False-positive Ultrasound Research Articles

Utility of Ultrasound Surveillance for Thyroid Cancer in Children.

Background: Differentiated thyroid cancer (DTC) is the most common pediatric endocrine malignancy. The utility of ultrasound (US) surveillance after initial treatment has not been clearly delineated. We sought to evaluate the clinical utility of US for the detection of residual or recurrent disease in pediatric patients with thyroid cancer beginning 1 year after initial therapy. Methods: This is a retrospective cohort study of pediatric patients (<19 years) diagnosed with DTC between 1998 and 2022 whose response to therapy (RTT) one year after initial treatment (thyroidectomy ± radioactive iodine) was excellent or indeterminate. We evaluated the association between sonographic and biochemical findings (thyroglobulin [Tg] and Tg antibodies [TgAb]) at one year with the subsequent diagnosis of residual/recurrent structural disease in the neck (SDN). Results: In total, 112 patients had 1-year RTT that was excellent (n = 61, 54.5%) or indeterminate (n = 51, 45.5%). Median length of subsequent follow-up was 6.4 (interquartile range 3.8-8.9) years. Overall, 683 surveillance neck US were performed, with a mean ± standard deviation of 1.0 ± 0.4 US per patient per year. Of 61 patients with excellent RTT, none developed SDN during follow-up. Eighteen patients (29.5%) had a false-positive indeterminate or abnormal US finding. Of 51 patients with indeterminate RTT, 9 (17.6%) developed SDN during follow-up. SDN was detected by US in 7/9 cases (77.8%). SDN was detected by I-123 scan, but not by US, in two cases (22.2%), both with abnormal Tg/TgAb. 7/9 (77.8%) cases of SDN were detectable by Tg/TgAb. Overall, fine-needle aspiration (FNA) was performed in 17/112 (15.2%) patients and diagnosed SDN in six patients. Overall, 11/112 patients (9.8%) underwent FNA but were not diagnosed with SDN. Conclusions: In pediatric DTC patients with excellent response to initial therapy, the utility of serial US surveillance is limited by the low risk of SDN and frequent false-positive US findings. In children with indeterminate RTT, SDN occurs in a significant proportion and may be detected by US or by abnormal Tg/TgAb levels. These patients may benefit from the combination of US and biochemical surveillance.

The diagnostic performance of neck ultrasound in follow-up of advanced stage differentiated thyroid cancer

BackgroundDifferentiated thyroid cancer (DTC) requires long-term follow-up due to the risk of delayed recurrence. Follow-up surveillance involves serial neck ultrasound (US) and thyroglobulin (Tg); however, the optimal frequency and diagnostic performance of neck US outside of specialized thyroid cancer centres in higher risk patients is not well defined. We sought to evaluate the diagnostic performance of US and serial Tg in advanced stage DTC.MethodsWe retrospectively reviewed our thyroid cancer database for patients with stage III and IV DTC from 2006 to 2018, total thyroidectomy, and at least 2 years follow-up to assess recurrence rates. Those with hemi-thyroidectomy or anti-Tg antibodies were excluded. Diagnostic performance of US and Tg were assessed using a composite reference standard of follow-up imaging and pathology. All relevant US were reviewed by a blinded expert radiologist for uniformity.ResultsOf 136 included patients (91 females, mean age 58.9), 26 (19%) had recurrence of DTC over median follow-up of 6.6 years (IQR 5.3–9.3). The sensitivity and specificity of US in diagnosing cervical recurrence were 73.3% (95% CI 0.51–0.96) and 68.3% (95% CI 0.60–0.77) based on historical reports, respectively, and 80% (95% CI 0.60-1.00) and 87.8% (95% CI 0.82–0.93) based on blinded expert review, respectively. Tg had a sensitivity of 95.5% (95% CI 0.89-1.0) and specificity of 96.2% (95% CI 0.92–0.99) in detecting cervical recurrence or distant metastases. False positive US findings on historical US and subsequent review occurred in 38 (28%) and 15 (11%) patients, respectively, while 5 (3.6%) had false positive Tg results.ConclusionSerial Tg has better sensitivity and specificity than US for detecting recurrence of advanced stage DTC. Furthermore, re-interpretation of abnormal findings using structured US reporting with a subspecialized reader may improve diagnostic performance of US and improve its utility in clinical care.

