Radial compressed sensing imaging improves the velocity detection limit of single cell tracking time-lapse MRI.

PURPOSE: Time-lapse MRI enables tracking of single iron-labeled cells. Yet, due to temporal blurring, only slowly moving cells can be resolved. To study faster cells for example during inflammatory processes, accelerated acquisition is needed. METHODS: A rotating phantom system was developed to quantitatively measure the current maximum detectable speed of cells in time-lapse MRI. For accelerated cell tracking, an interleaved radial acquisition scheme was applied to phantom and murine brain in vivo time-lapse MRI experiments at 9.4 T. Detection of iron-labeled cells was evaluated in fully sampled and undersampled reconstructions with and without compressed sensing. RESULTS: The rotating phantom system enabled ultra-slow rotation of phantoms and a velocity detection limit of full-brain Cartesian time-lapse MRI of up to 172 µm/min was determined. Both phantom and in vivo measurements showed that single cells can be followed dynamically using radial time-lapse MRI. Higher temporal resolution of undersampled reconstructions reduced geometric distortion, the velocity detection limit was increased to 1.1 mm/min in vitro, and previously hidden fast-moving cells were recovered. In the mouse brain after in vivo labeling, a total of 42 ± 4 cells were counted in fully sampled, but only 7 ± 1 in undersampled images due to streaking artifacts. Using compressed sensing 33 ± 4 cells were detected. CONCLUSION: Interleaved radial time-lapse MRI permits retrospective reconstruction of both fully sampled and accelerated images, enables single cell tracking at higher temporal resolution and recovers cells hidden before due to blurring. The velocity detection limit as determined with the rotating phantom system increased two- to three-fold compared to previous results.

Vascular response patterns to targeted therapies in murine breast cancer models with divergent degrees of malignancy.

BACKGROUND: Response assessment of targeted cancer therapies is becoming increasingly challenging, as it is not adequately assessable with conventional morphological and volumetric analyses of tumor lesions. The tumor microenvironment is particularly constituted by tumor vasculature which is altered by various targeted therapies. The aim of this study was to noninvasively assess changes in tumor perfusion and vessel permeability after targeted therapy in murine models of breast cancer with divergent degrees of malignancy. METHODS: Low malignant 67NR or highly malignant 4T1 tumor-bearing mice were treated with either the multi-kinase inhibitor sorafenib or immune checkpoint inhibitors (ICI, combination of anti-PD1 and anti-CTLA4). Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with i.v. injection of albumin-binding gadofosveset was conducted on a 9.4 T small animal MRI. Ex vivo validation of MRI results was achieved by transmission electron microscopy, immunohistochemistry and laser ablation-inductively coupled plasma-mass spectrometry. RESULTS: Therapy-induced changes in tumor vasculature differed between low and highly malignant tumors. Sorafenib treatment led to decreased tumor perfusion and endothelial permeability in low malignant 67NR tumors. In contrast, highly malignant 4T1 tumors demonstrated characteristics of a transient window of vascular normalization with an increase in tumor perfusion and permeability early after therapy initiation, followed by decreased perfusion and permeability parameters. In the low malignant 67NR model, ICI treatment also mediated vessel-stabilizing effects with decreased tumor perfusion and permeability, while ICI-treated 4T1 tumors exhibited increasing tumor perfusion with excessive vascular leakage. CONCLUSION: DCE-MRI enables noninvasive assessment of early changes in tumor vasculature after targeted therapies, revealing different response patterns between tumors with divergent degrees of malignancy. DCE-derived tumor perfusion and permeability parameters may serve as vascular biomarkers that allow for repetitive examination of response to antiangiogenic treatment or immunotherapy.

Dynamic cell tracking using time-lapse MRI with variable temporal resolution Cartesian sampling.

