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1.
Sci Rep ; 13(1): 628, 2023 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-36635425

RESUMO

This study aimed to develop a versatile automatic segmentation model of bladder cancer (BC) on MRI using a convolutional neural network and investigate the robustness of radiomics features automatically extracted from apparent diffusion coefficient (ADC) maps. This two-center retrospective study used multi-vendor MR units and included 170 patients with BC, of whom 140 were assigned to training datasets for the modified U-net model with five-fold cross-validation and 30 to test datasets for assessment of segmentation performance and reproducibility of automatically extracted radiomics features. For model input data, diffusion-weighted images with b = 0 and 1000 s/mm2, ADC maps, and multi-sequence images (b0-b1000-ADC maps) were used. Segmentation accuracy was compared between ours and existing models. The reproducibility of radiomics features on ADC maps was evaluated using intraclass correlation coefficient. The model with multi-sequence images achieved the highest Dice similarity coefficient (DSC) with five-fold cross-validation (mean DSC = 0.83 and 0.79 for the training and validation datasets, respectively). The median (interquartile range) DSC of the test dataset model was 0.81 (0.70-0.88). Radiomics features extracted from manually and automatically segmented BC exhibited good reproducibility. Thus, our U-net model performed highly accurate segmentation of BC, and radiomics features extracted from the automatic segmentation results exhibited high reproducibility.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias da Bexiga Urinária , Humanos , Estudos Retrospectivos , Reprodutibilidade dos Testes , Imageamento por Ressonância Magnética/métodos , Redes Neurais de Computação , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos
2.
JPGN Rep ; 3(2): e206, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-37168905

RESUMO

Kasai portoenterostomy (KP) is a standard treatment for patients with biliary atresia (BA). After KP, patients with BA occasionally develop biliary complications, such as recurrent cholangitis, biliary stricture, and cystic dilatation of the intrahepatic bile duct. Percutaneous transhepatic biliary drainage is one of the treatment options for these biliary complications. However, limited information is available on percutaneous transhepatic biliary drainage performed after KP in adult BA patients with native livers. Herein, we describe 8 cases of percutaneous transhepatic biliary interventions performed after KP in 7 adult BA patients with native livers. Cholangiography showed multiple cystic dilatation of the intrahepatic bile ducts. Advancing a guidewire and catheter was difficult due to the multiple dilatations and strictures of the bile duct. Successful biliary drainage tube placement and clinical improvement was achieved in 5 and 3 cases, respectively. Because of its technical difficulty and limited clinical effectiveness, it is not recommended that it be performed easily.

4.
Molecules ; 26(19)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34641390

RESUMO

Our previous work established a continuous-flow synthesis of pristane, which is a saturated branched alkane obtained from a Basking Shark. The dehydration of an allylic alcohol that is the key to a tetraene was carried out using a packed-bed reactor charged by an acid-silica catalyst (HO-SAS) and flow hydrogenation using molecular hydrogen via a Pd/C catalyst followed. The present work relies on the additional propensity of Pd/C to serve as an acid catalyst, which allows us to perform a flow synthesis of pristane from the aforementioned key allylic alcohol in the presence of molecular hydrogen using Pd/C as a single catalyst, which is applied to both dehydration and hydrogenation. The present one-column-two-reaction-flow system could eliminate the use of an acid catalyst such as HO-SAS and lead to a significant simplification of the production process.

5.
Radiol Case Rep ; 16(11): 3300-3303, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34484535

RESUMO

Metaplastic meningioma is a rare World Health Organization Grade I meningioma subtype, accounting for 0.2%-1.6% of all meningiomas. Primary extradural meningiomas represent less than 2% of all meningiomas, with intraosseous meningioma as a subtype of primary extradural meningiomas. Herein, we report the case of a 65-year-old male presenting with headache. His computed tomography scans showed an osteolytic left parietal bone mass, and magnetic resonance imaging revealed hyperintense dots in the mass on T1-weighted images. The mass was then resected and diagnosed on histopathological examination as an intraosseous metaplastic meningioma.

