Low Diagnostic Yield Research Articles

Identification of rare defective allelic variants in cases of thiopurine S-methyltransferase deficient activity.

Aim: To assess rare TPMT variants in patients carrying a deficient phenotype not predicted by the fourmore frequent genotypes (*2, *3A, *3B and *3C). Materials & methods: Next-generation sequencing of TPMT in 39 patients with a discordant genotype. Results: None of the variants identified explained the discordances assuming that they are of uncertain significance according to the Clinical Pharmacogenetics Implementation Consortium classification.Two unknown variants were detected and predicted to result in a splicing defect. We show that TPMT*16and TMPT*21 are defective alleles, and TPMT*8 and TPMT*24 are associated with a normal activity. Conclusion: Whole-exon sequencing for rareTPMT mutations has a low diagnostic yield. A reassessment of the functional impact of rare variants of uncertain significance is a critical issue.

Assessing the Impact of Electronic Ordering on Stool Parasite Testing Practices in an Academic Medical Center

Abstract Introduction While microscopic stool ova and parasite examination (MSOP) is the traditional testing method for intestinal parasites, it has low diagnostic yield when used inappropriately. To promote stewardship at our institution, MSOP was only orderable utilizing paper requisitions. The only stool parasite testing orderable in our electronic ordering system was the Giardia / Cryptosporidium immunoassay (available as stool O&P screen), which has adequate sensitivity to detect the most common regional intestinal parasites. This was changed during two regional cyclosporiasis outbreaks, when MSOP was added to our electronic ordering system (EOS) to facilitate Cyclospora detection (available as stool O&P examination). The stool O&P screen was also changed to Giardia and Cryptosporidium antigen to better reflect the testing performed. We aimed to measure the impact of this change in terms of test utilization. Methods We quantitated the amount of testing performed pre- and post-intervention over 12-month periods, outside of the outbreak period. We performed chart reviews of 141 patients who received stool parasite testing (Giardia/Cryptosporidium immunoassay and/or MSOP) and compared the proportion of appropriate vs. inappropriate stool parasite testing before (n = 73) and after (n = 68) MSOP was added to the EOS. We used the following criteria to define appropriate MSOP testing; the presence of (1) any travel history outside the continental US, (2) immunocompromised status or (3) intestinal parasite mentioned as a differential diagnosis in medical record. MSOP was considered overordered in patients who failed to fulfill criteria. Testing was deemed underordered if only Giardia/Cryptosporidium immunoassay was ordered on patients who fulfilled criteria for MSOP. Both underordering and overordering were considered inappropriate testing. Statistically significant differences were calculated using Fisher’s exact test (p<0.05). Results The number of patients tested per month by MSOP increased from an average of 10 pre-intervention to 56 post-intervention (p<0.0001). The proportion of appropriate MSOP utilization increased from 44% to 58% of (p=0.13). Inappropriate testing happened in both periods, though underordering was significantly higher pre-intervention (89% vs. 10% of inappropriate testing, p<0.0001), while overordering was significantly higher post intervention (90% vs. 11% of inappropriate testing, p<0.0001). Pre-intervention, 34 of 38 patients in whom underordering occurred were immunocompromised patients tested by the Giardia/Cryptosporidium immunoassay only. Notably, all patients who had intestinal parasite mentioned as a differential diagnosis in the electronic medical record were tested by MSOP, regardless of its availability in the ordering system. Conclusion These findings suggest that omission of MSOP from the electronic ordering system can prevent appropriate testing, particularly in immunocompromised patients. Transitioning to an electronic ordering format can promote overall test utilization and decrease the amount of inappropriately narrow testing, though this also promotes inappropriately broad testing which may represent an opportunity for future clinical decision support interventions.

Appropriate use of echocardiography for palpitations in paediatric cardiology clinics.

