Non-diagnostic CT Research Articles

Valuation of advanced Dosimetry in Transarterial Radioembolization of Hepatocellular Carcinoma with 90Y microspheres

Objective : The aim of our study was to analyze the relationships between tumor (T) and normal tissue (N) absorbed dose in relation to the clinical outcomes in hepatocellular carcinoma (HCC) patients treated with 90Y microspheres. Materials and methods : After transarterial radioembolization of HCC with 90Y microspheres, 62 patients (10 females: 52 males, mean age 68.2±8.2 years) were imaged using a four-ring, time-of-flight (TOF), PET/CT system. Low dose, non-diagnostic CT images from PET/CT were utilized for localization of the 90Y microspheres and attenuation correction of PET images. Response assessment was conducted using mRECIST criteria on MRI one month post treatment and subsequently every three months after 90Y treatment. Results : Among 62 patients, mean liver, tumor, and normal tissue doses (mean ± SD) were 51.38±23.32 Gy, 682.60±785.19 Gy and 45.54±21.19 Gy, respectively. Out of these patients, 39 exhibited complete response (CR), 11 showed partial response (PR), 2 had stable disease (SD), and 10 showed progression of the disease (PD). For CR+PR patients the mean T was 824.63±833.10 Gy, whereas for PD patients, the mean T was significantly lower at 205.70±183.22 Gy. The mean liver and normal tissue doses were comparable; for CR+PR patients had liver and normal tissue doses of 51.01±22.55 Gy and 45.18±20.68 Gy, respectively, and for PD patients, these values were 54.34±26.73 Gy and 49.10±22.97 Gy, respectively. Conclusion : Despite not considering the partial volume effect and having a limited number of PD cases, our data indicates a statistically significant lower (P = 0.0001) tumor dose in patients with disease progression compared to those with complete and partial response. These results suggest that post-therapy personalized, and image-based dosimetry provides promising predictive outcomes in 90Y microsphere radiation therapy for liver cancers.

Üreterde Cut-off İşareti

Obstructive uropathy occurs due to common causes such as kidney stones, vesicoureteral reflux, posterior urethral valve and urothelial tumors. In addition, there are rare causes such as solid tumors, retroperitoneal fibrosis, primary lymphomas (Non-Hodgkin lymphomas etc.). A 20-year old male with lower back pain underwent a bone scan for differential diagnosis of back pain. The bone scan findings were normal, except for the presence of unilateral renal stasis accompanied by a short segment ureteral stasis. Due to the abrupt termination of the ureteral activity, namely the “cutoff sign”, a subsequent SPECT/CT imaging was focused for differential diagnosis of ureteral stasis. Non-diagnostic CT sections revealed a para-aortic soft tissue mass compressing the ureter. This case underlines the added value of SPECT/CT imaging in subtle scintigraphic findings. The abrupt termination of stasis in the ureter may warrant the application of SPECT/CT in cases with no previous history of urinary tract pathology. SPECT / CT may provide additional benefits of clarifying the etiology.

Falsely Reassuring Head CT Delays Diagnosis in Childhood Arterial Ischemic Stroke (P14-9.001)

<h3>Objective:</h3> To describe the impact of non-diagnostic head CT in the evaluation of acute childhood stroke. <h3>Background:</h3> Diagnosis of childhood arterial ischemic stroke is often delayed. Head MRI is recommended to evaluate the stable child with acute neurologic deficit due to the high frequency of stroke mimics. However, head CT is often pursued first as it is easily available and routinely used in adult stroke codes. <h3>Design/Methods:</h3> We performed a retrospective single institution study of children age 1 month to 18 years seen between 2009 and 2021 who were diagnosed with stroke within 72 hours of symptom onset. Patients were identified using diagnostic codes for AIS were reviewed to confirm diagnosis and chart review was used to extract data about clinical presentation and neuroimaging. <h3>Results:</h3> 110 children (mean 9.9 years, 52% male) were diagnosed at a mean of 19.7 (median 14.3) hours. Mean time to diagnosis was 19.7 (median 13.6) hours in 34 patients diagnosed on initial head CT, 19.9 hours (med 15.3) in 50 patients with an initial non-diagnostic head CT followed by diagnostic head MRI, and 19.2 hours (median 13.5) in 26 patients patients diagnosed on head MRI alone. In the 24 patients with a diagnostic CT followed by confirmatory MRI, mean time from CT to MRI was 18.5 (median 12.3) hours. In the 50 patients with non-diagnostic CT followed by diagnostic MRI, the mean time from non-diagnostic CT to diagnostic MRI was 11.9 hours (median 8.1) hours. This difference in medians of 4.2 hours (95%CI: −3.4, 12.2), while not statistically significant, suggests clinically significant ordering patterns with room for improvement. <h3>Conclusions:</h3> Time to MRI following CT was not significantly different between children with and without diagnostic CT, suggesting that that in patients being evaluated for a suspected acute neurologic process, a negative head CT may be falsely reassuring and delay to diagnosis. <b>Disclosure:</b> Dr. Chiang has nothing to disclose. Dr. Barry has nothing to disclose. Dr. Amlie-Lefond has nothing to disclose.

