Language：English   Publisher：Vascular  

Objectives: This study aims to quantify changes in renal blood flow before and after endovascular aneurysm repair (EVAR) using four-dimensional (4D) flow magnetic resonance imaging (MRI) and evaluate its correlation with renal impairment. Methods: In this retrospective analysis, 18 patients underwent elective EVAR for infrarenal fusiform abdominal aortic aneurysms using Excluder or Endurant endografts. 4D flow MRI scans were conducted before and 1–4 days after EVAR. Hemodynamics were quantified at the suprarenal aorta (SupAo), bilateral renal arteries (RRA and LRA), and infrarenal aorta (InfAo). Cardiac phase-resolved blood flow values (BFVs), relative flow distribution (RFD), and flow change rates (FCRs) were assessed. Estimated glomerular filtration rate (eGFR) was measured pre- and postoperatively. Results: A total of 16 patients were analyzed after excluding two outliers. Pre-EVAR BFVs were 23.1 ± 8.3, 3.7 ± 1.3, 3.4 ± 1.2, and 15.1 ± 5.9 mL/cycle, while post-EVAR BFVs were 20.9 ± 6.9, 3.8 ± 1.1, 3.2 ± 0.9, and 12.1 ± 4.3 mL/cycle in SupAo, RRA, LRA, and InfAo, respectively. Comparing Excluder (N = 8) and Endurant (N = 8), the total renal FCR was 121.8% [106.6–144.7] versus 101.3% [63.8–121.8] (p = 0.110), suggesting a potential improvement in renal blood flow with the Excluder, although not statistically significant. A significant correlation was found between the total renal FCR and the relative eGFR at 6 months (Spearman correlation coefficient, 0.789; p < 0.001). Conclusions: The endografts, particularly the Excluder, showed potential in improving renal artery blood flow in some patients. The significant correlation between the total renal FCR and the relative eGFR at 6 months suggests that acute hemodynamic alterations induced by EVAR may impact post-operative renal function. Further research is needed to confirm these findings and assess their clinical implications.

DOI： 10.1177/17085381241277651

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Scopus

PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

BACKGROUND: Although endovascular aneurysmal repair (EVAR) is a preferred treatment for abdominal aortic aneurysm (AAA) owing to its low invasiveness, its impact on the local hemodynamics has not been fully assessed. PURPOSE: To elucidate how EVAR affects the local hemodynamics in terms of energy loss (EL). STUDY TYPE: Prospective single-arm study. FIELD STRENGTH/SEQUENCE: A 3.0 T/4D flow MRI using a phase-contrast three-dimensional cine-gradient-echo sequence. POPULATION: A total of 13 consecutive patients (median [interquartile range] age: 77.0 [73.0, 78.8] years, 11 male) scheduled for EVAR as an initial treatment for fusiform AAA. ASSESSMENT: 4D flow MRI covering the abdominal aorta and bilateral common iliac arteries and the corresponding stent-graft (SG) lumen was performed before and after EVAR. Plasma brain natriuretic peptide (BNP) was measured within 1 week before and 1 month after EVAR. The hemodynamic data, including mean velocity and the local EL, were compared pre-/post-EVAR. EL was correlated with AAA neck angle and with BNP. Patients were subdivided into deformed (N = 5) and undeformed SG subgroups (N = 8) and pre-/post-EVAR BNP compared in each. STATISTICS: Parametric or nonparametric methods. Spearman's rank correlation coefficients (r). The interobserver/intraobserver variabilities with Bland-Altman plots. A P value < 0.05 is considered significant. RESULTS: The mean velocity (cm/sec) at the AAA was five times greater after EVAR: 4.79 ± 0.32 vs. 0.91 ± 0.02. The total EL (mW) increased by 1.7 times after EVAR: 0.487 (0.420, 0.706) vs. 0.292 (0.192, 0.420). The total EL was proportional to the AAA neck angle pre-EVAR (r = 0.691) and post-EVAR (r = 0.718). BNP (pg/mL) was proportional to the total EL post-EVAR (r = 0.773). In the deformed SG group, EL (0.349 [0.261, 0.416]) increased 2.4-fold to 0.848 (0.597, 1.13), and the BNP 90.3 (53.6, 105) to 100 (67.2, 123) post-EVAR. CONCLUSION: The local EL showed a 1.7-fold increase after EVAR. The larger increase in the EL in the deformed SG group might be a potential concern for frail patients. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

