False-negative Scans Research Articles

Reasons for Discordance between 68Ga-PSMA-PET and Magnetic Resonance Imaging in Men with Metastatic Prostate Cancer.

PSMA PET has emerged as a "gold standard" imaging modality for assessing prostate cancer metastases. However, it is not universally available, and this limits its impact. In contrast, whole-body MRI is much more widely available but misses more lesions. This study aims to improve the interpretation of whole-body MRI by comparing false negative scans retrospectively to PSMA PET. This study was a retrospective sub-analysis of a prospectively collected database of patients who participated in a clinical trial of PSMA PET/MRI comparing PSMA PET and whole-body MRI from 2018-2021. Subjects whose separately read PSMA PET and MRI diagnostic reports showed discrepancies ("false negative" MRI cases) were selected for sub-analysis. The cases were reviewed by the same attending radiologist who originally read the scans. The radiologist noted specific features on MRI indicating metastatic disease that were initially missed. Of 263 cases, 38 (14%) met the inclusion criteria and were reviewed. Six classes of mpMRI false negatives were identified: anatomically normal (18, 47%), atypical MRI appearance (6, 16%), mischaracterization (1, 3%), undercall (6, 16%), obscured (4, 11%), and no abnormality on MRI (3, 8%). Considering that the atypical and undercalled cases could have been adjusted in retrospect, and that 4 additional cases had positive lesions to the same extent and 11 further cases had disease confined to the pelvis, only 11 (4%) of the original 263 would have had disease outside of a conventional radiation treatment plan. Notably, almost 50% of the cases, including most lymph node metastases, were anatomically normal using standard criteria. This suggests that current anatomic criteria for evaluating prostate cancer lymph node metastases are not ideal, and there is a need for improved criteria. In addition, 32% of cases involved some element of human interpretive error, and, therefore, improving reader training may lead to more accurate results.

Preclinical In Vivo Imaging of Multiple Myeloma with [ 18f]Fluorohomoleucine (FHL) PET/CT

Purpose: Imaging of patients with multiple myeloma (MM) remains challenging due to its multi-focal nature affecting bone marrow, bone structures and soft tissue. As a result, current diagnostic methods like X-rays, CT and MRI scans only provide a partial understanding of disease activity and treatment response, lacking a comprehensive overview. Although 2-deoxy-2-[ 18F]fluoro-D-glucose (FDG) positron emission tomography (PET) has become the standard for detecting multifocal cancer spread, its use in MM patients is limited due to metabolic heterogeneity of MM and limited sensitivity in detecting extramedullary disease leading to false negative and false positive scans. To overcome these limitations, we developed a novel radiopharmaceutical L-[ 18F]Fluorohomoleucine (FHL) targeting LAT1 amino acid transporter. LAT1 has been significantly correlated with the proliferative activity of MM cells, poor prognosis and response to treatment in MM patients, presenting an appealing molecular target for assessing disease activity. Methods: FHL was synthesized as described by Nodwell et al. (J Nucl Med, 2019) and FDG was obtained from BC Cancer. LAT1 expression in multiple myeloma (MM) cell lines was confirmed by flow cytometry. Cell uptake assays were conducted using luciferase-transfected MM1S, L363, NCI H929 and AMO1 MM cells, and 2-amino-bicyclo[2.2.1]heptanes-2-carboxylic acid (BCH) was used as a blocking agent. For in vivo studies, male NRG mice were injected either with 1 x 10 6 MM cells intravenously (i.v.) via the caudal vein or subcutaneously (SQ) with 1 x 10 7 cells. Tumor engraftment was monitored weekly on an in vivo bioluminescence imager Perkin Elmer's IVIS Ilumina 5, starting at 2 weeks post-injection (p.i.). Biodistribution and PET/CT imaging studies were conducted at 4-6 weeks p.i. Results: All MM cells tested exhibited LAT1-specific FHL uptake in vitro with L363 and NCI H929 demonstrating the highest tracer uptake and average blocking efficacy over 83% and 93%, respectively. We were able to observe weekly progression of disease in the i.v. cohort using IVIS imaging. Biodistribution and PET imaging studies revealed FHL accumulation in the SQ xenografts, pancreas and excretion via the urinary tract. The SQ tumor uptake values were 4.53±0.82 %ID/g in AMO1 xenografts, 5.55±0.82 %ID/g in NCI H929, and 6.37±0.70 %ID/g in L363 tumors. In the i.v. cohort, the mouse intravenously injected with L363 cells demonstrated accumulation of radioactivity in the skull and vertebrae, as anticipated from the IVIS images. Furthermore, preliminary data suggests that FHL was able to detect a more extensive bone and lymphatic involvement than FDG in MM xenografts. Conclusion: We have demonstrated the ability of FHL for in vivo imaging of three human multiple myeloma tumors in SQ murine models, with the tumor uptake ranging from 4.53±0.82 %ID/g in AMO1 xenografts to 6.37±0.70 %ID/g in L363 tumors. Work is underway to establish the utility of this tracer in detecting disease dissemination in the orthotopic murine models of multiple myeloma, with promising preliminary results presented herein.