Usefulness of Coronary Artery Calcium Score to Rule Out Obstructive Coronary Artery Disease Before Transcatheter Aortic Valve Implantation

Pretranscatheter aortic valve implantation (pre-TAVI) coronary evaluation using computed tomography coronary angiography (CTA) remains suboptimal. We aimed to evaluate whether coronary artery calcium score (CAC) may rule out obstructive coronary artery disease (CAD) pre-TAVI. TAVI candidates (n=230; mean age 80 ± 8 years), 49% men, underwent preprocedural CTA and invasive coronary angiography. Obstructive CAD was defined as luminal diameter stenosis of ≥50% of left main or 3 major vessels ≥70%. Vessels with coronary stents or bypass were excluded. CAC score was calculated using the Agatston method. Receiver operating characteristic was applied to establish the CAC threshold for obstructive CAD. Multivariable analysis with adjustment for clinical covariates was applied. Net reclassification for nonobstructive disease using CAC score was calculated among nondiagnostic CT scans. Median CAC score was 1,176 (interquartile range 613 to 1,967). Receiver operating characteristic analysis showed high negative predictive value (NPV) for obstructive CAD as follows: left main CAC score 252, NPV 99%; left anterior descending CAC score 250, NPV 97%; left circumflex CAC score 297, NPV 92%; and right coronary artery CAC score 250, NPV 91%. Multivariate analysis showed the highest tertile of CAC score (≥1,670) to be an independent predictor of obstructive CAD (odds ratio 10.7, 95% confidence interval 4.6 to 25, p <0.001). Among nondiagnostic CTA, net reclassification showed reclassification of 76%, 13%, 45%, and 34% of left main, left anterior descending, left circumflex, and right coronary artery for nonobstructive CAD, respectively. In conclusion, CAC score cutoffs can be used to predict nonobstructive CAD. Implementing CAC score on pre-TAVI imaging can reduce a significant proportion of invasive coronary angiography.

Bronchoscopic Journey of in vivo Real-Time Microscopic Imaging in ILD: A Case Series

Background: Patients with interstitial lung diseases (ILDs) frequently present with nondiagnostic high-resolution CT (HRCT) scan and bronchoalveolar lavage (BAL) results, resulting in the need for invasive surgical or cryo-lung biopsy that is associated with significant morbidity. Confocal laser endomicroscopy (CLE) and optical coherence tomography (OCT) are high-resolution laser and light-based techniques that provide real-time imaging of the alveolar compartment during bronchoscopy with a different depth and field of view. Objectives: The aim of the study was to correlate OCT and CLE imaging to HRCT imaging in ILD. Methods: This is a retrospective case series of 20 ILD patients who underwent alveolar CLE and OCT imaging during a standard bronchoscopy with BAL, followed by a lung biopsy when indicated. CLE and OCT imaging were compared to four main HRCT patterns and histology. The final diagnosis was based on the multidisciplinary discussion diagnosis. Results: Bronchoscopic CLE and OCT imaging were feasible and safe and provided additional high-detailed anatomical information compared to the HRCT. Bronchoscopic real-time CLE was capable of identification of “alveolar cells” (ground glass opacities) and lung fibrosis (increased alveolar elastin fibers). Bronchoscopic real-time OCT allowed for visualization of “patchy fibrotic disease”, “honeycombing” (microcysts), and mucosal granulomas in the airways. Conclusions: Bronchoscopic CLE and OCT of the alveolar compartment is feasible and safe and enables minimally invasive, high-resolution detection of specific ILD features with the potential to improve ILD diagnostics and monitoring and decrease the need for surgical or cryo-lung biopsies.

