from large randomised trials, meta‑analyses and systematic reviews, the use of ultrasound allows to make the right decisions regarding the tactics of treatment of the urgent patient, its transportation and choice of hospital, reduces the number of examinations, shortens the time to get the patient to the operating room and the duration of hospital stay, positively affects the outcome of the disease.

Prediction of acute lung injury assessed by chest computed tomography, oxygen saturation/fraction of inspired oxygen ratio, and serum lactate dehydrogenase in patients with COVID-19

IntroductionIn treating acute hypoxemic respiratory failure (AHRF) caused by coronavirus disease 2019 (COVID-19), clinicians choose respiratory therapies such as low-flow nasal cannula oxygenation, high-flow nasal cannula oxygenation, or mechanical ventilation after assessment of the patient's condition. Chest computed tomography (CT) imaging contributes significantly to diagnosing COVID-19 pneumonia. However, the costs and potential harm to patients from radiation exposure need to be considered. This study was performed to predict the quantitative extent of COVID-19 acute lung injury using clinical indicators such as an oxygenation index and blood test results. MethodsWe analyzed data from 192 patients with COVID-19 AHRF. Multiple logistic regression was used to determine correlations between the lung infiltration volume (LIV) and other pathophysiological or biochemical laboratory parameters. ResultsAmong 13 clinical parameters, we identified the oxygen saturation/fraction of inspired oxygen ratio (SF ratio) and serum lactate dehydrogenase (LD) concentration as factors associated with the LIV. In the binary classification of an LIV of ≥20 % or not and with the borderline LD = 2.2 × [SF ratio]−182.4, the accuracy, precision, diagnostic odds ratio, and area under the summary receiver operating characteristic curve were 0.828, 0.818, 23.400, and 0.870, respectively. ConclusionsThese data suggest that acute lung injury due to COVID-19 pneumonia can be estimated using the SF ratio and LD concentration without a CT scan. These findings may provide significant clinical benefit by allowing clinicians to predict acute lung injury levels using simple, minimally invasive assessment of oxygenation capacity and biochemical blood tests.

Lung ultrasound and postoperative follow-up of congenital diaphragmatic hernia.

Lung ultrasound (LU) has emerged as a valuable tool for assessing pulmonary aeration noninvasively, rapidly, and reliably in different neonatal conditions. However, its role in the preoperative and postoperative evaluation in congenital diaphragmatic hernia (CDH) is still poorly analyzed. We present a cohort of 8 patients diagnosed with CDH who underwent lung ultrasound examinations at various time points before and after surgical correction. The lung ultrasound patterns were compared between two groups: mechanical ventilation ≤ 7days (MV ≤ 7) and mechanical ventilation > 7days (MV > 7). The ultrasound findings were also compared to CT scans and chest X-ray images to assess its diagnostic capacity for identifying postoperative complications: pneumothorax, pleural effusion, and pneumonia. Group MV ≤ 7 exhibited a normal pattern even at 48h postsurgery, while group MV > 7 presented interstitial or alveolointerstitial pattern in both lungs for prolonged periods (2-3weeks). Furthermore, contralateral LU pattern may be predictive of respiratory evolution. Conclusion: Lung ultrasound is a valuable tool for evaluating the progressive reaeration of the lung following surgical correction in CDH patients. It demonstrates the ability to diagnose common postoperative complications without the need for radiation exposure while offering the advantages of quick and serial assessments. These findings highlight the potential of lung ultrasound as an effective alternative to conventional imaging methods in the management of CDH. What is Known: • Lung ultrasound evaluates lung aeration and predicts respiratory outcomes in neonatal patients. What is New: • Lung ultrasound is useful in the postsurgical management of congenital diaphragmatic hernia patients, detecting reaeration and respiratory complications.

Diagnostic value of systemic immune inflammation index in acute appendicitis.