Brain Point of Care Ultrasound in Young Children Receiving Computed Tomography in the Emergency Department: A Proof of Concept Study

Background: Point of Care Ultrasound (POCUS) is an important tool in pediatric emergency medicine. In neonatal intensive care medicine ultrasound is often used to evaluate the brains of sick neonates. In theory, POCUS could be used in the ED in young children to evaluate the brain for abnormal pathology. Objectives: To examine the ability of PEM faculty to use brain POCUS to identify clinically significant brain injuries in children with head injuries and/or abnormal neurological exams, and generate sensitivity and specificity of brain POCUS in assessing such findings. Methods: This study used a convenience sample of patients seen in a tertiary care pediatric centre who required a CT head. A team of physicians who were trained at a workshop for brain POCUS were on call to perform the POCUS while being blinded to the results of the CT. Results: 21 children were enrolled in the study. Five (24%) of the patients had a CT that was positive for intracranial bleeds. Of the 5 patients with a positive CT, 3 had a brain POCUS scan that was also positive. The two false negative brain POCUS scans were on patients with small bleeds (no surgical intervention required) on CT, as reported by radiology. The sensitivity of brain POCUS was 60% (CI 15% - 95%) with a specificity of 94% (CI 70%-100%). The diagnostic accuracy of brain POCUS was 86% (CI 64% - 97%). Conclusion: This small proof of concept study shows that brain POCUS is an imaging modality with reasonable sensitivity and specificity in identifying intracranial pathologies that are present on CT. Its use may be most beneficial to expedite definitive imaging and subspeciality involvement.

Artificial intelligence for detection of intracranial haemorrhage on head computed tomography scans: diagnostic accuracy in Hong Kong.

The use of artificial intelligence (AI) to identify acute intracranial haemorrhage (ICH) on computed tomography (CT) scans may facilitate initial imaging interpretation in the accident and emergency department. However, AI model construction requires a large amount of annotated data for training, and validation with real-world data has been limited. We developed an algorithm using an open-access dataset of CT slices, then assessed its utility in clinical practice by validating its performance on CT scans from our institution. Using a publicly available international dataset of >750 000 expert-labelled CT slices, we developed an AI model which determines ICH probability for each CT scan and nominates five potential ICH-positive CT slices for review. We validated the model using retrospective data from 1372 non-contrast head CT scans (84 [6.1%] with ICH) collected at our institution. The model achieved an area under the curve of 0.842 (95% confidence interval=0.791-0.894; P<0.001) for scan-based detection of ICH. A pre-specified probability threshold of ≥50% for the presence of ICH yielded 78.6% accuracy, 73% sensitivity, 79% specificity, 18.6% positive predictive value, and 97.8% negative predictive value. There were 62 true-positive scans and 22 false-negative scans, which could be reduced to six false-negative scans by manual review of model-nominated CT slices. Our model exhibited good accuracy in the CT scan-based detection of ICH, considering the low prevalence of ICH in Hong Kong. Model refinement to allow direct localisation of ICH will facilitate the use of AI solutions in clinical practice.

PD10-02 USING THE NEGATIVE PREDICTIVE VALUE AND SUVMAX OF PSMA PET/CT FOR AVOIDING PELVIC LYMPH NODE DISSECTION WITH RADICAL PROSTATECTOMY