Deep learning versus iterative image reconstruction algorithm for head CT in trauma

PurposeTo compare the image quality between a deep learning–based image reconstruction algorithm (DLIR) and an adaptive statistical iterative reconstruction algorithm (ASiR-V) in noncontrast trauma head CT.MethodsHead CT scans from 94 consecutive trauma patients were included. Images were reconstructed with ASiR-V 50% and the DLIR strengths: low (DLIR-L), medium (DLIR-M), and high (DLIR-H). The image quality was assessed quantitatively and qualitatively and compared between the different reconstruction algorithms. Inter-reader agreement was assessed by weighted kappa.ResultsDLIR-M and DLIR-H demonstrated lower image noise (p < 0.001 for all pairwise comparisons), higher SNR of up to 82.9% (p < 0.001), and higher CNR of up to 53.3% (p < 0.001) compared to ASiR-V. DLIR-H outperformed other DLIR strengths (p ranging from < 0.001 to 0.016). DLIR-M outperformed DLIR-L (p < 0.001) and ASiR-V (p < 0.001). The distribution of reader scores for DLIR-M and DLIR-H shifted towards higher scores compared to DLIR-L and ASiR-V. There was a tendency towards higher scores with increasing DLIR strengths. There were fewer non-diagnostic CT series for DLIR-M and DLIR-H compared to ASiR-V and DLIR-L. No images were graded as non-diagnostic for DLIR-H regarding intracranial hemorrhage. The inter-reader agreement was fair-good between the second most and the less experienced reader, poor-moderate between the most and the less experienced reader, and poor-fair between the most and the second most experienced reader.ConclusionThe image quality of trauma head CT series reconstructed with DLIR outperformed those reconstructed with ASiR-V. In particular, DLIR-M and DLIR-H demonstrated significantly improved image quality and fewer non-diagnostic images. The improvement in qualitative image quality was greater for the second most and the less experienced readers compared to the most experienced reader.

Tumour-to-normal tissue (T/N) dosimetry ratios role in assessment of 90Y selective internal radiation therapy (SIRT).

The purpose of our work is to assess the role of tumour-to-normal tissue (T/N) dosimetry ratios for predicting response in patients undergoing locoregional therapy to the liver with 90Y microspheres. A total of 39 patients (7 female:32 male, mean age 68.3 ± 7.6 years), underwent positron emission tomography (PET)/CT imaging after treatment with 90Y microspheres. For attenuation correction and localization of the 90Y microspheres, the low-dose, non-diagnostic CT images from PET/CT were used. The acquisition took 15 min and the reconstruction matrix size was 200 × 200 × 75 mm and voxel size of 4.07 × 4.07 × 3.00 mm. For dosimetry calculations, the local deposition method with known activity of 90Y was used. For each patient, regions of interest for tumour(s) and whole liver were manually created; the normal tissue region of interest was created automatically. mRECIST criteria on MRI done at 1 month post-treatment and subsequently every 3 months after 90Y treatment, were used to assess response. For 39 patients, the mean liver, tumour and normal tissue doses (mean ± SD) were, 55.17 ± 26.04 Gy, 911.87 ± 866.54 Gy and 47.79 ± 20.47 Gy, respectively. Among these patients, 31 (79%) showed complete response (CR) and 8 (21%) showed progression of disease (PD). For patients with CR, the mean T/N dose ratio obtained was 24.91 (range 3.09-80.12) and for patients with PD, the mean T/N dose ratio was significantly lower, at 6.69 (range 0.36-14.75). Our data show that patients with CR have a statistically higher T/N dose ratio than those with PD. Because, the number of PD cases was limited and partial volume effect was not considered, further investigation is warranted. T/N dosimetry ratios can be used for assessing response in patients undergoing locoregional therapy to the liver with 90Y microspheres.