Identify diagnostic yield and frequency of echocardiograms for palpitation-related indications at outpatient paediatric cardiology clinics in relation to the 2014 ACC/AAP/AHA/ASE/HRS/SCAI/SCCT/SCMR/SOPE appropriate use criteria for Initial Transthoracic Echocardiography in Outpatient Paediatric Cardiology. A single-centre, retrospective study of children presenting for evaluation of a chief complaint of palpitations to outpatient paediatric cardiology clinics from 2015 to 2017. Palpitations were defined as an unpleasant sensation of rapid, irregular, and/or forceful beating of the heart. Indications for echocardiogram in patients were retrospectively classified based on the appropriate use criteria as "appropriate," "may be appropriate," or "rarely appropriate." The incidence of abnormal and incidental echocardiographic findings for each category was determined. A total of 286 patients presented with palpitations, with 128 (52% female) meeting inclusion criteria. Exclusion criteria included patients with additional cardiac complaints, prior echocardiogram, or history of congenital heart disease. Echocardiograms were performed on 36 (28%) patients. The appropriate use criteria were retrospectively applied, and indications for their performance were classified as "appropriate" (n = 4), "may be appropriate" (n = 17), or "rarely appropriate" (n = 15). Minor echocardiographic abnormalities were present in 22% (n = 8) of echocardiograms obtained for all appropriate use criteria classifications. No moderate or severe echocardiographic abnormalities were found. Incidental findings were noted in eight echocardiograms. Echocardiography in the evaluation of "rarely appropriate" and "may be appropriate" palpitation-related indications is of low diagnostic yield.

Epilepsy and Seizure-Related Hospital Admissions to an Australian Neurology Unit: A Prospective Observational Study

This study provides contemporary data on patients admitted to a Neurology unit with seizures, the majority of whom have a diagnosis of epilepsy. There were 278 hospital presentations with seizure during the 6-month study period, with 60 admissions to the Neurology unit included for analysis. Provoking factors were identified in 40%, with poor medication adherence the commonest precipitant. CT-brain had low diagnostic yield in patients with epilepsy presenting with seizure and should be reserved for those with further indications for imaging. Patients with drug-resistant epilepsy comprised 54% of admissions suggesting management strategies in this cohort can be further optimized.

S0866 Stool Molecular Testing and Antibiotic Use for Acute Diarrheal Illness in Immunosuppressed Patients

INTRODUCTION: Conventional stool culture has low diagnostic yield in the evaluation of acute diarrheal illness (ADI). Thus, the decision to prescribe antibiotics for ADI is usually guided by a patient's medical history, severity of presenting symptoms, and immune-competence. PCR-based multiplex stool antigen panels (PCR panel) now allow for rapid and specific identification of causative pathogens and can help guide management of ADI, but its role in antibiotic use is unknown. This study compares rates of antibiotics prescribed for PCR panel-positive ADI in immunosuppressed and non-immunosuppressed patients. METHODS: We identified patients who presented from April 2018 to April 2019 with PCR panel-positive ADI. Those with C. difficile co-infection were excluded as these results were not available to providers. Patients were categorized as immunosuppressed or non-immunosuppressed, with immunosuppressed defined by active malignancy, history of organ transplant, primary immunodeficiency, HIV, or on immunosuppressive medications. Charts were reviewed for baseline characteristics and antibiotic management of the ADI. Baseline characteristics were compared using Student t-test, Wilcoxon rank-sum, Chi-squared, or Fishers exact test. Multinomial logistic regression was used to compare likelihood of antibiotic use. RESULTS: 749 patients presented with PCR panel-positive ADI, of whom 207 (27.6%) were immunosuppressed. A greater percentage of the immunosuppressed had received steroids (45.1% vs 4.1%) or antibiotics (47.3% vs 18.7%) in the 6 months prior to PCR testing. There were no clinically significant differences in vital signs or labs on presentation between the groups. The immunosuppressed had a higher odds of receiving antibiotics in response to a positive PCR panel vs no antibiotics (OR 1.85, P = 0.0016) than the non-immunosuppressed. This remained true after adjusting for potential confounding factors including age, sex, and recent steroid or antibiotic use (AOR 2.30, P = 0.0033). There was no significant difference in the odds of receiving empiric antibiotics prior to PCR results vs no antibiotics (OR 1.26, P = 0.2606) between the groups. CONCLUSION: We show that immunosuppressed patients are more likely to be prescribed antibiotics in response to a positive PCR panel than non-immunosuppressed patients, but there is no difference in the likelihood of being treated empirically prior to PCR results. This shows that PCR panels may be guiding management of ADI, especially in immunosuppressed patients.Table 1.: Comparison of baseline and clinical characteristics by immunosuppressed statusTable 2.: Antibiotic Management of ADITable 3.: Multinomial logistic regression models of treatment outcome