DOI： 10.1002/jmri.28359

Open Access

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PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society for Magnetic Resonance in Medicine  

PURPOSE: To elucidate MRI features of primary hepatic mucosa-associated lymphoid tissue (MALT) lymphoma, particularly, the "speckled enhancement" on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI. METHODS: The institutional review board approved this retrospective observational study and waived informed consent. Using our picture archiving and communication systems and electronic medical records, five patients histopathologically diagnosed as hepatic MALT lymphoma and clinically confirmed as primary lesions who had undergone dynamic contrast-enhanced (DCE)-CT and DCE-MRI with Gd-EOB-DTPA were identified from September 2009 to December 2020. Two radiologists assessed their CT and MRI data in consensus with a pathologist's advice. RESULTS: Overall, five lesions in five patients were included in this study. Precontrast CT showed hypoattenuation in all lesions. In the arterial phase of DCE-CT, four lesions (80%) showed hyperattenuation, whereas all lesions showed iso- to hypoattenuation in the delayed phase. A vessel penetration sign was also observed in all lesions. On MRI, all lesions showed hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and restricted diffusion on diffusion-weighted images. Both DCE-CT and DCE-MRI with Gd-EOB-DTPA showed similar enhancement patterns, except for the hepatocyte phase. Notably, however, four out of five lesions showed characteristic "speckled enhancement" that refers to punctate positive enhancements within the low signal lesions on the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI pathologically confirmed to be hepatocyte clusters that remained in the tumor. CONCLUSION: Primary hepatic MALT lymphomas were characterized by arterial phase enhancement, restricted diffusion, vessel penetration sign, and more specifically "speckled enhancement" in the hepatobiliary phase of DCE-MRI with Gd-EOB-DTPA.

DOI： 10.2463/mrms.mp.2021-0069

Open Access

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PubMed

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society for Magnetic Resonance in Medicine  

A man in his 50s with Budd-Chiari syndrome diagnosed with the suprahepatic inferior vena cava (IVC) obstruction on CT was assessed using 4D Flow MRI before and after balloon angioplasty. 4D Flow MRI acquired in two respiratory phases, depicted complex hemodynamic and respiratory variability, and a jet stream at the narrowed channel of the membranous IVC. Post-interventional 4D Flow MRI showed that the IVC blood flow increased with corrected flow directions in the infrarenal IVC.

DOI： 10.2463/mrms.ici.2021-0110

Open Access

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PubMed

CiNii Research

Language：English  

With the widespread use of three-dimensional printers, organ models created by these printers are now being used in the medical field for preoperative planning of surgeries. In this article, we report two cases in which embolization was expected to be difficult, and the three-dimensional printer-based vascular modeling was helpful in planning the surgery. The first case involved an aneurysm of the splenic artery. We attempted to embolize the aneurysm but were unable to advance the catheter into the distal artery and discontinued the procedure. The second case was a perianal varicose vein, which was initially treated with percutaneous transhepatic obliteration but was recanalized and required embolization. However, we expected difficulty in selecting the inferior mesenteric vein. In both cases, the vascular models were created using a 3D printer from the patients' computed tomography images. Preoperative planning, including treatment simulation, was based on these models. The time required to print a three-dimensional vascular model was approximately 12 hours at a cost of less than $10 each. Patient-specific vascular models using a three-dimensional printer can be a simple and inexpensive tool that can increase the success of embolization in difficult cases.

