Usefulness of cone-beam computed tomography-reformatted epidurography in percutaneous epidural adhesiolysis: A pilot study.

BACKGROUND: Conventional epidurography (CE) is thought to have insufficient usefulness on percutaneous epidural adhesiolysis (PEA). We aimed to evaluate the association between the outcome of PEA and cone-beam computed tomography-reformatted epidurography (CBCT-RE). METHODS: After ethics board approval and written informed consent were obtained, we performed 30 PEA in 26 participants, and evaluated their post-PEA image findings. Two independent radiologists categorized and recorded the occurrence of contrast in the intracanal ventral and extraforaminal regions on CE, and in the dorsal canal (DC), ventral canal (VC), dorsal foramen (DF), and ventral foramen (VF) on CBCT-RE. Reproducibility was assessed using intraclass correlation coefficients (ICCs). Baseline characteristics along with contrast distribution patterns of CE and CBCT-RE were analyzed in terms of their association with symptom relief at 1 month after PEA. RESULTS: The rate of patients with symptoms relief >50% after PEA was 63.3%. The inter-reader agreement was higher for CBCT-RE (ICC = 0.955) than for CE (ICC = 0.793). Participants with contrast coexisting in VC and DF adjacent to the irritated nerve root on CBCT-RE ( p = 0.015) had a significantly better response after PEA than those without contrast at these locations on CBCT-RE, independent of baseline characteristics (adjusted odds ratio: 11.414 [ p = 0.012]). CONCLUSION: CBCT-RE with identifying contrast distribution patterns is useful for predicting outcome of PEA.

Value of CT in targeted CT-guided epidural blood patching: Predictors for successful epidural punctures.

BACKGROUND AND PURPOSE: Differentiating epidural from intrathecal punctures before computed tomography (CT)-guided epidural blood patching (EBP) is subjective, relying on operator experience. This study aimed to investigate CT findings for epidural and intrathecal punctures and identify reliable predictors for successful epidural punctures before targeted CT-guided EBP. MATERIALS AND METHODS: We included 65 patients with low-cerebrospinal fluid (CSF)-pressure headache receiving targeted CT-guided EBP between January 2021 and October 2022 in this retrospective study. We analyzed clinical data, technical information, and CT features before EBP. Fisher's exact test was used for discrete variables, while Mann-Whitney U test was used for continuous variables. Positive (PLR) and negative likelihood ratios (NLR) were calculated to identify predictors for confirming epidural punctures. RESULTS: We confirmed 43 patients as epidural punctures and 22 patients as intrathecal punctures. Before contrast injection, epidural fat at the needle tip in the epidural group was higher than the intrathecal group (37.2 % [16/43] vs. 4.5 % [1/22], p = 0.006). After contrast injection, the "contrast-needle tip connection" sign was mostly observed in the epidural group than the intrathecal group (95.3 % [41/43] vs. 9.1 % [2/22], p < 0.001). Additionally, the epidural group had significantly higher boomerang-shaped contrast morphology than the intrathecal group (65.1 % [28/43] vs. 9.1 % [2/22], p < 0.001). The "contrast-needle tip connection" sign had the highest PLR (10.49) and lowest NLR (0.05). CONCLUSION: Identifying epidural fat at the needle tip, "contrast-needle tip connection" sign, and boomerang-shaped contrast morphology on CT scans are useful for confirming proper placement of the needle tip within the epidural space.

Efficacy and reliability of three-dimensional fusion guidance for fluoroscopic navigation in transarterial embolization for refractory musculoskeletal pain.