PURPOSE: Temporal resolution of time-lapse MRI to track individual iron-labeled cells is limited by the required data-acquisition time to fill k-space and to reach sufficient SNR. Although motion of slowly patrolling monocytes can be resolved, detection of fast-moving immune cells requires improved acquisition and reconstruction strategies. THEORY AND METHODS: For accelerated MRI cell tracking, a Cartesian sampling scheme was designed, in which the fully sampled and undersampled k-space data for different acceleration factors were acquired simultaneously, and multiple undersampling ratios could be chosen retrospectively. Compressed-sensing reconstruction was applied using dictionary learning and low-rank constraints. Detection of iron-labeled monocytes was evaluated with simulations, rotating phantom experiments and in vivo mouse brain measurements at 9.4 T. RESULTS: Fully sampled and 2.4-times and 4.8-times accelerated images were reconstructed and had sufficient contrast-to-noise ratio (CNR) for single cells to be resolved and followed dynamically. The phantom experiments showed an improvement in CNR of 6.1% per µm/s in the 4.8-times undersampled images. Geometric distortion of cells caused by motion was visibly reduced in the accelerated images, which enabled detection of moving cells with velocities of up to 7.0 µm/s. In vivo, additional cells were resolved in the accelerated images due to the improved temporal resolution. CONCLUSION: The easy-to-implement flexible Cartesian sampling scheme with compressed-sensing reconstruction permits simultaneous acquisition of both fully sampled and high temporal resolution images. The CNR of moving cells is effectively improved, enabling the recovery of high velocity cells with sufficient contrast at virtually no cost.

Multi-organ Radiomics-Based Prediction of Future Remnant Liver Hypertrophy Following Portal Vein Embolization.

BACKGROUND: Portal vein embolization (PVE) is used to induce remnant liver hypertrophy prior to major hepatectomy. The purpose of this study was to evaluate the predictive value of baseline computed tomography (CT) data for future remnant liver (FRL) hypertrophy after PVE. METHODS: In this retrospective study, all consecutive patients undergoing right-sided PVE with or without hepatic vein embolization between 2018 and 2021 were included. CT volumetry was performed before and after PVE to assess standardized FRL volume (sFRLV). Radiomic features were extracted from baseline CT after segmenting liver (without tumor), spleen and bone marrow. For selecting features that allow classification of response (hypertrophy ≥ 1.33), a stepwise dimension reduction was performed. Logistic regression models were fitted and selected features were tested for their predictive value. Decision curve analysis was performed on the test dataset. RESULTS: A total of 53 patients with liver tumor were included in this study. sFRLV increased significantly after PVE, with a mean hypertrophy of FRL of 1.5 ± 0.3-fold. sFRLV hypertrophy ≥ 1.33 was reached in 35 (66%) patients. Three independent radiomic features, i.e. liver-, spleen- and bone marrow-associated, differentiated well between responders and non-responders. A logistic regression model revealed the highest accuracy (area under the curve 0.875) for the prediction of response, with sensitivity of 1.0 and specificity of 0.5. Decision curve analysis revealed a positive net benefit when applying the model. CONCLUSIONS: This proof-of-concept study provides first evidence of a potential predictive value of baseline multi-organ radiomics CT data for FRL hypertrophy after PVE.

Evaluation of effectiveness and safety of the multizone NeVaTM stent retriever for mechanical thrombectomy in ischemic stroke.

PURPOSE: This study aimed to evaluate the effectiveness and safety of the NeVaTM stent retriever as first- and second-line device for mechanical thrombectomy in acute ischemic stroke. METHODS: In this retrospective single-center study, all consecutive patients that underwent mechanical thrombectomy with NeVaTM stent retriever as first- or second-line device due to intracranial vessel occlusion with acute ischemic stroke between March and November 2022 were included. RESULTS: Thirty-nine patients (m=18, f=21) with a mean age of 69.9 ± 13.3 years were treated with the NeVaTM stent retriever. NeVaTM stent retriever was used as first-line device in 24 (61.5%) of patients and in 15 (38.5%) as second-line device. First-pass rate (≥mTICI 2c) of NeVaTM stent retriever was both 66.7% when used as first- or second-line device. Final recanalization rate including rescue strategies was 92.3% for ≥mTICI2c and 94.9% for ≥mTICI2b. No device-related minor or major adverse events were observed. A hemorrhage was detected in 33.3% of patients at 24h post-thrombectomy dual-energy CT, of which none was classified as symptomatic intracerebral hemorrhage. NIHSS and mRS improved significantly at discharge compared to admission (p<0.05). CONCLUSION: The NeVaTM stent retriever has a high effectivity and good safety profile as first- and second-line device for mechanical thrombectomy in acute ischemic stroke.

