Comparative analysis of radiomics and deep-learning algorithms for survival prediction in hepatocellular carcinoma.

To examine the comparative robustness of computed tomography (CT)-based conventional radiomics and deep-learning convolutional neural networks (CNN) to predict overall survival (OS) in HCC patients. Retrospectively, 114 HCC patients with pretherapeutic CT of the liver were randomized into a development (n = 85) and a validation (n = 29) cohort, including patients of all tumor stages and several applied therapies. In addition to clinical parameters, image annotations of the liver parenchyma and of tumor findings on CT were available. Cox-regression based on radiomics features and CNN models were established and combined with clinical parameters to predict OS. Model performance was assessed using the concordance index (C-index). Log-rank tests were used to test model-based patient stratification into high/low-risk groups. The clinical Cox-regression model achieved the best validation performance for OS (C-index [95% confidence interval (CI)] 0.74 [0.57-0.86]) with a significant difference between the risk groups (p = 0.03). In image analysis, the CNN models (lowest C-index [CI] 0.63 [0.39-0.83]; highest C-index [CI] 0.71 [0.49-0.88]) were superior to the corresponding radiomics models (lowest C-index [CI] 0.51 [0.30-0.73]; highest C-index [CI] 0.66 [0.48-0.79]). A significant risk stratification was not possible (p > 0.05). Under clinical conditions, CNN-algorithms demonstrate superior prognostic potential to predict OS in HCC patients compared to conventional radiomics approaches and could therefore provide important information in the clinical setting, especially when clinical data is limited.

Improved Visualization and Quantification of Net Water Uptake in Recent Small Subcortical Infarcts in the Thalamus Using Computed Tomography.

Diagnosing recent small subcortical infarcts (RSSIs) via early computed tomography (CT) remains challenging. This study aimed to assess CT attenuation values (Hounsfield Units (HU)) and net water uptake (NWU) in RSSI and explore a postprocessing algorithm's potential to enhance thalamic RSSI detection. We examined non-contrast CT (NCCT) data from patients with confirmed thalamic RSSI on diffusion-weighted magnetic resonance imaging (DW-MRI) between January 2010 and October 2017. Co-registered DW-MRI and NCCT images enabled HU and NWU quantification in the infarct area compared to unaffected contralateral tissue. Results were categorized based on symptom onset to NCCT timing. Postprocessing using window optimization and frequency-selective non-linear blending (FSNLB) was applied, with interpretations by three blinded Neuroradiologists. The study included 34 patients (median age 70 years [IQR 63-76], 14 women). RSSI exhibited significantly reduced mean CT attenuation compared to unaffected thalamus (29.6 HU (±3.1) vs. 33.3 HU (±2.6); p < 0.01). Mean NWU in the infarct area increased from 6.4% (±7.2) at 0-6 h to 16.6% (±8.7) at 24-36 h post-symptom onset. Postprocessed NCCT using these HU values improved sensitivity for RSSI detection from 32% in unprocessed CT to 41% in FSNLB-optimized CT, with specificities ranging from 86% to 95%. In conclusion, CT attenuation values and NWU are discernible in thalamic RSSI up to 36 h post-symptom onset. Postprocessing techniques, particularly window optimization and FSNLB, moderately enhance RSSI detection.

Impact of the COVID-19 pandemic on therapeutic interventional oncology procedures and diagnostic CT/MRI examinations at a German university hospital.

PURPOSE: The COVID-19 pandemic led to the implementation of severe restrictions on public life in Germany and a reduction in the number of non-COVID patients presenting for care. The aim of this study was to measure the impact on the number of therapeutic interventional oncology procedures in relation to diagnostic imaging studies at a high-volume radiology department. MATERIALS AND METHODS: The numbers of therapeutic interventional oncology procedures and diagnostic CT/MRI examinations for the years 2010 to 2021 were extracted using the hospital information system. Monthly data from January 2010 to December 2019 were used to build forecasting models for the timeframe from January 2020 to December 2021. Real procedure numbers were compared with predicted numbers to calculate residual differences, which were considered statistically significant if the real number was outside the 95 % confidence interval (p < 0.05). RESULTS: During the first German lockdown (March/April 2020), the number of outpatient CT/MRI examinations decreased significantly, with a less pronounced decrease of overall CT/MRI numbers. The second German lockdown (January-May 2021) led to lower than predicted outpatient CT numbers, whereas outpatient MRI numbers in part even exceeded predicted numbers and overall CT/MRI numbers stayed within confidence limits. The lockdowns had a more pronounced negative effect on the number of oncological MRI examinations compared to CT examinations. The number of therapeutic interventional oncology procedures showed no significant decrease during both lockdowns. CONCLUSION: Lockdown measures had minor impact on the number of therapeutic interventional oncology procedures, possibly due to a shift from more resource-intensive therapies like surgery towards interventional oncology. The overall numbers of diagnostic imaging decreased during the first lockdown, while the second lockdown had less negative impact. The number of oncological MRI examinations was affected most severely. To avoid adverse outcomes, specific protocols for patient management during future pandemic outbreaks should be implemented and continuously adapted. KEY POINTS: · COVID-19 lockdowns had minor effect on therapeutic interventional oncology procedures.. · Numbers of diagnostic outpatient imaging procedures dropped markedly, especially during the first lockdown.. · The number of oncological MRI examinations showed a significant decrease during both lockdowns.. CITATION FORMAT: · Nebelung H, Radosa CG, Schön F et al. Impact of the COVID-19 pandemic on therapeutic interventional oncology procedures and diagnostic CT/MRI examinations at a German university hospital. Fortschr Röntgenstr 2023; 195: 707 - 712.

