Establishing a Foundation for the In Vivo Visualization of Intravascular Blood with Photon-Counting Technology in Spectral Imaging in Cranial CT.

BACKGROUND: Advances in computed tomography (CT) technology, particularly photon-counting CT (PCCT), are reshaping the possibilities for medical imaging. PCCT in spectral imaging enables the high-resolution visualization of tissues with material-specific accuracy. This study aims to establish a foundational approach for the in vivo visualization of intracranial blood using PCCT, focusing on non-enhanced imaging techniques and spectral imaging capabilities. METHODS: We employed photon-counting detector within a spectral CT framework to differentiate between venous and arterial intracranial blood. Our analysis included not only monoenergetic +67 keV reconstructions, but also images from virtual non-contrast and iodine phases, enabling detailed assessments of blood's characteristics without the use of contrast agents. RESULTS: Our findings demonstrate the ability of PCCT to provide clear and distinct visualizations of intracranial vascular structures. We quantified the signal-to-noise ratio across different imaging phases and found consistent enhancements in image clarity, particularly in the detection and differentiation of arterial and venous blood. CONCLUSION: PCCT offers a robust platform for the non-invasive and detailed visualization of intravascular intracranial blood. With its superior resolution and specific imaging capabilities, PCCT lays the groundwork for advancing clinical applications and research, notably in the diagnosis and management of intracranial disorders. This technology promises to improve diagnostic accuracy by enabling more precise imaging assessments.

Cranial Computer Tomography with Photon Counting and Energy-Integrated Detectors: Objective Comparison in the Same Patients.

This study provides an objective comparison of cranial computed tomography (CT) imaging quality and radiation dose between photon counting detectors (PCCTs) and energy-integrated detectors (EIDs). We retrospectively analyzed 158 CT scans from 76 patients, employing both detector types on the same individuals to ensure a consistent comparison. Our analysis focused on the Computed Tomography Dose Index and the Dose-Length Product together with the contrast-to-noise ratio and the signal-to-noise ratio for brain gray and white matter. We utilized standardized imaging protocols and consistent patient positioning to minimize variables. PCCT showed a potential for higher image quality and lower radiation doses, as highlighted by this study, thus achieving diagnostic clarity with reduced radiation exposure, underlining its significance in patient care, particularly for patients requiring multiple scans. The results demonstrated that while both systems were effective, PCCT offered enhanced imaging and patient safety in neuroradiological evaluations.

Advanced Imaging of Shunt Valves in Cranial CT Scans with Photon-Counting Scanner.

This brief report aimed to show the utility of photon-counting technology alongside standard cranial imaging protocols for visualizing shunt valves in a patient's cranial computed tomography scan. Photon-counting CT scans with cranial protocols were retrospectively surveyed and four types of shunt valves were encountered: proGAV 2.0®, M.blue®, Codman Certas®, and proSA®. These scans were compared with those obtained from non-photon-counting scanners at different time points for the same patients. The analysis of these findings demonstrated the usefulness of photon-counting technology for the clear and precise visualization of shunt valves without any additional radiation or special reconstruction patterns. The enhanced utility of photon-counting is highlighted by providing superior spatial resolution compared to other CT detectors. This technology facilitates a more accurate characterization of shunt valves and may support the detection of subtle abnormalities and a precise assessment of shunt valves.

Three-Dimensional Visualization of Shunt Valves with Photon Counting CT and Comparison to Traditional X-ray in a Simple Phantom Model.

This study introduces an application of innovative medical technology, Photon Counting Computer Tomography (PC CT) with novel detectors, for the assessment of shunt valves. PC CT technology offers enhanced visualization capabilities, especially for small structures, and opens up new possibilities for detailed three-dimensional imaging. Shunt valves are implanted under the skin and redirect excess cerebrospinal fluid, for example, to the abdominal cavity through a catheter. They play a vital role in regulating cerebrospinal fluid drainage in various pathologies, which can lead to hydrocephalus. Accurate imaging of shunt valves is essential to assess the rate of drainage, as their precise adjustment is a requirement for optimal patient care. This study focused on two adjustable shunt valves, the proGAV 2.0® and M. blue® (manufactured by Miethke, Potsdam, Germany). A comprehensive comparative analysis of PC CT and traditional X-ray techniques was conducted to explore this cutting-edge technology and it demonstrated that routine PC CT can efficiently assess shunt valves' adjustments. This technology shows promise in enhancing the accurate management of shunt valves used in settings where head scans are already frequently required, such as in the treatment of hydrocephalus.

Photon Counting Computed Tomography for Accurate Cribriform Plate (Lamina Cribrosa) Imaging in Adult Patients.