Clinical impact of a celiac axis stenosis in patients undergoing hepatobiliary surgery.

BACKGROUND: Celiac axis stenosis (CAS) often is an incidental finding in terms of diagnostic for hepatobiliary surgery since most cases remain asymptomatic. It remains unclear whether CAS is a risk factor for postoperative complications after hepatobiliary surgery. Therefore, the aim of this study was to evaluate the impact of an asymptomatic CAS on the postoperative morbidity and survival of patients undergoing hepatobiliary surgery. METHODS: We retrospectively analyzed CT scans and clinicopathological data of 250 consecutive patients undergoing hepatobiliary surgery between 2011 and 2018 in our tertiary center. We compared the postoperative course between patients with and without an incidental CAS as well as their overall survival. RESULTS: CAS was caused by atherosclerotic stenosis in 16 (64%) patients, by ligamentous stenosis in 4 (16%) and by combined conditions in 5 cases (20%). Mean age of patients in the CAS group was significantly higher in comparison to patients of the non-CAS group (71.0 vs. 59.1 years, p < 0.001). Major hepatectomy was conducted in 40% of the CAS patients and 19.6% of non-CAS patients, respectively (p = 0.036). Interestingly, no statistically significant differences in postoperative morbidity (40 vs. 46.2%, p = 0.673) or in overall survival between the groups (41.3 vs. 51.9 months, p = 0.611) were observed. CONCLUSION: Our analysis found no correlation between an asymptomatic celiac axis stenosis and postoperative complications or overall survival after hepatobiliary surgery. Which impact the incidental CAS may have in highly complex cases remains unclear. Further studies are needed to identify patients who benefit from CAS treatment before hepatobiliary surgery.

Medical imaging training with eye movement modeling examples: A randomized controlled study.

PURPOSE: To determine whether ultrasound training in which the expert's eye movements are superimposed to the underlying ultrasound video (eye movement modeling examples; EMMEs) leads to better learner outcomes than traditional eye movement-free instructions. MATERIALS AND METHODS: 106 undergraduate medical students were randomized in two groups; 51 students in the EMME group watched 5-min ultrasound examination videos combined with the eye movements of an expert performing the task. The identical videos without the eye movements were shown to 55 students in the control group. Performance and behavioral parameters were compared prepost interventional using ANOVAs. Additionally, cognitive load, and prior knowledge in anatomy were surveyed. RESULTS: After training, the EMME group identified more sonoanatomical structures correctly, and completed the tasks faster than the control group. This effect was partly mediated by a reduction of extraneous cognitive load. Participants with greater prior anatomical knowledge benefited the most from the EMME training. CONCLUSION: Displaying experts' eye movements in medical imaging training appears to be an effective way to foster medical interpretation skills of undergraduate medical students. One underlying mechanism might be that practicing with eye movements reduces cognitive load and helps learners activate their prior knowledge.

Detection of Early Endothelial Dysfunction by Optoacoustic Tomography.

