The Best of Both Worlds: Ultra-high-pitch Pulmonary Angiography with Free-Breathing Technique by Means of Photon-Counting Detector CT for Diagnosis of Acute Pulmonary Embolism.

RATIONALE AND OBJECTIVES: To assess image quality and radiation dose of ultra-high-pitch CT pulmonary angiography (CTPA) with free-breathing technique for diagnosis of pulmonary embolism using a photon-counting detector (PCD) CT compared to matched energy-integrating detector (EID)-based single-energy CTPA. MATERIALS AND METHODS: Fifty-one PCD-CTPAs were prospectively compared to 51 CTPAs on a third-generation dual-source EID-CT. CTPAs were acquired with an ultra-high-pitch protocol with free-breathing technique (40 mL contrast medium, pitch 3.2) at 140 kV (PCD) and 70-100 kV (EID). Iodine maps were reconstructed from spectral PCD-CTPAs. Image quality of CTPAs and iodine maps was assessed independently by three radiologists. Additionally, CT attenuation numbers within pulmonary arteries as well as signal-to-noise and contrast-to-noise ratios (SNR, CNR) were compared. Administered radiation dose was compared. RESULTS: CT attenuation was higher in the PCD-group (all P < 0.05). CNR and SNR were higher in lobar pulmonary arteries in PCD-CTPAs (P < 0.05), whereas no difference was ascertained within the pulmonary trunk (P > 0.05). Image quality of PCD-CTPA was rated best by all readers (excellent/good image quality in 96.1% of PCD-CTPAs vs. 50.9% of EID-CTPAs). PCD-CT produced no non-diagnostic scans vs. three non-diagnostic (5.9%) EID-CTPAs. Radiation dose was lower with PCD-CT than with EID-CT (effective dose 1.33 ± 0.47 vs. 1.80 ± 0.82 mSv; all P < 0.05). CONCLUSION: Ultra-high-pitch CTPA with free-breathing technique with PCD-CT allows for superior image quality with significantly reduced radiation dose and full spectral information. With the ultra-high pitch, only PCD-CTPA enables reconstruction of iodine maps containing additional functional information.

[Optimizing radiological diagnostic management via mobile devices in trauma surgery]. / Anforderung von radiologischer Diagnostik in der Unfallchirurgie mittels mobiler Endgeräte.

BACKGROUND: Time is a scarce resource for physicians. One medical task is the request for radiological diagnostics. This process is characterized by high administrative complexity and sometimes considerable time consumption. Measures that lead to an administrative relief in favor of patient care have so far been lacking. AIM OF THE STUDY: Process optimization of the request for radiological diagnostics. As a proof of concept the request for radiological diagnostics was conducted using a mobile, smartphone and tablet-based application with dedicated voice recognition software in the Department of Trauma Surgery at the University Hospital of Würzburg (UKW). MATERIAL AND METHODS: In a prospective study, time differences and efficiency of the mobile app-based method (ukw.mobile based Application = UMBA) compared to the PC-based method (PC-based application = PCBA) for requesting radiological services were analyzed. The time from the indications to the completed request and the time required to create the request on the device were documented and assessed. Due to the non-normal distribution of the data, a Mann-Whitney U test was performed. RESULTS: The time from the indications to the completed request was significantly (p < 0.05) reduced using UMBA compared to PCBA (PCBA: mean ± standard difference [SD] 19.57 ± 33.24 min, median 3.00 min, interquartile range [IQR] 1.00-30.00 min vs. UMBA: 9.33 ± 13.94 min, median 1.00 min, IQR 0.00-20.00 min). The time to complete the request on the device was also significantly reduced using UMBA (PCBA: mean ± SD 63.77 ± 37.98 s, median 51.96 s, IQR 41.68-68.93 s vs. UMBA: 25.21 ± 11.18 s, median 20.00 s, IQR 17.27-29.00 s). CONCLUSION: The mobile, voice-assisted request process leads to a considerable time reduction in daily clinical routine and illustrates the potential of user-oriented, targeted digitalization in healthcare. In future, the process will be supported by artificial intelligence.

Gantry-Free High-Resolution Cone-Beam CT: Efficacy for Distal Radius and Scaphoid Fracture Detection and Characterization.