DOI： 10.18999/nagjms.84.2.477

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PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Diagnosis and severity assessments of portosystemic shunts (PSSs) are important because the pathology sometimes results in severe hepatic encephalopathy, which can be treated almost completely by shunt embolization. At present, morphological assessment of PSS is performed mainly by computed tomography, and ultrasound is used for blood flow assessment. In two cases of PSS-related hepatic encephalopathy, we used time-resolved 3D cine phase-contrast (4D-flow) magnetic resonance imaging (MRI) to assess blood flow before and after shunt embolization. Before the intervention, blood flow in the main trunk of the superior mesenteric vein was mostly hepatofugal. However, post-interventional 4D-flow MRI revealed hepatopetal superior mesenteric vein flow with significantly increased portal vein blood flow. 4D-flow MRI is an ideal adjunct to Doppler ultrasonography, allowing for objective and visual assessment of morphology and blood flow of the portal venous system, including PSSs, and is useful in determining the indications for, and outcome of, PSS embolization.

DOI： 10.1111/hepr.13616

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PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society for Magnetic Resonance in Medicine  

We present a case of a patient who underwent portal vein (PV) stenting for PV stenosis after a living-donor liver transplantation. A pretreatment 3D cine phase-contrast (4D-flow) MRI showed decreased, though hepatopetal, blood flow in the PV. After stenting, 4D-flow MRI confirmed an improvement in PV flow, with a more homogeneous flow distribution to each hepatic segment. 4D-flow MRI are valuable for understanding the hemodynamics of this area, planning for treatments, and evaluating the outcome of the interventions.

DOI： 10.2463/mrms.ici.2020-0057

Open Access

Web of Science

Scopus

PubMed

CiNii Research

Language：Japanese   Publisher：学研メディカル秀潤社  

DOI： 10.15105/gz.0000001162

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

BACKGROUND: The aim of the present study was to assess the clinical efficiency of portal vein (PV) stenting when performed with preoperative percutaneous transhepatic portal vein embolization (PTPVE) in patients with severe PV stenosis due to tumor invasion. METHODS: Between 2007 and 2013, four consecutive patients (one male, three females; mean age, 52 years; age range, 25-73 years) with perihilar cholangiocarcinoma and PV stenosis underwent PTPVE and PV stenting. Patients were analyzed with regard to the procedure, hypertrophy of the future remnant liver (FRL), and plasma clearance rate of indocyanine green by the FRL (ICGK-F). Further, the %FRL volume increase in PTPVE was compared between the stenting group and the usual PTPVE group who have perihilar cholangiocarcinomas without PV stenosis. RESULTS: Preoperative PTPVE with PV stenting was successfully performed and portal flow to the FRL improved after stenting in all four patients. The %FRL volume increase was 18-60% (mean, 34%) in the stenting group and was 12-51% (mean, 21%) in the usual PTPVE group. The ICGK-F value after PTPVE exceeded 0.05 in all four patients. All patients achieved R0 resection. CONCLUSIONS: Preoperative PTPVE with PV stenting appears to be feasible in cases of severe PV tumor invasion and stenosis. This procedure may allow a broader indication for surgery.

DOI： 10.1002/jhbp.200

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PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：NAGOYA UNIV, SCH MED  

The purpose of this study was to describe the magnetic resonance imaging (MRI) and computed tomography (CT) findings for solitary fibrous tumors (SFTs) in the extremities in correlation with histopathological findings. Between 2006 and 2013, 6 consecutive patients with SFT in an extremity were studied with MRI (6 patients) and CT (4 patients). Diffusion-weighted images were also performed in 3 patients and dynamic contrast-enhanced CT in 2 patients. All 6 tumors were diagnosed after surgical excision, and the pre-surgical imaging findings were correlated with the histopathological findings. As a result, all 6 patients were female, and each had a clearly palpable, well-circumscribed, round or oval mass adjacent to fascia in an extremity, of less than 10 cm maximum diameter in 5 patients. On MRI, the tumors were iso-intense with muscle on T1-weighted image, and appeared heterogeneous and high-intensity on T2-weighted image. After injection of a contrast agent, the tumors demonstrated strong enhancement. A vascular pedicle was detected in 4 patients with tumors having a maximum diameter more than 5 cm. Diffusion-weighted images demonstrated high signal intensities, and apparent diffusion coefficient values were iso to high compared to muscle (from 1.41-2.10x10(-3) mm(2)/s). All the tumors were benign histopathologically and clinically. In 1 patient, the imaging appearance revealed underlying histopathological components, including fibrous-rich, cellular-rich, and myxoid change areas. In conclusion, a SFT in an extremity comprises a well-circumscribed mass adjacent to fascia having a fibrous-dominant area, strong contrast enhancement, and a vascular pedicle.