Variations in vascular wall shear stress are often presumed to result in the formation of atherosclerotic lesions at specific arterial regions, where continuous laminar flow is disturbed. The influences of altered blood flow dynamics and oscillations on the integrity of endothelial cells and the endothelial layer have been extensively studied in vitro and in vivo. Under pathological conditions, the Arg-Gly-Asp (RGD) motif binding integrin αvß3 has been identified as a relevant target, as it induces endothelial cell activation. Animal models for in vivo imaging of endothelial dysfunction (ED) mainly rely on genetically modified knockout models that develop endothelial damage and atherosclerotic plaques upon hypercholesterolemia (ApoE-/- and LDLR-/-), thereby depicting late-stage pathophysiology. The visualization of early ED, however, remains a challenge. Therefore, a carotid artery cuff model of low and oscillating shear stress was applied in CD-1 wild-type mice, which should be able to show the effects of altered shear stress on a healthy endothelium, thus revealing alterations in early ED. Multispectral optoacoustic tomography (MSOT) was assessed as a non-invasive and highly sensitive imaging technique for the detection of an intravenously injected RGD-mimetic fluorescent probe in a longitudinal (2-12 weeks) study after surgical cuff intervention of the right common carotid artery (RCCA). Images were analyzed concerning the signal distribution upstream and downstream of the implanted cuff, as well as on the contralateral side as a control. Subsequent histological analysis was applied to delineate the distribution of relevant factors within the carotid vessel walls. Analysis revealed a significantly enhanced fluorescent signal intensity in the RCCA upstream of the cuff compared to the contralateral healthy side and the downstream region at all time points post-surgery. The most obvious differences were recorded at 6 and 8 weeks after implantation. Immunohistochemistry revealed a high degree of αv-positivity in this region of the RCCA, but not in the left common carotid artery (LCCA) or downstream of the cuff. In addition, macrophages could be detected by CD68 immunohistochemistry in the RCCA, showing ongoing inflammatory processes. In conclusion, MSOT is capable of delineating alterations in endothelial cell integrity in vivo in the applied model of early ED, where an elevated expression of integrin αvß3 was detected within vascular structures.

18F-FDG-PET-MRI for the assessment of acute intestinal graft-versus-host-disease (GvHD).

BACKGROUND: Graft versus host disease (GvHD) is a frequent complication of allogeneic stem cell transplantation (alloSCT), significantly increasing mortality. Previous imaging studies focused on the assessment of intestinal GvHD with contrast-enhanced MRI/CT or 18F-FDG-PET imaging alone. The objective of this retrospective study was to elucidate the diagnostic value of a combined 18F-FDG-PET-MRI protocol in patients with acute intestinal GvHD. METHODS: Between 2/2015 and 8/2019, 21 patients with acute intestinal GvHD underwent 18F-FDG-PET-MRI. PET, MRI and PET-MRI datasets were independently reviewed. Readers assessed the number of affected segments of the lower gastrointestinal tract and the reliability of the diagnosis on a 5-point Likert scale and quantitative PET (SUVmax, SUVpeak, metabolic volume (MV)) and MRI parameter (wall thickness), were correlated to clinical staging of acute intestinal GvHD. RESULTS: The detection rate for acute intestinal GvHD was 56.8% for PET, 61.4% for MRI and 100% for PET-MRI. PET-MRI (median Likert-scale value: 5; range: 4-5) offers a significantly higher reliability of the diagnosis compared to PET (median: 4; range: 2-5; p = 0.01) and MRI alone (median: 4; range: 3-5; p = 0.03). The number of affected segments in PET-MRI (rs = 0.677; p <  0.001) and the MV (rs = 0.703; p <  0.001) correlated significantly with the clinical stage. SUVmax (rs = 0.345; p = 0.14), SUVpeak (rs = 0.276; p = 0.24) and wall thickening (rs = 0.174; p = 0.17) did not show a significant correlation to clinical stage. CONCLUSION: 18F-FDG-PET-MRI allows for highly reliable assessment of acute intestinal GvHD and adds information indicating clinical severity.

Value Improvement by Assessing IR Care via Time-Driven Activity-Based Costing.

PURPOSE: To evaluate time-driven activity-based costing (TDABC) in interventional radiology for image-guided vascular malformation treatment as an example. MATERIALS AND METHODS: Retrospective analysis was performed on consecutive vascular malformation treatment cycles [67 venous malformations (VMs) and 11 arteriovenous malformations (AVMs)] in a university hospital in 2018. All activities were integrated with a process map, and spent resources were assigned accordingly. TDABC uses 2 parameters: (i) practical capacity cost rate, calculated as 80% of theoretical capacity, and (ii) time consumption of each resource determined by interviews (23 items). Thereby, the total costs were calculated. Treatment cycles were modified according to identified resource waste and TDABC-guided negotiations with health insurance. RESULTS: Total personnel time required was higher for AVM (1,191 min) than for VM (637 min) treatment. The interventional procedure comprised the major part (46%) of personnel time required in AVM, whereas it comprised 19% in VM treatment. Materials represented the major cost type in AVM (75%) and VM (45%) treatments. TDABC-based treatment process modification led to a decrease in personnel time need of 16% and 30% and a cost reduction of 5.5% and 15.7% for AVM and VM treatments, respectively. TDABC-guided cost reduction and TDABC-informed negotiations improved profit from -56% to +40% and from +41% to +69% for AVM and VM treatments, respectively. CONCLUSIONS: TDABC facilitated the precise costing of interventional radiologic treatment cycles and optimized internal processes, cost reduction, and revenues. Hence, TDABC is a promising tool to determine the denominator of interventional radiology's value.