Background: This study aimed to evaluate the efficacy and reliability of three-dimensional (3D) fusion guidance in roadmapping for fluoroscopic navigation during trans-arterial embolization for refractory musculoskeletal pain (TAE-MSK pain) in the extremities. Methods: The included research patients were divided into two groups: group A-TAE-MSK pain performed without the use of 3D fusion guidance; group B-TAE-MSK pain performed with the use of 3D fusion guidance for fluoroscopic navigation. We compared the procedure time, radiation dose, visual analogue scale for pain scores, and adverse effects (before and 3 months after TAE-MSK pain) among the two groups. In the group B, we determined the reliability of ideal branch angle for pre-operative non-contrast 3D magnetic resonance angiography (MRA) and intra-operative 3D cone beam computed tomography (CBCT) angiography. Results: We recruited 65 patients, including 23 males and 42 females (average age 58.20±12.58 years), with 38 and 27 patients in groups A and B. A total of 247 vessels were defined as target branch vessels. Significant changes were observed in the fluoroscopy time which was 32.31±12.39 and 14.33±3.06 minutes, in group A and group B (P<0.001), respectively; procedure time, which was 46.45±17.06 in group A and 24.67±9.78 in group B (P<0.001); and radiation exposure dose, determined as 0.71±0.64 and 0.34±0.29 mSv (P<0.01) in group A and group B, respectively. Furthermore, the number of target branch vessels, that underwent successful catheterization were 107 (97%) in group B as compared to 96 (70%) in group A, which was also significant (P<0.001). The study also showed that the ideal branch-angle has a similarly high consistency in pre-operative and intra-operative angiography based on the intra-class correlation coefficient (ICC) (0.994; 0.990, respectively). Conclusions: 3D fusion guidance for fluoroscopic navigation not only is a reliable process, but also effectively reduces the operation time and radiation dose of TAE-MSK pain.

The Value of 18F-FDG PET/MRI in Detecting Lumbar Radiculopathy for Selective Percutaneous Endoscopic Discectomy: a Case Report.

Magnetic resonance imaging (MRI) is the most popular imaging modality for investigating intervertebral disc herniation. However, it has a high chance for identifying incidental findings that are morphologically or structurally abnormal but not responsible for patients' symptoms. Although a previous study suggested that 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) may help identify neuroinflammation in lumbar radiculopathy, there is currently no direct evidence obtained from surgery. Here, we describe the case of a 32-year-old man with low back pain and right leg paresthesia for 7 months. MRI demonstrated disc herniation at the L3-L4, L4-L5 and L5-S1 levels, causing bilateral L5 and left S1 root compression. 18F-FDG PET/MRI demonstrated increased 18F-FDG uptake at the right L5 root, which was compatible with the patient's symptoms. Transforaminal percutaneous endoscopic lumbar discectomy (PELD) was performed. Intraoperative images revealed a swollen nerve root at the right L5 after removal of the herniated disc. After surgery, the patient experienced immediate pain relief and had no recurrence at the 6-month follow-up. When performing PELD in patients with multilevel radiculopathy identified on MRI, the use of 18F-FDG PET/MRI can help in accurate localization of the symptomatic roots and minimize surgical incision and soft-tissue injury.

Risk Factors Associated with Cartilage Defects after Anterior Cruciate Ligament Rupture in Military Draftees.

This study aimed to evaluate the different clinical results and factors associated with cartilage defects in military draftees who underwent different treatments after anterior cruciate ligament (ACL) rupture. Overall, 105 patients who had sustained ACL rupture were military draftees who underwent a conscription examination for physical status assessment from January 2012 to December 2020. Patients were divided into three groups: conservative treatment after ACL rupture, status post-anterior cruciate ligament reconstruction (ACLR), but graft rupture, and status post-ACLR with graft intact. Inter-group comparisons and statistical analyses were performed for age, body mass index (BMI), thigh circumference difference, side-to-side difference in anterior knee translation by KT-2000, meniscus tear, and cartilage defect. Multivariate logistic regression analysis was used to determine the factors associated with cartilage defects. The multivariable regression model showed that BMI (odds ratio OR: 1.303; 95% CI: 1.016-1.672; p = 0.037), thigh circumference difference (OR: 1.403; 95% CI: 1.003-1.084; p = 0.034), tear of lateral meniscus (LM) and medial meniscus (MM) (OR: 13.773; 95% CI: 1.354-140.09; p = 0.027), and graft rupture group (OR: 5.191; 95% CI: 1.388-19.419; p = 0.014) increased the risk of cartilage defects. There was no correlation between cartilage defects and age, KT-2000 difference, tear of LM or MM, or graft intact group. Progression of osteoarthritis was concerned after ACL rupture, and this study identified several factors of post-ACLR graft rupture, greater thigh circumference difference, BMI, and meniscus tear of both LM and MM affecting cartilage defects, which represent early degenerative osteoarthritis changes of the knee. The results of this study should be customized for rehabilitation and military training, especially in military draftees with ACL injuries.