S1137 Low Yield of Head Computed Tomography (HCT) in Cirrhotic Patients Presenting With Altered Mentation

INTRODUCTION: Hepatic encephalopathy is a known complication of liver cirrhosis that often manifests as a change in mental status. This study aims to investigate the utility in obtaining a head computerized tomography (HCT) in patients presenting with hepatic encephalopathy by correlating presence or absence of focal neurological deficits (FND) to imaging findings. METHODS: Retrospective review of cirrhotic patient admissions with hepatic encephalopathy between 2016-2018 at William Beaumont Hospital in Michigan was performed. Two reviewers independently reviewed automated reports generated for variables of interest using an electronic health record query tool. Low risk indication for HCT was defined as altered mental status in the absence of trauma or FNDs. Descriptive statistics, univariate analyses by t-tests/2 tests and logistic regression were performed to identify clinical features associated with acute abnormalities on HCT using SPSS. RESULTS: 520 unique admissions were reviewed. Mean age was 63.4 ± 12.1 years, M:F ratio was 1.31:1, 187 (36.0%) had alcoholic cirrhosis, and median MELD score was 17 (13-23). Indication for HCT was altered mental status (AMS) in 408 (78.5%) patients and FNDs only reported in 24 (4.6%) patients. 13 (2.5%) patients had acute intracranial pathology (7 hemorrhagic stroke, 2 ischemic stroke, 4 subdural hematoma) on HCT. Presence of FNDs (OR: 6.9, 95% CI: 1.8–27.1), a high risk indication for HCT (OR: 6.2, 95% CI: 2.0–19.3), and antiplatelet use (OR: 5.8, 95% CI: 1.6–21.2) were positive correlates of acute intracranial pathology on HCT. Age, sex, MELD score, hemoglobin, platelet count, race, and cirrhosis etiology did not correlate with HCT abnormalities. Number needed to screen to identify one acute pathology was 14 vs. 82 for high risk indications vs. low risk indications. CONCLUSION: Routine HCTs in cirrhotic patients presenting with hepatic encephalopathy with AMS in the absence of history of trauma, FNDs, or aspirin use are costly and of low diagnostic yield. In addition, in patients with liver cirrhosis, the risks and benefits of aspirin use should be carefully weighed.Table 1.: Cohort demographics and clinical characteristicsTable 2.: Head computed tomography (HCT) findings and indications

Coronary computed tomography angiography versus invasive coronary angiography: medical staff perceptions and diagnostic interest in Gaza-Palestine.

Invasive coronary angiography (ICA) and coronary computed tomography angiography (CCTA) are used in the diagnosis of coronary artery disease (CAD). The medical benefits, as well as the ethical and logistical implications, should be explored, particularly in the scarcity of medical resources. We explore the perception of medical staff toward the interest of CCTA and ICA in diagnosis CAD to maximize the utility of both procedures. A triangulated observational, analytical prospective cohort study carried out among patients suspected with CAD who underwent CCTA and ICA. The quantitative part included 381 patients (250 underwent ICA and 131 underwent CCTA). The qualitative part included a purposive sample of two radiologists, three cardiologists, and two medical imaging specialists. Low diagnostic yield of the ICA through 31.3% and 39.7% diagnosed without CAD and non-significant CAD, respectively. Risk factors such as the family history of heart disease, obesity, high cholesterol, and diabetes were with high frequency in the patients with significant CAD. The sensitivity, specificity, PPV, and NPV of CCTA technique was 94.74%, 94.23%, 92.31%, and 96.08% respectively. Cardiologist's perceptions focused on radiation concerns and difficulties for convincing patients to perform the CCTA procedure. Radiologists and medical imaging specialists focused on complete cooperation from the cardiologist to better preparation of patients to perform optimal CCTA procedures. Efficient diagnostic benefits of CCTA and overuse of ICA for stable CAD are documented. Clear diagnostic strategy with medical, ethical, and logistical issues should be considered when selecting the CCTA or ICA for diagnosis CAD.