CT-Guided Percutaneous Drainage of Pneumoperitoneum Presenting as Acute Abdomen.

PURPOSE: To evaluate the feasibility and effectiveness of computed tomography (CT)-guided percutaneous drainage (PD) in patients with iatrogenic pneumoperitoneum presenting as acute abdomen. MATERIALS AND METHODS: In this retrospective, single-center cohort study, 16 consecutive patients (9 males, 7 females; median age, 67.5 [51-85] years) undergoing PD for managing acute abdomen caused by iatrogenic pneumoperitoneum between 2013 and 2019 were analyzed. Inclusion criteria were clinical signs of acute abdomen that was unresponsive to conservative management and pneumoperitoneum due to an iatrogenic cause after PD, observed using CT imaging. Volumetry of pneumoperitoneum was performed using computer-aided image segmentation. To evaluate the clinical outcome, the paired t-test was performed to analyze the course of pain intensity on the numerical pain rating scale (NPRS, 0-10). Patient records were reviewed to determine PD-related adverse events and median drain duration. RESULTS: The median pneumoperitoneum volume was 891.1 (127.7-3,677.0) mL. All PD procedures were successfully performed, with symptom relief and immediate abdominal decompression (mean segmental volume reduction, 79.8% ± 13.5). Acute abdomen symptoms were resolved, with significant improvement in pain intensity between the day of the PD procedure and the first day after the procdure (mean NPRS scores, 3.3 ± 1.9 vs 0.8 ± 1.0; P < .001). The median drain duration was 2 (1-3) days. No PD-associated adverse events were observed. After PD, 14 patients required only conservative management, whereas 2 patients with anastomotic leakage required additional surgery as they showed signs of persisting sepsis and generalized peritonitis. CONCLUSIONS: PD is a safe and suitable procedure for the management of symptoms in patients with iatrogenic pneumoperitoneum presenting as acute abdomen.

Combined Transarterial Embolization and Percutaneous Sclerotherapy as Treatment for Refractory and Nonresectable Aneurysmal Bone Cysts.

PURPOSE: To evaluate the safety and effectiveness of combined transarterial embolization and percutaneous sclerotherapy in the treatment of refractory and nonresectable aneurysmal bone cysts (ABCs) as assessed by imaging and clinical outcomes. MATERIALS AND METHODS: This retrospective, single-center study included 16 consecutive patients (9 women and 7 men; median age, 17 years [range, 6-25 years]) who underwent combined transarterial embolization (using ethylene vinyl alcohol) and percutaneous sclerotherapy (using ethanol gel and polidocanol) for refractory and nonresectable ABCs. The median follow-up was 27.3 months (range, 6.7-47.5 months). Grade of mineralization (5-point Likert scale), grade of fluid-fluid levels (FFLs; 4-point Likert scale), and contrast-enhancing lesion volume were evaluated before and after treatment. The quality of life was determined before and after treatment using the Musculoskeletal Tumor Society (MSTS) score and the 36-Item Short Form Survey (SF-36) health questionnaire. RESULTS: A mean of 1.6 ± 0.7 transarterial embolizations and 3.2 ± 1.7 percutaneous sclerotherapies were performed. No adverse events were observed. All patients showed either partial or complete response; no patient showed ABC recurrence. The grade of mineralization (3.7 ± 0.7 after therapy vs 1.4 ± 0.5 at baseline; P < .0001) and grade of FFL (3.5 ± 0.8 after therapy vs 1.9 ± 0.6 at baseline; P < .0001) significantly improved after therapy compared with baseline. The mean contrast-enhancing lesion volume significantly decreased after treatment compared with baseline (45.9 mm³ ± 96.1 vs 156.0 mm³ ± 115.3, respectively; P = .0003). The MSTS scores (28.8 ± 1.8 after treatment vs 14.1 ± 8.6 at baseline; P < .0001) and SF-36 findings revealed a significant improvement in the quality of life after treatment compared with baseline, leaving most patients without relevant constraints. CONCLUSIONS: Combined transarterial embolization and percutaneous sclerotherapy is a minimally invasive, safe, and effective treatment option for refractory and nonresectable ABCs. Treatment fostered bone mineralization and significantly improved patients' quality of life.