Clinical diagnosis of acute appendicitis is often difficult and involves a synthesis of clinical, laboratory, and radiological findings. The aim of this study was to investigate whether the systemic immune inflammation index can be used as an effective parameter in the diagnosis of acute appendicitis and its reliability in the differentiation of complicated vs. non-complicated appendicitis. The study was conducted retrospectively with patients admitted to the emergency department with abdominal pain and diagnosed with acute appendicitis. In total, 150 patients and 150 control cases were included in the study. Demographic data, medical history, white blood cell count, platelet count, neutrophil count, systemic immune inflammation index values, Alvarado score, adult appendicitis score, and pathology result of appendectomy material were retrieved from the hospital automation system and recorded in the data form. Neutrophil-lymphocyte ratio and systemic immune inflammation index were significantly higher, and platelet-neutrophil ratio and lymphocyte-neutrophil ratio were significantly lower in the patient group compared to the control group (p<0.001). Receiver operating characteristic analysis revealed that the sensitivity and specificity of systemic immune inflammation index with a cutoff value of 840.13 was 82 and 66.7%, respectively, for the diagnosis of acute appendicitis. Correlation analysis revealed that systemic immune inflammation index, Alvarado score, and adult appendicitis score were positively correlated, and this correlation was statistically significant. Systemic immune inflammation index may be used to promote the diagnosis of acute appendicitis and may reduce the need for radiation exposure and diagnostic imaging tests such as contrast-enhanced abdominal computed tomography. It can also be used to differentiate between complicated and non-complicated acute appendicitis cases.

The accuracy (trueness and precision) of Bellus3DARC-7 and an in-vivo analysis of intra and inter-examiner reliability of digital and manual anthropometry

Abstract Background Three dimensional (3D) facial imaging is becoming a popular method of facial analysis and a means of anthropometry. There is potential for 3D imaging to provide enough diagnostic information to parallel lateral cephalograms, which could, in time, reduce the need for radiation exposure to patients. The present study aimed to assess the accuracy of the Bellus3D ARC-7 (Bellus) camera by comparing the measurements of soft tissue facial landmarks obtained from Bellus scans to the measurements taken using Vernier callipers. Method Nineteen anatomical points were located on four subjects using a standard black ballpoint pen on a white, circular sticker. Distances were measured between these points using digital callipers, with the subject in a resting pose. This was repeated twice by two examiners for each subject. Two examiners subsequently performed measurements of each subject in a smiling pose. Following landmark identification, images were captured under standard conditions, using the Bellus camera. The same measurements were obtained digitally, repeated twice by two examiners for each subject in both resting and smiling poses. Results There was high precision in repeated measurements on the digital models, with less than 1.5 mm deviation between measurements. Both intra-examiner and inter-examiner reproducibility were greater following the digital measurements compared to manual measurements, with 100% of the digital measurements of landmarks falling within a set threshold deviation of ≤1.5 mm. When comparing the manual and digital measurements, the greatest deviations (&gt;1.0 mm) occurred in regions around the cheeks and lower third of the face, while the measurements for the ears and midline structures (forehead and nose bridge) deviated the least (≤1.0 mm). This was demonstrated in models at rest and smiling. Conclusions The Bellus system produced an accurate and true image of the face from which reproducible measurements can be made within and between examiners. 3D facial images from the Bellus3D ARC-7 system were comparable to direct anthropometry, therefore the use of 3D facial scanning in orthodontics for diagnosis and treatment planning appears promising.

457 Single Vs Biplane 3d Augmented Overlay Guidance To Assist Congenital Cardiac Catheterisation Interventions

Introduction: Patients with congenital heart disease (CHD) undergoing cardiac catheterisation procedures often require higher radiation and contrast usage as it is often difficult to track catheter movement through complex anatomy. On a prior study, we showed reduction in need for radiation exposure and contrast usage using a fused single plane fluoroscopy display augmented by 3D magnetic resonance imaging (MRI) and Computed Tomography (CT) models. Recently, a biplane fusion overlay system was made available, which was hypothesised to be of higher benefit as congenital interventions are traditionally performed on a biplane system.

Highly Sensitive Detection Method of DICER1 Tumor Hotspot Mutations by Drop-off Droplet Digital PCR.