OBJECTIVES: Gantry-free cone-beam CT (CBCT) allows for comfortable patient positioning due to an open scanner architecture. Since CBCT without gantry is not yet established for clinical wrist trauma imaging, this study's aim was to investigate its diagnostic value in the preoperative workup of patients with distal radius and scaphoid fractures. METHODS: Within a 12-month period, 113 patients with severe wrist trauma underwent both radiography and CBCT with the same gantry-free multi-use scanner before surgery. Two radiologists retrospectively analyzed all datasets for the morphology of distal radius (n = 95) and scaphoid fractures (n = 20). In all 115 wrists (two bilateral injuries), surgical reports served as the standard of reference. RESULTS: While accuracy for distal radius fractures was comparable among CBCT and radiographs, the former was superior with regard to scaphoid fractures (Reader 1: 100.0% vs. 75.0%; Reader 2: 100.0% vs. 65.0%). Accuracy for multi-fragmentary radius injuries (100.0% vs. 90.5%; 100.0% vs. 93.7%), and articular affliction (99.0% vs. 84.2%; 100.0% vs. 83.2%) was also higher in CBCT. Regarding scaphoid fractures, CBCT proved superior for diagnosis of proximal pole or waist involvement (100.0% vs. 70.0%; 100.0% vs. 65.0%) and comminuted patterns (100.0% vs. 70.0%; 100.0% vs. 75.0%). Median effective dose of CBCT was as low as 3.65 µSv compared with 0.16 µSv for standard radiography. CONCLUSION: Gantry-free CBCT allows for excellent diagnostic accuracy in the assessment of distal radius and scaphoid fracture morphology. Even in patients with limited mobility, very low radiation dose is sufficient to maintain high image quality.

Simultaneous treatment of trauma patients in a dual room trauma suite with integrated movable sliding gantry CT system: an observational study.

The trauma center of the University Hospital Wuerzburg has developed an advanced trauma pathway based on a dual-room trauma suite with an integrated movable sliding gantry CT-system. This enables simultaneous CT-diagnostics and treatment of two trauma patients. The focus of this study was to investigate the quality of the concept based on defined outcome criteria in this specific setting (time from arrival to initiation of CT scan: tCT; time from arrival to initiation of emergency surgery: tES). We analyzed all trauma patients admitted to the hospital's trauma suite from 1st May 2019 through 29th April 2020. Two subgroups were defined: trauma patients, who were treated without a second trauma patient present (group 1) and patients, who were treated simultaneously with another trauma patient (group 2). Simultaneous treatment was defined as parallel arrival within a period of 20 min. Of 423 included trauma patients, 46 patients (10.9%) were treated simultaneously. Car accidents were the predominant trauma mechanism in this group (19.6% vs. 47.8%, p < 0.05). Prehospital life-saving procedures were performed with comparable frequency in both groups (intubation 43.5% vs. 39%, p = 0.572); pleural drainage 3.2% vs. 2.2%, p = 0.708; cardiopulmonary resuscitation 5% vs. 2.2%, p = 0.387). At hospital admission, patients in group 2 suffered significantly more pain (E-problem according to Advanced Trauma Life Support principles©; 29.2% vs. 45.7%, p < 0.05). There were no significant differences in the clinical treatment (emergency procedures, vasopressor and coagulant therapy, and transfusion of red blood cells). tCT was 6 (4-10) minutes (median and IQR) in group 1 and 8 (5-15.5) minutes in group 2 (p = 0.280). tES was 90 (78-106) minutes in group 1 and 99 (97-108) minutes in group 2 (p = 0.081). The simultaneous treatment of two trauma patients in a dual-room trauma suite with an integrated movable sliding gantry CT-system requires a medical, organizational, and technical concept adapted to this special setting. Despite the oftentimes serious and life-threatening injuries, optimal diagnostic and therapeutic procedures can be guaranteed for two simultaneous trauma patients at an individual medical level in consistent quality.

Twin Robotic X-Ray System for 3D Cone-Beam CT of the Wrist: An Evaluation of Image Quality and Radiation Dose.