SAT526 Limited Utility of Routine Neck Ultrasound Follow-up in Advanced Stage Differentiated Thyroid Cancer

Abstract Disclosure: V. Munro: None. S. Mustafa: None. F.S. Siddiqi: None. M. Rajaraman: None. S.A. Imran: None. Background: Most guidelines recommend periodic cervical ultrasound (US) for ongoing surveillance of differentiated thyroid cancer (DTC). While recent studies do not support routine US surveillance in low-risk DTC, to date, no study has assessed the clinical utility of cervical US in advanced DTC. Methods: We conducted a retrospective study of our hospital DTC registry using the following criteria: a) AJCC stage III and IV, b) minimum follow-up of &amp;gt;4 years since total thyroidectomy +/-I-131 ablation, and c) at least one US per 3 years of follow-up. Patients with hemithyroidectomy only or positive anti-thyroglobulin antibody at the initial visit were excluded. Two years after initial treatment, patients were categorized by Dynamic Risk Stratification (DRS) as excellent, indeterminate, biochemically incomplete, or structurally incomplete response. Data obtained at each visit included: treatment response, thyroglobulin (TG) level, and US findings. Results: A total of 114 patients (85 AJCC stage III and 29 stage IV patients) met the inclusion criteria. Mean age (yrs) at diagnosis was 59, and 67% were female. Mean duration of follow-up was 8.5 years. Based on DRS, 73 patients had excellent response, 28 indeterminate, 8 biochemically incomplete, and 5 structurally incomplete. Recurrence or progression was detected in 20 patients (17.5%): 5 excellent response, 6 indeterminate, 5 biochemically incomplete, and 4 structurally incomplete. Recurrence sites included cervical region (14), distant metastases (5) and both (1). The TG rose from a mean of 4.76 ng/mL at baseline to 40.37 ng/mL at time of recurrence/progression. In those with structurally incomplete disease, US demonstrated progression in all 4 patients. However in other DRS categories, only 5/10 had definite US abnormalities. Of those without recurrence, 4 patients (4.3%) had false positive TG (mean baseline TG 0.08 rose to 11.8 ng/ml) without clinical/radiologic recurrence whereas the rate of false positive US abnormalities was 32% (37/114). The sensitivity and specificity of US vs. TG in diagnosing recurrence was 45% and 60% vs 100% and 95.7%, respectively. Conclusion: Our study suggests that routine cervical US surveillance after initial DRS does not improve the detection of recurrence in patients with excellent, indeterminate, or biochemically incomplete disease, and has a high false positive rate. Therefore, we suggest TG should be considered the mainstay of surveillance and any further imaging guided by DRS status and change in TG. Presentation Date: Saturday, June 17, 2023

Prenatal ultrasound finding of atypical genitalia: Counseling, genetic testing and outcomes.

To report uptake of genetic counseling (GC) and prenatal genetic testing after the finding of atypical genitalia on prenatal ultrasound (US) and the clinical and genetic findings of these pregnancies. A retrospective cohort study (2017-2019) of atypical fetal genitalia in a large expert center for disorders/differences of sex development. We describe counseling aspects, invasive prenatal testing, genetic and clinical outcome of fetuses apparently without [group 1, n=22 (38%)] or with [group 2, n=36 (62%)] additional anomalies on US. In group 1, 86% of parents opted for GC versus 72% in group 2, and respectively 58% and 15% of these parents refrained from invasive testing. Atypical genitalia were postnatally confirmed in 91% (group 1) and 64% (group 2), indicating a high rate of false positive US diagnosis of ambiguous genitalia. Four genetic diagnoses were established in group 1 (18%) and 10 in group 2 (28%). The total genetic diagnostic yield was 24%. No terminations of pregnancy occurred in group 1. For optimal care, referral for an expert fetal US scan, GC and invasive diagnostics including broad testing should be offered after prenatal detection of isolated atypical genitalia.