DICER1 syndrome is an autosomal dominant inherited syndrome predisposing to various benign and malignant tumors, mainly occurring in children and young adults, requiring broad surveillance starting at birth with repeated irradiating imaging exams and sedations for young patients. It is caused by monoallelic germline pathogenic variants in the DICER1 gene. More than 90% of tumors bear an additional somatic DICER1 missense hotspot mutation, as a second hit, involving 1 of 6 codons clustered in exons 24 and 25. We designed and in vitro validated a drop-off droplet digital PCR (ddPCR) system to scan all DICER1 hotspot codons, allowing for a liquid biopsy test, an alternative to sedation and radiation exposure. Three drop-off ddPCR assays were designed, with 2 TaqMan probes per assay, 1 complementary to the wild-type sequence of the region containing hotspots and another 1 used as a reference. Eight tumor-derived DNAs and 5 synthetic oligonucleotides bearing DICER1 hotspot mutations were tested. All tested mutations were detected, with a limit of detection ranging from 0.07% to 0.31% for codons p. E1705, p. D1709, and p. D1713 in exon 24 and from 0.06% to 0.15% for codons p. G1809, p. D1810, and p. E1813 in exon 25. The high sensitivity of this method is compatible with its use for plasma circulating tumor DNA (ctDNA) analysis for early tumor detection in DICER1 syndrome patients. It may reduce the need for radiation exposure and sedation in surveillance protocols and may also improve patient prognosis. Clinical trials are needed to evaluate ctDNA analysis in these patients.

Population Level Contribution of Clonal Hematopoiesis of Indeterminate Potential to Myeloid Neoplasm Development: Pooled Analysis and Population Attributable Risk Percent Determination from Case-Control and Cohort Studies

Background. Clonal hematopoiesis of indeterminate potential (CHIP) represents a precursor state of myeloid leukemogenesis. Several studies thus far have convincingly demonstrated that presence of CHIP is associated with increased risks of myeloid neoplasm (MN) development. These findings have important intrinsic utility; however, there has been lack of attempts to translate this knowledge into estimates of disease burden suitable for determining its potential at population level. Therefore, the aim of this analysis was to estimate the population attributable fraction (PAF) for MNs associated with CHIP using risk ratio estimates derived from pooled analysis of observational studies. Methods. Eligible studies were case-control (n=3) and cohort (n=3) studies with dichotomous outcome (MN or no MN) and the presence or absence of the risk factor (CHIP). Mantel-Haenszel method for calculating the weighted pooled odds ratio (OR) under the fixed effects model was used, using software RevMan 5.3. OR being the key statistic for case-control studies was the preferred risk estimate to measure association between CHIP and MN in the selected case-control studies. We used OR as risk estimate for cohort studies as well, since MN occurred in less than 10% of the CHIP negative population, and therefore, OR provided a reasonable approximation of the relative risk. From the pooled OR, estimate of population attributable risk% (PAR%) was calculated using the formula: 100*(Px*(OR-1))/(1+(Px*(OR-1))), where Px represented estimate of population exposure (proportion of CHIP positive cases in the population). Results. 23,983 participants with 345 MN cases in six studies were included in the pooled analyses (Figure 1). In the CHIP positive population, there were total 230 MN cases of the total 2304 participants. There were 115 MN cases in the CHIP negative population (n= 21,679). For all studies, the pooled OR for those with CHIP compared with those without was 5.45 (95% CI, 4.06-7.30) with low overall heterogeneity (I2=2%, Fig. 1). Estimate of population exposure (Px) was 0.088 (2074/23638). PAR% calculated using formula 100*(Px*(OR-1))/(1+(Px*(OR-1))), was 28.14%, suggesting that of all the MN cases, including those with or without CHIP, 28.14% could be attributed to CHIP. Conclusion. CHIP's strong association with myeloid neoplasm development was confirmed in this pooled analysis. Individuals with MN were 5.45 times more likely to be CHIP positive than those without MN. Further, in this analysis, we estimate population level contribution of CHIP to MN development. We estimate that 28% of MNs were attributable to positive CHIP status, thus representing 28% of the cases in the total population that can be prevented by intervening against the exposure- CHIP. Determining PAR% is an especially useful and often underutilized first step in designing public health interventions directed against harmful exposures. These findings also brings forth an important consideration, that CHIP though an important risk factor is not obligatory for MN development. Majority of MNs can not attributed to positive CHIP status. Therefore, importance of traditionally known risk factors such as smoking, chemotherapy and radiation exposure need appropriate quantification, especially as they can be entirely preventable and are established risk factors for CHIP positivity as well. Disclosures No relevant conflicts of interest to declare.