OBJECTIVE. The purpose of this study was to assess image quality and radiation dose of a novel twin robotic x-ray system's 3D cone-beam CT (CBCT) function for the depiction of cadaveric wrists. MATERIALS AND METHODS. Sixteen cadaveric wrists were scanned using dedicated low-dose and standard-dose CBCT protocols as well as clinical MDCT for comparison. Three readers assessed overall image quality, noise, and artifacts in bone and soft tissue on 5-point Likert scales. For radiation dose analysis, volume CT dose indexes (CTDIvol) were compared. RESULTS. Overall image quality of most studies was very good or excellent in MDCT (for readers 1, 2, and 3: 100%, 100%, and 88%, respectively), standard-dose CBCT (100%, 100%, and 94%), and low dose CBCT (100%, 94%, and 88%) with two readers favoring standard-dose CBCT over MDCT image quality (readers 1 and 2; p ≤ 0.046). In soft tissue, standard-dose (readers 1, 2, and 3; p ≤ 0.021) and low-dose (all p ≤ 0.001) CBCT images had more noise than MDCT in all cases. Standard-dose (all p ≤ 0.003) and low-dose (all p < 0.001) CBCT images also displayed more artifacts. In osseous tissue, one reader observed more noise (p < 0.001) and artifacts (p = 0.020) for low-dose CBCT than for MDCT, whereas no difference was found between standard-dose CBCT and MDCT. Mean CTDIvol was significantly lower for standard-dose (5.2 ± 0.6 mGy; p < 0.001) and low-dose CBCT (1.8 ± 0.2 mGy; p < 0.001) than for clinical MDCT without automatic dose modulation (15.0 ± 0.0 mGy). CONCLUSION. The tested CBCT function delivers suitable image quality for clinical wrist imaging at significantly lower radiation levels than conventional MDCT. In combination with comfortable positioning options and the ability to perform additional radiographic and fluoroscopic examinations, the twin robotic x-ray system may hold the potential to be a one-stop shop device for trauma-associated wrist imaging.

Patterns of Lymph Node Recurrence in Adrenocortical Carcinoma: Possible Implications for Primary Surgical Treatment.

BACKGROUND: In the surgical treatment of adrenocortical carcinoma (ACC), lymphadenectomy may improve oncologic outcome. However, patterns of metastatic lymphatic spread in ACC are unknown. METHODS: Clinical data of patients included in the European Network for the Study of Adrenal Tumors (ENSAT) registry were retrospectively reviewed. Inclusion criteria were: nonmetastatic ACC, complete resection of the primary tumor, a disease-free time of > 3 months, and lymph node metastases as the first disease relapse. The retroperitoneal lymphatic drainage area was evaluated by using follow-up imaging. RESULTS: Of 971 patients from the ENSAT registry, 56 patients were included. In left-sided ACC (n = 36), lymphatic recurrence was detected in the left renal hilum (50%), in the perirenal fat tissue cranial to the renal hilum (ventral, 47%; dorsal, 55%), para-aortic (47%), interaorto-caval (22%), and/or in the perirenal fat tissue caudal to the renal hilum (ventral, 20%; dorsal, 17%). In right-sided ACC (n = 20), lymph node metastases were detected in the perirenal fat tissue cranial to the renal hilum (dorsal, 55%; ventral, 45%), interaorto-caval (35%), in the area of the right renal artery (10%), and/or paracaval (15%). Patients with right-sided ACC showed left-paraaortic lymph node recurrences in 10% of cases. CONCLUSION: Metastatic lymphatic spread appears to be more extensive than previously thought. The distribution pattern of lymph node metastases described in our study could be used as a guide for a more extended lymph node dissection.

In vitro evaluation of a new iterative reconstruction algorithm for dose reduction in coronary artery calcium scoring.

