Objectives
To evaluate image quality and reconstruction times of a commercial deep learning reconstruction algorithm (DLR) compared to hybrid-iterative reconstruction (Hybrid-IR) and model-based ...iterative reconstruction (MBIR) algorithms for cerebral non-contrast CT (NCCT).
Methods
Cerebral NCCT acquisitions of 50 consecutive patients were reconstructed using DLR, Hybrid-IR and MBIR with a clinical CT system. Image quality, in terms of six subjective characteristics (noise, sharpness, grey-white matter differentiation, artefacts, natural appearance and overall image quality), was scored by five observers. As objective metrics of image quality, the noise magnitude and signal-difference-to-noise ratio (SDNR) of the grey and white matter were calculated. Mean values for the image quality characteristics scored by the observers were estimated using a general linear model to account for multiple readers. The estimated means for the reconstruction methods were pairwise compared. Calculated measures were compared using paired
t
tests.
Results
For all image quality characteristics, DLR images were scored significantly higher than MBIR images. Compared to Hybrid-IR, perceived noise and grey-white matter differentiation were better with DLR, while no difference was detected for other image quality characteristics. Noise magnitude was lower for DLR compared to Hybrid-IR and MBIR (5.6, 6.4 and 6.2, respectively) and SDNR higher (2.4, 1.9 and 2.0, respectively). Reconstruction times were 27 s, 44 s and 176 s for Hybrid-IR, DLR and MBIR respectively.
Conclusions
With a slight increase in reconstruction time, DLR results in lower noise and improved tissue differentiation compared to Hybrid-IR. Image quality of MBIR is significantly lower compared to DLR with much longer reconstruction times.
Key Points
• Deep learning reconstruction of cerebral non-contrast CT results in lower noise and improved tissue differentiation compared to hybrid-iterative reconstruction.
• Deep learning reconstruction of cerebral non-contrast CT results in better image quality in all aspects evaluated compared to model-based iterative reconstruction.
• Deep learning reconstruction only needs a slight increase in reconstruction time compared to hybrid-iterative reconstruction, while model-based iterative reconstruction requires considerably longer processing time.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
Contrast-induced encephalopathy (CIE) is a rare encephalopathic condition after the administration of a contrast agent. The diagnosis of CIE is challenging because of the heterogeneity and ...non-specificity of the clinical presentation. The clinical course is usually favorable with full recovery within 48–72 h in most patients, although comorbidity is of relevance and contributes to the clinical outcome. It is expected that the incidence of CIE is currently increasing, due to an increase in endovascular and diagnostic imaging procedures using iodinated contrast. It is important to include CIE in the differential diagnosis when patients deteriorate during, or immediately after, contrast administration, even when only a small amount of non-ionic contrast agent is used. When CIE is considered to be the most likely explanation for the clinical symptoms, it is advised to refrain from unnecessary additional contrast studies such as angiography or perfusion CT.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
The objective of the current study is to integrate results from extensive neuropsychological assessment, subjective wellbeing reports and structural neuroimaging findings in successfully treated ...HIV-infected patients in comparison with a HIV-negative control group.
A cross-sectional study.
Neuropsychological functioning and self-reported wellbeing were assessed in a group of 102 virologically suppressed HIV-infected patients on combination antiretroviral therapy (cART) and 56 controls. Both groups underwent magnetic resonance (MR) examinations and grey matter, white matter and subcortical volumes were determined. Brain parenchymal fraction (BPF) was calculated as an estimated measure of global brain atrophy.
HIV-infected patients showed worse information processing speed (P = 0.01) and motor function (P = 0.03) than controls. Also, higher levels of anxiety and depressive symptoms, somatic and cognitive complaints, sleep problems and health distress were found, as well as lower levels of general health perceptions, social functioning and energy (P < 0.05). No differences in wellbeing reports were found between patients on regimens containing either efavirenz or nevirapine and patients on cART without these drugs (P > 0.05). Patients had a smaller BPF (P = 0.04) and thalamus (P = 0.05) than controls. A lower BPF was related to worse motor function and information processing speed in the patients. A smaller thalamus volume was related to lower motor function in the patient group and lower speed of information processing in the controls.
No profound deficits were found in the current study. The present results demonstrate that HIV has a minor impact on brain, cognition and wellbeing among HIV-infected patients who are otherwise healthy and maintained on a good control of cART.
Objectives
To develop a prediction model to predict vestibular schwannoma (VS) growth for patients in a wait and scan (W&S) strategy.
