Literature review: Imaging in prostate cancer.

Imaging plays an increasingly important role in the detection and characterization of prostate cancer (PC). This review summarizes the key conventional and advanced imaging modalities including multiparametric magnetic resonance imaging (MRI) and positron emission tomography (PET) imaging and tries to instruct clinicians in finding the best image modality depending on the patient`s PC-stage. We aim to give an overview of the different image modalities and their benefits and weaknesses in imaging PC. Emphasis is put on primary prostate cancer detection and staging as well as on recurrent and castration resistant prostate cancer. Results from studies using various imaging techniques are discussed and compared. For the different stages of PC, advantages and disadvantages of the different imaging modalities are discussed. Moreover, this review aims to give an outlook about upcoming, new imaging modalities and how they might be implemented in the future into clinical routine. Imaging patients suffering from PC should aim for exact diagnosis, accurate detection of PC lesions and should mirror the true tumor burden. Imaging should lead to the best patient treatment available in the current PC-stage and should avoid unnecessary therapeutic interventions. New image modalities such as long axial field of view PET/CT with photon-counting CT and radiopharmaceuticals like androgen receptor targeting radiopharmaceuticals open up new possibilities. In conclusion, PC imaging is growing and each image modality is aiming for improvement.

Influence of Lung Reconstruction Algorithms on Interstitial Lung Pattern Recognition on CT.

Despite current recommendations, there is no recent scientific study comparing the influence of CT reconstruction kernels on lung pattern recognition in interstitial lung disease (ILD).To evaluate the sensitivity of lung (i70) and soft (i30) CT kernel algorithms for the diagnosis of ILD patterns.We retrospectively extracted between 15-25 pattern annotations per case (1 annotation = 15 slices of 1 mm) from 23 subjects resulting in 408 annotation stacks per lung kernel and soft kernel reconstructions. Two subspecialized chest radiologists defined the ground truth in consensus. 4 residents, 2 fellows, and 2 general consultants in radiology with 3 to 13 years of experience in chest imaging performed a blinded readout. In order to account for data clustering, a generalized linear mixed model (GLMM) with random intercept for reader and nested for patient and image and a kernel/experience interaction term was used to analyze the results.The results of the GLMM indicated, that the odds of correct pattern recognition is 12 % lower with lung kernel compared to soft kernel; however, this was not statistically significant (OR 0.88; 95%-CI, 0.73-1.06; p = 0.187). Furthermore, the consultants' odds of correct pattern recognition was 78 % higher than the residents' odds, although this finding did not reach statistical significance either (OR 1.78; 95%-CI, 0.62-5.06; p = 0.283). There was no significant interaction between the two fixed terms kernel and experience. Intra-rater agreement between lung and soft kernel was substantial (κ = 0.63 ±â€Š0.19). The mean inter-rater agreement for lung/soft kernel was κ = 0.37 ±â€Š0.17/κ = 0.38 ±â€Š0.17.There is no significant difference between lung and soft kernel reconstructed CT images for the correct pattern recognition in ILD. There are non-significant trends indicating that the use of soft kernels and a higher level of experience lead to a higher probability of correct pattern identification. · There is no significant difference between lung and soft kernel reconstructed CT images for the correct pattern recognition in interstitial lung disease.. · There are even non-significant tendencies that the use of soft kernels lead to a higher probability of correct pattern identification.. · These results challenge the current recommendations and the routinely performed separate lung kernel reconstructions for lung parenchyma analysis.. CITATION FORMAT: · Klaus JB, Christodoulidis S, Peters AA et al. Influence of Lung Reconstruction Algorithms on Interstitial Lung Pattern Recognition on CT. Fortschr Röntgenstr 2023; 195: 47 - 54.

Acute Pulmonary Embolism in COVID-19: A Potential Connection between Venous Congestion and Thrombus Distribution.