Practice Pattern, Diagnostic Yield, and Long-Term Prognostic Impact of Coronary Computed Tomographic Angiography.

BackgroundAlthough guidelines recommend the use of coronary computed tomographic angiography (CTA) in patients with stable pain syndromes, the clinical benefits of the use of coronary CTA in a broad spectrum of patients is unknown. We evaluated the contemporary practice pattern and diagnostic yield of coronary CTA and their impact on the subsequent diagnostic‐therapeutic cascade and clinical outcomes.Methods and ResultsWe identified 39 906 patients without known coronary artery disease (CAD) who underwent coronary CTA between January 2007 and December 2013. The patients' demographic characteristics, risk factors, symptoms, results of coronary CTA, the appropriateness of downstream diagnostic and therapeutic interventions, and long‐term outcomes (death or myocardial infarction) were evaluated. The number of coronary CTAs had increased over time, especially in asymptomatic patients. Coronary CTA revealed that 6108 patients (15.3%) had obstructive CAD (23.7% of symptomatic and 9.3% of asymptomatic patients). Subsequent cardiac catheterization was performed in 19.2% of symptomatic patients (appropriate, 80.6%) and in 3.9% of asymptomatic patients (appropriate, 7.9%). The 5‐year rate of death or myocardial infarction was significantly higher in patients with obstructive CAD on CTA than those without (7.2% versus 3.0%; P<0.001; adjusted hazard ratio [95% CI], 1.34 [1.17–1.54]). However, obstructive CAD on CTA had limited added value over conventional risk factors for predicting death or myocardial infarction.ConclusionsAlthough the use of coronary CTA had substantially increased, CTA had a low diagnostic yield for obstructive CAD, especially in asymptomatic patients. The use of CTA in asymptomatic patients seemed to have led to inappropriate subsequent diagnostic or therapeutic interventions without clinical benefit.

Identification of disease-causing variants by comprehensive genetic testing with exome sequencing in adults with suspicion of hereditary FSGS

In about 30% of infantile, juvenile, or adolescent patients with steroid-resistant nephrotic syndrome (SRNS), a monogenic cause can be identified. The histological finding in SRNS is often focal segmental glomerulosclerosis (FSGS). Genetic data on adult patients are scarce with low diagnostic yields. Exome sequencing (ES) was performed in patients with adult disease onset and a high likelihood for hereditary FSGS. A high likelihood was defined if at least one of the following criteria was present: absence of a secondary cause, ≤25 years of age at initial manifestation, kidney biopsy with suspicion of a hereditary cause, extrarenal manifestations, and/or positive familial history/reported consanguinity. Patients were excluded if age at disease onset was <18 years. In 7/24 index patients with adult disease onset, a disease-causing variant could be identified by ES leading to a diagnostic yield of 29%. Eight different variants were identified in six known genes associated with monogenic kidney diseases. Six of these variants had been described before as disease-causing. In patients with a disease-causing variant, the median age at disease onset and end-stage renal disease was 26 and 38 years, respectively. The overall median time to a definite genetic diagnosis was 9 years. In 29% of patients with adult disease onset and suspected hereditary FSGS, a monogenic cause could be identified. The long delay up to the definite genetic diagnosis highlights the importance of obtaining an early genetic diagnosis to allow for personalized treatment options including weaning of immunosuppressive treatment, avoidance of repeated renal biopsy, and provision of accurate genetic counseling.

Magnetic resonance imaging in chronic headache: our experiences and perspectives.