The Role of Power Doppler Ultrasonography in Caudal Epidural Injection.

Background and Objectives: Although the ultrasound-guided technique is used in caudal epidural injections, severe complications can happen if ultrasound cannot identify the occurrence of intravascular injection. To determine intraepidural and intravascular injection during caudal epidural injections, we used power Doppler ultrasonography (PDU) when injecting medications into the epidural space. Materials and Methods: This is a retrospective study that enrolled a total of 277 patients with refractory low back pain or degenerative disc from January 2019 to December 2019. The injectate flow of caudal epidural injections was examined with the assistance of PDU and confirmed by fluoroscopy. Four flow patterns were identified by PDU in our study: the "Earthworm sign," the "Patch sign," the "Tubular sign" and the "Absent flow sign." The accuracy of PDU in identifying intraepidural and intravascular injections was determined by fluoroscopy images recorded during each injection. Results: We evaluated 277 patients (mean age, 68.6 ± 13.2 years; 106 men). The "Patch sign" showed a sensitivity of 88.76% and a specificity of 80% in predicting epidural injection without intravascular injection. The "Earthworm sign" demonstrated a sensitivity of 70% and a specificity of 100% in detecting intravascular injection. The "Tubular sign" showed a specificity of 100% and a sensitivity of 9.4% in predicting successful epidural injection. The absence of a flow signal showed a sensitivity of 1.87% and a specificity of 90% in predicting successful epidural injection. Conclusions: Ultrasound-guided caudal epidural injection can accurately determine intraepidural and intravascular injections with the assistance of PDU and is thus a good alternative technique to fluoroscopy-guided caudal epidural injection.

Case Report: Nerve Root Entrapment Due to Epidural Fibrosis in a Patient With Failed Back Surgery Syndrome: Value of 2-18F-Fluorodeoxyglucose Simultaneous Positron Emission Tomography-Magnetic Resonance Imaging.

Failed back surgery syndrome (FBSS) is a highly prevalent condition in patients after spine surgery. Although magnetic resonance imaging (MRI) is the gold standard for the diagnosis of epidural fibrosis, it is sometimes difficult to determine if epidural fibrosis contributes to radiculopathy. Herein, we share our experience in locating radiculopathy lesions using simultaneous positron emission tomography (PET)/MRI. 2-[18F]-FDG (18F-fluorodeoxyglucose) simultaneous PET/MRI maps of body glucose metabolism detected using PET can be used to correlate anatomical details provided by MRI to offer a very clear picture of neural inflammation due to extensive epidural fibrosis. More applications of 2-[18F]-FDG simultaneous PET/MRI in low back pain and other musculoskeletal diseases should be further investigated in the future.

Combination therapy of sorafenib and drug-eluting bead transarterial chemoembolization for advanced hepatocellular carcinoma with and without hepatic arteriovenous shunt.

BACKGROUND: To compare the efficacy and safety of combination therapy with sorafenib and drug-eluting bead transarterial chemoembolization (DEB-TACE) in advanced hepatocellular carcinoma (HCC) with or without hepatic arteriovenous shunt (HAVS). METHODS: This retrospective, single-center study enrolled 59 advanced HCC patients treated with combination therapy, of whom 33 (55.9%) patients had HAVS. Tumor response according to the mRECIST criteria was evaluated based on the CT images 1 month after TACE, and changes in the arterial enhancement ratio (AER) of tumors and portal vein tumor thrombosis were also documented. Time-to-progression (TTP), overall survival (OS), and prognostic factors were analyzed. Safety was evaluated with the incidence of TACE-related complications within 6 weeks after TACE. RESULTS: The tumor response between the two groups showed no significant difference in the objective response rate (69.2% in the group without HAVS vs 60.6% in the group with HAVS, p = 0.492) or disease control rate (92.3% vs 87.9%, p = 0.685). The two groups showed comparable TTP (4.23 vs 2.33 months, p = 0.235) and OS (12.77 vs 12.97 months, p = 0.910). A drop in the AER of tumors of more than 20% on post-TACE CT independently predicted better OS. With regard to safety, there was no significant difference between the two groups. CONCLUSION: For advanced HCC, combination therapy had equal efficacy and safety in patients with HAVS compared to those without HAVS, indicating that DEB-TACE is an optional and effective treatment in these patients.