You have accessJournal of UrologyCME1 Apr 2023PD10-02 USING THE NEGATIVE PREDICTIVE VALUE AND SUVMAX OF PSMA PET/CT FOR AVOIDING PELVIC LYMPH NODE DISSECTION WITH RADICAL PROSTATECTOMY Amandeep Arora, Archi Agarwal, Mahendra Pal, Ganesh Bakshi, Santosh Menon, Gujela Ajit, and Gagan Prakash Amandeep AroraAmandeep Arora More articles by this author , Archi AgarwalArchi Agarwal More articles by this author , Mahendra PalMahendra Pal More articles by this author , Ganesh BakshiGanesh Bakshi More articles by this author , Santosh MenonSantosh Menon More articles by this author , Gujela AjitGujela Ajit More articles by this author , and Gagan PrakashGagan Prakash More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003250.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The prostate-specific membrane antigen positron-emission-tomography (PSMA-PET) scan is increasingly being utilized for staging prostate cancer (PCa). Here, we sought to evaluate the accuracy of the PSMA-PET scan with the aim of identifying patients who could be spared a pelvic lymph node dissection (PLND) at the time of radical prostatectomy (RP) based on the results of the PSMA-PET scan. METHODS: We retrospectively reviewed records of patients who underwent a PSMA-PET scan followed by an RP with extended PLND (external iliac, obturator and common iliac nodes) at our tertiary cancer care centre from Aug 2015 - September 2022. Patients were classified as clinically node negative or positive (cN0 or cN+) based on the PSMA PET scan. The nodal status in the PSMA-PET scan was compared with the final histopathology of the PLND (pN0 or pN+). RESULTS: A total of 205 patients were included and were stratified as follows based on MRI and PSMA-PET scans: 6 (2.9%) low-risk, 49 (23.9%) intermediate-risk, 46 (22.4%) high-risk localized, 89 (43.4%) locally-advanced node-negative and 15 (7.3%) node-positive patients. The sensitivity, specificity, positive predictive value, and negative predictive value of the PSMA PET scan for nodal status were 37.5%, 98.2%, 80% and 89.4% respectively. The NPV was 89.4%, 93.8%, 87% and 86.6% for overall, intermediate-risk, high-risk localized and locally-advanced node-negative patients respectively. The median SUVmax of the primary prostate lesion in patients who were true negatives for nodes, as identified by the PSMA-PET scan, was significantly lower (12.8 vs 26.4, p<0.001) than that in patients who were false negative (cN0 on PSMA but pN+ in final pathology). Of the 190 cN0 patients, 20 had a false negative PSMA PET scan. Three of the 49 intermediate-risk patients had a false negative PSMA PET scan for nodes; the SUVmax scores of their prostate lesions were 26.59, 40.06 and 54.55 which were much higher than the median SUVmax score (12.8) in patients with a true negative scan. For the 135 high-risk cN0 patients, the 17 false negative patients had a median SUVmax of 24.37 compared to those with a true negative scan (13.57), p<0.001. CONCLUSIONS: The high NPV of PSMA-PET scan coupled with the SUVmax of the primary prostatic lesion can help avoid a PLND in intermediate and high-risk patients with a ‘negative’ PSMA-PET scan. The results can be considered as hypothesis generating and indicate the use of PSMA as a biomarker for predicting nodal disease. Further larger studies can help determine the ideal cut-off values for the SUVmax of the primary lesion. Source of Funding: No © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e326 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Amandeep Arora More articles by this author Archi Agarwal More articles by this author Mahendra Pal More articles by this author Ganesh Bakshi More articles by this author Santosh Menon More articles by this author Gujela Ajit More articles by this author Gagan Prakash More articles by this author Expand All Advertisement PDF downloadLoading ...

Clinical progress note: Noncardiac complications in adults with congenital heart disease.

Clinical progress note: Noncardiac complications in adults with congenital heart disease.

Diagnostic value of FDG PET/CT imaging in patients with surgically managed infective endocarditis: results of a retrospective analysis at a tertiary center

BackgroundWe assessed the diagnostic value of FDG PET/CT in a real-world cohort of patients with surgically managed infective endocarditis (IE). MethodsWe performed a retrospective analysis of all patients hospitalized in a tertiary IE referral medical center from January 2014 to October 2018 fulfilling the following criteria: ICD-10 code for IE and OPS code for both, heart surgery and FDG PET/CT. ResultsFinal analysis included 29 patients, whereof 28 patients had surgically proven IE. FDG PET/CT scan was true-positive in 15 patients (sensitivity (SEN) 56%) and false-negative in 12 patients. Combination of Duke criteria (DC) with FDG PET/CT scan resulted in gain of SEN for all patients with confirmed IE (SEN of DC 79% vs SEN of combination DC and FDG PET/CT 89%), driven by a relevant gain in PVE patients only (SEN of DC 78% vs SEN of combination DC and FDG PET/CT 94%). Interestingly, higher prosthesis age was observed in patients with false-negative scans. ConclusionsWe found a SEN of 56% for FDG PET/CT in a real-world cohort of patients with surgically proven IE which was associated with a 16% gain of IE diagnosis in patients with PVE when combined with DC.

Meckel's Diverticulum - Clinical Presentation and Pitfalls in Diagnosis in the Pediatric Age Group in Singapore.

ABSTRACTPurpose:The purpose of this study was to study the presentation of patients who underwent Meckel's diverticulectomy (MD) and utility of pertechnetate Meckel's scan in the diagnosis of MD.Methods:The clinical presentation of a retrospective cohort of patients who underwent MD from January 2007 to December 2019 was studied. The modes of presentation, treatment, and the diagnostic utility of pertechnetate Meckel's scans were evaluated. False-positive and false-negative scans were reviewed. The presence of gastric mucosa on histology of Meckel's was correlated with presentation as gastrointestinal bleeding and positive scan results.Results:Ninety-nine patients underwent MD. Thirty-five out of 263 (13.3%) Meckel's scans done were positive. There was a male preponderance (86.9%). The peak age of presentation was 0–4 years (rectal bleeding or intestinal obstruction). Only a third of the patients with Meckel's diverticulum Meckel's had a preoperative diagnosis of Meckel's. The sensitivity/specificity of Meckel's scan was higher in patients presenting with painless rectal bleeding. Seven patients were false positive (weak tracer uptake or ectopic uptake) and five were false negative. Two patients with false-negative Meckel's scan, having gastrointestinal bleeding had gastric mucosa on histology of Meckel's.Conclusion:Meckel's diverticulum has a male predominance. Meckel's scan has a high sensitivity in the children presenting with fresh painless rectal bleeding but is of limited use in the diagnosis of Meckel's diverticulum in other forms of presentations. False-positive scans can be anticipated in the presence of weak or ectopic uptake. False-negative scans can occur even in the presence of bleeding and in spite of the presence of gastric mucosa in the Meckel's diverticulum. Laparoscopy is a useful tool in diagnosis and treatment.

