Impact of intelligent virtual and AI-based automated collimation functionalities on the efficiency of radiographic acquisitions.

INTRODUCTION: Intelligent virtual and AI-based collimation functionalities have the potential to enable an efficient workflow for radiographers, but the specific impact on clinical routines is still unknown. This study analyzes primarily the influence of intelligent collimation functionalities on the examination time and the number of needed interactions with the radiography system. METHODS: An observational study was conducted on the use of three camera-based intelligent features at five clinical sites in Europe and the USA: AI-based auto thorax collimation (ATC), smart virtual ortho (SVO) collimation for stitched long-leg and full-spine examinations, and virtual collimation (VC) at the radiography system workstation. Two people conducted semi-structured observations during routine examinations to collect data with the functionalities either activated or deactivated. RESULTS: Median exam duration was 31 vs. 45 s (p < 0.0001) for 95 thorax examinations with ATC and 94 without ATC. For stitched orthopedic examinations, 34 were performed with SVO and 40 without SVO, and the median exam duration was 62 vs. 82 s (p < 0.0001). The median time for setting the ortho range - i.e., the time between setting the upper and the lower limits of the collimation field - was 7 vs. 16 s for 39 examinations with SVO and 43 without SVO (p < 0.0001). In 109 thorax examinations with ATC and 112 without ATC, the median number of system interactions was 1 vs. 2 (p < 0.0001). VC was used to collimate in 2.4% and to check the collimation field in 68.5% of 292 observed chest and other examinations. CONCLUSION: ATC and SVO enable the radiographer to save time during chest or stitched examinations. Additionally, ATC reduces machine interactions during chest examinations. IMPLICATIONS FOR PRACTICE: System and artificial intelligence can support the radiographer during the image acquisition by providing a more efficient workflow.

Magnetic resonance imaging-guided prostate biopsy: institutional analysis and systematic review.

OBJECTIVES: To evaluate the detection rate of prostate cancer (PCa) after magnetic resonance-guided biopsy (MRGB); to monitor the patient cohort with negative MRGB results and to compare our own results with other reports in the current literature. MATERIALS AND METHODS: A group of 41 patients was included in this IRB-approved study and subjected to combined MRI and MRGB. MRGB was performed in a closed 1.5 T MR unit and the needle was inserted rectally. The follow-up period ranged between 12 and 62 months (mean 3.1 years). To compare the results with the literature, a systematic literature search was performed. Eighteen publications were evaluated. RESULTS: The cancer-suspicious regions were punctured successfully in all cases. PCa was detected in eleven patients (26.9 %) who were all clinically significant. MRGB showed a benign histology in the remaining 30 patients. In the follow-up (mean 3.1 years) of patients with benign histology, no new PCa was diagnosed. The missed cancer rate during follow-up was 0.0 % in our study. CONCLUSION: MRGB is effective for the detection of clinically significant cancer, and this is in accordance with the recent literature. In the follow-up of patients with benign histology, no new PCa was discovered. Although the probability of developing PCa after negative MRGB is very low, active surveillance is reasonable.

[Imaging in oncology: terms and definitions]. / Onkologische Bildgebung: Begriffe und Definitionen.

Oncologic imaging includes the morphological description of the primary tumor region for an accurate classification of the tumor and lymph node stage and whether distant metastases have occurred according to the TNM staging system. Knowing the stage of the disease helps to plan the treatment and to estimate the prognosis. In clinical routine this is accomplished by conventional imaging techniques, such as ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI). Additionally, oncologic imaging is essential in treatment monitoring to visualize and quantify the effect of cancer therapy according to response evaluation criteria in solid tumors (RECIST) and World Health Organization (WHO) criteria. The tremendous development in oncology and technical innovations in imaging represent a particular challenge for radiology.

Feasibility of transrectal ultrasonography for assessment of cervical cancer.

PURPOSE: To retrospectively compare the maximum target width and target thickness in patients with locally advanced cervical cancer between magnetic resonance imaging (MRI) and transrectal ultrasonography (TRUS) in the course of primary radiochemotherapy. PATIENTS AND METHODS: T2-weighted MRI and TRUS were performed on patients with locally advanced cervical cancer at the same timepoint-either at the time of diagnosis, or at the time of brachytherapy before or after insertion of the applicator. Patients treated from 2009 to 2011 were selected for this study based on the availability of MRI and TRUS at the defined time points. The target was defined as the complete macroscopic tumor mass and the remaining cervix and was measured on transversal planes. Descriptive statistics and a linear regression analysis were performed for the groups. RESULTS: Images from 17 patients were available for analysis. Mean maximum target width was 4.2 ± 0.83 cm and 4.2 ± 0.79 cm for MRI and TRUS, respectively. Mean maximum target thickness was 3.3 ± 1.03 cm and 3.1 ± 1.15 cm for MRI and TRUS, respectively. Linear regression analysis for target width and thickness between TRUS and MRI demonstrated a correlation with R(2) = 0.842 and R(2) = 0.943, respectively. CONCLUSION: The feasibility of TRUS for the assessment of local target extension could be demonstrated. Comparison of the target width and thickness showed a high correlation between TRUS and MRI, indicating the potential of TRUS for target definition in image-guided adaptive brachytherapy.