Relationship of the pulmonary disease severity scoring with thromboembolic complications in COVID-19

PurposeTo correlate thromboembolic (TE) complications secondary to COVID-19 with the extent of the pulmonary parenchymal disease using CT severity scores and other comorbidities.MethodsIn total, 185 patients with COVID-19 and suspected thromboembolic complications were classified into two groups based on the presence or absence of thromboembolic complications. Thromboembolic complications were categorized based on location. Chest CT severity scoring system was used to assess the pulmonary parenchymal disease severity in all patients. Based into severity scores, patients were categorized into three groups (mild, moderate, and sever disease).ResultsThe final study cohort consisted of 171 patients (99 male and 72 female) after excluding 14 patients with non-diagnostic CT pulmonary angiography. The TE group included 53 patients with a mean age of 55.1 ± 7.1, while the non-TE group included 118 patients with a mean age of 52.9 ± 10.8. Patients with BMI > 30 kg/m2 or having a history of smoking and HTN were found more frequently in the TE group (p < 0.05). Patients admitted to ICU were significantly higher in the TE group (p < 0.001). There was statistically significant difference (p = 0.002) in chest CT-SS between the TE group (22.8 ± 11.4) and non-TE group (17.6 ± 10.7). The percentage of severe parenchymal disease in the TE group was significantly higher compared to the non-TE group (p < 0.05). Severe parenchymal disease, BMI > 30 kg/m2, smoking, and HTN had a higher and more significant odds ratio for developing TE complications.ConclusionThe present data suggest that severe pulmonary parenchymal disease secondary to COVID-19 is associated with a higher incidence of thromboembolic complications.

EUS and secretin endoscopic pancreatic function test predict evolution to overt structural changes of chronic pancreatitis in patients with nondiagnostic baseline imaging.

Background and Objectives:The accuracy of EUS and endoscopic pancreatic function test (ePFT) for diagnosis of early or minimal-change chronic pancreatitis (MCCP) is poorly understood. We hypothesized that the natural history of the disease may be used as a “gold standard” to assess the ability of EUS and ePFT to predict the eventual development of overt chronic pancreatitis (CP) changes on computed tomography/magnetic resonance cholangiopancreatography (CT/MRCP). The aim of the study was to determine the ability of EUS and ePFT to predict disease progression in patients with suspected MCCP who had nondiagnostic baseline imaging.Methods:A retrospective cohort study was conducted. Patients who underwent EUS and ePFT for suspected CP and who had nondiagnostic CT or MRCP were included. Patients without repeat imaging performed more than 1 year after their initial EUS/ePFT were excluded. Imaging was considered diagnostic if calcifications, main duct dilation (Cambridge Class III/IV), or severe atrophy were identified. Patients lost to follow-up were contacted to complete a survey documenting current symptoms and whether patients progressed to CP based on imaging. Univariable and multivariable analyses were performed using Cox regression.Results:Two hundred and thirty patients who underwent EUS/ePFT for suspected MCCP were identified between 2006 and 2012. Of these, 90 had a non-diagnostic baseline imaging test and subsequently a follow-up imaging test greater than 1 year later.These 90 patients constituted our study population. During a mean follow-up of 7 years, 19 (21%) patients developed CP by histology and imaging. Abnormal ePFT (peak bicarbonate <80 mmol) was a significant predictor of progression (hazard ratio [HR]: 4.7, confidence interval [CI]: 1.8, 12.4). Likewise, EUS Rosemont classification “suggestive/most-consistent” was a significant predictor of progression (HR: 7.3, CI: 2.4, 22.1).Conclusions:In patients with abdominal pain of suspected pancreatic origin and with nondiagnostic cross-sectional imaging, EUS and ePFT results predict the development of classic CP structural changes over time. These results support EUS and ePFT as effective tools for predicting progression of minimal change to overt CP.

EUS and secretin endoscopic pancreatic function test predict evolution to overt structural changes of chronic pancreatitis in patients with nondiagnostic baseline imaging