Efficacy of 90Y-Radioembolization in Metastatic Colorectal Cancer Depending on the Primary Tumor Side.

BACKGROUND: Metastatic colorectal cancer (mCRC) is associated with different molecular biology, clinical characteristics, and outcome depending on the primary tumor localization. We aimed to evaluate the effectiveness of 90Y-radioembolization (RE) for therapy of colorectal liver metastases depending on the primary tumor side. METHODS: We performed a retrospective analysis of n = 73 patients with mCRC and RE in our university liver center between 2009 and 2018. Patients were stratified according to the primary tumor side (left vs. right hemicolon), treatment response was assessed by the Response Evaluation Criteria in Solid Tumors (RECIST) at follow-up after 3 months. Kaplan-Meier analysis was performed to analyze survival followed by Cox regression to determine independent prognostic factors for survival. RESULTS: Prior to RE, all patients had received systemic therapy, with either stable or progressive disease, but no partial or complete response. In n = 22/73 (30.1%) patients, the primary tumor side was in the right colon; in n = 51/73 (69.9%) patients, in the left colon. Hepatic tumor burden was ≤25% in n = 36/73 (49.3%) patients and >25% in n = 37/73 (50.7%) patients. At 3 months, n = 21 (33.8%) patients showed treatment response (n = 2 [3.2%]; complete response, n = 19 [30.6%]; partial response), n = 13 (21.0%) stable disease, and n = 28 (45.2%) progressive disease after RE. The median survival in case of primary tumor side in the left colon was significantly higher than for primary tumors in the right colon (8.7 vs. 6.0 months, p = 0.033). The median survival for a hepatic tumor burden ≤25% was significantly higher than that of >25% (13.9 vs. 4.3 months, p < 0.001). The median overall survival was 6.1 months. CONCLUSION: The median survival after RE in hepatic-mCRC depends on the primary tumor side and the preprocedural hepatic tumor burden.

Intraosseous contrast administration for emergency stroke CT.

Computed tomography (CT) imaging in acute stroke is an established and fairly widespread approach, but there is no data on applicability of intraosseous (IO) contrast administration in the case of failed intravenous (IV) cannula placement. Here, we present the first case of IO contrast administration for CT imaging in suspected acute stroke providing a dedicated CT examination protocol and analysis of achieved image quality as well as a review of available literature.

Evaluation of 311 contemporary cases of stereotactic biopsies in patients with neoplastic and non-neoplastic lesions-diagnostic yield and management of non-diagnostic cases.

Stereotactic biopsies are an established tool for obtaining diagnosis of unclear brain lesions. However, non-diagnostic biopsies still occur. We aimed to analyze the contemporary diagnostic yield of stereotactic biopsies, predictors for non-diagnostic biopsies, outcome, and follow-up strategy after non-diagnostic biopsy. We conducted a single-center retrospective study of 311 adult patients undergoing stereotactic biopsies due to a newly diagnosed lesion at our department between 2012 and 2018. Patient data regarding comorbidities, presenting symptoms, imaging features, and non-invasive diagnostic procedures were obtained. The overall diagnostic yield was 86.2% and differed significantly between the various suspected diagnosis groups and was the highest when suspecting primary brain tumor compared with non-neoplastic lesions (91.2% vs. 73.3%, p > 0.001). Predicators for non-diagnostic biopsies were small lesion size, lack of contrast-enhancement, presence of sepsis, or underlying hemato-oncological disease. In case of non-diagnostic biopsy, a re-biopsy was performed in 12 cases, revealing a final diagnosis in 75%. In 16 cases, empiric therapy was started based on the suspected underlying disease. Close follow-up was performed in the remaining 15 cases. We showed that stereotactic biopsy is a safe procedure with reasonable diagnostic yield even for non-neoplastic lesions, when non-invasive diagnostic was inconclusive. In addition, we developed treatment recommendations for cases of non-diagnostic biopsies.