6.
J Magn Reson Imaging ; 54(6): 1979-1988, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34085328

RESUMO

BACKGROUND: Diffusion-weighted imaging (DWI) is an important method for clinically significant prostate cancer (csPCa) diagnosis; however, the Prostate Imaging-Reporting and Data System (PI-RADS) requires the subjective assessment of "markedly hypointense or not" on apparent diffusion coefficient (ADC) map. We hypothesize that weighted diffusion subtraction (WDS) images, created by weighted subtraction of high and low b-value DWIs, might better show areas of ADC values below a set threshold, thus decreasing the subjectivity of the assessment. PURPOSE: To evaluate the diagnostic ability of WDS for csPCa by comparing scores based on WDS images (DWI/WDS) with those based on PI-RADS DWI (DWI/ADC). STUDY TYPE: Retrospective. SUBJECTS: Eighty-six PCa patients. FIELD STRENGTH/SEQUENCES: 3.0 T; DWI. ASSESSMENT: Four readers assessed the probability of csPCa in lesions (overall, in the peripheral zone [PZ] and transitional zone [TZ]) using 5-point DWI/ADC and DWI/WDS scores. Prostatectomy specimens were the reference standard. ADC values and contrast between csPCa and normal prostate tissue on ADC maps and WDS images were calculated with reference to the pathological map. STATISTICAL TESTS: Diagnostic ability was evaluated by Jackknife alternative free-response receiver-operating characteristic curve. Figure of merit (FOM), sensitivity, and positive predictive value (PPV) between the DWI/ADC and DWI/WDS scores were compared using paired t-test. Inter-reader agreement was analyzed using κ statistics, and the significance probability was calculated using the Z statistic. Wilcoxon signed-rank test was used to compare contrast between csPCa and normal prostate tissue on ADC maps and WDS images. A P value <0.05 was considered statistically significant. RESULTS: FOM and sensitivity of the DWI/WDS scores were significantly better than those of the DWI/ADC scores overall, in the PZ and TZ (FOM: overall, 0.715 vs. 0.783; PZ, 0.756 vs. 0.815; TZ, 0.653 vs. 0.738. Sensitivity: overall, 0.512 vs. 0.607; PZ, 0.485 vs. 0.573; TZ, 0.636 vs. 0.761). For PPV, a statistically significant difference was observed overall (0.727 vs. 0.777). The κ value of DWI/WDS score was significantly higher than that of DWI/ADC score overall and in the PZ (overall, 0.614 vs. 0.792; PZ, 0.609 vs. 0.797). Contrast was significantly higher overall in the PZ and TZ in WDS images (median, 1.26, 1.19, and 1.61) than in ADC maps (0.46, 0.47, and 0.41). DATA CONCLUSION: WDS images performed better than ADC maps in the diagnosis of csPCa and in inter-reader agreement of the diagnosis. LEVEL OF EVIDENCE: 4 Technical Efficacy Stage: 2.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias da Próstata , Imagem de Difusão por Ressonância Magnética , Humanos , Masculino , Próstata/diagnóstico por imagem , Prostatectomia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/cirurgia , Estudos Retrospectivos , Sensibilidade e Especificidade
7.
Jpn J Radiol ; 39(9): 857-867, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34021462

RESUMO

Granulocyte colony-stimulating factor (G-CSF)-producing tumors have an aggressive clinical course. Here, we report five cases of G-CSF-producing tumors and review the literature, focusing on imaging findings related to tumor-produced G-CSF. In addition to our cases, we identified 30 previous reports of G-CSF-producing tumors on which 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT, bone scintigraphy, or evaluation of bone marrow MR findings was performed. White blood cell count, serum C-reactive protein, and serum interleukin-6 were elevated in all cases for which these parameters were measured. G-CSF-producing tumors presented large necrotic masses (mean diameter 83.2 mm, range 17-195 mm) with marked FDG uptake (mean maximum standardized uptake value: 20.09). Diffuse FDG uptake into the bone marrow was shown in 28 of the 31 cases in which FDG-PET/CT was performed. The signal intensity of bone marrow suggested marrow reconversion in all seven MRI-assessable cases. Bone scintigraphy demonstrated no significant uptake, except in two cases with bone metastases. Splenic FDG uptake was increased in 8 of 10 cases in which it was evaluated. These imaging findings may reflect the effects of tumor-produced G-CSF. The presence of G-CSF-producing tumors should be considered in patients with cancer who show these imaging findings and marked inflammatory features of unknown origin.


Assuntos
Neoplasias Ósseas , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Fluordesoxiglucose F18 , Fator Estimulador de Colônias de Granulócitos , Humanos , Tomografia Computadorizada por Raios X
8.
Diagn Interv Radiol ; 27(1): 65-71, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33252338