Background and Objectives: The accuracy of EUS and endoscopic pancreatic function test (ePFT) for diagnosis of early or minimal-change chronic pancreatitis (MCCP) is poorly understood. We hypothesized that the natural history of the disease may be used as a “gold standard” to assess the ability of EUS and ePFT to predict the eventual development of overt chronic pancreatitis (CP) changes on computed tomography/magnetic resonance cholangiopancreatography (CT/MRCP). The aim of the study was to determine the ability of EUS and ePFT to predict disease progression in patients with suspected MCCP who had nondiagnostic baseline imaging. Methods: A retrospective cohort study was conducted. Patients who underwent EUS and ePFT for suspected CP and who had nondiagnostic CT or MRCP were included. Patients without repeat imaging performed more than 1 year after their initial EUS/ePFT were excluded. Imaging was considered diagnostic if calcifications, main duct dilation (Cambridge Class III/IV), or severe atrophy were identified. Patients lost to follow-up were contacted to complete a survey documenting current symptoms and whether patients progressed to CP based on imaging. Univariable and multivariable analyses were performed using Cox regression. Results: Two hundred and thirty patients who underwent EUS/ePFT for suspected MCCP were identified between 2006 and 2012. Of these, 90 had a non-diagnostic baseline imaging test and subsequently a follow-up imaging test greater than 1 year later. These 90 patients constituted our study population. During a mean follow-up of 7 years, 19 (21%) patients developed CP by histology and imaging. Abnormal ePFT (peak bicarbonate <80 mmol) was a significant predictor of progression (hazard ratio [HR]: 4.7, confidence interval [CI]: 1.8, 12.4). Likewise, EUS Rosemont classification “suggestive/most-consistent” was a significant predictor of progression (HR: 7.3, CI: 2.4, 22.1). Conclusions: In patients with abdominal pain of suspected pancreatic origin and with nondiagnostic cross-sectional imaging, EUS and ePFT results predict the development of classic CP structural changes over time. These results support EUS and ePFT as effective tools for predicting progression of minimal change to overt CP.

Comparison of posttherapy 90Y positron emission tomography/computed tomography dosimetry methods in liver therapy with 90Y microspheres.

The aim of our study was to compare dosimetry methods for yttrium-90 (90Y) positron emission tomography/computed tomography (PET/CT). Twenty-five patients were taken to a PET/CT suite following therapy with 90Y microspheres. The low mA, nondiagnostic CT images were used for attenuation correction and localization of the 90Y microspheres. The acquisition time was 15 min, the reconstruction matrix size was 200 mm × 200 mm × 75 mm, and voxel size was 4.07 mm × 4.07 mm × 3.00 mm. Two software packages, MIM 6.8 and Planet Dose, were utilized to calculate 90Y dosimetry. Three methods were used for voxel-based dosimetry calculations: the local deposition method (LDM), LDM with scaling (LDMwS) for known injected activity, and a dose point kernel (DPK) method using the MIRD kernel. Only the DPK approach was applied to the Planet Dose software. LDM and LDMwS were only applied to the MIM software. The average total liver dosimetry values (mean ± standard deviation) were 60.93 ± 28.62 Gy, 53.59 ± 23.47 Gy, 55.33 ± 24.80 Gy, and 54.25 ± 23.70 Gy for LDMwS, LDM, DPK with MIM, and DPK with Planet Dose (DOSI), respectively. In most cases, the LDMwS method produced slightly higher dosimetry values than the other methods. The MIM and Planet Dose DPK dosimetry values (i.e., DPK vs. DOSI) were highly comparable. Bland–Altman analysis calculated a mean difference of 1.1 ± 2.2 Gy. The repeatability coefficient was 4.4 (7.9% of the mean). The MIM and Planet Dose DPK dosimetry values were practically interchangeable. 90Y dosimetry values obtained by all methods were similar, but LDMwS tended to produce slightly higher values.

Combined 18F-naf and fluciclovine administration for PET imaging of prostate cancer.

e17533 Background: 18F-fluciclovine is FDA approved for the detection of recurrent and metastatic prostate cancer. At our institution, 18F-fluciclovine PET had replaced 18F-NaF PET, but fluciclovine has mild to no uptake in dense sclerotic bony lesions. F18-NaF offers increased sensitivity and specificity in detection of osseous metastases and therefore we converted to using a combination of 18F-NaF and 18F-fluciclovine in patients with biochemical recurrence. In this study, we assessed the feasibility of performing a combined F18- fluciclovine and F18-NaF study, and evaluated the biodistribution of the combined radiotracers in patients with prostate cancer. Methods: We retrospectively reviewed 16 consecutive patients over a period of 3 months. 5 mCi of F18-NaF was injected, followed 45 minutes later by a 10 mCi injection of F18-fluciclovine. Patients were asked to hydrate after NaF injection and empty their bladder immediately prior to scanning. A non-diagnostic CT for attenuation correction and an emission PET scan were acquired on a time of flight Discovery 690 PET/CT (GE Healthcare) within 5 minutes of fluciclovine injection. We characterized the extent of soft tissue and osseous disease, as well as assessed the image quality, taking note for F18-NaF excretion in the bladder and the potential scatter artifact limiting evaluation of the prostate bed. Results: On average patients received 5.5 +/- 0.5 mCi of F18-NaF and 10.4 +/- 0.8 mCi of F18-fluciclovine. All 16 patients had diagnostic quality scans. None had limited evaluation of the prostate bed secondary to artifacts from bladder scatter. 10 patients (62.5%) had residual or recurrent prostate cancer within the prostate bed, of which 3 (18.8%) had distant nodal disease in the perirectal, pelvis, retroperitoneal, or periaortic lymph node regions. 7 patients (43.8%) demonstrated osseous metastatic lesions within the clavicle, sternum, iliac wing, vertebra, coccyx, or sacrum. Conclusions: Combined 18F-NaF and 18F-fluciclovine scans in patients with prostate cancer is a feasible method for detecting soft tissue recurrence and osseous disease. Bladder excretion from F18-NaF does not obscure the prostate bed nor degrades the diagnostic quality of the exam. The combined use of 18F-fluciclovine and F18-NaF in one PET/CT acquisition has the potential to increase the sensitivity for detecting prostate cancer and limit the time and radiation dose delivered compared to the conventional, separate acquisitions of the two radiotracers.