Multicenter External Validation of a Nomogram for Predicting Positive Prostate-specific Membrane Antigen/Positron Emission Tomography Scan in Patients with Prostate Cancer Recurrence

BackgroundA nomogram has recently been developed to predict 68Ga-labeled prostate-specific membrane antigen (PSMA)-11 positron emission tomography (PET)/computed tomography (PSMA-PET) results in recurrent prostate cancer (PCa) patients. ObjectiveTo perform external validation of the original nomogram in a multicentric setting. Design, setting, and participantsA total of 1639 patients who underwent PSMA-PET for prostate-specific antigen (PSA) relapse after radical therapy were retrospectively included from six high-volume PET centers. The external cohort was stratified according to clinical setting categories: group 1: first-time biochemical recurrence (n = 774); group 2: PSA relapse after salvage therapy (n = 499); group-3: biochemical persistence after radical prostatectomy (n = 210); and group-4: advanced-stage PCa before second-line systemic therapies (n = 124). InterventionPSMA-PET in recurrent PCa. Outcome measurements and statistical analysisPSMA-PET detection rate was assessed in the overall population and in each subgroup. A multivariable logistic regression model was produced to evaluate the predictors of a positive scan. The performance characteristics of the model were assessed by quantifying the predictive accuracy (PA) according to model calibration. The Youden’s index was used to find the best nomogram’s cutoff. Decision curve analysis (DCA) was implemented to quantify the nomogram’s clinical net benefit. Results and limitationsIn the external cohort, the overall detection rate was 53.8% versus 51.2% in the original population. At multivariate analysis, International Society of Urological Pathology grade group, PSA, PSA doubling time, and clinical setting were independent predictors of a positive scan (all p ≤ 0.02). The PA of the nomogram was identical to the original model (82.0%); the model showed an optimal calibration curve. The best nomogram’s cutoff was 55%. In the DCA, the nomogram revealed clinical net benefit when the threshold nomogram probabilities were ≥20%. The retrospective design is a major limitation. ConclusionsThe original nomogram exhibited excellent characteristics on external validation. The incidence of a false negative scan can be reduced if PSMA-PET is performed when the predicted probability is ≥20%. Patient summaryA nomogram has been developed to predict prostate-specific membrane antigen/positron emission tomography (PSMA-PET) results for recurrent prostate cancer (PCa). The nomogram represents an easy tool in the decision-making process of recurrent PCa.

EFAST exam errors at a level 1 trauma center: A retrospective cohort study.

Extended Focused Assessment with Sonography for Trauma (eFAST) ultrasound exams are central to the care of the unstable trauma patient. We examined six years of eFAST quality assurance data to identify the most common reasons for false positive and false negative eFAST exams. This was an observational, retrospective cohort study of trauma activation patients evaluated in an urban, academic Level 1 trauma center. All eFAST exams that were identified as false positive or false negative exams compared with computed tomography (CT) imaging were included. 4860 eFAST exams were performed on trauma patients. 1450 (29.8%) were undocumented, technically limited, or incomplete (missing images). Of the 3410 remaining exams, 180 (5.27%) were true positive and 3128 (91.7%) were true negative. 27 (0.79%) exams were identified as false positive and 75 (2.19%) were identified as false negative. Of the false positive scans, 7 had no CT scan and 8 had correct real-time trauma paper documentation of eFAST exam results when compared to CT and were excluded, leaving 12 false positive scans. Of the false negative scans, 11 were excluded for concordant documentation in real-time trauma room paper documentation, 20 were excluded for no CT scan, and 2 were excluded as incomplete, leaving 42 false negative scans. Pelvic fluid, double-line sign, pericardial fat pad, and the thoracic portion of the eFAST exam were the most common source of errors. The eFAST exams in trauma activation patients are highly accurate. Unfortunately poor documentation and technically limited/incomplete studies represent 29.8% of our eFAST exams. Pelvic fluid, double-line sign, pericardial fat pad, and the thoracic portion of the eFAST exam are the most common source of errors.