Comparison of Outcomes of Percutaneous Arteriovenous Fistulae Creation by Ellipsys and WavelinQ Devices

PurposeThe purpose of this study was to compare the clinical outcomes of Ellipsys with those of WavelinQ-4F percutaneous arteriovenous fistulae (pAVF) devices in a single center by a single operator. Materials and MethodsA retrospective review was conducted in 100 patients who underwent pAVFs procedures (65 Ellipsys and 35 WavelinQ patients) and created between December 2017 and December 2019. A total of 69% were male and 37% were diabetic. Median age was 64.1 years (range: 28–86), and median body mass index was 27.2 (range: 15–45.1) kg/m2. A procedure sequence algorithm was followed for selecting all vascular accesses created. ResultsEllipsys outcomes were compared to WavelinQ outcomes. Technical success was 100% versus 97%, respectively, and median procedure times were 14 versus 63 minutes, respectively (P < .001), with 183 (1–487) versus 185 (0–760) days follow-up, respectively. Maturation at 4 weeks was 68.3% versus 54.3%, respectively, and median times to cannulation were 60 (1–164) versus 90 (1–180) days, respectively. Successful pAVF dialysis was established in 31 of 39 patients (79.5%) versus 14 of 24 patients (58%), respectively (P = .071), dialysis patients with access-related adverse events observed in 4 individuals (1 Ellipsys versus 3 WavelinQ). Six patients (5 versus 1) with matured outflow from previous AVFs underwent first-day cannulations. Interventions were performed in 27.7% (33 Ellipsys) and 26.5% (15 WavelinQ) patients, and the number of interventions per patient-years was 0.96 versus 0.46, respectively. pAVF failure was seen in 15.4% versus 37.1% patients, respectively (P = .0137). Secondary patency at 12 months was significantly higher among patients who had an Ellipsys procedure (82%) than among those who underwent the WavelinQ procedure (60%). ConclusionspAVFs were created with high technical success and low complications with both devices. Ellipsys pAVFs demonstrated significantly shorter procedure times without a need for radiation exposure and with superior secondary patency.

Ultrasound Evaluation of Pediatric Orthopaedic Patients.

Ultrasonography is a valuable tool that can be used in many capacities to evaluate and treat pediatric orthopaedic patient. It has the capability to depict bone, cartilaginous and soft-tissue structures, and provide dynamic information. This technique can be readily applied to a wide range of pediatric conditions, including developmental dysplasia of the hip, congenital limb deficiencies, fracture management, joint effusions, and many other musculoskeletal pathologies. There are many benefits of implementing ultrasonography as a regular tool. It is readily accessible at most centers, and information can be quickly obtained in a minimally invasive way, which limits the need for radiation exposure. Ultrasonography is a safe and reliable tool that pediatric orthopaedic surgeons can incorporate into the diagnosis and management of a broad spectrum of pathology.