Routine Use of Structured Reporting in Whole-body Trauma CT Facilitates Quality Improvement.

PURPOSE: Structured reporting (SR) is increasingly used. So far, there is minimal experience with SR in whole-body computed tomography (WBCT). The aim of this study was to investigate the value of routine use of SR in WBCT in trauma with a focus on reporting time, reporting errors, and referrer satisfaction. MATERIALS AND METHODS: Reporting time and reporting errors of CT reports were prospectively quantified for residents and board-certified radiologists 3 months before and for 6 months after implementation of a structured report in the clinical routine. Referrer satisfaction was prospectively quantified by means of a survey before and after the implementation period of SR using a 5-point Likert scale. Before and after results were compared to determine the effect of structured reporting on WBCT in trauma at our institution. RESULTS: The mean reporting time was lower when using SR (65 ±â€Š52 min. vs. 87 ±â€Š124 min., p = .25). After 4 months, the median reporting time was significantly lower with SR (p = .02). Consequently, the rate of reports that were finished within one hour rose from 55.1 % to 68.3 %. Likewise, reporting errors decreased (12.6 % vs. 8.4 %, p = .48). Residents and board-certified radiologists reported fewer errors when using SR with 16.4 % vs. 12.6 % and 8.8 % vs. 2.7 %, respectively. General referrer satisfaction improved (1.7 ±â€Š0.8 vs. 1.5 ±â€Š1.1, p = .58). Referrers graded improvements for standardization of reports (2.2 ±â€Š1.1 vs. 1.3 ±â€Š1.1, p = .03), consistency of report structure (2.1 ±â€Š1.1 vs. 1.4 ±â€Š1.1, p = .09), and retrievability of relevant pathologies (2.1 ±â€Š1.2 vs. 1.6 ±â€Š1.1, p = .32). CONCLUSION: SR has the potential to facilitate process improvement for WBCT in trauma in the daily routine with a reduction of reporting time and reporting mistakes while increasing referrer satisfaction. KEY POINTS: · SR for WBCT in trauma is feasable in clinical routine.. · Reporting time in WBCT in trauma decreases by SR.. · SR for WBCT in trauma has the potential to decrease reporting mistakes.. · SR for WBCT in trauma might increase referrer satisfaction.. CITATION FORMAT: · Blum SF, Hertzschuch D, Langer E et al. Routine Use of Structured Reporting in Whole-body Trauma CT Facilitates Quality Improvement. Fortschr Röntgenstr 2023; 195: 521 - 528.

Value of Clinical Information on Radiology Reports in Oncological Imaging.

Radiological reporting errors have a direct negative impact on patient treatment. The purpose of this study was to investigate the contribution of clinical information (CI) in radiological reporting of oncological imaging and the dependence on the radiologists' experience level (EL). Sixty-four patients with several types of carcinomas and twenty patients without tumors were enrolled. Computed tomography datasets acquired in primary or follow-up staging were independently analyzed by three radiologists (R) with different EL (R1: 15 years; R2: 10 years, R3: 1 year). Reading was initially performed without and 3 months later with CI. Overall, diagnostic accuracy and sensitivity for primary tumor detection increased significantly when receiving CI from 77% to 87%; p = 0.01 and 73% to 83%; p = 0.01, respectively. All radiologists benefitted from CI; R1: 85% vs. 92%, p = 0.15; R2: 77% vs. 83%, p = 0.33; R3: 70% vs. 86%, p = 0.02. Overall, diagnostic accuracy and sensitivity for detecting lymphogenous metastases increased from 80% to 85% (p = 0.13) and 42% to 56% (p = 0.13), for detection of hematogenous metastases from 85% to 86% (p = 0.61) and 46% to 60% (p = 0.15). Specificity remained stable (>90%). Thus, CI in oncological imaging seems to be essential for correct radiological reporting, especially for residents, and should be available for the radiologist whenever possible.