Headache is a common symptomatology necessitating hospital consultations. Despite the prohibitive cost to patients in Nigeria, Magnetic resonance imaging (MRI) has become an evaluating tool for headache. To determine the yield of cranial MRI and frequency of significant intracranial lesions among patients with chronic headache. A three-year retrospective analysis of cranial MR images and records of patients referred to Medicaid Diagnostic Centre in Abuja, Nigeria on account of chronic headache was done. Data was analyzed using SAS software version 9.3. 150 patients aged 9 to 73 years (mean= 39.5 years) with chronic headache were studied. There were 54 males and 96 females with a ratio of 1:1.8. 48% and 52% had normal and abnormal MRI findings respectively. Although the number with abnormal MRI was higher than those with normal exams, this difference was not significant (p=0.624). The commonest neoplastic and non-neoplastic abnormalities were pituitary macroadenoma (4%) and sinusitis (21.3%) respectively. In our study, MRI had a low diagnostic yield in patients with chronic headache. Therefore, it is expedient that physicians stratify patients with chronic headache based on red flag signs to determine the need for cranial MRI in view of financial burden.

Pro-cathepsin D as a diagnostic marker in differentiating malignant from benign pleural effusion: a retrospective cohort study

BackgroundMalignant pleural effusion (MPE) causes substantial symptomatic burden in advanced malignancy. Although pleural fluid cytology is a commonly accepted gold standard of diagnosis, its low diagnostic yield is a challenge for clinicians. The aim of this study was to determine whether pro-cathepsin D can serve as a novel biomarker to discriminate between MPE and benign pleural effusion (BPE).MethodsThis study included 81 consecutive patients with exudative pleural effusions who had underwent thoracentesis or pleural biopsy. Pleural fluid and serum were collected as a standard procedure for all individuals at the same time. The level of pro-cathepsin D was measured by the sandwich enzyme-linked immunosorbent assay method.ResultsThough there were no significant differences in plasma pro-cathepsin D between the two groups, the level of pleural fluid pro-cathepsin D was significantly higher in the MPE group than the BPE group (0.651 versus 0.590 pg/mL, P = 0.034). The discriminative power of pleural fluid pro-cathepsin D for diagnosing MPE was moderate, with 81% sensitivity and 53% specificity at a pro-cathepsin D cut-off ≥0.596 pg/mL (area under the curve: 0.656). Positive and negative predictive values for MPE were 38 and 89%, respectively, with pro-cathepsin D cut-off value (> 0.596 pg/mL).ConclusionsThe level of pleural fluid pro-cathepsin D was found to be significantly higher in MPE than in BPE. Although results of this study could not support the sole use of pleural fluid pro-cathepsin D to diagnose MPE, pleural fluid pro-cathepsin D can be added to pre-existing diagnostic methods for ruling-in or ruling-out MPE.

Diagnostic yield of repeat testing for SARS-CoV-2: Experience from a large health system in Los Angeles

ObjectiveTo determine the diagnostic yield of repeat testing for SARS-CoV-2. MethodsA retrospective analysis was performed of all SARS-CoV-2 test results within the UCLA Health System between March 9th and April 29th, 2020. All patients with repeat test results were identified and those with discordant results were reviewed. ResultsBetween March 9th and April 29th there were 10,165 SARS-CoV-2 test results, of which 630 (6.2%) were positive. Among the 904 patients with repeat test results, 808 (89.4%) were initially negative and 96 (10.6%) were initially positive. Among the 808 patients with an initial negative test, 15 (1.9%) subsequently tested positive. Eleven cases with an initial negative SARS-CoV-2 test and without a known prior positive SARS-CoV-2 test were reviewed; 6 were employed as healthcare workers and 10 were positive on the second test. ConclusionsWe found a low diagnostic yield of repeat testing for SARS-CoV-2 in our health system. Repeat testing might prove useful in certain clinical scenarios, such as in healthcare workers, when symptoms develop after a negative test, and in hospitalized patients with a high clinical suspicion for COVID-19.