BACKGROUND: Coronary artery calcium (CAC) scoring is a widespread tool for cardiac risk assessment in asymptomatic patients and accompanying possible adverse effects, i.e. radiation exposure, should be as low as reasonably achievable. PURPOSE: To evaluate a new iterative reconstruction (IR) algorithm for dose reduction of in vitro coronary artery calcium scoring at different tube currents. MATERIAL AND METHODS: An anthropomorphic calcium scoring phantom was scanned in different configurations simulating slim, average-sized, and large patients. A standard calcium scoring protocol was performed on a third-generation dual-source CT at 120 kVp tube voltage. Reference tube current was 80 mAs as standard and stepwise reduced to 60, 40, 20, and 10 mAs. Images were reconstructed with weighted filtered back projection (wFBP) and a new version of an established IR kernel at different strength levels. Calcifications were quantified calculating Agatston and volume scores. Subjective image quality was visualized with scans of an ex vivo human heart. RESULTS: In general, Agatston and volume scores remained relatively stable between 80 and 40 mAs and increased at lower tube currents, particularly in the medium and large phantom. IR reduced this effect, as both Agatston and volume scores decreased with increasing levels of IR compared to wFBP (P < 0.001). Depending on selected parameters, radiation dose could be lowered by up to 86% in the large size phantom when selecting a reference tube current of 10 mAs with resulting Agatston levels close to the reference settings. CONCLUSION: New iterative reconstruction kernels may allow for reduction in tube current for established Agatston scoring protocols and consequently for substantial reduction in radiation exposure.

Self-gated Non-Contrast-enhanced Functional Lung MR Imaging for Quantitative Ventilation Assessment in Patients with Cystic Fibrosis.

Purpose To assess the clinical feasibility of self-gated non-contrast-enhanced functional lung (SENCEFUL) magnetic resonance (MR) imaging for quantitative ventilation (QV) imaging in patients with cystic fibrosis (CF). Materials and Methods Twenty patients with CF and 20 matched healthy volunteers underwent functional 1.5-T lung MR imaging with the SENCEFUL imaging approach, in which a two-dimensional fast low-angle shot sequence is used with quasi-random sampling. The lungs were manually segmented on the ventilation-weighted images to obtain QV measurements, which were compared between groups. QV values of the patients were correlated with results of pulmonary function testing. Three radiologists rated the images for presence of ventilation deficits by means of visual inspection. Mann-Whitney U tests, receiver operating characteristic analyses, Spearman correlations, and Gwet agreement coefficient analyses were used for statistical analysis. Results QV of the entire lungs was lower for patients with CF than for control subjects (mean ± standard deviation, 0.09 mL/mL ± 0.03 vs 0.11 mL/mL ± 0.03, respectively; P = .007). QV ratios of upper to lower lung halves were lower in patients with CF than in control subjects (right, 0.84 ± 0.2 vs 1.16 ± 0.2, respectively [P < .001]; left, 0.88 ± 0.3 vs 1.11 ± 0.1, respectively [P = .017]). Accordingly, ventilation differences between the groups were larger in the upper halves (Δ = 0.04 mL/mL, P ≤ .001-.002). QV values of patients with CF correlated with forced vital capacity (r = 0.7; 95% confidence interval [CI]: 0.21, 0.91), residual volume (static hyperinflation, r = -0.8; 95% CI: -0.94, 0.42), and forced expiratory volume in 1 second (airway obstruction, r = 0.7; 95% CI: 0.21, 0.91). Disseminated small ventilation deficits were the most frequent involvement pattern, present in 40% of the functional maps in CF versus 8% in the control subjects (P < .001). Conclusion SENCEFUL MR imaging is feasible for QV assessment. Less QV, especially in upper lung parts, and correlation to vital capacity and to markers for hyperinflation and airway obstruction were found in patients with CF. © RSNA, 2016.

In Vitro Comparison of Second- and Third-generation Dual-source CT for Coronary Stent Visualization at Different Tube Potentials.

RATIONALE AND OBJECTIVES: The study aimed to evaluate in vitro stent lumen visibility of coronary stents in a second- and third-generation dual-source computed tomography (CT) system at 100 and 120 kVp tube potential. MATERIALS AND METHODS: Twenty-six coronary stents ranging from 2.25 to 4.0 mm in diameter were implanted in a coronary vessel phantom. Scans were performed at 100 and 120 kVp tube potential. Evaluation was performed using a medium-sharp kernel in both systems (B46f in the second-generation and Bv49 in the third-generation model) and a sharp (Bv59) convolution kernel optimized for vascular imaging in the third-generation CT. RESULTS: The median visible stent lumen diameter in the second-generation system was higher at 120 kVp with a median of 62.0% compared to 56.3% at 100 kVp (P < 0.001). The median visible diameter in the third-generation system was significantly higher applying the Bv49 kernel with 66.7% at 120 kVp and 61.1% at 100 kVp (both P < 0.001). When applying the Bv59 kernel, visible stent lumen further increased to 69.3% at 120 kVp and 66.7% at 100 kVp. Additionally, stent lumen was assessed using full width at half maximum, resulting in a comparable increase in luminal diameter at corresponding tube potential. CONCLUSIONS: Third-generation dual-source CT provides superior stent lumen visibility at equivalent tube potential and at reduced tube potential of 100 kVp when compared to 120 kVp in a second-generation system, at least when manually assessed.