Design
Retrospective cohort study.
Setting
Tertiary hospital ...(Radboud university medical center, Nijmegen, the Netherlands).
Participants
Patients with unilateral VS, entering a W&S strategy and at least one follow‐up MRI available. Data on demographics, symptoms, audiometry and MRI characteristics at time of diagnosis were collected from medical records.
Main outcome measures
Following multiple imputation, a multivariable Cox regression model was used to select variables, using VS growth (≥2 mm) as outcome. Decision curve analyses (DCA) were performed to compare the model to the current strategy.
Results
Of 1217 analysed VS patients, 653 (53.7%) showed growth during follow‐up. Balance complaints (HR 1.57 (95% CI: 1.31‐1.88)) and tinnitus complaints in the affected ear (HR 1.36 (95% CI: 1.15‐1.61)), Koos grade (Koos 1 is reference, Koos 2 HR 1.03 (95% CI: 0.80‐1.31), Koos 3 HR 1.55 (95% CI: 1.16‐2.06), Koos 4 HR 2.18 (95% CI: 1.60‐2.96)), time since onset of symptoms (IQR HR 0.83 (95% CI: 0.77‐0.88) and intrameatal diameter on MRI (IQR HR 1.67 (95% CI: 1.42‐1.96)) were selected as significant predictors. The model's discrimination (Harrell's C) was 0.69 (95% CI: 0.67‐0.71), and calibration was good. DCA showed that the model has a higher net benefit than the current strategy for probabilities of VS growth of >12%, 15% and 21% for the first consecutive 3 years, respectively.
Conclusions
Patients with balance and tinnitus complaints, a higher Koos grade, short duration of symptoms and a larger intrameatal diameter at time of diagnosis have a higher probability of future VS growth. After external validation, this model may be used to inform patients about their prognosis, individualise the W&S strategy and improve (cost‐)effectiveness.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
To evaluate whether brain CT perfusion (CTP) aids in the detection of intracranial vessel occlusion on CT angiography (CTA) in acute ischemic stroke.
Medical-ethical committee approval of our ...hospital was obtained and informed consent was waived. Patients suspected of acute ischemic stroke who underwent non-contrast CT(NCCT), CTA and whole-brain CTP in our center in the year 2015 were included. Three observers with different levels of experience evaluated the imaging data of 110 patients for the presence or absence of intracranial arterial vessel occlusion with two strategies. In the first strategy, only NCCT and CTA were available. In the second strategy, CTP maps were provided in addition to NCCT and CTA. Receiver-operating-characteristic (ROC) analysis was used for the evaluation of diagnostic accuracy.
Overall, a brain perfusion deficit was scored present in 87–89% of the patients with an intracranial vessel occlusion, more frequently observed in the anterior than in the posterior circulation. Performance of intracranial vessel occlusion detection on CTA was significantly improved with the availability of CTP maps as compared to the first strategy (P=0.023), due to improved detection of distal and posterior circulation vessel occlusions (P-values of 0.032 and 0.003 respectively). No added value of CTP was found for intracranial proximal vessel occlusion detection, with already high accuracy based on NCCT and CTA alone.
The performance of intracranial vessel occlusion detection on CTA was improved with the availability of brain CT perfusion maps due to the improved detection of distal and posterior circulation vessel occlusions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
Current intraoperative methods of visual inspection and tissue palpation by the surgeon, and frozen section analysis cannot reliably prevent inadequate surgical margins in patients treated ...for oral squamous‐cell carcinoma (OSCC). This study assessed feasibility of MRI for the assessment of surgical resection margins in fresh OSCC specimens.
Methods
Ten consecutive tongue specimens containing OSCC were scanned using 3 T clinical whole‐body MRI. Two radiologists independently annotated OSCC location and minimal tumor‐free margins. Whole‐mount histology was the reference standard.
Results
The positive predictive values (PPV) and negative predictive values (NPV) for OSCC localization were 96% and 75%, and 87% and 79% for reader 1 and 2, respectively. The PPV and NPV for identification of margins <5 mm were 38% and 91%, and 5% and 87% for reader 1 and 2, respectively.
Conclusions
MRI accurately localized OSCC with high inter‐reader agreement in fresh OSCC specimens, but it seemed not yet feasible to accurately assess the surgical margin status.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Background
Timely and efficient diagnostic workup of patients with head and neck cancer (HNC) is challenging. This observational study describes the implementation of an optimized multidisciplinary ...oncological diagnostic workup for patients with HNC and its impact on diagnostic and treatment intervals, survival, costs, and patient satisfaction.