Utility of magnetic resonance spectroscopy and diffusion-weighted imaging for detecting changes in the femoral head in divers with hip pain at risk for dysbaric osteonecrosis.

BACKGROUND: Ischemia before the development of dysbaric osteonecrosis (DON) in femoral heads has never been investigated. We assessed whether quantitative magnetic resonance spectroscopy (MRS) and diffusion weighted imaging (DWI) could detect dysbaric changes in divers with hip pain. METHODS: This IRB-approved exploratory study recruited 17 divers [9 with hip pain (Group 1); 8 asymptomatic (Group 2)] with normal findings on radiographs and conventional magnetic resonance imaging scans were age-, gender- and body-mass-index matched to 17 non-divers as controls (Group 1C, 2C). Apparent diffusion coefficients (ADCs) and MRS spectra were obtained from regions/voxels of interest on the femoral heads of all subjects. LCModel was used to determine water content, lipid composition, and the unsaturation index in bone marrow. Mann-Whitney non-parametric test was used to compare results of quantitative MRS and ADCs of ipsilateral femoral heads between divers and controls. RESULTS: MRS of the ipsilateral femoral heads revealed higher water (peak: 4.7 ppm) content, lower total lipid fraction (TLF), and higher unsaturation index (UI) of lipids in Group 1 than in Group 2 (water: P=0.040; UI: P=0.022) and Group 1C (water: P=0.027; TLF: P=0.039; UI: P=0.009). In contrast, femoral head ADCs were comparable between divers and controls. Five out of nine symptomatic divers were contacted for follow-up MRS and DWI studies, and the mean difference in water content in the femoral heads of patients with osteonecrosis was also higher than that in patients with symptom relief (osteonecrosis: 0.077±0.130 vs. symptom relief: 0.003±0.010). CONCLUSIONS: Dysbaric change in the femoral heads of divers with hip pain can be detected using quantitative MRS, which reveals increases in water content and UI of lipids, and a decrease in TLF.

Detection of Left Ventricular Systolic Dysfunction Using an Artificial Intelligence-Enabled Chest X-Ray.

BACKGROUND: Assessment of left ventricular systolic dysfunction provides essential information related to the prognosis and management of cardiovascular diseases. The aim of this study was to develop a deep-learning model to identify left ventricular ejection fraction (LVEF) ≤ 35% via chest X-ray (CXR [CXR-EF≤35%]) features and investigate the performance and clinical implications. METHODS: This study collected 90,547 CXRs with the corresponding LVEF according to transthoracic echocardiography from the outpatient department in an academic medical center. Among these, 77,227 CXRs were used to develop the identification of CXR-EF≤35%. Another 13,320 CXRs were used to validate the performance, which was evaluated by area under the receiver operating characteristic curve (AUC). Furthermore, CXR-EF≤35% was tested to assess the long-term risks of developing LVEF ≤ 35% and cardiovascular outcomes, which were evaluated by Kaplan-Meier survival analysis and the Cox proportional hazards model. RESULTS: The AUCs of CXR-EF≤35% for the detection of LVEF ≤ 35% were 0.888 and 0.867 in the internal and external validation cohorts, respectively. Patients with baseline LVEF > 50% but detected as CXR-EF≤35% were at higher risk of long-term development of LVEF ≤ 35% (hazard ratio, internal validation cohort [HRi] 3.91, 95% CI 2.98-5.14; hazard ratio, external validation cohort [HRe] 2.49, 95% CI 1.89-3.27). Furthermore, patients detected as LVEF ≤ 35% by CXR-EF≤35% had significantly higher future risks of all-cause mortality (HRi 1.40, 95% CI 1.15-1.71; HRe 1.38, 95% CI 1.15-1.66), cardiovascular mortality (HRi 3.02, 95% CI 1.84-4.98; HRe 2.60, 95% CI 1.77-3.82), and new-onset atrial fibrillation (HRi 2.81, 95% CI 2.15-3.66; HRe 2.93, 95% CI 2.34-3.67) compared with those detected as no LVEF ≤ 35%. CONCLUSIONS: CXR-EF≤35% may serve as a screening tool for early detection of LVEF ≤ 35% and could independently contribute to predictions of long-term development of LVEF ≤ 35% and cardiovascular outcomes. Further prospective studies are needed to confirm the model performance.