RESUMO

PURPOSE: We aimed to evaluate mid- to long-term results of endovascular treatment for portal vein thrombosis (PVT) after living-donor liver transplantation (LDLT). METHODS: Thirty cases (14 males, 16 females; age range, 0.67-65 years) who underwent endovascular treatment including thrombolysis, angioplasty, stent placement, and/or collateral embolization for PVT after LDLT from 2001 to 2017 were retrospectively reviewed. Clinical and procedural data were collected and analyzed regarding the patency of the PVT site at the last follow-up date (PVT-free persistency) using Log-rank test. Results were considered statistically significant at P < 0.05. RESULTS: Median follow-up was 120 months. The technical success rate was 80% (n=24). Patency rates at 1 week and 1, 3, 6, 12, 36, and 60 months were 73%, 59%, 55%, 51%, 51%, 51%, and 51% for primary patency and 80%, 70%, 66%, 66%, 66%, 61%, and 61% for assisted patency after secondary endovascular treatment. PVT-free persistency rates regarding the subgroups were as follows: children under 12 years vs. adults, 50% vs. 68% (P = 0.42); acute vs. nonacute, 76% vs. 46% (P = 0.10); localized vs. extensive, 90% vs. 50% (P = 0.035); transileocolic approach vs. percutaneous-transhepatic approach, 71% vs. 54% (P = 0.39); and thrombolysis-based treatment vs. non-thrombolysis-based treatment, 71% vs. 44% (P = 0.12), respectively. Among technically successful cases, PVT-free persistency rate was 94% for those with hepatopetal flow in the peripheral portal vein vs. 17% for those without hepatopetal flow (P < 0.001). The only major complication occurring was pleural hemorrhage (n=1). Minor complications (i.e., fever) occurred in 18 patients (60%). CONCLUSION: In conclusion, mid- to long-term portal patency following endovascular treatment was approximately 50%-60% in PVT patients after LDLT. PVT site patency over three months after the first endovascular treatment, localized PVT, and hepatopetal flow in the peripheral portal vein were identified as key prognostic factors for mid- to long-term portal patency.


Assuntos
Transplante de Fígado , Trombose Venosa , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos de Viabilidade , Feminino , Humanos , Lactente , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Veia Porta , Estudos Retrospectivos , Resultado do Tratamento , Trombose Venosa/terapia , Adulto Jovem
9.
Acta Radiol ; 62(5): 567-573, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32586122

RESUMO

BACKGROUND: Ultrasonography (US) is useful when implanting fiducial markers in the liver. However, the implant position is sometimes lost. Recently, real-time image fusion technology (Volume Navigation [V-navi]; GE Healthcare, Milwaukee, WI, USA) has been introduced as a technique for using images from different modalities, and its utility for fiducial marker implantation has been hypothesized. PURPOSE: To evaluate the utility of US-guided fiducial marker implantation in the liver using V-navi compared to conventional US. MATERIAL AND METHODS: We retrospectively reviewed 35 patients who underwent fiducial marker implantation for stereotactic body radiation therapy of liver tumors in 2013-2018. To avoid artifacts obscuring the tumor, the target point of implantation was set 10 mm cranial or caudal to the tumor. Marker implantation was then performed using US alone (US group, n = 24) or V-navi with computed tomography (CT) or magnetic resonance imaging (V-navi group, n = 11). Postprocedural CT was evaluated to determine technical success, distances between marker and either tumor surface or target point, and whether marker-induced artifacts obscured the tumor. Complications were also evaluated. Results were compared between groups. RESULTS: Technical success was obtained in 33 patients. Distance between the tumor and marker showed no significant difference between groups. Distance between target point and marker was shorter in the V-navi group (P = 0.0093). Tumor-obscuring artifacts were seen in 12 patients (V-navi group, n = 1; US group, n = 11; P = 0.055). The only complication was minor bleeding in the US group (n = 1). CONCLUSION: V-navi appears useful for US-guided fiducial marker implantation in the liver compared with conventional US.


Assuntos
Marcadores Fiduciais , Neoplasias Hepáticas/radioterapia , Implantação de Prótese/métodos , Radiocirurgia/métodos , Cirurgia Assistida por Computador , Ultrassonografia de Intervenção , Idoso , Idoso de 80 Anos ou mais , Sistemas Computacionais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
10.
Intern Med ; 59(19): 2397-2403, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32611954

RESUMO

The selective arterial calcium stimulation test (SACST) is one of the most useful localization tests for insulinoma but can cause false-positive and/or unexpected multi arterial positive results that hamper clinical decisions. There are also several adverse effects, such as nausea and hypoglycemia, at the conventional dose (0.025 mEq/kg) of calcium injection. We herein report five consecutive insulinoma cases in which low-dose (0.005-0.007 mEq/kg) calcium injection for SACST led to successful insulinoma localization. No adverse effects of SACST were observed. In conclusion, a low-dose SACST can be a favorable option as an insulinoma localization test in terms of accuracy and safety.