Characterization of Atypical Pheochromocytomas with Correlative MRI and Planar/Hybrid Radionuclide Imaging: A Preliminary Study

Pheochromocytomas may show atypical imaging findings leading to diagnostic pitfalls. We correlated the results of magnetic resonance imaging (MRI) with those of radionuclide studies in patients with pheochromocytomas. T2-weighted (-w), T1-w chemical-shift and T1-w dynamic contrast enhanced (DCE) MRI sequences were evaluated to assess tumor structure. 131Iodine metaiodobenzylguanidine (MIBG) scintigraphy, 18fluoro (F) deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) or FDG PET/MRI were evaluated for direct comparison. Of a total of 80 adrenal lesions in 73 patients, 20 in 18 patients were pheochromocytomas. More than half (55%) of the pheochromocytomas (n = 11) had the typical increased signal intensity on T2-w and T1-w DCE, while the remaining (n = 9) lesions showed atypical findings; of these nine latter atypical lesions, seven (35%) were cystic (two totally, three predominantly and two partially) and two (10%) were hemorrhagic on MRI. In these atypical lesions, MIBG scintigraphy (n = 5), FDG PET/CT (n = 6) or FDG PET/MRI (n = 2) showed inhomogeneous tracer uptake in the residual viable tissue providing tumor characterization; however, one predominantly cystic pheochromocytoma showed false negative MIBG scan. Our preliminary results show that cystic degeneration may be frequent in pheochromocytoma being so marked that only a thin rim of viable cells may residue to disclose the true nature of the tumor. MRI findings together with those of correlative planar/hybrid radionuclide images are helpful to characterize these atypical pheochromocytomas. In particular, tumor accumulation of MIBG and/or FDG is able to classify these lesions as not simple cysts; in detail, the presence of partial MIBG uptake allows the diagnosis of pheochromocytomas, while the presence of partial FDG uptake generically reflects the presence of viable solid tissue of such cystic tumors.

MISSED DIAGNOSIS OF ACUTE TYPE A AORTIC DISSECTION TREATED AS NON-ST ELEVATION MYOCARDIAL INFARCTION: A TEACHABLE MOMENT

TOPIC: Cardiovascular Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Acute type A aortic dissection (ATAAD) is a life threatening emergency, with a mortality rate of 1% to 2% per hour during the first 24 to 48 hours, reaching 75% at 2 weeks and 91% at 1 year, if left untreated. CASE PRESENTATION: A 35-year-old male, nonsmoker with a history of untreated hypertension (HTN), presented with sudden onset, severe, non-radiating, "twisting" mid-sternal chest pain. Initial vital signs showed an elevated blood pressure (BP) to 210/132 mmHg in both arms, heart rate 85 beats/minute, afebrile and arterial saturation of 100% on room air. He was in severe distress due to chest pain and sweating profusely. The cardiac examination did not reveal a murmur, rub or gallop, his radial pulse was regular, and equal bilaterally. Electrocardiogram (EKG) showed sinus rhythm with T-wave inversions in inferior and lateral leads. Initial work up was significant for an elevated creatine kinase (CK) 636 U/L (normal range < 200 U/L). Chest X-ray did not reveal cardiomegaly, mediastinal widening or infiltrates. CT aortic dissection including iliac arteries - chest, abdomen and pelvis with and without contrast was read as negative for dissection, aneurysm, pulmonary embolism or pericardial effusion. Subsequent labs were significant for up trending CK of 751 U/L (normal range < 200 U/L) and Troponin 0.42 ng/ml (normal range < 0.10 ng/ml). In view of rising cardiac biomarkers, dual anti-platelets and anticoagulants for acute coronary syndrome (ACS) were started. A transthoracic echocardiogram (TTE) was ordered which was performed 12 hours later and showed dissection flap in proximal ascending aorta, moderate eccentric aortic regurgitation, and bicuspid aortic valve. DISCUSSION: Some reports of CT scanning in acute dissection have reported sensitivities close to 100%, but false negative scans are well recognized. True sensitivity is likely lower at 94% to 100% and specificity around 77% to 100%. False negative results can be secondary to a reader's error or a true false negative image. Second imaging tests are frequently obtained in cases of suspected aortic dissection, with transthoracic or transesophageal echocardiography being the most commonly used modality. Point of Care Ultrasound (POCUS) has become commonplace in many critical care settings, studies have shown good sensitivity and specificity for the diagnosis of ATAAD [5]. This may allow the treating clinician to diagnose an acute aortic dissection at the point of care, avoiding the clinical and time dissociation inherent to consultative echocardiography. Intimal flap visualization has a sensitivity of 67-80% and a specificity of 99 - 100%. CONCLUSIONS: Our case is a reminder that the sensitivity of CTA to rule out acute aortic syndrome is not 100% and second diagnostic modality should be used if clinical suspicion is high. The pre-test probability of a diagnosis should dictate the type of imaging/testing warranted and its urgency. REFERENCE #1: Afifi RO, Sandhu HK, Leake SS, et al.: Determinants of Operative Mortality in Patients With Ruptured Acute Type A Aortic Dissection. Ann Thorac Surg. 2016, 101:64-71. 10.1016/j.athoracsur.2015.07.007 REFERENCE #2: Abbas A, Brown IW, Peebles CR, Harden SP, Shambrook JS: The role of multidetector-row CT in the diagnosis, classification and management of acute aortic syndrome. Br J Radiol. 2014, 87:20140354. 10.1259/bjr.20140354 REFERENCE #3: Wang Y, Yu H, Cao Y, Wan Z: Early Screening for Aortic Dissection With Point-of-Care Ultrasound by Emergency Physicians: A Prospective Pilot Study. J Ultrasound Med. 2020, 39:1309-15. 10.1002/jum.15223 DISCLOSURES: No relevant relationships by SYED ABBAS, source=Web Response No relevant relationships by Syeda Hamadani, source=Web Response No relevant relationships by Seth Koenig, source=Web Response, value=Honoraria Removed 05/16/2021 by Seth Koenig, source=Web Response No relevant relationships by Seth Koenig, source=Web Response, value=Honoraria Removed 05/16/2021 by Seth Koenig, source=Web Response No relevant relationships by Abeer Zeeshan, source=Web Response