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

The purpose of this study was to describe the magnetic resonance imaging (MRI) and computed tomography (CT) findings for solitary fibrous tumors (SFTs) in the extremities in correlation with histopathological findings. Between 2006 and 2013, 6 consecutive patients with SFT in an extremity were studied with MRI (6 patients) and CT (4 patients). Diffusion-weighted images were also performed in 3 patients and dynamic contrast-enhanced CT in 2 patients. All 6 tumors were diagnosed after surgical excision, and the pre-surgical imaging findings were correlated with the histopathological findings. As a result, all 6 patients were female, and each had a clearly palpable, well-circumscribed, round or oval mass adjacent to fascia in an extremity, of less than 10 cm maximum diameter in 5 patients. On MRI, the tumors were iso-intense with muscle on T1-weighted image, and appeared heterogeneous and high-intensity on T2-weighted image. After injection of a contrast agent, the tumors demonstrated strong enhancement. A vascular pedicle was detected in 4 patients with tumors having a maximum diameter more than 5 cm. Diffusion-weighted images demonstrated high signal intensities, and apparent diffusion coefficient values were iso to high compared to muscle (from 1.41-2.10×10(-3) mm(2)/s). All the tumors were benign histopathologically and clinically. In 1 patient, the imaging appearance revealed underlying histopathological components, including fibrous-rich, cellular-rich, and myxoid change areas. In conclusion, a SFT in an extremity comprises a well-circumscribed mass adjacent to fascia having a fibrous-dominant area, strong contrast enhancement, and a vascular pedicle.

PubMed

Language：Japanese   Publisher：Nagoya Journal of Medical Science  

The purpose of this study was to describe the magnetic resonance imaging (MRI) and computed tomography (CT) findings for solitary fibrous tumors (SFTs) in the extremities in correlation with histopathological findings. Between 2006 and 2013, 6 consecutive patients with SFT in an extremity were studied with MRI (6 patients) and CT (4 patients). Diffusion-weighted images were also performed in 3 patients and dynamic contrast-enhanced CT in 2 patients. All 6 tumors were diagnosed after surgical excision, and the pre-surgical imaging findings were correlated with the histopathological findings. As a result, all 6 patients were female, and each had a clearly palpable, well-circumscribed, round or oval mass adjacent to fascia in an extremity, of less than 10 cm maximum diameter in 5 patients. On MRI, the tumors were iso-intense with muscle on T1-weighted image, and appeared heterogeneous and high-intensity on T2-weighted image. After injection of a contrast agent, the tumors demonstrated strong enhancement. A vascular pedicle was detected in 4 patients with tumors having a maximum diameter more than 5 cm. Diffusion-weighted images demonstrated high signal intensities, and apparent diffusion coefficient values were iso to high compared to muscle (from 1.41-2.10×10-3 mm2/s). All the tumors were benign histopathologically and clinically. In 1 patient, the imaging appearance revealed underlying histopathological components, including fibrous-rich, cellular-rich, and myxoid change areas. In conclusion, a SFT in an extremity comprises a well-circumscribed mass adjacent to fascia having a fibrous-dominant area, strong contrast enhancement, and a vascular pedicle.

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Event date： 2024.9

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