Methods
All patients with newly diagnosed HNC who underwent staging and treatment at the Radboud University Medical Center were included. Conventional workup (CW) in 2009 was compared with the fast‐track, multidisciplinary, integrated care program, that is, optimized workup (OW), as implemented in 2014.
Results
The study included 486 patients with HNC (218 with CW and 268 with OW). The time‐to‐treatment interval was significantly lower in the OW cohort than the CW cohort (21 vs 34 days; P < .0001). The 3‐year overall survival rate was 12% higher after OW (72% in the CW cohort vs 84% in the OW cohort; P = .002). After correction for confounders, the 3‐year risk of death remained significantly lower in the OW cohort (hazard ratio, 1.73; 95% confidence interval, 1.14‐2.63; P = .010). Total diagnostic costs were comparable in the 2 cohorts. The general satisfaction score, as measured with the Consumer Quality Index for Oncological Care, was significantly better in a matched OW group than the CW group (9.1 vs 8.5; P = .007).
Conclusions
After the implementation of a fast‐track, multidisciplinary, integrated care program, the time‐to‐treatment interval was significantly reduced. Overall survival and patient satisfaction increased significantly, whereas costs did not change. This demonstrates the impact and improved quality of care achieved by efficiently organizing the diagnostic phase of HNC management.
After the implementation of a fast‐track, multidisciplinary, integrated care program for patients with head and neck cancer, this study shows a significant reduction in the time‐to‐diagnosis and time‐to‐treatment intervals, a significant increase in 3‐year overall survival, and an increase in patient satisfaction without increased diagnostic costs. This demonstrates the impact and improved quality of care achieved by efficiently organizing the diagnostic phase of head and neck cancer management.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
To evaluate the value of computed tomographic (CT) myelography in the detection of root damage and differentiation of root avulsions from neurotmesis in a large cohort of patients with an obstetric ...brachial plexus lesion (OBPL).
Institutional review board approval was obtained. Informed consent was waived by the medical ethics committee. One hundred eighteen patients with OBPL born in the cephalic position and six patients born in the breech position were selected for surgery by two neurosurgeons in a multidisciplinary team. Functional loss of the C5 through T1 innervated muscles was noted. All patients underwent preoperative CT myelography at an average age of 19 weeks. CT myelographic examination results were reviewed by two radiologists, who were blinded to the clinical findings, for the presence of root avulsions and pseudocysts. Interobserver agreement was assessed by calculating κ values.
CT myelographic results showed root avulsions in at least one level in 66 (56%) of 118 patients born in the cephalic position and in six (100%) of six patients born in the breech position. Levels C7 and C8 showed the most root avulsions, even if not expected from clinical examination results. A large number of root avulsions showed pseudocysts (73 68% of 107 levels in patients born in the cephalic position and 11 73% of 15 levels in patients born in the breech position).
CT myelographic results showed root avulsions in more than half of patients with OBPL. Root avulsions were even detected at levels that were not expected at clinical examination. Because root avulsions require specific reconstructive techniques, CT myelography is recommended for every preoperative patient with OBPL.
Different pathogenetic pathways have been proposed for neuropsychiatric (NP) manifestations in systemic lupus erythematosus (SLE).
To describe the patient characteristics of a large cohort of ...patients with SLE with NP manifestations (NPSLE) in a single centre and to review whether these and other data are compatible with immune-mediated mechanisms.
A total of 212 patients were identified from MRI scans of the brain ordered for suspected NPSLE. Data were collected from the medical records. NP syndromes were classified according to the American College of Rheumatology (ACR) nomenclature and case definitions.
155 patients fulfilled the criteria for SLE. In 102 patients NP manifestations were attributed to SLE itself (primary NPSLE) whereas, in the remaining patients, the NP symptoms were due to other causes. The median age at the time of SLE diagnosis in patients with primary NPSLE was 27.5 years and the median duration prior to NPSLE was 2.8 years. Forty patients (39%) had a NP manifestation in the first year of the disease. Cerebrovascular disease, cognitive dysfunction, seizures and headache were the most prevalent syndromes. In 47% of patients with primary NPSLE the MRI scan of the brain showed no abnormalities.
Most NP manifestations in SLE occur early in the disease. This finding, as well as data from quantitative imaging studies and recent pathological studies, point to an immune-mediated pathogenesis.
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