Median Nerve Injury in Ultrasound-Guided Hydrodissection and Corticosteroid Injections for Carpal Tunnel Syndrome.

PURPOSE: Permanent nerve damage after corticosteroid injection has been suggested when symptoms of median nerve injury (MNI) are irreversible. We assess the outcomes of MNI and their association with ultrasonography (US)-guided hydrodissection and the following corticosteroid injection for symptomatic carpal tunnel syndrome (CTS). METHODS: US-guided hydrodissection and the following corticosteroid injections were administered to 126 CTS patients. Occurrence of MNI, clinical data, and post-hydrodissection findings were evaluated. Post-hydrodissection findings included vascular injury during hydrodissection, altered echogenicity, reduced flattening ratio, and increased cross-sectional area of the MN at the inlet of the carpal tunnel (MN-CSA-Inlet) on ultrasonography after hydrodissection. The relevance of MNI with respect to these clinical data and findings was determined. The outcome was rated using Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) scores. RESULTS: Nine patients suffered MNI (incidence, 7.1 %) but improved significantly at follow-up. Clinical data and vascular injury during hydrodissection, altered echogenicity, and reduced flattening ratio after hydrodissection were unrelated to prolonged transient MNI (p > 0.05). MNI was significantly associated with increased CSA (p = 0.005). A CSA increase > 2 mm2 after hydrodissection yielded the greatest performance (0.979) for MNI in the receiver operating characteristic analysis. Decreases in BCTQ scores after injection did not differ significantly between groups with and without MNI (p > 0.05). CONCLUSION: MNI during hydrodissection may be reversible. MNI is indicated by an increase in MN-CSA-inlet immediately after hydrodissection.

MRI contributes to accurate and early diagnosis of non-radiographic HLA-B27 negative axial spondyloarthritis.