Cost-effectiveness for imaging stable ischemic disease.

Stable ischemic heart disease remains a major cause of morbidity and mortality. Although there are multiple imaging modalities to diagnose and/or assist in the clinical management, the most cost-effective approach remains unclear. We reviewed the relevant and recent evidence-based clinical studies and trials to suggest the most cost-effective approach to stable ischemic heart disease. The limitations of these studies are discussed. Incorporating the results of recent multicenter trials, we suggest that for appropriate patients with coronary artery disease with any degree of stenosis or presence of coronary calcium, optimal medical therapy may be most cost-effective. Invasive coronary angiography and/or coronary revascularization would be primarily for non-responders or >/=50% left main stenosis. Stress cardiac magnetic imaging would be performed for those patients with non-diagnostic coronary CT angiography from motion and non-responders from optimal medical therapy in non-diagnostic coronary CT angiography group from high coronary calcium. These paths seem to be safe and cost-effective but requires modeling for confirmation.

Quantitative Susceptibility Mapping and Vessel Wall Imaging as Screening Tools to Detect Microbleed in Sentinel Headache.

Background: MR-quantitative susceptibility mapping (QSM) can identify microbleeds (MBs) in intracranial aneurysm (IA) wall associated with sentinel headache (SH) preceding subarachnoid hemorrhage. However, its use is limited, due to associated skull base bonny and air artifact. MR-vessel wall imaging (VWI) is not limited by such artifact and therefore could be an alternative to QSM. The purpose of this study was to investigate the correlation between QSM and VWI in detecting MBs and to help develop a diagnostic strategy for SH. Methods: We performed a prospective study of subjects with one or more unruptured IAs in our hospital. All subjects underwent evaluation using 3T-MRI for MR angiography (MRA), QSM, and pre- and post-contrast VWI of the IAs. Presence/absence of MBs detected by QSM was correlated with aneurysm wall enhancement (AWE) on VWI. Results: A total of 40 subjects harboring 51 unruptured IAs were enrolled in the study. MBs evident on the QSM sequence was detected in 12 (23.5%) IAs of 11 subjects. All these subjects had a history of severe headache suggestive of SH. AWE was detected in 22 (43.1%) IAs. Using positive QSM as a surrogate for MBs, the sensitivity, specificity, positive predictive value, and negative predictive value of AWE on VWI for detecting MBs were 91.7%, 71.8%, 50%, and 96.6%, respectively. Conclusions: Positive QSM findings strongly suggested the presence of MBs with SH, whereas, the lack of AWE on VWI can rule it out with a probability of 96.6%. If proven in a larger cohort, combining QSM and VWI could be an adjunctive tool to help diagnose SH, especially in cases with negative or non-diagnostic CT and lumbar puncture.

27 - Is a bronchoscopy following a non-diagnostic CT useful for a patient presenting with hemoptysis under the two-week wait referral for lung cancer?

27 - Is a bronchoscopy following a non-diagnostic CT useful for a patient presenting with hemoptysis under the two-week wait referral for lung cancer?