An investigation into potential gender-specific differences in myocardial triglyceride content assessed by 1H-Magnetic Resonance Spectroscopy at 3Tesla.

OBJECTIVE: Over the past decade, myocardial triglyceride content has become an accepted biomarker for chronic metabolic and cardiac disease. The purpose of this study was to use proton (hydrogen 1)-magnetic resonance spectroscopy ((1)H-MRS) at 3Tesla (3 T) field strength to assess potential gender-related differences in myocardial triglyceride content in healthy individuals. METHODS: Cardiac MR imaging was performed to enable accurate voxel placement and obtain functional and morphological information. Double triggered (i.e., ECG and respiratory motion gating) (1)H-MRS was used to quantify myocardial triglyceride levels for each gender. Two-sample t-test and Mann-Whitney U-test were used for statistical analyses. RESULTS: In total, 40 healthy volunteers (22 male, 18 female; aged >18 years and age matched) were included in the study. Median myocardial triglyceride content was 0.28% (interquartile range [IQR] 0.17-0.42%) in male and 0.24% (IQR 0.14-0.45%) in female participants, and no statistically significant difference was observed between the genders. Furthermore, no gender-specific difference in ejection fraction was observed, although on average, male participants presented with a higher mean ± SD left ventricular mass (136.3 ± 25.2 g) than female participants (103.9 ± 16.1 g). CONCLUSIONS: The study showed that (1)H-MRS is a capable, noninvasive tool for acquisition of myocardial triglyceride metabolites. Myocardial triglyceride concentration was shown to be unrelated to gender in this group of healthy volunteers.

Long term evolution of magnetic resonance imaging characteristics in a case of atypical left lateral wall hypertrophic cardiomyopathy.

We are reporting a long-time magnetic resonance imaging (MRI) follow-up in a rare case of cardiac left lateral wall hypertrophy. Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disorder and a significant cause of sudden cardiac death. Cardiac magnetic resonance (CMR) imaging can be a valuable tool for assessment of detailed information on size, localization, and tissue characteristics of hypertrophied myocardium. However, there is still little knowledge of long-term evolution of HCM as visualized by magnetic resonance imaging. Recently, our group reported a case of left lateral wall HCM as a rare variant of the more common forms, such as septal HCM, or apical HCM. As we now retrieved an old cardiac MRI acquired in this patient more than 20 years ago, we are able to provide the thrilling experience of an ultra-long MRI follow-up presentation in this rare case of left lateral wall hypertrophy. Furthermore, this case outlines the tremendous improvements in imaging quality within the last two decades of CMR imaging.

Partial segmental thrombosis of the corpus cavernosum (PSTCC) diagnosed by contrast-enhanced ultrasound: a case report.

BACKGROUND: Partial segmental thrombosis of the corpus cavernosum (PSTCC) is a rare disease predominantly occurring in young men. Cardinal symptoms are pain and perineal swelling. Although several risk factors are described in the literature, the exact etiology of penile thrombosis remains unclear in most cases. MRI or ultrasound (US) is usually used for diagnosing this condition. CASE PRESENTATION: We report a case of penile thrombosis after left-sided varicocele ligature in a young patient. The diagnosis was established using contrast-enhanced ultrasound (CEUS) and was confirmed by contrast-enhanced magnetic resonance imaging (ceMRI). Successful conservative treatment consisted of systemic anticoagulation using low molecular weight heparin and acetylsalicylic acid. CONCLUSION: PSTCC is a rare condition in young men and appears with massive pain and perineal swelling. In case of suspected PSTCC utilization of CEUS may be of diagnostic benefit.