MP22-05 DOES CT SCAN AFTER ULTRASOUND CHANGE SURGICAL PLANNING FOR NEPHROLITHIASIS?

You have accessJournal of UrologyImaging/Radiology: Uroradiology II (MP22)1 Sep 2021MP22-05 DOES CT SCAN AFTER ULTRASOUND CHANGE SURGICAL PLANNING FOR NEPHROLITHIASIS? Adam Ludvigson, and Piruz Motamedinia Adam LudvigsonAdam Ludvigson More articles by this author , and Piruz MotamediniaPiruz Motamedinia More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002013.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Ultrasound (US) is less accurate for diagnosis of nephrolithiasis than CT scan, potentially affecting surgical plans. We examined how often obtaining a CT scan after US changed the indicated management of nephrolithiasis, to identify risk factors that determine inaccurate US scans. METHODS: Approval was obtained through our institutional IRB. From those who presented to our health system over the past 3 years with suspected nephrolithiasis, we selected patients who had undergone first a retroperitoneal US, and then a CT scan within 30 days. We recorded stone size and location for all studies. We recorded stone density and skin-to-stone distance for each CT scan. Using current AUA guidelines, we determined the indicated procedure based on findings of each imaging study: shockwave lithotripsy (SWL), ureteroscopy (URS), or percutaneous nephrolithotomy (PCNL). We used Minitab software to perform general linear models and two-tailed Student's t-tests. RESULTS: 305 patients met inclusion criteria. Of these, the CT scan changed the indicated procedure 108 times (35.4%). 26 US studies indicated SWL; CT changed 19 of these (73%). 129 US studies indicated URS; CT changed 62 of these (48%). 24 US studies suggested PCNL; CT changed 9 of these (37.5%). Using CT as the gold standard, 18 US studies were false positive for stones (sensitivity=0.72). 51 US studies were false negative for stones (specificity=0.86). Average body mass index (BMI) was significantly lower in the patients with a false positive US as compared to those with a true positive US (26.59 versus 29.13 kg/m2, t(24)=2.33, p=0.029). When comparing patients who had their indicated procedure changed by the CT scan to those who did not, there were no significant differences in age, BMI, or skin-to-stone distance. However, those who had their procedure changed had significantly lower density stones (566.1 versus 747.5 HU, t(154)=2.92, p=0.004). When patients were examined in subgroups based on what their indicated procedure was before and after the CT scan, there were also no significant differences based on age, BMI, or skin-to-stone distance. There was a significant difference based on HU, with stone density explaining 22.88% of the variation (F(11,154)=4.15, p<0.001). CONCLUSIONS: US has many advantages over CT, but cannot always be used in place of it. CT scan changed the indicated stone treatment in more than 1/3 of cases in our study, and lower-density stones were a risk factor for inaccurate US findings. US should be used with particular caution in those with a history of low-density stone types, and for SWL surgical planning. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e392-e392 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Adam Ludvigson More articles by this author Piruz Motamedinia More articles by this author Expand All Advertisement Loading ...