Portal and hepatic vein embolization prior to major hepatectomy.

PURPOSE: To analyze safety and effectiveness of simultaneous portal and hepatic vein embolization (PHVE) or sequential hepatic vein embolization (HVE) compared to portal vein embolization (PVE) for future remnant liver (FRL) hypertrophy prior to major hepatic surgery. METHODS: Patients undergoing PVE, PHVE or HVE at our tertiary care center between 2018 and 2020 were retrospectively included. FRLV, standardized FRLV (sFRLV) and sFRLV growth rate per day were assessed via volumetry, as well as laboratory parameters. RESULTS: 36 patients (f = 15, m = 21; median 64.5 y) were included, 16 patients received PHVE and 20 patients PVE, of which 4 received sequential HVE. Significant increase of FRLV was achieved with both PVE and PHVE compared to baseline (p < 0.0001). sFRLV growth rate did not significantly differ following PHVE (2.2 ±â€Š1.2 %/d) or PVE (2.2 ±â€Š1.7 %/d, p = 0.94). Left portal vein thrombosis (LPVT) was observed after PHVE in 6 patients and in 1 patient after PVE. Sequential HVE showed a considerably high growth rate of 1.42 ±â€Š0.45 %/d after PVE. CONCLUSION: PHVE effectively induces FRL hypertrophy but yields comparable sFRLV to PVE. Sequential HVE further induces hypertrophy after insufficient growth due to PVE. Considering a potentially higher rate of LPVT after PHVE, PVE might be preferred in patients with moderate baseline sFRLV, with optional sequential HVE in non-sufficient responders.

Invasive diagnostic and therapeutic measures are unnecessary in patients with symptomatic van Neck-Odelberg disease (ischiopubic synchondrosis): a retrospective single-center study of 21 patients with median follow-up of 5 years.

Background and purpose - Van Neck-Odelberg disease (VND) is a self-limiting skeletal phenomenon characterized by a symptomatic or asymptomatic uni- or bilateral overgrowth of the pre-pubescent ischiopubic synchondrosis. It is frequently misinterpreted as a neoplastic, traumatic, or infectious process, often resulting in excessive diagnostic and therapeutic measures. This study assessed the demographic, clinical, and radiographic features of the condition and analyzed diagnostic and therapeutic pathways in a large single-center cohort.Patients and methods - We retrospectively analyzed 21 consecutive patients (13 male) with a median age of 10 years (IQR 8-13) and a median follow-up of 5 years (IQR 42-94 months), who were diagnosed at our department between 1995 and 2019.Results - VND was unilateral in 17 cases and bilateral in 4 cases. Initial referral diagnoses included suspected primary bone tumor (n = 9), fracture (n = 3), osteomyelitis (n = 2), and metastasis (n = 1). The referral diagnosis was more likely to be VND in asymptomatic than symptomatic patients (4/6 vs. 2/15). More MRI scans were performed in unilateral than bilateral VND (median 2 vs. 0). All 15 symptomatic patients underwent nonoperative treatment and reported a resolution of symptoms and return to physical activity after a median time of 5 months (IQR 0-6).Interpretation - By understanding the physiological course of VND during skeletal maturation, unnecessary diagnostic and therapeutic measures can be avoided and uncertainty and anxiety amongst affected patients, their families, and treating physicians can be minimized.

Introducing Specificity to Iron Oxide Nanoparticle Imaging by Combining 57Fe-Based MRI and Mass Spectrometry.

