Addressing selection bias in the UK Biobank neurological imaging cohort

The UK Biobank is a national prospective study of half a million participants between the ages of 40 and 69 at the time of recruitment between 2006 and 2010, established to facilitate research on diseases of aging. The imaging cohort is a subset of UK Biobank participants who have agreed to undergo extensive additional imaging assessments. However, Fry et al (2017) find evidence of "healthy volunteer bias" in the UK Biobank -- participants are less likely to smoke, be obese, consume alcohol daily than the target population of UK adults. Here we examine selection bias in the UK Biobank imaging cohort. We address two common misconceptions: first, that study size can compensate for bias in data collection, and second that selection bias does not affect estimates of associations, which are the primary interest of the UK Biobank. We introduce inverse probability weighting (IPW) as an approach commonly used in survey research that can be used to address selection bias in volunteer health studies like the UK Biobank. We discuss 6 such methods -- five existing and one novel --, assess relative performance in simulation studies, and apply them to the UK Biobank imaging cohort. We find that our novel method, BART for predicting the probability of selection combined with raking, performs well relative to existing methods, and helps alleviate selection bias in the UK Biobank imaging cohort.

Evaluation of a Symptom-Based Algorithm for Managing Battery Ingestions in Children

Objectives While complications from battery ingestion can be severe, especially with the emergence of stronger battery elements, not all ingestions require prompt removal. We aim to evaluate a symptom-focused algorithm for battery ingestion that emphasizes observation over intervention to investigate its safety. Materials and Methods Patients were identified through a query of foreign-body ingestion radiographs obtained between 2017 and 2020. A retrospective chart review was then performed of all patients who presented with button battery ingestions to identify compliance with our algorithm, overall outcomes, and complications. Results In total, 2% of all radiographs (44/2,237) demonstrated button battery ingestions. The median age of patients was 3.8 years (interquartile range, 2.6–5.3). Most batteries were found in the stomach (64%, n = 28), but were also identified in the esophagus (14%, n = 6), small bowel (14%, n = 6), and colon (9%, n = 4). All esophageal batteries were managed with immediate endoscopic retrieval. Ten gastric batteries were not managed per protocol, with seven admitted for observation despite being asymptomatic and repeat abdominal X-rays demonstrating persistent gastric location of the battery. Four patients underwent esophagogastroduodenoscopy; however, in two patients the battery had migrated past the stomach prior to intervention. All small bowel batteries and three of four asymptomatic colon batteries were managed per protocol; one patient had additional imaging that demonstrated battery passage. Conclusion Adherence to a symptom-focused protocol for conservative management of button battery ingestions beyond the gastroesophageal junction is safe and frequently does not require admission, serial imaging, or intervention.

Changes in Brain Energy and Membrane Metabolism in Glioblastoma following Chemoradiation

Brain parenchyma infiltration with glioblastoma (GB) cannot be entirely visualized by conventional magnetic resonance imaging (MRI). The aim of this study was to investigate changes in the energy and membrane metabolism measured with phosphorous MR spectroscopy (31P-MRS) in the presumably “normal-appearing” brain following chemoradiation therapy (CRT) in GB patients in comparison to healthy controls. Twenty (seven female, thirteen male) GB patients underwent a 31P-MRS scan prior to surgery (baseline) and after three months of standard CRT (follow-up examination. The regions of interest “contrast-enhancing (CE) tumor” (if present), “adjacent to the (former) tumor”, “ipsilateral distant” hemisphere, and “contralateral” hemisphere were compared, differentiating between patients with stable (SD) and progressive disease (PD). Metabolite ratios PCr/ATP, Pi/ATP, PCr/Pi, PME/PDE, PME/PCr, and PDE/ATP were investigated. In PD, energy and membrane metabolism in CE tumor areas have a tendency to “normalize” under therapy. In different “normal-appearing” brain areas of GB patients, the energy and membrane metabolism either “normalized” or were “disturbed”, in comparison to baseline or controls. Differences were also detected between patients with SD and PD. 31P-MRS might contribute as an additional imaging biomarker for outcome measurement, which remains to be investigated in a larger cohort.

The PROCEM study protocol: Added value of preoperative contrast-enhanced mammography in staging of malignant breast lesions - a prospective randomized multicenter study