Frequency and Causes of False Negative Diffusion-Weighted Imaging in Acute Ischemic Stroke

Objective: The high sensitivity of diffusion-weighted magnetic resonance imaging (DWI MRI) has led to its frequent use in the diagnosis of acute ischemic stroke (AIS). However, false negative DWI MRI results have been obtained for some patients diagnosed with stroke, which led us to initiate this study. Our aim was to determine the prevalence of false negative DWI MRI scans and prevent the clinician from making a late diagnosis or misdiagnosis by relying on MRI results only.Methods: In a retrospective file screening conducted between February 2017- February 2019, after the patients hospitalized with a diagnosis of ischemic stroke who couldn't have an MRI or who were diagnosed with transient ischemic attack were excluded, the frequency of patients with a normal initial cranial DW MRI scan whose follow up scans revealed acute diffusion restriction was identified, and vascular anatomical localization of stroke was classified according to OCSP (Oxfordshire Community Stroke Project).Results: Of 235 patients admitted to our clinic with a diagnosis of ischemic stroke, 21 couldn't have a DWI MRI, and of 214 stroke patients who had a DWI MRI, 23 were admitted with a transient ischemic stroke attack. Of the remaining 191 patients, 14 had initially negative DWI MRI images but their clinical findings lasted longer than 24 hrs so they had a follow up MRI, which revealed an ischemic lesion in brain diffusion. In our clinic, the percentage of false negative diffusion MR images was 7.3% (14/191). The distribution of ischemia in the aforementioned 14 patients was as follows: 6 patients with posterior circulation ischemia (POCI), including 4 in brain stem and 2 in cerebellum, 2 patients with lacunar stroke (LACI), 5 patients with partial anterior circulation ischemia (PACI) and 1 patient with total anterior circulation ischemia (TACI).When the time of symptom onset was questioned, data could be derived from only 8 patients' files, and DWI MR images were obtained within the first 6 hours according to the onset of the symptoms.Conclusion: In acute stroke patients, if symptoms of the patient are consistent with stroke during physical examination, the diagnosis of stroke should not be automatically ruled out even if brain DWI MRI is negative. The decision of urgent thrombolytic or endovascular intervention that can be taken for eligible patients should not be overlooked based on false negative DWI MRI findings. With this study, we aim to help clinicians avoid misdiagnosis or delays in diagnosis.

Complete pathological response (pCR) in gastroesophageal cancer: Correlation with metabolic response

PurposeNeoadjuvant chemoradiotherapy (nCRT) followed by surgery in patients with resectable esophageal or esophagogastric junctional (GEJ) (Siewert I) cancer is associated with long term overall survival benefits. Up to one third of all patients submitted to nCRT present pathological complete response (pCR). 18F-fluorodeoxyglucose positron emission tomography with CT (18F-FDG PET-CT) is an important tool for assessing treatment response. Purpose was to assess retrospectively the power of 18F-FDG PET-CT in predicting pCR to evaluate the feasibility of a “watch and wait” approach. Patients and methodsRetrospective analysis of a prospective database with esophageal or GEJ submitted to pre-operative chemoradiation. Pre and pos treatment 18F-FDG PET-CT were reviewed and classified using visual assessment and PERCIST criteria and the values of maximum standard uptake value were also recorded. Patients were classified as pCR or non-PCR. 18F-FDG PET-CT and pathological findings were compared against each other. ResultsForty-three patients were included. The median age was 67 years and 90.7% were male. All patients underwent preoperative CRT and were evaluated with 18F-FDG PET-CT pre and post treatment. Transthoracic surgery was performed in all patients. Histological type was adenocarcinoma in 37% and squamous cell carcinoma in 58%. pCR was achieved in 56% of cases. Visual assessment of 18F-FDG PET-CT showed overall sensitivity 57.9%, specificity 62.5% and PERCIST criteria had 100% sensibility and 16.7% specificity. Conclusions18F-FDG PET-CT is not an ideal predictor of pCR but if we use the PERCIST criteria we will have a high sensitivity and negative predictive value, avoiding false negative scans.

Dual-tracer radionuclide imaging in hyperparathyroidism: thallium-201 parathyroid scintigraphy revisited.