Perforated gallbladder managed by robotic approach

Presenter: Michael Caparelli MD | The Jewish Hospital Background: The rate of gallbladder perforation in the setting of acute cholecystitis is 2-11% with the fundus, the most distal location with regard to blood supply being the most common site of perforation. The mortality rate of gallbladder perforation is alarmingly high at 12-16% and attributed to delayed diagnosis due to limitations of modern imaging. A high suspicion of gallbladder perforation and early operative intervention are key to reducing morbidity and mortality. Gallbladder perforation may be managed with laparoscopic cholecystectomy, although there is a high conversion rate due to unclear anatomy. We describe a case of robotic cholecystectomy for gallbladder perforation and discuss the advantages of this operative modality. Methods: The patient is a 62 year-old male with history of hypertension, type 2 diabetes, pulmonary embolism (on apixaban) and schizoaffective disorder who presented with 3 days of right upper quadrant pain. Computed tomography showed acute cholecystitis and a 6.5 cm subscapsular hepatic fluid collection. Due to current use of anticoagulation he underwent percutaneous drainage the subhepatic fluid collection, which was bilious and suggestive of gallbladder perforation. Magnetic resonance cholangiopancreatography revealed fundal gallbladder perforation with leakage of bile into the subcapsular hepatic space. He subsequently spiked fevers and went into atrial fibrillation with rapid ventricular rate. Collaboration with hepatobiliary surgery was had and it was determined that the benefits of early cholecystectomy outweigh the risks of long-term percutaneous drainage. The patient underwent indocyanine green (ICG) aided robotic cholecystectomy with intraoperative cholangiogram (IOC). IOC showed free flow into the duodenum with normal intra and extra hepatic ducts. Subcapsular hepatic (segments 4a & 5) and subdiaphragmatic abscesses were evacuated. Results: The subhepatic drain was removed on postoperative day (POD) 3. The patient was transitioned to oral antibiotics and discharged to his group home on POD 5. Pathology showed chronic cholecysitis with transmural fistula. He is doing well two months from surgery. Conclusion: Acute cholecystitis with gallbladder perforation carries a high mortality rate secondary to delayed diagnosis. Early diagnosis and surgical intervention is key. Management of gallbladder perforation may be performed open or laparoscopically with a high risk of conversion. To our knowledge this is the first video documented case of a robotic cholecystectomy for gallbladder perforation. Robotic cholecystectomy offers unique advantages when compared to laparoscopic or open techniques. The robotic camera allows for 3D images, which enhance the visual field when compared to laparoscopic imaging. This allows for better visualization of anatomy during dissection, which may lead to decreased conversion rates. Additionally, instrument articulation reproduces that of the human wrist, allowing for dissection in more difficult angles. ICG fluorescence helps to define biliary anatomy in real time and reduces the need for radiation exposure from traditional cholangiopancreatography. In this case ICG-cholangiography allowed for visualization of the common bile and cystic ducts, and differentiation of hepatic and gallbladder tissue for safe dissection. Robotic cholecystectomy should not be considered standard, but a valuable tool in experienced hands for management of difficult cholecystectomies.

Diagnostic Algorithm Reduces the Need for Radiation Exposure to Rule Out Pulmonary Embolism in Pregnant Women

Diagnostic Algorithm Reduces the Need for Radiation Exposure to Rule Out Pulmonary Embolism in Pregnant Women

Could the YEARS algorithm be used to exclude pulmonary embolism during pregnancy? Data from the CT‐PE‐pregnancy study

IntroductionThe recently proposed YEARS algorithm was shown to safely exclude pulmonary embolism (PE) and reduce the use of computed tomography pulmonary angiography (CTPA) among pregnant women with suspected PE. Our aim was to externally validate this finding. MethodsWe performed a post hoc analysis of a prospective management outcome study for PE diagnosis in pregnant women. PE was diagnosed with an algorithm that combined the revised Geneva score, D‐dimer testing, bilateral lower‐limb compression ultrasonography, and CTPA. All women had a 3‐month follow‐up. All of the items necessary to use the YEARS algorithm were prospectively collected at the time of the study. ResultsOf the 395 women included in the original study, 371 were available for the present analysis. The PE prevalence was 6.5%. Ninety‐one women had no YEARS items, and 280 had one or more items. When the YEARS items were combined with D‐dimer levels (<1000 ng/mL in women with no items, and <500 ng/mL in women with one or more items), 77 women (21%) met the criteria for PE exclusion and would not have undergone CTPA as per the YEARS algorithm. None of these 77 women had PE diagnosed during the initial work‐up or 3‐month follow‐up. Therefore, the failure rate of the YEARS algorithm in our pregnant women population was 0/77 (95% confidence interval 0.0‐3.9). ConclusionIn our study, application of the YEARS algorithm would have resulted in safe exclusion of PE in one of five pregnant women without the need for radiation exposure, further supporting the use of the algorithm in this population.