[Diagnose importance of multiparametric magnetic resonance tomography for prostate cancer]. / Stellenwert der multiparametrischen Magnetresonanztomographie beim Prostatakarzinom.

Prostate cancer is biologically and clinically a heterogeneous disease which makes imaging evaluation challenging. Magnetic resonance imaging (MRI) has considerable potential to improve prostate cancer detection and characterization. Until recently morphologic MRI has not been routinely incorporated into clinical care because of its limitation to detect, localize and characterize prostate cancer. Performing prostate gland MRI using functional techniques has the potential to provide unique information regarding tumor behavior, including treatment response. In order for multiparametric MRI data to have an impact on patient management, the collected data need to be relayed to clinicians in a standardized way for image construction, analysis and interpretation. This will ensure that patients are treated effectively and in the most appropriate way. Scoring systems similar to those employed successfully for breast imaging need to be developed.

[Magnetic resonance tomography-guided interventional procedure for diagnosis of prostate cancer]. / MRT-gezielte interventionelle Verfahren zur Abklärung des Prostatakarzinoms.

In recent years magnetic resonance imaging (MRI) has been increasingly established in the diagnosis of prostate cancer in addition to transrectal ultrasonography (TRUS). The use of T2-weighted imaging allows an exact delineation of the zonal anatomy of the prostate and its surrounding structures. Other MR imaging tools, such as dynamic contrast-enhanced T1-weighted imaging or diffusion-weighted imaging allow an inference of the biochemical characteristics (multiparametric MRI). Prostate cancer, which could only be diagnosed using MR imaging or lesions suspected as being prostate cancer, which are localized in the anterior aspect of the prostate and were missed with repetitive TRUS biopsy, need to undergo MR guided biopsy. Recent studies have shown a good correlation between MR imaging and histopathology of specimens collected by MR-guided biopsy. Improved lesion targeting is therefore possible with MR-guided biopsy. So far data suggest that MR-guided biopsy of the prostate is a promising alternative diagnostic tool to TRUS-guided biopsy.

[Functional and molecular imaging of breast tumors]. / Funktionelle und molekulare Bildgebung bei Brusttumoren.

Molecular imaging is concerned with the presentation, description and quantification of biological and physiological processes at the cellular and molecular level. Most recently molecular imaging has started to become established in breast diagnostics. This review article will give an overview of procedures which are either in the preclinical development stage or which have already become clinically established. Molecular nuclear medicine breast imaging (breast-specific gamma imaging [BSGI] and positron emission mammography [PEM]) together with specific radiotracers and contrast media will be discussed. The possibilities for magnetic resonance imaging in functional (DWI) and metabolic (MRSI) imaging of breast lesions and the combined application of nuclear medicine and magnetic resonance imaging (PET/MRI) will be explained. Furthermore, an overview on the preclinical procedure and the possible clinical applications of optical and photoacoustic imaging will be given.

Relationship between 31P metabolites and oncolytic viral therapy sensitivity in human colorectal cancer xenografts.

BACKGROUND: Studies using phosphorus magnetic resonance spectroscopy (MRS) have pointed to the significance of phospholipid metabolite alterations as biochemical markers for tumour progression or therapy response. METHODS: Spectroscopic imaging was performed in colorectal flank tumours in nude mice. In vivo tumour doubling times for each cell line were measured. In vivo sensitivity of each tumour line to treatment with G207 and NV1020 oncolytic viruses was assessed. Correlations between viral sensitivity and tumour doubling time and phosphorus MRS were estimated. RESULTS: For G207 virus, in vitro cytotoxicity tests showed cell viability at multiplicities of infection (ratio of viral particles per tumour cell) of 0.1 on day 6 as follows: C85, less than 1 per cent; HCT8, 1 per cent; LS174T, 9 per cent; HT29, 18 per cent; and C18, 92 per cent. Respective values for NV1020 were 1, 18, 4, 18 and 86 per cent. The phosphoethanolamine to phosphocholine ratio was significantly lower in virus-sensitive than -insensitive cells, and was dependent on tumour doubling time. CONCLUSION: Alterations in membrane phospholipid metabolites that relate to proliferation of cancer cells affect the efficacy of oncolytic viral therapy. MRS proved a highly sensitive non-invasive tool for predicting the efficacy of viruses.