Tc-sestamibi is the current radiopharmaceutical of choice for the localization of hyperactive lesions of the parathyroid glands in patients with hyperparathyroidism. However, there are multiple factors that adversely affect the accumulation and retention Tc-sestamibi in the hyperfunctioning parathyroid tissue, resulting in a false-negative scan. The objective of this study was to investigate the possibility of an incremental diagnostic role of thallium-201 parathyroid scintigraphy in patients with presumably false-negative Tc-sestamibi scan results. The study comprised of 22 patients including 16 with primary hyperparathyroidism (PHPT) and 6 with secondary hyperparathyroidism where Tc-sestambi scan was initially negative, inconclusive or where additional lesions were suspected on the single-photon computed tomography/computed tomography (SPECT/CT) scan with the CT component identifying lesion(s) without significant Tc-sestamibi uptake. The results of our study show that in 22 patients (5 male, 17 female; age range 26-81; median age 53.4) further imaging with thallium-201 SPECT/CT scan showed 46.5% additional lesions in patients with hyperparathyroidism caused by an adenomatous or hyperplastic parathyroid lesion. In patients with PHPT caused by an adenomatous or hyperplastic parathyroid lesion, further imaging with thallium-201 showed 59% additional hyperactive parathyroid lesions. In patients with secondary hyperparathyroidism, further imaging with thallium-201 SPECT/CT showed additional 33.3% hyperplastic parathyroid lesions. The results of this pilot study strongly advocate a role for thallium parathyroid SPECT/CT imaging in patients with primary and secondary hyperparathyroidism where the initial Tc-sestamibi scan is deemed to be false-negative in the presence of biochemical hyperparathyroidism.

68Ga-PSMA-11 PET/CT in recurrent hormone-sensitive prostate cancer (HSPC): a prospective single-centre study in patients eligible for salvage therapy.

The primary objective is to assess the efficacy of 68Ga-PSMA-11-PET/CT to detect recurrent location(s) in hormone-sensitive prostate cancer (PCa). Secondary objectives are (1) to evaluate changes in clinical management; (2) to determine which covariates independently predict positive scan; (3) to assess 68Ga-PSMA-11-PET/CT performance in different settings of PSA relapse. Inclusion criteria include (1) histologically diagnosed PCa; (2) previous radical therapy; (3) proven biochemical recurrence (BCR) or biochemical persistence (BCP); (4) hormone-sensitive PCa (HSPC); (5) androgen deprivation therapy (ADT)-free for at least 6months; (6) PSA < 1.5ng/mL or any PSA in case of negative choline-PET/CT (n= 38). Changes in clinical management were defined by multidisciplinary tumour-board. Clinical settings were BCP (group-1, n= 25); first-time BCR (group-2, n= 121); BCR after salvage therapy (group-3, n= 77). Two hundred twenty-three (223) consecutive patients were enrolled: median PSA = 0.65ng/mL (0.2-8.9) and median PSAdt = 9.3months (0.4-144.6). 96.9% received RP as primary therapy. 68Ga-PSMA-11-PET/CT positivity rate was 39.9% (CI95% 33.5-46.7%). Disease confined to pelvis was detected in 23.3% of cases. At least one distant lesion was observed in 16.6% of cases. Secondary objectives are as follows: (1) changes in clinical management were observed in 34.5% of patients; (2) PSA, PSAdt and T stage > 3a were independent predictors (all p< 0.03); (3) 68Ga-PSMA-11-PET/CT positivity rate was 56% (in group 1, 36.3% in group 2, 40.3% in group 3. This study attested the overall good performance of 68Ga-PSMA-11-PET/CT to detect PCa locations in HSPC patients eligible for salvage therapy, influencing the therapy management in 35.4% of cases. Furthermore, patient characteristics are influencing factors of 68Ga-PSMA-11-PET/CT positivity rate and should be considered to reduce false negative scan.

Direct access CT for suspicion of brain tumour: an analysis of referral pathways in a population-based patient group

BackgroundBrain tumour patients see their primary care doctor on average three or more times before diagnosis, so there may be an opportunity to identify ‘at risk’ patients earlier. Suspecting a brain tumour diagnosis is difficult because brain tumour-related symptoms are typically non-specific.MethodsWe explored the predictive value of referral guidelines (Kernick and NICE 2005) for brain imaging where a tumour is suspected, in a population-based patient group referred for direct access CT of the head. A consensus panel reviewed whether non-tumour findings were clinically important or whether further investigation was necessary.ResultsOver a 5-year period, 3257 head scans were performed; 318 scans were excluded according to pre-specified criteria. 53 patients (1.8%) were reported to have intracranial tumours, of which 42 were significant (diagnostic yield of 1.43%). There were no false negative CT scans for tumour. With symptom-based referral guidelines primary care doctors can identify patients with a 3% positive predictive value (PPV). 559 patients had non-tumour findings, 31% of which were deemed clinically significant. In 34% of these 559 patients, referral for further imaging and/or specialist assessment from primary care was still thought warranted.ConclusionExisting referral guidelines are insufficient to stratify patients adequately based on their symptoms, according to the likelihood that a tumour will be found on brain imaging. Identification of non-tumour findings may be significant for patients and earlier specialist input into interpretation of these images may be beneficial. Improving guidelines to better identify patients at risk of a brain tumour should be a priority, to improve speed of diagnosis, and reduce unnecessary imaging and costs. Future guidelines may incorporate groups of symptoms, clinical signs and tests to improve the predictive value.