The Role of MR Imaging and MR Angiography in the Evaluation of Patients with Headache

BACKGROUND: Headache is one of the most common complaint in medical practice and the most often neurological symptom.&#x0D; AIM: The aim of our study was to estimate the frequency of abnormal magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) findings in patients with non-acute headache without focal neurological abnormalities.&#x0D; MATERIAL AND METHODS: The results of the MRI and MRA were retrospectively analyzed. As major abnormalities, we took into account tumor, stroke, extraaxial collection, Chiari malformations, and vascular pathology (aneurysm and arterial-venous malformation).&#x0D; RESULTS: Two hundred twenty-five patients fulfilled the criteria. Out of 225 patients with median age of 37 (18–85) years, 78% of the patients were female and 22% were male. In total, we found 8.4% of major abnormalities. On MRI head scan without MRA analysis, we found 50.7% of normal finding, 47.1% of minor abnormalities and 2.2% of major abnormalities. On MRA scan, we found we found 52.9% of normal finding, 40.9% of minor abnormalities, and 6.2% of major abnormalities.&#x0D; CONCLUSION: Our study demonstrates a low but important diagnostic yield of MRI and MRA examination for patients with non-acute headache without focal neurological abnormalities.

Percutaneous image-guided sternal biopsy: a cross-institutional retrospective review of diagnostic yield and safety in 50 cases.

Image-guided sternal biopsy may be technically daunting given the immediately subjacent critical structures. There is a paucity of literature describing technique, safety, and efficacy. This study aims to quantify the diagnostic yield and safety of image-guided sternal biopsies. Secondary aims include (1) describing the preferred approach/technique and (2) identifying imaging features and disease entities associated with higher and lower diagnostic yields. A retrospective review of 50 image-guided sternal biopsies performed at two quaternary care centers from 2000 to 2019 was performed. Recorded lesion-related variables included as follows: location, density, extraosseous extension, and size. Recorded variables from electronic medical records included as follows: patient demographics, histologic or microbiological diagnosis, and complications. Recorded technique-related variables included as follows: needle obliquity, type, and gauge; biopsy core number and length; and modality. Of the 50 biopsies, 88.0% resulted in a definitive histologic diagnosis. Six biopsies were non-diagnostic. The majority of biopsies were performed under computed tomography (88.0%), followed by ultrasound (12.0%). Tumor was the most common biopsy indication (90.0%), followed by infection (10.0%). Of the diagnostic biopsies indicated for tumor, 88.9% were malignant. Seventy-four percent of the lesions were predominantly lytic. Fifty percent of lesions had extraosseous extension. Lesion locations were as follows: manubrium (48.0%), sternal body (48.0%), and sternomanubrial joint (4.0%). No minor or major, acute, or delayed procedure-related complications were encountered. Image-guided sternal biopsy is an efficacious and safe method of obtaining a definitive histologic diagnosis regardless of lesion-specific features or location.

COVID-19: An Opportunity to Reimagine Colorectal Cancer Diagnostic Testing—A New Paradigm Shift

ABSTRACT Colorectal cancer is the third leading cause of cancer related deaths and to date, the COVID-19 pandemic has led to major disruptions of the diagnosis and treatment pathways of this cancer, which may adversely affect survival outcomes for many years. Colorectal cancer pathways must be maintained at a near normal throughput with urgent attention to the backlog of patients to avoid a potential crisis of avoidable cancer deaths. A radical review and revamping of endoscopy services to improve efficiency during COVID-19 is urgently required. To date most endoscopy units have severely restricted their activity, except for time-critical diagnostic and therapeutic procedures. In the post- COVID-19 recovery phase, access to endoscopy services will increase but capacity will be reduced compared to before the pandemic, due to infection control measures. A pragmatic and safe strategy is urgently needed to clear the backlog of endoscopic procedures and for managing the new symptomatic referrals. We propose the use of non-invasive tests, such as FIT and mSEPT9 combined with “safety netting” to “rule out” colorectal cancer and to reduce the utilization of colonoscopy by up to 80% and limit the procedure to those patients at high risk of cancer.

Functional Dyspepsia: Diagnostic and Therapeutic Approaches.