BACKGROUND: Nonradiographic axial spondyloarthropathies (nr-axSpA) are diagnosed by the absence of radiographic sacroiliitis and the presence of bone marrow edema (BME) on magnetic resonance imaging (MRI). According to the classification criteria of the international Assessment of Spondyloarthritis Society (ASAS), structural changes to sacroiliac joints (SIJs) on MRI cannot be used as criteria in the absence of BME. However, less than half the Asian patients with clinically active axSpA show BME. The incidence of human leukocyte antigen (HLA)-B27 is low in Asian populations, which makes it more difficult to identify nr-axSpA. We used MRI to evaluate the structural damage to SIJs in patients with nr-axSpA with and without BME with the aim of identifying the best methodology for accurate diagnosis, especially in populations with less common BME and HLA-B27. METHODS: One hundred three patients with inflammatory back pain were included in this prospective study. No patient's radiograph met the definition of positive modified New York criteria. BME and structural damage to SIJ including sclerosis and erosion were assessed independently on coronal and axial short-tau inversion recovery and T1-weighted spin echo MRI scans by two well-trained musculoskeletal radiologists using the Spondyloarthritis Research Consortium of Canada (SPARCC) score. Demographics of patients were collected. Disease characteristics and structural damage were analyzed in patients with and without BME on SIJ MRI. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of structural damage. RESULTS: All individuals in the cohort had at least one abnormal finding on SIJ MRI, including BME or structural damage; 36 of 103 patients had BME. We identified a significant positive correlation between SPARCC scores and severe erosion assessed by focal joint space widening (fJSW) (p = 0.001) in these 36 patients. Fifty-eight of the 103 enrolled patients fulfilled the ASAS criteria for nr-axSpA in the either absence or presence of BME. Of these 58 patients, 57 and 19 had erosions or fJSW, respectively, and the presence of BME was significantly correlated with fJSW (phi score of 0.319 and p = 0.015). We demonstrated a significant positive correlation between fJSW and either the presence or the severity of BME in patients with nr-axSpA who met the ASAS definition. There was a positive correlation between BME and fJSW across the whole study cohort (phi score of 0.389; p < 0.001). The area under the ROC curve (AUC) for fJSW on SIJ MRI was 0.736, p < 0.001. In both HLA-B27-positive and -negative groups, BME was more common in the presence of fJSW (phi scores of 0.370 and 0.377, p = 0.018 and 0.003, respectively) and SPARCC scores were higher in patients with fJSW (p < 0.001 and p = 0.005). We also identified a positive correlation between fJSW and BME in patients with nr-axSpA and normal serum levels of C-reactive protein (phi score of 0.362 and p = 0.001). CONCLUSION: Structural damage detected on SIJ MRI, sclerosis, erosions and fJSW may be present in patients without detectable inflammation on SIJ MRI. However, fJSW is significantly correlated with the severity of inflammation seen on SIJ MRI, which contributes to the accurate diagnosis of nr-axSpA, and it could be used as an alternative diagnostic test for nr-axSpA in the general population, especially for those who do not carry the HLA-B27 gene, Asian patients without BME, or patients with normal serum inflammatory biomarkers.

Fried egg sign: A typical ultrasonography feature of neurolymphomatosis.

Neurolymphomatosis (NL) is a rare condition caused by non-Hodgkin's lymphoma or leukemia. We present a case of NL and describe ultrasound features, including the "fried egg sign" in which there is a clear demarcation between an avascular echogenic core and a hypoechoic vascularized peripheral zone that may help to distinguish NL from primary nerve sheath tumors.

Hypoperfusion of the infrapatellar fat pad and its relationship to MRI T2* relaxation time changes in a 5/6 nephrectomy model.

The purpose of present study was to longitudinally investigate the alterations in infrapatellar fat pad (IPFP) vascularity in 5/6 nephrectomized rats by using dynamic contrast enhanced (DCE) MRI and IPFP degeneration by using MRI T2* relaxation time. Twelve male Sprague-Dawley rats were assigned to a control group and a 5/6 nephrectomy CKD group. The right knees of all rats were longitudinally scanned by 4.7 T MRI, and serial changes in the IPFP were assessed at 0, 8, 16, 30, and 44 weeks by DCE-MRI (parameters A, kel and kep) and MRI T2* mapping. After MRI measurements, knee specimens were obtained and evaluated histologically. The CKD group had IPFPs with lower blood volume A and lower permeability kep values from 16 weeks (p < 0.05), lower venous washout kel value from 30 weeks (p < 0.001), and significantly higher T2* values reflecting adipocyte degeneration beginning at 16 weeks (p < 0.05). The histopathological results confirmed the MRI findings. Hypoperfusion and adipocytes degeneration related to CKD were demonstrated in a rodent 5/6 nephrectomy model. DCE parameters and MRI T2* can serve as imaging biomarkers of fat pad degeneration during CKD progression.

Post-operative assessment in patients after liver transplantation: imaging parameters associated with 1-year graft failure.