Quantitative ultrasound (US) imaging for fatty liver disease

Hepatic steatosis, which indicates the accumulation of fat in hepatocytes, is common and has a broad disease spectrum according to its pathogenesis and its severity. Clinically, the occurrence of non-alcoholic fatty liver disease (NAFLD), the most common type of hepatic steatosis, is strongly correlated with metabolic disease, and atherosclerotic cardiovascular disease. NAFLD having potential to progress into more advanced stage of fibrosis/cirrhosis has been the most common cause of chronic liver disease in Western counties, and the incidence of NAFLD has been known to be increasing. NAFLD is strongly associated with metabolic syndrome characterized by concomitant existence of obesity, diabetes mellitus, dyslipidemia and hypertension. Therefore, NAFLD can be considered as emerging major health problem. Traditionally, liver biopsy with histopathologic examination has been the gold standard method to diagnose and quantify hepatic steatosis. However, invasive nature with potential complication, small sample volume of biopsy specimen as well as high variability in measurement among the pathologists are major drawbacks of liver biopsy, and therefore, liver biopsy cannot be widely used for the evaluation of NAFLD. US which is widely available noninvasive imaging modality with no need of radiation exposure has been used for the screening of NAFLD for patients at risk, providing fairly good diagnostic accuracy to detect moderate to severe degree hepatic steatosis. However, limited diagnostic performances to detect mild degree hepatic steatosis and subjective nature examination with high intra- and inter-observer variability are major limitations of US. To overcome these limitations, several quantitative method using US images including hepatorenal ratio, ASQ and CAP have been implemented, showing promising results. Recently developed ultrasound based quantification tool for hepatic steatosis is controlled attenuation parameter (CAP) obtained from transient elastography (Fibroscan, Echosens, Paris, France). CAP assesses the degree of ultrasound beam attenuation by the intracellular fat vacuoles at the center frequency of M probe (3.5 MHz), and results are appeared as decibels per meter (dB/m), ranging from 100 to 400 dB/m. Considering NAFLD is usually associated with obesity as a manifestation of metabolic syndrome, failure to obtain CAP values in obese patients could be an important limitation of this technique. Acoustic structure quantification (ASQ) which analyses echo amplitude of ultrasound beam and evaluates changes in variance within region of interests has been introduced in clinical practice, and used for the evaluation of diffuse liver disease. Several initial studies using ASQ reported very promising diagnostic accuracy for assessing hepatic steatosis quantitatively both animal and human studies. A commercially available quantification method, acoustic structure quantification (ASQ), was introduced into clinical practice for the evaluation of diffuse liver disease. The method is based on statistical analysis of the difference between theoretical and real echo amplitude distribution. Theoretical echo amplitude distribution indicates that a speckle pattern in a certain liver region is approximated by a function of a Reyleigh distribution based on the assumption that the speckle pattern is generated only by ultrasonic interference of very small scattering objects that are located closer than the wavelength of US. However, real echo amplitude distribution of normal liver does not fit a Reyleigh distribution mainly because of the presence of small vessel walls. As hepaticsteatosis progresses, the real echo amplitude distribution more likely approaches the theoretical echo amplitude distribution with masking of the small structures, such as small vessel walls. In an animal model of hepatic steatosis, a significant correlation was observed between focal disturbance (FD) ratio, calculated by using ASQ, and either fat droplet area or fat droplet size. In a population of living donors for liver transplantation, acoustic structure quantification (ASQ) provides an excellent quantitative tool for hepatic steatosis, and there is a strong linear correlation (r = -0.87; P

Minimally invasive guidewireless, navigated pedicle screw placement: a technical report and case series.

OBJECTIVE Percutaneous pedicle screw insertion (PPSI) is a mainstay of minimally invasive spinal surgery. Traditionally, PPSI is a fluoroscopy-guided, multistep process involving traversing the pedicle with a Jamshidi needle, placement of a Kirschner wire (K-wire), placement of a soft-tissue dilator, pedicle tract tapping, and screw insertion over the K-wire. This study evaluates the accuracy and safety of PPSI with a simplified 2-step process using a navigated awl-tap followed by navigated screw insertion without use of a K-wire or fluoroscopy. METHODS Patients undergoing PPSI utilizing the K-wire-less technique were identified. Data were extracted from the electronic medical record. Complications associated with screw placement were recorded. Postoperative radiographs as well as CT were evaluated for accuracy of pedicle screw placement. RESULTS Thirty-six patients (18 male and 18 female) were included. The patients' mean age was 60.4 years (range 23.8-78.4 years), and their mean body mass index was 28.5 kg/m2 (range 20.8-40.1 kg/m2). A total of 238 pedicle screws were placed. A mean of 6.6 pedicle screws (range 4-14) were placed over a mean of 2.61 levels (range 1-7). No pedicle breaches were identified on review of postoperative radiographs. In a subgroup analysis of the 25 cases (69%) in which CT scans were performed, 173 screws were assessed; 170 (98.3%) were found to be completely within the pedicle, and 3 (1.7%) demonstrated medial breaches of less than 2 mm (Grade B). There were no complications related to PPSI in this cohort. CONCLUSIONS This streamlined 2-step K-wire-less, navigated PPSI appears safe and accurate and avoids the need for radiation exposure to surgeon and staff.