Accuracy of unenhanced, non-sedated MRI in the diagnosis of acute appendicitis in children

BackgroundChildren with suspected appendicitis generally undergo an ultrasound (most commonly) or a CT scan (rarely) as the first imaging study. At our hospital, patients with non-diagnostic ultrasound or CT scan results undergo a non-contrast (unenhanced), non-sedated MRI. We aimed to determine the accuracy of this study for this purpose in a large cohort of children. MethodsA retrospective review of all unenhanced, non-sedated MRIs done for suspected appendicitis was performed from January 2014 to December 2018. MRI reports were correlated with pathology reports in cases that underwent appendectomy, and with clinical outcomes if no operation was done (clinical follow up: 30d). No patient was treated for appendicitis non-operatively. ResultsThree hundred fifty unenhanced, non-sedated MRIs were done and reviewed with median age: 12 (3 to 18) years. Sixty-five (18.6%) MRIs were positive for appendicitis, and 62 of those underwent appendectomy (3 excluded clinically). Pathology was positive in 59/62 cases. 256 (73.1%) MRIs were negative for appendicitis. Six cases underwent appendectomy (persistent symptoms). Pathology was positive in 2/6 cases. The overall diagnostic accuracy was: sensitivity 96.7% (95% CI: 88.6–99.6), specificity 97.7% (95% CI: 95.0–99.1), PPV: 90.8% (95% CI: 81.6–95.6; false positives 6/65), and NPV: 99.2% (95% CI: 97.0–99.8; false negatives 2/254). Twenty-nine (8.3%) MRIs were non-diagnostic. None of those 29 cases had appendicitis (4 negative pathology, 25 excluded clinically). ConclusionsThe unenhanced, non-sedated MRI is highly accurate for the diagnosis of appendicitis in children. It should be considered as an alternative to CT in the work-up of patients with suspected appendicitis to eliminate the risks associated with ionizing radiation. Level of EvidenceLevel IV.

Systematic assessment of procedural parameters, influence on downstream testing and 12-month outcomes of a CT-myocardial perfusion service

AimsThis study describes the real-world referral pattern of patients to a CT myocardial perfusion service, the technical issues associated with providing the service, the results of the studies, and the subsequent downstream utilization of other investigations, and patient outcomes. Methods and results115 consecutive patients underwent CTA, dynamic rest and dipyridamole-stress perfusion scanning. There were 29 (25%) and 14 (12%) patients who had reversible defects and fixed defects respectively, indicating abnormal flow reserve and previous infarction respectively. In the patients with fixed defects, delayed hyperenhancement was noted in all, indicative of prior infarction, scarring and non-viability. With the existing CTA Appropriateness Criteria, the categorization of “Appropriate,” “Of Uncertain Appropriateness”, and “Inappropriate” would have been applied to 25%, 25% and 50% of the present studies respectively. Up to 72% could have been referred for ischemia evaluation with other modalities of functional imaging after the non-diagnostic CT angiogram. Follow up was complete in 113 subjects (98%) over a period of 14 ± 8 months. In the 29 patients with abnormal flow reserve and CAD, 62% underwent invasive angiography and 94%, angioplasty within a 90-day period. In the patients who underwent angioplasty, all remained free of myocardial infarction or death and 88% remained free of myocardial infarction, death or readmission over a mean of 14 ± 8 months. ConclusionA CT-myocardial perfusion service provided measures of ischemia and infarct detection over that of CTA alone. The information was utilized clinically by doctors to support a strategy of referral to revascularization versus conservative medical management.

CTA Evaluation of Bioresorbable Scaffolds versus Metallic Coronary Stents – a Feasibility Study

Abstract Background: Computed tomography angiography (CTA) presents important limits in in-stent restenosis (ISR) evaluation in case of metallic coronary stents, due to the artifacts determined by stent struts, which alter in-stent plaque analysis. In case of bioresorbable scaffolds, stent strut resorption allows accurate evaluation of the vessel wall. Aim of the study: This study aims to compare the feasibility of CTA as a follow-up imaging method for ISR diagnosis following elective PTCA procedures, between bioresorbable scaffolds and metallic coronary stents. Material and methods: We conducted a prospective, observational study on 73 patients with elective PTCA procedures in their medical history, in whom 113 stents were assessed via CTA in order to diagnose ISR. Based on stent type, the patients were divided into two groups: Group 1 – patients with bioresorbable vascular scaffolds (BVS) (n = 30); and Group 2 – patients with bare metal stents (BMS) (n = 43). Plaque analysis was possible only in the BVS group with a post-processing research-dedicated software, Syngo.via Frontier, which identified plaque morphology and virtual histology composition. Results: After CTA evaluation, the BVS group presented a significantly higher incidence of severe coronary artery disease (CAD) (Group 1 – 73% vs. Group 2 – 30%, p &lt;0.0001). The proximal part of the right coronary artery (RCA) presented a significantly higher percentage of metallic stents (14% BMS vs. 2% BVS, p = 0.0029). The comparative analysis of CTA sensibility for the visual evaluation of ISR identified a significantly higher percentage of diagnostic CT evaluations in the BVS group (Group 1 – 94% vs. Group 2 – 76.19%, p = 0.0006). CTA evaluation provided the most accurate results for the 3.0 and 3.5 mm devices. Regarding CTA sensibility for ISR diagnosis, the BVS group presented the smallest incidence of non-diagnostic CT evaluations. Conclusions: CTA evaluation of bioresorbable scaffolds is superior to metallic stent assessment, the latter being influenced by numerous sources of error dependent mainly on the presence of the metal structure.