False-Positive Rates for Nerve Conduction Studies and Ultrasound in Patients Without Clinical Signs and Symptoms of Carpal Tunnel Syndrome

The purpose of the study was to determine the rate of false positives for nerve conduction studies (NCSs) and ultrasound (US) in a population without signs and symptoms of carpal tunnel syndrome (CTS) using a CTS-6 score of 0 as the reference standard. Patients were included in this study if they were referred for NCSs for a reason other than CTS (cubital tunnel syndrome and/or cervical radiculopathy) and they had a CTS-6 score of 0. An US measurement of the cross-sectional area (CSA) of the median nerve at the level of the carpal tunnel inlet was performed by a certified ultrasound technician. An a priori CSA cutoff of 10 mm2 or greater measured using US at the carpal tunnel inlet qualified as a positive diagnosis. The NCSs were performed and interpreted according to national standards by a certified electrodiagnostician. All patients in this study were considered to not have a diagnosis of CTS based on the CTS-6 of0. Forty hands with a CTS-6 of 0 were included in this study. The US was positive in 9 of 40(23%) and NCS was positive in 17 of 40 (43%). There were only 2 patients with a false-positive US that did not also have a positive NCS. However, there were 11 patients who had a false-positive NCS that did not have a positive US. This prospective cohort series has demonstrated that US has a lower false-positive rate than NCSs in asymptomatic patients as measured by the CTS-6 diagnostic tool. Studies with a low false-positive rate are preferred when ordering a confirmatory diagnostic test. Therefore, if a confirmatory diagnostic test is desired, we recommend that US be used ratherthan NCSs. Diagnostic II.

Is Hepatoiminodiacetic Acid Scan a Better Imaging Modality Than Abdominal Ultrasound for Diagnosing Gallbladder Disease?

Introduction: Hepatoiminodiacetic acid (HIDA) scan is a nuclear imaging modality used to determine the health of gallbladder. Several studies have suggested using HIDA scan to diagnose hepaobiliary pathology; however, and it is not clear whether the results will lead to any changes in patients’ management. The aim of the study is to evaluate how HIDA scans are being utilized and how often the results of this study change the patient management with a definitive intervention, such as cholecystectomy and how often other imaging modalities were being ordered concomitantly with HIDA scan. Methods: Retrospective cohort study of patients who had HIDA scan between 10/1/2008 and 12/31/2012. Data was obtained from electronic medical records of patients from a single VA medical center. Data included age, sex, ordering specialist, indications, HIDA result, imaging modalities before HIDA, any intervention if HIDA result was abnormal, pathology and follow up outcomes up to 2 years. Results: 222 total patients were included in the study, with a mean age 57, mean BMI of 29, and 84.7% (188) males. A total of 171 had no gallbladder disease (GBDz) and 22.9% (51) had GBDz on pathologic examination. A false positive HIDA was seen in 39.2% (67/171), while 25.5% (13/51) had a false negative HIDA. 174 patients had ultrasound (US) done before HIDA, 133 of whom had no GBDz, while 41 had GBDz. There were 35.3% (47/133) who had a false positive US, and 46.6% (19/41) had a false negative US. Conclusion: HIDA scan is overutilized and it is increasing the cost to the patient in addition to the radiation exposure. In our study 174 patients had US done before the HIDA, and inappropriately ordering HIDA had substantial medical cost, radiation risk and possible a delay in management.

Serial Neck Ultrasound is More Likely to Identify False-Positive Abnormalities than Clinically Significant Disease in Low-Risk Papillary Thyroid Cancer Patients

American Thyroid Association (ATA) low-risk papillary thyroid cancer (PTC) patients without structural evidence of disease on initial posttreatment evaluation have a low risk of recurrence. Despite this, most patients undergo frequent surveillance neck ultrasound (US). The objective of the study was to evaluate the clinical utility of routine neck US in ATA low-risk PTC patients with no structural evidence of disease after their initial thyroid surgery. We performed a retrospective review of 171 ATA low-risk PTC patients after total thyroidectomy, with or without radioactive iodine (RAI) ablation, who had a neck US without suspicious findings after therapy. The main outcome measure was a comparison of the frequency of finding false-positive US abnormalities and the frequency of identifying structural disease recurrence. Over a median follow-up of 8 years, 171 patients underwent a median of 5 neck US (range 2-17). Structural recurrence with low-volume disease (≤1 cm) was identified in 1.2% (2/171) of patients at a median of 2.8 years (range 1.6-4.1 years) after their initial diagnosis. Recurrence was associated with rising serum thyroglobulin (Tg) level in 1 of the 2 patients and was detected without signs of biochemical recurrence in the other patient. Conversely, false-positive US abnormalities were identified in 67% (114/171) of patients after therapy, leading to additional testing without identifying clinically significant disease. In ATA low-risk patients without structural evidence of disease on initial surveillance evaluation, routine screening US is substantially more likely to identify false-positive results than clinically significant structural disease recurrence.