Computed tomography in suspected anastomotic leakage after colorectal surgery: evaluating mortality rates after false-negative imaging.

We sought to investigate the accuracy of abdominal CT scanning for anastomotic leakage and the effect of false-negative scans on the delay in therapeutic intervention and clinical outcome. Data from a prospectively bi-institutionally maintained database of all patients who underwent elective colorectal surgery with primary anastomosis for malignant or benign disease between 2010 and 2017 were reviewed. Patients with confirmed anastomotic dehiscence at reintervention who underwent a postoperative CT scan for suspected leakage were identified and radiological reports were retrieved. Seventy-six patients with anastomotic dehiscence were included in the study. American Society of Anesthesiologists score, sex, type of surgical procedure, malignancy, and type of anastomosis do not correlate with postoperative false-negative CT imaging. Postoperative false-negative CT scan, however, led to delayed reintervention (3 vs. 6h, p = 0.023) and increased mortality (five deaths vs. no deaths, p = 0.043). Free abdominal air (p = 0.001) and extraluminal contrast extravasation (p = 0.001) were found to be predictive of accuracy in anastomotic leakage diagnosis. The suboptimal specificity of a postoperative CT scan in suspected anastomotic leakage after colorectal surgery can delay reintervention and increase mortality.

Emergency Focused Assessment with Sonography in Blunt Trauma Abdomen.

Background:Focused assessment with sonography in trauma (FAST) being a rapid noninvasive examination is used primarily to evaluate for the evidence of traumatic free fluid suggestive of injury in the peritoneal, pericardial, and pleural cavities. It is widely recognized as a mainstream emergency skill in the management of trauma.Aim:The aim of the study is to evaluate the accuracy of FAST in patients presenting with blunt abdominal trauma.Methods:Data were collected prospectively from FAST scans conducted in blunt trauma abdomen (BTA) patients. Positive and negative FAST scans were confirmed either with contrast-enhanced computed tomography (CECT) abdomen or with exploratory laparotomy, thus dividing it further into four groups, i.e., true-positive, false-positive, true-negative, and false-negative scans. After collecting the data, accuracy of FAST was calculated.Results:In this study, a total of 104 patients were included. The mean age was 38.17 years. Most common cause of BTA was road traffic accident. The overall sensitivity, specificity, and accuracy of FAST were 69.8%, 92.1%, and 80.8%, respectively.Conclusion:This study showed that FAST is of paramount importance in patients who are hemodynamically unstable as it has a high positive predictive value. However, a FAST-negative result should always be confirmed by other modalities.

Clinical value of 18F-FDG-PET/CT in suspected serious disease with special emphasis on occult cancer.

Suspected serious disease (SSD) is a disease designation often given to patients with one or more non-specific symptoms of severe disease that could be due to cancer; the optimal diagnostic strategy is largely left to the clinician's discretion. Being a sensitive non-invasive whole-body imaging modality 18F-FDG-PET/CT may have a potential role in this cancer-prevalent group of patients to confirm or refute suspected malignancy. We aimed to investigate the diagnostic value of 18F-FDG-PET/CT in SSD using long-term follow-up as reference. We retrospectively studied results obtained in all SSD patients referred for 18F-FDG-PET/CT at a single institution in 2010-2011 retrieving the following clinical data in all patients: journal entries, examinations, and evaluations made from 6 months before the scan and until the latest recorded entry. A true positive PET scan was a positive scan with a subsequently biopsy-confirmed diagnosis of cancer in the same target organ, whereas a false positive scan had no subsequent cancer diagnosis. A true negative PET scan was a negative scan without a cancer diagnosis during follow-up, whereas a false negative PET scan was one with a subsequently confirmed cancer diagnosis. Ninety-three patients, aged 67years (range 25-89) were included and followed for up to 7.3years (median 6). Of these, 21 [22.6% (95% CI 15.3-32.1)] turned out to have cancer. With 18F-FDG-PET/CT, the sensitivity was 81.0% (95% CI 60.0-92.3), specificity 76.4% (95% CI 65.4-84.7), positive predictive value 50% (95% CI 34.1-65.9), and negative predictive value 93.2% (95% CI 83.8-97.3). Five patients with negative scans were subsequently diagnosed with cancer. Cancer prevalence is substantial among patients with SSD. 18F-FDG-PET/CT is a promising option in this setting, in particular because a high negative predictive value equals a low incidence of cancer during follow-up. Further studies are needed to establish the role of 18F-FDG-PET/CT in SSD.