Background: Vascular abnormalities, including venous congestion (VC) and pulmonary embolism (PE), have been recognized as frequent COVID-19 imaging patterns and proposed as severity markers. However, the underlying pathophysiological mechanisms remain unclear. In this study, we aimed to characterize the relationship between VC, PE distribution, and alveolar opacities (AO). Methods: This multicenter observational registry (clinicaltrials.gov identifier NCT04824313) included 268 patients diagnosed with SARS-CoV-2 infection and subjected to contrast-enhanced CT between March and June 2020. Acute PE was diagnosed in 61 (22.8%) patients, including 17 females (27.9%), at a mean age of 61.7 ± 14.2 years. Demographic, laboratory, and outcome data were retrieved. We analyzed CT images at the segmental level regarding VC (qualitatively and quantitatively [diameter]), AO (semi-quantitatively as absent, <50%, or >50% involvement), clot location, and distribution related to VC and AO. Segments with vs. without PE were compared. Results: Out of 411 emboli, 82 (20%) were lobar or more proximal and 329 (80%) were segmental or subsegmental. Venous diameters were significantly higher in segments with AO (p = 0.031), unlike arteries (p = 0.138). At the segmental level, 77% of emboli were associated with VC. Overall, PE occurred in 28.2% of segments with AO vs. 21.8% without (p = 0.047). In the absence of VC, however, AO did not affect PE rates (p = 0.94). Conclusions: Vascular changes predominantly affected veins, and most PEs were located in segments with VC. In the absence of VC, AOs were not associated with the PE rate. VC might result from increased flow supported by the hypothesis of pulmonary arteriovenous anastomosis dysregulation as a relevant contributing factor.

Full core technology versus notch sampling technology: evaluation of the diagnostic accuracy and the risk of a pneumothorax after transthoracic needle biopsy of suspicious lung lesions.

BACKGROUND: Percutaneous needle biopsy of the lung (PCBL) under image guidance has become a safe and effective minimal invasive method to obtain a specimen related histological diagnosis of pulmonary lesions. PURPOSE: To evaluate the diagnostic yield and safety of two different coaxial biopsy technologies: full core and notch sampling technology. The former allowing the removal of full punch cylinders and the latter using a cutting-edge mechanism. MATERIAL AND METHODS: A retrospective analysis of 48 consecutive PCBL procedures has been carried out for this prognostic study, involving patients with a documented pulmonary nodule or mass lesion on previous computed tomography (CT) scans. The study population included 38 men and 10 women (mean age = 67 years). Of these 48 patients who underwent a procedure with a co-axial cutting system, 24 have been performed with notch sampling technology and 24 with full core technology. RESULTS: Out of the 48 biopsy procedures, 46 yielded specimens were adequate for histopathological evaluation, consistent with a technical success rate of 96%. The most common induced image-guided biopsy complication was a pneumothorax, occurring in 14 patients (35%). Seven patients with a pneumothorax were attributed to the full core technology and seven to the notch sampling technology (odds ratio = 1, 95% confidence interval = 0.28-3.51, P = 1). CONCLUSION: In the setting of full core versus notch sampling percutaneous CT-guided coaxial needle biopsy of the lung, no significant difference in the diagnostic accuracy and the incidence of pneumothoraces could be shown, while both technologies have an excellent diagnostic performance.

Performance of an AI based CAD system in solid lung nodule detection on chest phantom radiographs compared to radiology residents and fellow radiologists.

BACKGROUND: Despite the decreasing relevance of chest radiography in lung cancer screening, chest radiography is still frequently applied to assess for lung nodules. The aim of the current study was to determine the accuracy of a commercial AI based CAD system for the detection of artificial lung nodules on chest radiograph phantoms and compare the performance to radiologists in training. METHODS: Sixty-one anthropomorphic lung phantoms were equipped with 140 randomly deployed artificial lung nodules (5, 8, 10, 12 mm). A random generator chose nodule size and distribution before a two-plane chest X-ray (CXR) of each phantom was performed. Seven blinded radiologists in training (2 fellows, 5 residents) with 2 to 5 years of experience in chest imaging read the CXRs on a PACS-workstation independently. Results of the software were recorded separately. McNemar test was used to compare each radiologist's results to the AI-computer-aided-diagnostic (CAD) software in a per-nodule and a per-phantom approach and Fleiss-Kappa was applied for inter-rater and intra-observer agreements. RESULTS: Five out of seven readers showed a significantly higher accuracy than the AI algorithm. The pooled accuracies of the radiologists in a nodule-based and a phantom-based approach were 0.59 and 0.82 respectively, whereas the AI-CAD showed accuracies of 0.47 and 0.67, respectively. Radiologists' average sensitivity for 10 and 12 mm nodules was 0.80 and dropped to 0.66 for 8 mm (P=0.04) and 0.14 for 5 mm nodules (P<0.001). The radiologists and the algorithm both demonstrated a significant higher sensitivity for peripheral compared to central nodules (0.66 vs. 0.48; P=0.004 and 0.64 vs. 0.094; P=0.025, respectively). Inter-rater agreements were moderate among the radiologists and between radiologists and AI-CAD software (K'=0.58±0.13 and 0.51±0.1). Intra-observer agreement was calculated for two readers and was almost perfect for the phantom-based (K'=0.85±0.05; K'=0.80±0.02); and substantial to almost perfect for the nodule-based approach (K'=0.83±0.02; K'=0.78±0.02). CONCLUSIONS: The AI based CAD system as a primary reader acts inferior to radiologists regarding lung nodule detection in chest phantoms. Chest radiography has reasonable accuracy in lung nodule detection if read by a radiologist alone and may be further optimized by an AI based CAD system as a second reader.