Functional dyspepsia is a common functional gastrointestinal (GI) disorder of gastroduodenal origin, diagnosed clinically in the presence of prototypical symptoms of epigastric pain and meal-related symptoms, and without structural explanation. The most recent diagnostic criteria provide for two functional dyspepsia subtypes, epigastric pain syndrome (EPS) and post-prandial distress syndrome (PDS) based on the predominant symptom pattern. The evaluation of dyspepsia should keep laboratory, imaging, and invasive testing to a minimum, as extensive or repetitive investigations are of rather low diagnostic yield in the absence of localizing symptoms or alarm features. Factors with etiopathologic relationships to functional dyspepsia include micro-inflammation, GI infections, abnormalities of gastroduodenal motility, visceral hypersensitivity, disturbances along the brain-gut axis, and psychological factors; all of these causative mechanisms have potential to partially explain symptoms in some functional dyspepsia patients, thus providing a rationale for the efficacy of a diversity of therapeutic approaches to functional dyspepsia. Management of dyspepsia symptoms relies upon both pharmacologic treatments and non-pharmacologic approaches, including psychological and complementary interventions. The evidence in support of established functional dyspepsia therapies is reviewed, and forms the basis for an effective functional dyspepsia treatment strategy emphasizing the patient's current symptom severity, pattern, and impact on the function and quality of life of the individual.

Neck CT angiography examinations for pediatric oropharyngeal trauma: diagnostic yield and proposal of a new targeted technique.

Neck computed tomography (CT) angiography is commonly ordered for pediatric patients with soft palate trauma to exclude vascular injury. Debate exists regarding what type of imaging is indicated in this setting, particularly amid growing concern that standard neck CT angiography results in considerable radiation exposure. To assess the diagnostic yield and estimated dose reduction of a novel targeted protocol extending from the skull base to the hyoid bone to evaluate pediatric oropharyngeal trauma. A retrospective imaging and medical chart review was performed of patients for whom a neck CT angiography was obtained for an indication of oropharyngeal trauma between 2008 and 2018. Effective dose and size-specific dose estimates (SSDEs) were estimated for standard and targeted neck CT angiography protocols with calculation of percent dose reduction of the targeted exams. Ninety-eight CT angiography examinations were reviewed. No cases were positive for neurological or major vessel injury; one case was positive for small vessel extravasation. Clinically significant nonvascular findings included phlegmonous change, retained foreign body, retropharyngeal/mediastinal air and pterygoid process fracture. With the exception of mediastinal air, all findings would have been included in the targeted protocol. Effective dose and SSDE were calculated for all cases where CTDIvol (volume CT dose index) had been reported (n=72). There was a statistically significant reduction in dose for the targeted protocol with an effective dose decrease of 69.7%±10.5% (P=0.009) and SSDE decrease of 53.9%±14.7% (P=0.01). Limiting ionizing radiation to the lung apices, esophagus and thyroid gland provided the greatest dose savings. Based on low diagnostic yield and high radiation dose associated with standard neck CT angiography for evaluating oropharyngeal trauma, a targeted protocol is recommended, resulting in significantly less dose to the neck, while preserving diagnostic yield.

The Diagnostic Yield of CT Urography in the Workup of Hematuria With Negative Cystoscopy [Formula: see text

To determine the diagnostic yield of computed tomography urography (CTU) in patients evaluated for hematuria with negative cystoscopy and to assess the added value of CTU when compared with ultrasound (US) in this patient population. A retrospective study was conducted of patients who underwent CTU within 12 months of negative cystoscopy for workup of hematuria at our institution from January 2016 to December 2017. Computed tomography urography findings were recorded and compared to clinical diagnoses to determine diagnostic yield. Computed tomography urography and US findings were compared in patients who underwent both examinations. Patient characteristics (age, sex, smoking history, and hematuria subtype) were reported. A total of 657 patients met the inclusion criteria, including 108 patients aged 50 years and younger. No cause for hematuria was identified in 41% of patients overall and 58% of patients aged 50 years and younger. The most common diagnoses were benign prostatic hyperplasia and urolithiasis, accounting for 25% and 21% of patients, respectively; 0.6% of patients were diagnosed with an upper urinary tract malignancy, all older than 50 years. Although US was superior or equal to CTU for diagnosis in 83% of patients who underwent both examinations, US had a 0% sensitivity for detection of upper urinary tract malignancy. The low diagnostic yield of CTU and low prevalence of upper urinary tract malignancy in patients evaluated for hematuria with negative cystoscopy, particularly those aged 50 years and younger, call into question the appropriateness of multiphasic CTU as a first-line imaging modality in this population.