Negative exploration for pyloric stenosis--is it preventable?

BackgroundThe diagnosis of infantile hypertrophic pyloric stenosis (IHPS), although traditionally clinical, is now increasingly dependent on radiological corroboration. The rate of negative exploration in IHPS has been reported as 4%. The purpose of our study was to look at elements of supportive clinical evidence leading to positive diagnosis, and to review these with respect to misdiagnosed cases undergoing negative exploration.MethodsAll infants undergoing surgical exploration for IHPS between January 2000 and December 2004 were retrospectively analysed with regard to clinical symptoms, examination findings, investigations and operative findings.ResultsDuring the study period, 343 explorations were performed with a presumptive diagnosis of IHPS. Of these, 205 infants (60%) had a positive test feed, 269 (78%) had a positive ultrasound scan and 175 (55%) were alkalotic (pH ≥7.45 and/or base excess ≥2.5). The positive predictive value for an ultrasound (US) diagnosis was 99.1% for canal length ≥14 mm, and 98.7% for muscle thickness ≥4 mm.Four infants (1.1%) underwent a negative surgical exploration; Ultrasound was positive in 3, and negative in 1(who underwent surgery on the basis of a positive upper GI contrast). One US reported as positive had a muscle thickness <4 mm. Two false positive US were performed at peripheral hospitals. One infant had a false positive test feed following a positive ultrasound diagnosis. Two infants had negative test feeds.ConclusionA 1% rate of negative exploration in IHPS compares favourably with other studies. However potential causes of error were identified in all 4 cases. Confident diagnosis comprises a combination of positive test feed and an 'in house US' in an alkalotic infant. UGI contrast study should not be used in isolation to diagnose IHPS. If the test feed is negative, strict diagnostic measurements should be observed on US and the pyloric 'tumour' palpated on table under anaesthetic before exploration.

Portal vein thrombosis in adults undergoing liver transplantation: risk factors, screening, management, and outcome.