Nuevos factores de riesgo de hemorragia pulmonar que complican la biopsia pulmonar guiada por TC en técnica coaxial / Novel risk factors of pulmonary hemorrhage complicating CT-guided lung biopsy in coaxial technique

Objetivos: Evaluar la frecuencia y gravedad de la hemorragia parenquimatosa pulmonar tras la biopsia pulmonar con aguja transtorácica coaxial, según factores de procedimiento, aún no descritos en la literatura. El objetivo de este estudio fue determinar si la elección de la tecnología de biopsia coaxial, el posicionamiento del paciente y la dignidad de la lesión son tres nuevas variables que influyen en el riesgo de hemorragia parenquimatosa tras biopsias coaxiales de pulmón. Métodos: Se revisaron retrospectivamente los registros de 117 pacientes que se sometieron a biopsias con aguja transtorácica del pulmón entre enero de 2018 y abril de 2020. El resultado primario fue la hemorragia pulmonar. Se ha utilizado un sistema de clasificación para clasificar la hemorragia parenquimatosa pulmonar: Grado 0 - Grado 3. Se evaluaron tres variables novedosas relacionadas con el paciente, la técnica y la lesión como predictores de hemorragia pulmonar: tecnología de biopsia coaxial, posición del paciente y dignidad de la lesión. Resultados: De los 117 pacientes, 18 (15,4%) pacientes con tecnología de biopsia coaxial de corte, versus 29 (24,8%) pacientes con tecnología coaxial de núcleo completo mostraron hemorragia significativa en las exploraciones de control posteriores a la biopsia. (IC del 95% 0,06-0,33, p <0,0001). No hubo diferencias significativas en la hemorragia pulmonar entre el diagnóstico histológico benigno y maligno (IC 95% 0,84-4,44, p = 0,1199) y la posición del paciente en decúbito prono o supino (IC 95%: 0,57-2,57, p = 0,6232). Conclusiones: La incidencia y gravedad de la hemorragia pulmonar depende de la tecnología de biopsia coaxial utilizada; siendo mayor en pacientes sometidos a una biopsia con tecnología full-core y menor después del uso de tecnología de corte. En este estudio de pronóstico no se estableció una correlación significativa entre la hemorragia pulmonar parenquimatosa y la posición del paciente o la dignidad de la lesión

Objectives: To evaluate the frequency and severity of pulmonary parenchymal hemorrhage after coaxial transthoracic needle biopsy of the lung, according to procedural factors, not yet described in literature. The aim of this study was to determine whether the choice of the coaxial biopsy technology, patient positioning and the lesion dignity are three new variables influencing the risk of parenchymal hemorrhage after coaxial biopsies of the lung. Methods: Records from 117 patients who underwent transthoracic needle biopsies of the lung between January 2018 and April 2020 have been retrospectively reviewed. The primary outcome was pulmonary hemorrhage. A grading system has been used to classify pulmonary parenchymal hemorrhage: Grade 0 ­ Grade 3. Three novel patient, technique and lesion-related variables were evaluated as predictors of pulmonary hemorrhage: coaxial biopsy technology, patient positioning and lesion dignity. Results: Out of the 117 patients, 18 (15,4%) patients with cutting coaxial biopsy technology, versus 29 (24,8%) patients with full core coaxial technology showed significant hemorrhage on the post-biopsy control scans. (95% CI 0,06-0,33, p<0,0001). No significant difference in pulmonary hemorrhage between benign and malignant histological diagnosis (95% CI 0,84-4,44, p=0,1199) and prone or supine patient positioning (95% CI: 0,57-2,57, p= 0,6232) was found. Conclusions: The incidence and severity of pulmonary hemorrhage depends on the coaxial biopsy technology used; being higher in patients undergoing a biopsy with full-core technology and lower after the use of cutting technology. No significant correlation between parenchymal pulmonary hemorrhage and patient positioning or lesion dignity was established in this prognostic study.