Iron oxide nanoparticles (ION) are highly sensitive probes for magnetic resonance imaging (MRI) that have previously been used for in vivo cell tracking and have enabled implementation of several diagnostic tools to detect and monitor disease. However, the in vivo MRI signal of ION can overlap with the signal from endogenous iron, resulting in a lack of detection specificity. Therefore, the long-term fate of administered ION remains largely unknown, and possible tissue deposition of iron cannot be assessed with established methods. Herein, we combine nonradioactive 57Fe-ION MRI with ex vivo laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging, enabling unambiguous differentiation between endogenous iron (56Fe) and iron originating from applied ION in mice. We establish 57Fe-ION as an in vivo MRI sensor for cell tracking in a mouse model of subcutaneous inflammation and for assessing the long-term fate of 57Fe-ION. Our approach resolves the lack of detection specificity in ION imaging by unambiguously recording a 57Fe signature.

Gorham-Stout disease: good results of bisphosphonate treatment in 6 of 7 patients.

Background and purpose - Gorham-Stout disease (GSD) is a rare mono- or polyostotic condition characterized by idiopathic intraosseous proliferation of angiomatous structures resulting in progressive destruction and resorption of bone. Little is known about the course of disease and no previous study has evaluated patients' quality of life (QoL).Patients and methods - This is a retrospective analysis of 7 consecutive patients (5 males) with a median age at diagnosis of 14 years and a median follow-up of 7 years who were diagnosed with GSD in our department between 1995 and 2018. Data regarding clinical, radiographic, and histopathological features, and treatment, as well as sequelae and their subsequent therapy, were obtained. QoL was assessed by Musculoskeletal Tumor Society Score (MSTS), Toronto Extremity Salvage Score (TESS), and Reintegration to Normal Living (RNL) Index.Results - 3 patients had a monoostotic and 4 patients a polyostotic disease. Besides a diagnostic biopsy, 4 of the 7 patients had to undergo 8 surgeries to treat evolving sequelae. Using an off-label therapy with bisphosphonates in 6 patients, a stable disease state was achieved in 5 patients after a median of 20 months. The median MSTS, TESS, and RNL Index at last follow-up was between 87% and 79%.Interpretation - Due to its rare occurrence, diagnosis and treatment of GSD remain challenging. Off-label treatment with bisphosphonates appears to lead to a stable disease state in the majority of patients. QoL varies depending on the individual manifestations but good to excellent results can be achieved even in complex polyostotic cases with a history of possibly life-threatening sequelae.

Multispectral optoacoustic tomography of the human breast: characterisation of healthy tissue and malignant lesions using a hybrid ultrasound-optoacoustic approach.

BACKGROUND AND AIM: Multispectral optoacoustic tomography (MSOT) represents a new in vivo imaging technique with high resolution (~250 µm) and tissue penetration (>1 cm) using the photoacoustic effect. While ultrasound contains anatomical information for lesion detection, MSOT provides functional information based on intrinsic tissue chromophores. We aimed to evaluate the feasibility of combined ultrasound/MSOT imaging of breast cancer in patients compared to healthy volunteers. METHODS: Imaging was performed using a handheld MSOT system for clinical use in healthy volunteers (n = 6) and representative patients with histologically confirmed invasive breast carcinoma (n = 5) and ductal carcinoma in situ (DCIS, n = 2). MSOT values for haemoglobin and oxygen saturation were assessed at 0.5, 1.0 and 1.5 cm depth and selected wavelengths between 700 and 850 nm. RESULTS: Reproducible signals were obtained in all wavelengths with consistent MSOT signals in superficial tissue in breasts of healthy individuals. In contrast, we found increased signals for haemoglobin in invasive carcinoma, suggesting a higher perfusion of the tumour and tumour environment. For DCIS, MSOT values showed only little variation compared to healthy tissue. CONCLUSIONS: This preliminary MSOT breast imaging study provided stable, reproducible data on tissue composition and physiological properties, potentially enabling differentiation of solid malignant and healthy tissue. KEY POINTS: • A handheld MSOT probe enables real-time molecular imaging of the breast. • MSOT of healthy controls provides a reproducible reference for pathology identification. • MSOT parameters allows for differentiation of invasive carcinoma and healthy tissue.