Background Correct preoperative estimation of the malignant extent is crucial for optimal planning of breast cancer surgery. The sensitivity of mammography is lower in dense breasts, and additional imaging techniques are sometimes warranted. Contrast-enhanced mammography (CEM) has shown similar sensitivity and in some cases better specificity, than magnetic resonance imaging (MRI) in small, observational studies. CEM may be more cost-effective than MRI, and may provide better identification of the tumor extent, however, no randomized trials have been performed to date to investigate the added value of CEM. In a feasibility study, we found that the treatment was changed in 10/47 (21%) cases after additional CEM. The purpose of the present study is to evaluate the added value of CEM in preoperative staging of breast cancer in a randomized study. Method This prospective randomized study will include 440 patients with strongly suspected or established diagnosis of breast malignancy, based on assessment with mammography, ultrasound and core biopsy/cytology, and for whom primary surgery is planned. Patients will be randomized 1:1 using a web-based randomization tool to additional investigation with CEM or no further imaging. The CEM findings will be taken into consideration, which may lead to changes in primary treatment, which is the primary endpoint of this study. Secondary endpoints include rate of reoperation and number of avoidable mastectomies, as well as a cost-benefit analysis of additional CEM. Patient-reported health-related quality of life will be investigated at 1 year with the validated Breast-Q™ questionnaire. The rate of local recurrence or new cancer ipsi- or contralaterally within 5 years will be assessed from medical records and pathology reports. Discussion The aim of this trial is to explore the added value of CEM in preoperative staging of breast cancer. The results obtained from this study will contribute to our knowledge on CEM as an additional imaging method to standard investigation with digital mammography and ultrasound. The findings may also provide additional information on which patient groups would benefit from CEM, and on the economic aspects of CEM in standard preoperative practice. Trial registration This trial is registered at clinicaltrials.gov, registration no: NCT04437602, date of registration: June 18, 2020.

Incidence and underreporting of osseous wrist and hand injuries on whole-body computed tomographies at a level 1 trauma center

Background To investigate the incidence of osseous wrist and hand injuries on whole-body computed tomographies (WBCT) at an urban maximum-care trauma center, to report the number of missed cases in primary radiology reports, and to develop an algorithm for improved detection of these injuries. Methods Retrospective analysis reviewing all WBCT for a period of 8 months for osseous wrist and hand injuries. (1) Reconstruction of hands/wrists in three planes (thickness 1–2 mm) and analysis by a blinded musculoskeletal radiologist. (2) Scanning of primary radiology reports and comparison to the re-evaluation. (3) Calculation of the diagnostic accuracy of WBCT during primary reporting. (4) Search for factors potentially influencing the incidence (trauma mechanism, associated injuries, Glasgow Coma Scale, artifacts). (5) Development of an algorithm to improve the detection rate. Results Five hundred six WBCT were included between 01/2020 and 08/2020. 59 (11.7%) WBCT showed 92 osseous wrist or hand injuries. Distal intra-articular radius fractures occurred most frequently (n = 24, 26.1%); 22 patients (37.3%) showed multiple injuries. The sensitivity of WBCT in the detection of wrist and hand fractures during primary evaluation was low with 4 positive cases identified correctly (6.8%; 95% CI 1.9 to 16.5), while the specificity was 100% (95% CI 99.2 to 100.0). Forty-three cases (72.9%) were detected on additional imaging after clinical reassessment. Twelve injuries remained undetected (20.3%). Motorcycle accidents were more common in positive cases (22.0% vs. 10.1%, p = 0.006). 98% of positive cases showed additional fractures of the upper and/or lower extremities, whereas 37% of the patients without osseous wrist and hand injuries suffered such fractures (p < 0.001). The remaining investigated factors did not seem to influence the occurrence. Conclusion Osseous wrist and hand injuries are present in 11.7% on WBCT after polytrauma. 93.2% of injuries were missed primarily, resulting in a very low sensitivity of WBCT during primary reporting. Motorcycle accidents might predispose for these injuries, and they often cause additional fractures of the extremities. Clinical re-evaluation of patients and secondary re-evaluation of WBCT with preparation of dedicated multiplanar reformations are essential in polytrauma cases to detect osseous injuries of wrist and hand reliably. Trial registration The study was registered prospectively on November 17th, 2020, at the German register for clinical trials (DRKS-ID: DRKS00023589).

Retrograde urethrography, sonouretrography and magnetic resonance urethrography in evaluation of male urethral strictures. Should the novel methods become the new standard in radiological diagnosis of urethral stricture disease?

Purpose To verify which of the diagnostic modalities: Voiding cystouretrography (VCUG), Sonouretrography (SUG) or Magnetic resonance uretrography (MRU) is the most accurate in the assessment of urethral strictures in males and in what cases the application of novel imaging techniques benefits most. Methods 55 male patients with a diagnosis of urethral stricture, were enrolled in this prospective study. Initial diagnosis of urethral stricture was based on anamnesis, uroflowmetry and VCUG. Additional imaging procedures—SUG and MRU were performed before the surgery. Virtual models and 3D printed models of the urethra with the stricture were created based on the MRU data. Exact stricture length and location were evaluated by each radiological method and accuracy was verified intraoperatively. Agreement between SUG and MRU assessments of spongiofibrosis was evaluated. MRU images were independently interpreted by two radiologists (MRU 1, MRU 2) and rater reliability was calculated. Results MRU was the most accurate [(95% CI 0.786–0.882), p < 0.0005] with an average overestimation of 1.145 mm (MRU 1) and 0.727 mm (MRU 2) as compared with the operative measure. VCUG was less accurate [(95% CI 0.536–0.769), p < 0.0005] with an average underestimation of 1.509 mm as compared with operative measure. SUG was the least accurate method [(95% CI 0.510–0.776), p < 0.0005] with an average overestimation of 2.127 mm as compared with the operative measure. There was almost perfect agreement of MRU interpretations between the radiologists. Conclusions VCUG is still considered as a ‘gold standard’ in diagnosing urethral stricture disease despite its limitations. SUG and MRU provide extra guidance in preoperative planning and should be considered as supplemental for diagnosing urethral stricture. Combination of VCUG and SUG may be an optimal set of radiological tools for diagnosing patients with urethral strictures located in the penile urethra. MRU is the most accurate method and should particularly be considered in cases of post-traumatic or multiple strictures and strictures located in the posterior urethra.