Can a CT be Omitted in Pediatric Minor Head Trauma?

AbstractThis study aimed to evaluate the need for radiation exposure in pediatric minor head trauma. Symptomatic patients after minor head trauma were observed for at least 24 hours in a 13-month period. A computed tomography (CT) scan was performed on children with a depressed neurological status. Two hundred fourteen patients with a mean age of 9.3 years were included. An intracranial hemorrhage (ICH) was diagnosed in three (1.4%) patients. The overall CT rate was 10.7%. The study concluded that neuro-observation without initial CT scans is safe in infants and children following minor head trauma. Special pediatric CT protocol can limit radiation exposure.

PD11-05 CONTRAST-ENHANCED ULTRASOUND AS A REPLACEMENT FOR FLUOROSCOPIC NEPHROSTOGRAM FOLLOWING PERCUTANEOUS NEPHROLITHOTOMY

You have accessJournal of UrologyImaging/Radiology: Uroradiology II1 Apr 2017PD11-05 CONTRAST-ENHANCED ULTRASOUND AS A REPLACEMENT FOR FLUOROSCOPIC NEPHROSTOGRAM FOLLOWING PERCUTANEOUS NEPHROLITHOTOMY Thomas Chi, Manint Usawachintachit, David Tzou, Helena Chang, Benjamin Sherer, Marshall Stoller, Stefanie Weinstein, and John Mongan Thomas ChiThomas Chi More articles by this author , Manint UsawachintachitManint Usawachintachit More articles by this author , David TzouDavid Tzou More articles by this author , Helena ChangHelena Chang More articles by this author , Benjamin ShererBenjamin Sherer More articles by this author , Marshall StollerMarshall Stoller More articles by this author , Stefanie WeinsteinStefanie Weinstein More articles by this author , and John MonganJohn Mongan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.581AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Fluoroscopic nephrostogram is commonly used to evaluate ureteral patency after percutaneous nephrolithotomy. However, it can incur a significant exposure to ionizing radiation. We have reported feasibility and safety for contrast-enhanced ultrasound nephrostogram with collecting system microbubble contrast injection to obviate the need for radiation exposure. In this study, we compared contrast-enhanced ultrasound to fluoroscopic nephrostogram in evaluating ureteral patency after percutaneous nephrolithotomy. METHODS After obtaining institutional review board approval for off-label use of an ultrasound contrast agent, consecutive patients with kidney stones who underwent percutaneous nephrolithotomy at our medical center were eligible for enrollment in this prospective cohort non-inferiority study. Postoperative day 1 after surgery, contrast-enhanced ultrasound and fluoroscopic nephrostogram were performed within 2 hours of one other for each patient to identify ureteral patency, the primary outcome for this study. Results from both imaging studies were reviewed in a blinded fashion by two experienced radiologists and compared. RESULTS Eighty-six imaging studies were performed in 76 patients during the study period from September 2015 to September 2016. Females (58.3%) predominated males (41.7%) with a mean age of 51.2±16.1 years and a mean body mass index of 29.6±8.4 kg/m2. Four studies were excluded due to technical factors preventing imaging interpretation. For the remaining 82 studies, 66 (80.5%) demonstrated concordance for detecting ureteral patency between the two imaging techniques. Within the 16 (19.5%) discordant studies,15 showed antegrade urine flow on contrast-enhanced ultrasound but not on fluoroscopic nephrostogram, and one antegrade flow on fluoroscopic nephrostogram but not on ultrasound. For discordant studies, 97.5% of tubes were managed according to ultrasound results. No adverse events were noted related to any contrast-enhanced ultrasound studies. While contrast-enhanced ultrasound utilized no ionizing radiation, fluoroscopic nephrostograms provided a mean radiation exposure dose of 13.1±17.5 mGycm2 for patients. CONCLUSIONS Contrast-enhanced ultrasound can be used to perform a nephrostogram with ultrasound contrast administered via a nephrostomy tube. This novel imaging technique is non-inferior to fluoroscopic nephrostogram, safe for patients, and devoid of radiation exposure in evaluating ureteral patency following percutaneous nephrolithotomy. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e207-e208 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Thomas Chi More articles by this author Manint Usawachintachit More articles by this author David Tzou More articles by this author Helena Chang More articles by this author Benjamin Sherer More articles by this author Marshall Stoller More articles by this author Stefanie Weinstein More articles by this author John Mongan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