PURPOSE: To identify post-liver transplant CT findings which predict graft failure within 1 year. MATERIALS AND METHODS: We evaluated the CT scans of 202 adult liver transplants performed in our institution who underwent CT within 3 months after transplantation. We recorded CT findings of liver perfusion defect (LPD), parenchymal homogeneity, and the diameters and attenuations of the hepatic vessels. Findings were correlated to 1-year graft failure, and interobserver variability was assessed. RESULTS: Forty-one (20.3%) of the 202 liver grafts failed within 1 year. Graft failure was highly associated with LPD (n = 18/25, or 67%, versus 15/98, or 15%, p < 0.001), parenchymal hypoattenuation (n = 20/41, or 48.8% versus 17/161, or 10.6%, p < 0.001), and smaller diameter of portal veins (right portal vein [RPV], 10.7 ± 2.7 mm versus 14.7 ± 2.2 mm, and left portal vein [LPV], 9.8 ± 3.0 mm versus 12.4 ± 2.2 mm, p < 0.001, respectively). Of these findings, LPD (hazard ratio [HR], 5.43, p < 0.001) and small portal vein diameters (HR, RPV, 3.33, p < 0.001, and LPV, 3.13, p < 0.05) independently predicted graft failure. All the measurements showed fair to moderate interobserver agreement (0.233~0.597). CONCLUSION: For patients who have CT scan within the first 3 months of liver transplantation, findings of LPD and small portal vein diameters predict 1-year graft failure. KEY POINTS: •Failed grafts are highly associated with liver perfusion defect, hypoattenuation, and small portal vein. •Right portal vein < 11.5 mm and left portal vein < 10.0 mm were associated with poor graft outcome. •Liver perfusion defect and small portal vein diameter independently predicted graft failure.

The impact of edema and fiber crossing on diffusion MRI metrics assessed in an ex vivo nerve phantom: Multi-tensor model vs. diffusion orientation distribution function.

Diffusion tensor imaging (DTI) has been employed for over 2 decades to noninvasively quantify central nervous system diseases/injuries. However, DTI is an inadequate simplification of diffusion modeling in the presence of coexisting inflammation, edema and crossing nerve fibers. We employed a tissue phantom using fixed mouse trigeminal nerves coated with various amounts of agarose gel to mimic crossing fibers in the presence of vasogenic edema. Diffusivity measures derived by DTI and diffusion basis spectrum imaging (DBSI) were compared at increasing levels of simulated edema and degrees of fiber crossing. Furthermore, we assessed the ability of DBSI, diffusion kurtosis imaging (DKI), generalized q-sampling imaging (GQI), q-ball imaging (QBI) and neurite orientation dispersion and density imaging to resolve fiber crossing, in reference to the gold standard angles measured from structural images. DTI-computed diffusivities and fractional anisotropy were significantly confounded by gel-mimicked edema and crossing fibers. Conversely, DBSI calculated accurate diffusivities of individual fibers regardless of the extent of simulated edema and degrees of fiber crossing angles. Additionally, DBSI accurately and consistently estimated crossing angles in various conditions of gel-mimicked edema when compared with the gold standard (r2 = 0.92, P = 1.9 × 10-9 , bias = 3.9°). Small crossing angles and edema significantly impact the diffusion orientation distribution function, making DKI, GQI and QBI less accurate in detecting and estimating fiber crossing angles. Lastly, we used diffusion tensor ellipsoids to demonstrate that DBSI resolves the confounds of edema and crossing fibers in the peritumoral edema region from a patient with lung cancer metastasis, while DTI failed. In summary, DBSI is able to separate two crossing fibers and accurately recover their diffusivities in a complex environment characterized by increasing crossing angles and amounts of gel-mimicked edema. DBSI also indicated better angular resolution compared with DKI, QBI and GQI.

Acute ischemic stroke induces magnetic resonance susceptibility signs dominated by endothelial nitric oxide synthase activation.