Portal vein thrombosis (PVT) has been seen as an obstacle to liver transplantation (LTx). Recent data suggest that favorable results may be achieved in this group of patients but only limited information from small size series is available. The present study was conducted in an effort to review the surgical options in patients with PVT and to assess the impact of PVT on LTx outcome. Risk factors for PVT and the value of screening tools are also analyzed. Adult LTx performed from 1987 through 1996 were reviewed. PVT was retrospectively graded according to the operative findings: grade 1: <50% PVT +/- minimal obstruction of the superior mesenteric vein (SMV); grade 2: grade 1 but >50% PVT; grade 3: complete PV and proximal SMV thrombosis; grade 4: complete PV and entire SMV thrombosis. Of 779 LTx, 63 had operatively confirmed PVT (8.1%): 24 had grade 1, 23 grade 2, 6 grade 3, and 10 grade 4 PVT. Being male, treatment for portal hypertension, Child-Pugh class C, and alcoholic liver disease were associated with PVT. Sensitivity of ultrasound (US) in detecting PVT increased with PVT grade and was 100% in grades 3-4. In patients with US-diagnosed PVT, an angiogram was performed and ruled out a false positive US diagnosis in 13%. In contrast with US, angiograms differentiated grade 1 from grade 2, and grade 3 from grade 4 PVT. Grade 1 and 2 PVT were managed by low dissection and/or a thrombectomy; in grade 3 the distal SMV was directly used as an inflow vessel, usually through an interposition donor iliac vein; in grade 4 a splanchnic tributary was used or a thrombectomy was attempted. Transfusion requirements in PVT patients (10 U) were higher than in non-PVT patients (5 U) (P<0.01). In-hospital mortality for PVT patients was 30% versus 12.4% in controls (P<0.01). Patients with PVT had more postoperative complications, renal failure, primary nonfunction, and PV rethrombosis. The overall actuarial 5-year patient survival rate in PVT patients (65.6%) was lower than in controls (76.3%; P=0.04). Patients with grade 1 PVT, however, had a 5-year survival rate (86%) identical to that of controls, whereas patients with grades 2, 3, and 4 PVT had reduced survival rates. The 5-year patient survival rate improved from the 1st to the 2nd era in non-PVT patients (from 72% to 83%; P<0.01), in grade 1 PVT (from 53% to 100%; P<0.01), and in grades 2 to 4 PVT (from 38% to 62%; P=0.11). The value of US diagnosis in patients with PVT depends on the PVT grade, and false negative diagnoses occur only in incomplete forms of PVT (grades 1-2). The degree of PVT dictates the surgical strategy to be used, thrombectomy/low dissection in grade 1-2, mesoportal jump graft in grade 3, and a splanchnic tributary in grade 4. Taken altogether, PVT patients undergo more difficult surgery, have more postoperative complications, have higher in-hospital mortality rates, and have reduced 5-year survival rates. Analysis by PVT grade, however, reveals that grade 1 PVT patients do as well as controls; only grades 2 to 4 PVT patients have poorer outcomes. With increased experience, results of LTx in PVT patients have improved and, even in severe forms of PVT, a 5-year survival rate >60% can now be achieved.

Improved survival for congenital diaphragmatic hernia, based on prenatal ultrasound diagnosis and referral to a combined obstetric-pediatric surgical center

Between January 1990 and January 1993, 36 patients with antenatal ultrasound (US) diagnosis and/or postnatal diagnosis of congenital diaphragmatic hernia (CDH) were referred to the authors' high-risk obstetric and pediatric hospital. Among the 36, there were four spontaneous abortions (11%), five deaths after live births (14%), one false-positive US examination, and 26 patients who underwent surgery, 23 of whom survived (66% overall, 74% of live births, and 89% postoperatively). Only one survivor had extracorporeal membrane oxygenation (ECMO). Thirty-five ultrasound examinations were performed in 24 patients; there were 18 true-positives results (51%), one false-positive (3%), and 16 false-negatives (46%). In this series, there were 25 left-sided CDHs, eight right-sided, one bilateral, and one central. Of the four right-sided hernias having antenatal US, only one was diagnosed prenatally; 15 of the 17 left-sided CDHs were diagnosed correctly (88%). All 19 babies with the prenatal diagnosis were born at the authors' institution. US diagnosis before 25 weeks' gestation and polyhydramnios separately resulted in a mortality rate of only 50%. Patients born at this institution tend to be sicker than those transferred from elsewhere, as reflected by the lower 1- and 5-minute Apgar scores (3.7 v 6.9, P < .001, and 5.4 v 6.9, P < .16, respectively), lower gestational ages (37.0 v 39.2 weeks, P < .007), and lower birth weights (2,525 v 3,049 g, P < .02). Nevertheless, transferred patients had a mortality rate (3 of 15 patients, 20%) similar to that of nontransferred patients (5 of 20 patients, 25%). The authors conclude that (1) systematic prenatal US can diagnose CDH and enable referral to a center that provides high-risk obstetric and pediatric surgical care, thus providing optimal postnatal treatment, and (2) contrary to other reports, antenatal diagnosis of CDH did not presage a high mortality rate.