Detailed visualization of the cribriform plate is challenging due to its intricate structure. This study investigates how computed tomography (CT) with a novel photon counting (PC) detector enhance cribriform plate visualization compared to traditionally used energy-integrated detectors in patients. A total of 40 patients were included in a retrospective analysis, with half of them undergoing PC CT (Naeotom Alpha Siemens Healthineers, Forchheim, Germany) and the other half undergoing CT scans using an energy-integrated detector (Somatom Sensation 64, Siemens, Forchheim, Germany) in which the cribriform plate was visualized with a temporal bone protocol. Both groups of scans were evaluated for signal-to-noise ratio, radiation dose, the imaging quality of the whole scan overall, and, separately, the cribriform plate and the clarity of volume rendering reconstructions. Two independent observers conducted a qualitative analysis using a Likert scale. The results consistently demonstrated excellent imaging of the cribriform plate with the PC CT scanner, surpassing traditional technology. The visualization provided by PC CT allowed for precise anatomical assessment of the cribriform plate on multiplanar reconstructions and volume rendering imaging with reduced radiation dose (by approximately 50% per slice) and higher signal-to-noise ratio (by approximately 75%). In conclusion, photon-counting technology provides the possibility of better imaging of the cribriform plate in adult patients. This enhanced imaging could be utilized in skull base-associated pathologies, such as cerebrospinal fluid leaks, to visualize them more reliably for precise treatment.

Correlation Between Traumatic Skin and Subcutaneous Injuries and the Severity of Polytrauma Injury.

PURPOSE: To examine the relationship between superficial lesions (such as bruises, hematomas, deep abrasions, and soft tissue emphysema) and internal post-traumatic injuries, assessed using whole-body computed tomography (WBCT), and to determine if these are valid markers for internal injuries. METHODS AND MATERIALS: 250 patients who underwent WBCT emergency scans for suspected polytrauma were retrospectively analyzed after institutional review board approval of the study. The scans were carried out on patients who met the criteria for standard operating procedures for WBCT emergency scans. WBCT covering the entire head, neck, chest, and abdomen (including pelvis and proximal lower extremities) and at least one phase with intravenous contrast agent were included in the study. Initial analyses of immediate WBCT scans was carried out by a consultant radiologist and a radiological resident. The first reading focused on internal damage that needed immediate therapy. The second reading focused on a detailed analysis of the skin and subcutaneous tissue and their relation to internal injuries without the time pressure of an emergency setting, carried out by another experienced radiologist. All skin lesions and the degree of penetration and a comparison between the two readings were reported in tables. RESULTS: Superficial lesion of the chest was detected in 19 patients, 17 of them had an internal injury of the thorax while only two patients, with hematoma of the chest wall, had no internal injuries. Skin and subcutaneous lesions of the chest had the strongest association with an internal injury. Skin lesions of the abdominal wall were observed in 30 patients. In only 11 cases, these lesions were correlated with internal injuries, such as fractures or active bleeding. 52 skin and subgaleal lesions of the scalp were observed. In 20 of these patients, an intracranial or internal injury was detected. In 3 patients, skin abrasions of the neck were present and in only one of them, this finding was associated with an internal injury. CONCLUSION: Trauma patients whose history and clinical presentation meet the standard operating procedures for WBCT emergency scans and who present with a cutaneous lesion, especially at the neurocranium or chest wall, should be observed for internal injuries by WBCT. KEY POINTS: · Presence or lack of a superficial injury of the abdominal wall is not a reliable predictive indication of any internal abdominal injury.. · Superficial lesions of the chest and the neurocranium require a CT scan.. · Superficial injuries of the chest wall had the strongest association with internal injuries.. CITATION FORMAT: · Klempka A, Fischer C, Kauczor H et al. Correlation Between Traumatic Skin and Subcutaneous Injuries and the Severity of Trauma. Fortschr Röntgenstr 2021; 193: 177 - 185.

Outcome analysis and risk factors for postoperative colonic ischaemia after aortic surgery.

PURPOSE: Colonic ischaemia (CI) represents a serious complication after aortic surgery. This study aimed to analyse risk factors and outcome of patients suffering from postoperative CI. METHODS: Data of 1404 patients who underwent aortic surgery were retrospectively analysed regarding CI occurrence. Co-morbidities, procedural parameters, colon blood supply, procedure-related morbidity and mortality as well as survival during follow-up (FU) were compared with patients without CI using matched-pair analysis (1:3). RESULTS: Thirty-five patients (2.4%) with CI were identified. Cardiovascular, pulmonary and renal comorbidity were more common in CI patients. Operation time was longer (283 ± 22 vs. 188 ± 7 min, p < 0.0001) and blood loss was higher (2174 ± 396 vs. 1319 ± 108 ml, p = 0.0049) in the CI group. Patients with ruptured abdominal aortic aneurysm (AAA) showed a higher rate of CI compared to patients with intact AAA (5.4 vs. 1.9%, p = 0.0177). CI was predominantly diagnosed by endoscopy (26/35), generally within the first 4 postoperative days (20/35). Twenty-eight patients underwent surgery, all finalised with stoma creation. Postoperative bilateral occlusion and/or relevant stenosis of hypogastric arteries were more frequent in CI patients (57.8 vs. 20.8%, p = 0.0273). In-hospital mortality was increased in the CI group (26.7 vs. 2.9%, p < 0.0001). Survival was significantly reduced in CI patients (median: 28.2 months vs. 104.1 months, p < 0.0001). CONCLUSION: CI after aortic surgery is associated with considerable perioperative sequelae and reduced survival. Especially in patients at risk, such as those with rAAA, complicated intraoperative course, severe cardiovascular morbidity and/or perioperative deterioration of the hypogastric perfusion, vigilant postoperative multimodal monitoring is required in order to initiate diagnosis and treatment.