The Incidence of Central Neurological Disorders Among Patients With Isolated Dizziness and the Diagnostic Yield of Neuroimaging Studies.

Dizziness is a common symptom among emergency department (ED) patients and is often associated with benign processes. The aim of this study was to investigate the incidence of severe central neurological pathologies in isolated dizziness cases and the diagnostic efficiency of neuroimaging studies. All applications for isolated dizziness to an academic ED between January 1, 2011, and December 31, 2017 were retrospectively reviewed. The frequency of these admissions, the demographic data of the patients, the results of cranial computed tomography (CT) and diffusion-weighted magnetic resonance imaging (DW-MRI) studies, and the central neurological causes of isolated dizziness were recorded. The percentage of patients with isolated dizziness among all ED admissions was 2.5% (29,510/1,190,857). The median age of these patients was 52 years (interquartile range: 38 to 66) and 58% were female. During the study period, the rate of neuroimaging studies for isolated dizziness increased year by year, and a total of 6406 (21.7%) cranial CTs and 2896 (9.8%) DW-MRIs were performed. The diagnostic yield of neuroimaging studies was 0.6% for cranial CT and 3.9% for DW-MRI. Central neurological disorders were detected in 143 (0.48%) patients with isolated dizziness. The most common causes were posterior circulation ischemic strokes (47.5%), other ischemic strokes (18.9%), vertebrobasilar insufficiency (10.5%), and transient ischemic attack (8.4%). Isolated dizziness is rarely associated with central neurological pathologies. Neuroimaging studies, especially cranial CT, have low diagnostic yield in isolated dizziness and should therefore not be routine in the evaluation process.

Diagnostic utility of additional whole-chest CT as part of an acute abdominal pain CT imaging pathway during the COVID-19 pandemic

AimTo evaluate the diagnostic utility of additional whole-chest computed tomography (CT) in identifying otherwise unheralded COVID-19 lung disease as part of an acute abdominal pain CT imaging pathway in response to the COVID-19 pandemic.MATERIALS AND METHODSConsecutive patients (n=172) who underwent additional whole-chest CT via a COVID-19 acute abdominal pain CT imaging pathway between 27 March and 3 May 2020 were evaluated in this retrospective single-centre study. Chest CT examinations were graded as non-COVID-19, indeterminate for, or classic/probable for COVID-19. CT examinations in the latter two categories were further divided into one of three anatomical distributions (lung base, limited chest [below carina], whole chest [above carina]) based on location of findings. Reverse transcriptase-polymerase chain reaction (RT-PCR) results and clinical features of COVID-19 were assessed to determine if COVID-19 was clinically suspected at the time of CT referral.RESULTSTwenty-seven of the 172 (15.7%) patients had CT features potentially indicative of COVID-19 pneumonia, 6/27 (3.5%) demonstrating a classic/probable pattern and 21/27 (12.2%) demonstrating an indeterminate pattern. After correlation with clinical features and RT-PCR 8/172 (4.7%) were defined as COVID-19 positive, of which only 1/172 (0.6%) was clinically unsuspected of COVID-19 at the time of CT referral. All COVID-19 positive cases could be identified on review of the lung base alone.CONCLUSIONWhole-chest CT as part of an acute abdominal pain CT imaging pathway has a very low diagnostic yield for our cohort of patients. All COVID-19-positive patients in our cohort were identified on review of the lung bases on the abdominal CT and this offers an alternative imaging approach in this patient group.