Dental use of cone beam computed tomography in pediatric embolized arteriovenous maxillofacial malformation

Objective: Pediatric facial arteriovenous malformations (AVMs) are rare but can cause potentially fatal hemorrhages during dental procedures and oral surgery. In this article we present a systematic review of the medical open access literature on pediatric facial AVM. Case report: We illustrate our purpose with clinical dental use of cone beam computed tomography (CBCT) in pediatric embolized facial AVM to define the presence and the position of the right upper impacted canine. Conclusions: We advocate the use of CBCT as additional imaging tool in the follow-up of pediatric dentomaxillofacial AVM, and for depiction of dentoalveolar structures that are inaccessible by conventional dental radiography.

TP8.1.12 Diagnostic Utility of MRI in the Evaluation of Potential Malignancy in Patients Presented with Nipple Discharge

Aims Nipple discharge is a presentation commonly seen at breast clinics. It is conventionally evaluated with physical examination and sonography( or mammography). The aim of this study is to investigate the diagnostic value of magnetic resonance imaging (MRI) as an additional imaging tool in the evaluation of potential malignancy in patients presented with nipple discharge. Methods A retrospective evaluation of 85 patients with nipple discharge who underwent breast ultrasound (USS) and MRI between 04/06/2008 and 25/10/2019 was conducted. Clinical notes, radiographic reports and biopsy results were reviewed. Sensitivity, specificity, positive predictive value and negative predictive value of USS and MRI were calculated. Results Out of the 85 patients (all female; mean age 45.33 +/- 12.93 years old) with nipple discharge, 11 were found to have biopsy-proven malignancy (invasive ductal carcinoma/ ductal carcinoma in situ; 12.94% risk). USS failed to identify seven malignancies (27.27% sensitivity) while MRI missed three malignancies (72.72% sensitivity). USS falsely identified four malignancies from 74 patients with no malignancy (94.59% specificity) while MRI only falsely identified one case (98.65% specificity). For patients with negative USS results (U1/U2/U3) or negative MRI results (BI-RADS category 1,2 or 3), the negative predictive values of USS is 89.74% while that of MRI is 96.05%. The positive predictive values of USS and MRI are 42.86% and 88.88% respectively. Conclusion Compared to USS, MRI has a higher sensitivity, specificity, positive predictive value and predictive value. It will be a valuable addition to the standard nipple discharge evaluation workup to help rule out malignancy.

Radiographic interpretation using high-resolution Cbct to diagnose degenerative temporomandibular joint disease

The objective of this study was to use high-resolution cone-beam computed images (hr- CBCT) to diagnose degenerative joint disease in asymptomatic and symptomatic subjects using the Diagnostic Criteria for Temporomandibular Disorders DC/TMD imaging criteria. This observational study comprised of 92 subjects age-sex matched and divided into two groups: clinical degenerative joint disease (c-DJD, n = 46) and asymptomatic control group (n = 46). Clinical assessment of the DJD and high-resolution CBCT images (isotropic voxel size of 0.08mm) of the temporomandibular joints were performed for each participant. An American Board of Oral and Maxillofacial Radiology certified radiologist and a maxillofacial radiologist used the DC/TMD imaging criteria to evaluate the radiographic findings, followed by a consensus of the radiographic evaluation. The two radiologists presented a high agreement (Cohen’s Kappa ranging from 0.80 to 0.87) for all radiographic findings (osteophyte, erosion, cysts, flattening, and sclerosis). Five patients from the c- DJD group did not present radiographic findings, being then classified as arthralgia. In the asymptomatic control group, 82.6% of the patients presented radiographic findings determinant of DJD and were then classified as osteoarthrosis or overdiagnosis. In conclusion, our results showed a high number of radiographic findings in the asymptomatic control group, and for this reason, we suggest that there is a need for additional imaging criteria to classify DJD properly in hr-CBCT images.

UNILATERAL SCROTAL HERNIA WITH DUAL URETER HERNIATION: THE FIRST EXPERIENCE OF SUCCESSFUL SURGICAL CORRECTION

Objective of the study: the purpose of the research, based on the example of a specific clinical case, is to draw the attention of specialists to a specific approach to the diagnosis and treatment of the inguinal hernia with atypical contents. A rare, unpublished in the Slovak Republic, observation of the left-sided scrotum hernia with dual ureter herniation in combination with congenital kidney pathology in a 3-month-old boy is presented. The diagnosis was based on physical examination, ultrasound examination, radiography, scintigraphy, and urethrocystoscopy. This anomaly has been successfully corrected through several successive phases of the operation. Conclusion: the combination of scrotal hernia and congenital renal anomaly may indirectly indicate a possible hernia in the distal part of the ureter and requires a thorough examination, including additional imaging methods.