PURPOSE: Acute ischemic stroke induces deoxyhemoglobin accumulation around the ischemic region while activating endothelial nitric oxide synthase (eNOS) coupling and the subsequent release of nitric oxide (NO). Because deoxyhemoglobin is a natural NO spin trap, its interplay with NO could be prominent during acute stroke. Its interaction with NO has been shown to induce overt paramagnetic signals in vitro; our goal was to investigate whether this interplay can be detected using MRI. METHODS: To verify the in vivo image effects using the deoxyhemoglobin-NO interaction during acute stroke, eNOS states were manipulated in an animal model of acute ischemia, and the susceptibility signals, cerebral perfusion, and infarction were assessed noninvasively via MR susceptibility weighted imaging (SWI). RESULTS: Occlusion of the right middle cerebral artery increased eNOS coupling and susceptibility signals in the ischemic cortex while abolishing regional cerebral blood flow. Pharmacological eNOS blockage led to weakened susceptibility signals in the ischemic cortex as well as worsened tissue survival. Consistently, abolishment of eNOS coupling through genetic editing reduced the regional susceptibility signals in the ischemic cortex, causing large infarcts. CONCLUSION: Upregulation of eNOS during acute ischemia sustains tissue viability through the interaction between NO and deoxyhemoglobin. This interplay can be traced in vivo using SWI and can be considered a sensitive marker revealing the delicate oxygenation status of the ischemic tissue, therefore, guiding the management of acute stroke in clinical settings.

Efficacy and Safety of Supplemental Transarterial Chemoembolization Through Extrahepatic Collateral Arteries with Drug-eluting Beads: Treatment for Unresectable Hepatocellular Carcinoma.

PURPOSE: To evaluate the therapeutic efficacy and safety of supplement transarterial chemoembolization (TACE) with drug-eluting beads TACE (DEB-TACE) through extrahepatic collateral (EHC) arteries for the treatment of hepatocellular carcinoma (HCC). PATIENTS AND METHODS: In this retrospective study, 61 unresectable HCC patients with treatment-naïve EHC blood supplies who received TACE from January 2016 to March 2019 were enrolled; of these patients, 42 (68.9%) received DEB-TACE, and 19 (31.1%) received cTACE. The hepatic tumor feeding arteries were treated in the same TACE session if it presented. The tumor response, time-to-progression (TTP), and overall survival (OS) were analyzed. Safety was assessed based on the occurrence of liver function deterioration and major complications within three months after TACE. RESULTS: DEB-TACE showed better efficacy than cTACE in the disease control rate (p=0.001), overall response rate (p=0.005), the TTP (eight months vsthree months, p=0.002) and the OS (23.8 months vs nine months, p=0.045). Nine patients in the DEB-TACE group and one patient in the cTACE group were downstaged to resection or liver transplantation (21.4% vs 5.3%, p=0.151). DEB-TACE and cTACE have no difference in the acute and chronic liver toxicity. With regard to complications, there was no significant difference in the occurrence of both major (16.7% vs 21.1%, p=0.72) and minor (57.1% vs 47.4%, p=0.48) complications between DEB-TACE and cTACE. CONCLUSION: DEB-TACE through EHC arteries has a potential therapeutic effect in the treatment of unresectable HCC, with comparable safety compared with cTACE.

Time to peak enhancement of malignant hypervascular hepatic tumors versus that of the aorta evaluating by test bolus sequence of magnetic resonance imaging.

PURPOSE: To determine the relationship between time to peak enhancement (TPE) of malignant hypervascular hepatic tumors and that of the aorta. METHOD: Sixty patients with malignant hypervascular hepatic tumors (48 with hepatocellular carcinoma and 12 with metastatic neuroendocrine tumor) who received abdominal MRI with test bolus sequence between January 2015 and May 2019 were enrolled. The test bolus images were monitored every 3 s after the injection of 2 mL gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) and 10 mL saline flush, to evaluate the TPE of the tumors and aorta. We used linear regression with a least squares approach to show the relationship between TPE of the malignant hypervascular hepatic tumors and that of the aorta. RESULTS: TPE of malignant hypervascular hepatic tumors and abdominal aorta were 43.4 ±â€¯12.9 and 23.3 ±â€¯7.4 s, respectively (mean ±â€¯standard deviation). In univariate regression analysis, the TPE of malignant hypervascular hepatic tumors have a positively linear correlation with that of the aorta by the following equation: (TPE of malignant hypervascular hepatic tumor) = 1.4 X (TPE of the aorta) + 10.6 s (r = 0.65, p < 0.005). CONCLUSIONS: TPE of malignant hypervascular hepatic tumors can be predicted by a simple linear transformation from that of the aorta.