Correlation between fat signal ratio on T1-weighted MRI in the lower vertebral bodies and age, comparing 1.5-T and 3-T scanners.

BACKGROUND: The hypothesis was that the fat-dependent T1 signal intensity in vertebral bodies increases with age due to red-yellow marrow conversion. PURPOSE: To analyze the increasing fatty conversion of red bone marrow with age. MATERIAL AND METHODS: A continuous sample of 524 patients (age range 2-96 years) with normal lumbar spine MRIs (T11-L5) was retrospectively selected in order to get a representative sample from our 1.5-T and 3-T MRI units (Siemens, Erlangen, Germany). Four radiologists read the images independently. Absolute T1 signal intensities were measured in the lower vertebral bodies and standardized by dividing their value by the signal of the subcutaneous fat on lumbar and sacral level. RESULTS: The standardized T1 signal correlated significantly with patients' age at the 1.5-T unit, with the best correlation demonstrated by thoracic vertebra T11, followed by lumbar vertebra L1, with correlation coefficients (R) of 0.64 (95% CI 0.53-0.72, P < 0.0001) and 0.49 (95% CI 0.38-0.59, P < 0.0001), respectively. For women and men, the R values were similar in thoracic vertebra T11 at 0.62 (95% CI 0.49-0.72) and 0.64 (95% CI 0.44-0.77), respectively. The vertebral signal correlated significantly better with age in the 1.5-T compared to the 3-T unit on all vertebral levels: the best R value of the 3-T unit was only 0.20 (95% CI 0.09-0.30, P < 0.0001). Our study showed an average increase of the relative T1 signal in T11 of 10% per decade. CONCLUSION: T1 fat signal ratio increases with age in the vertebral bodies, which could help estimating the age of a person. Best age correlation was found when measuring T1 signal in T11, standardized by the sacral subcutaneous fat signal and using a 1.5-T MRI.

Kerley B lines in the lung apex - a distinct CT sign for pulmonary congestion.

AIMS OF THE STUDY: The purpose of this study was to establish a new computed tomography (CT) sign for pulmonary congestion (Kerley B lines in the lung apex in patients with cardiac or renal insufficiency) and to find the best signs to differentiate between pulmonary congestion and interstitial lung disease (ILD). METHODS: 180 consecutive patients undergoing CT were retrospectively included: 43 patients with cardiac, 17 with renal and 30 with mixed cardiac/renal insufficiency. In addition, we selected 90 patients with known ILD (usual interstitial pneumonia and nonspecific interstitial pneumonia). The cases were retrieved by means of a full text search of radiological reports and electronic patient files. The cardiothoracic ratio and diameters of the superior and inferior vena cava were measured. Pleural effusion, peribronchial cuffing, Kerley B lines (interlobular septa), ground glass opacity (GGO) and consolidation were analysed for prevalence, distribution and quantity (1 to 3). Fisher’s exact and Mann-Whitney-test were applied using Bonferroni correction. RESULTS: Kerley B lines in the lung apex were present in 81% and 76% of the cardiac and renal groups, respectively, which was significantly more than in the ILD group (26%, p <0.0001). In the insufficiency group, Kerley B lines were distributed more homogenously throughout the lungs compared with the ILD group in which they increased in amount from 32% in the upper lobe to 90% in the lower lobe. The septal lines were thinner in the ILD than in the insufficiency group (p <0.0001). Peribronchial cuffing was significantly more frequent in the cardiac group (67%) compared with the renal group (29%, p = 0.040) and the ILD group (0%, p <0.0001). Other pulmonary congestion signs such as cardiothoracic ratio, enlargement of the superior and inferior vena cava and pleural effusion did not vary between the cardiac and the renal groups but were significantly lower in the ILD group. However, ILD patients showed more GGO in the lower lobes (87%) then patients with insufficiency (42%, p <0.0001). CONCLUSION: Interlobular septal thickening (Kerley B lines) in the lung apex is a specific sign for pulmonary congestion, although not exclusive (since in ILD there may be apical reticulation). In combination with peribronchial cuffing and increased cardiothoracic ratio, it allows differentiation between cardiac/renal insufficiency and pulmonary ILD.