Changes in Patterns of 99mTc-Macroaggregated Albumin Use Between 2000 and 2015.

Since the early 2000s, the method of evaluating pulmonary embolism has shifted from 99mTc-macroaggregated albumin (MAA) perfusion lung scans to CT angiography. 99mTc-MAA continues to be applied for patients with contraindications to CT angiography and for other uses. A reduced number of 99mTc-MAA particles is administered to patients with pulmonary hypertension or other risk factors. This study assessed the changing patterns of 99mTc-MAA use between 2000 and 2015 at a single institution by comparing snapshots of the procedures performed in those two years. Methods: Records for all patients receiving 99mTc-MAA in 2000 and 2015 were reviewed, making note of the type of imaging procedure, whether there was any contraindication to CT angiography, and whether a reduced number of 99mTc-MAA particles was administered. Results: In 2000, 99mTc-MAA was used for 489 lung scans for pulmonary embolism, 2 for peritoneovenous shunts, and 1 for a cardiac shunt. Of the lung scan patients, 46 (9%) had pulmonary hypertension. A reduced number of particles was administered to the pulmonary hypertension and cardiac shunt patients (47/492, or 9%). In 2015, 99mTc-MAA was used for 263 lung scans for pulmonary embolism, 33 for presurgical planning, 33 for patients with a lung transplant, 16 for pulmonary artery stenosis, 5 to determine hepatic artery microsphere eligibility, and 1 for a peritoneovenous shunt. Of the lung scans for pulmonary embolism, 256 of the 263 patients (97%) had a contraindication to CT angiography or a nondiagnostic CT angiogram, including 99 (38%) with pulmonary hypertension. A reduced number of particles was administered to the pulmonary hypertension patients, presurgical patients, and lung-transplant patients (165/351, or 47%). Conclusion: Comparing 2015 with 2000, lung scans for pulmonary embolism decreased 46%, from 489 to 263, apparently because of a shift to CT angiography, whereas other uses rose from 3 to 88. Administration of a reduced number of particles rose significantly from 9% to 47% of 99mTc-MAA doses. Although the total number of 99mTc-MAA doses dropped 29%, from 492 to 351, 99mTc-MAA remains an important radiopharmaceutical for both pulmonary embolism and other uses.

The role of 18F-FDG PET-CT in the detection of unknown primary malignancy: a retrospective study.

This study aimed to retrospectively evaluate the role of 18F-FDG PET/CT imaging in the detection of unknown primary tumor sites in patients with a suspicious malignancy. We retrospectively examined the 18F-FDG PET/CT images of 50 unknown primary malignancy patients. The malignancy of the lesions with increased 18F-FDG uptake on PET images was defined by interpreting the nondiagnostic CT images that were obtained with the PET study. The primary tumor site was decided according to the combined PET/CT findings, and the results were subsequently confirmed with a histopathological examination. Fifty patients (29 M; 21 F) aged 18-85 years were included in the study. The sample included 32 malignant and 18 benign lesions according to the histopathological evaluation. 18F-FDG PET/CT study accurately identified malignant lesions in 28 (average SUVmax ± SD: 8.27 ± 7.22) and benign lesions in 12 (average SUVmax ± SD: 3.63 ± 3.07) patients; these findings were histopathologically confirmed. PET/CT correctly detected the primary tumor site in 16 (50%) of 32 patients. 18F-FDG-PET/CT identified the primary tumor site well in 50% of our cases. We propose that 18F-FDG PET/CT imaging may help to accurately detect malignant lesions in patients with unknown primary tumors.