MP15-11 OUTPATIENT ULTRASOUND URETHROGRAM FOR ASSESSMENT OF ANTERIOR URETHRAL STRICTURE RENDERS RADIATION EXPOSURE UNNECESSARY

You have accessJournal of UrologyTrauma/Reconstruction: Urethral Reconstruction (including Stricture) I1 Apr 2015MP15-11 OUTPATIENT ULTRASOUND URETHROGRAM FOR ASSESSMENT OF ANTERIOR URETHRAL STRICTURE RENDERS RADIATION EXPOSURE UNNECESSARY Darren J. Bryk, Yuka Yamaguchi, Shpetim Telegrafi, Mariana Kozirovsky, and Lee C. Zhao Darren J. BrykDarren J. Bryk More articles by this author , Yuka YamaguchiYuka Yamaguchi More articles by this author , Shpetim TelegrafiShpetim Telegrafi More articles by this author , Mariana KozirovskyMariana Kozirovsky More articles by this author , and Lee C. ZhaoLee C. Zhao More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.894AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Knowledge of urethral stricture anatomy is essential for appropriate surgical management. While retrograde urethrogram is considered the gold standard for evaluation, ultrasound urethrogram has been shown to be more accurate in determining anterior urethral stricture length and extent of spongiofibrosis. To date, ultrasound urethrograms have been primarily performed intra-operatively. We report the results of an outpatient ultrasound urethrogram technique, which eliminates the need for radiation exposure. METHODS Twelve consecutive adult men presenting for anterior urethral reconstruction from 10/2013-10/2014 underwent outpatient ultrasound urethrogram. Patients were excluded from this study if any urethral imaging has been performed using radiation (retrograde urethrogram or voiding cystourethrogram). The Siemens Acuson S2000 Ultrasound System is used at our institution. Outpatient retrograde ultrasound urethrogram is performed with the patient in the frog-leg position. Lidocaine gel is injected through the meatus to distend the urethra and act as contrast. Linear High-frequency multi-hertz 18L6 and curved multi-hertz 6C2 probes are used to study the penile and bulbar urethra, respectively. Lengths of strictures as determined by outpatient ultrasound urethrogram and direct intra-operative measurements were analyzed by a paired t-test. RESULTS Table 1 shows the differences between ultrasound urethrogram and intra-operative stricture lengths. The difference between ultrasound urethrogram stricture length measurement (mean=1.7833, standard deviation=0.8892) and intra-operative stricture length measurement (mean=1.7500, standard deviation=1.011) was not significant with t(11)=0.358, p=0.727. Further, the correlation coefficient between the two length measurements is 0.950 (p<0.001). CONCLUSIONS Our technique of outpatient ultrasound urethrogram for the diagnosis and characterization of anterior urethral strictures is simple, accurate, and eliminates the need for radiation exposure for evaluation of anterior urethral strictures. Table 1. Difference between ultrasound urethrogram and intra-operative measured stricture length ultrasound urethrogram length minus intra-operative length (cm) n (total=12) % of sample 0 8 66.6 > 0 to 0.5 2 16.7 < 0 to -0.5 2 16.7 > 0.5 or < -0.5 0 0 © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e163 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Darren J. Bryk More articles by this author Yuka Yamaguchi More articles by this author Shpetim Telegrafi More articles by this author Mariana Kozirovsky More articles by this author Lee C. Zhao More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...