Assuntos
Cálcio/administração & dosagem , Veias Hepáticas/cirurgia , Insulinoma/diagnóstico , Insulinoma/cirurgia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/cirurgia , Adulto , Cálcio/metabolismo , Relação Dose-Resposta a Droga , Feminino , Veias Hepáticas/metabolismo , Humanos , Insulinoma/metabolismo , Japão , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/metabolismo , Estudos Retrospectivos , Resultado do Tratamento
11.
Int J Clin Oncol ; 25(4): 732-740, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31792635

RESUMO

BACKGROUND: We investigated whether the detectability of prostate cancer with 3-Tesla (3T) multiparametric magnetic resonance imaging (mpMRI) differs by tumor location. METHODS: We identified 136 patients with prostate cancer who underwent 3-T mpMRI before prostatectomy at a single academic center. Two uroradiologists scored all MRIs with Prostate Imaging-Reporting and Data System version 2 (PI-RADS v2). A genitourinary pathologist mapped tumor foci from serial whole-mount radical prostatectomy sections. We assessed concordance of images with cancer sites. Tumor foci with Gleason score ≥  3 + 4 or volume ≥ 0.5 mL were considered significant. RESULTS: A total of 122 foci in 106 cases were identified with mpMRI. Twenty-four were PI-RADS 3, 52 were 4, and 46 were 5. A total of 274 tumor foci were identified with whole-mount pathology. The sensitivity stratified by location to detect significant cancer with a PI-RADS cutoff value of 3 was 56.0% overall, 50.0% in the peripheral zone (PZ), 71.2% in the transitional zone (TZ), 62.4% anterior, 49.5% posterior, 42.0% apical, 63.6% in the midgland, and 43.8% in the gland base. In multivariate analysis, tumor location was not a significant predictor of identification by mpMRI. Tumor volume, Gleason score, and index tumor status were significantly associated with identification by mpMRI. CONCLUSIONS: mpMRI detected the majority of high-grade and large cancers, but had low sensitivity in the PZ, posterior, and apex and base of the gland. The high prevalence of low-volume, low-Gleason score index tumors, as well as satellite tumors in those areas, accounted for the difference.


Assuntos
Imageamento por Ressonância Magnética Multiparamétrica/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Gradação de Tumores , Prostatectomia/métodos , Neoplasias da Próstata/cirurgia , Sensibilidade e Especificidade , Carga Tumoral
12.
AJR Am J Roentgenol ; 214(3): 687-693, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31642696

RESUMO

OBJECTIVE. The purpose of this article is to evaluate the radiologic findings predicting the future liver remnant hypertrophy ratio after portal vein embolization of the right branch. MATERIALS AND METHODS. The associations between the radiologic findings and the future liver remnant hypertrophy ratio for 79 patients who underwent portal vein embolization of the right branch between July 2007 and April 2017 were retrospectively analyzed. Multiple linear regression was performed to adjust for potential confounders, and the volume ratio of the right lobe anterior segment, number of proximal small branches from the right anterior and posterior portal veins, transient hepatic parenchymal enhancement, portal vein invasion, and variants of main portal vein anatomy were evaluated. The potential confounders were age, ratio of future liver remnant hypertrophy to total liver volume, indocyanine green clearance rate, maximum serum total bilirubin before portal vein embolization, and history of chemotherapy. RESULTS. Statistically significant associations were found between the future liver remnant hypertrophy ratio and the number of proximal small branches from the right anterior and posterior portal veins (p < 0.001), transient hepatic parenchymal enhancement (p < 0.001), portal vein invasion (p = 0.017), and variants of main portal vein anatomy (p = 0.048). The mean future liver remnant hypertrophy rate was 51.0% (n = 16) in patients without the radiologic findings showing statistically significant differences, and 25.8% (n = 63) in patients with at least one significant finding. CONCLUSION. When added to previously reported factors, the radiologic findings identified can help determine the indications for portal vein embolization and novel strategies for major hepatectomy.


Assuntos
Embolização Terapêutica/métodos , Hepatomegalia/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/terapia , Veia Porta , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Interpretação de Imagem Radiográfica Assistida por Computador , Estudos Retrospectivos
14.
Abdom Radiol (NY) ; 44(4): 1223-1229, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30600382

RESUMO

Bladder cancer usually forms a papillary structure. Progression along the cavity or membranous structures surrounding the bladder, rectum, or retroperitoneum without formation of a discrete mass is rare. We here present two patients with duodenal obstruction caused by retroperitoneal progression of bladder cancer, in both of whom computed tomography revealed bladder and rectal wall thickening with a malignant target sign, thickened mesorectal fascia with abnormal tissue stranding, and increased perirectal fat density. Both cancers progressed despite treatment, as indicated by faint abnormal tissue stranding and increased retroperitoneal fat density along the retromesenteric plane from the pelvis to the duodenum. Subsequently, both patients developed obstruction in the horizontal portion of the duodenum, still without formation of a mass lesion. These two patients highlight the challenges associated with retroperitoneal invasion by bladder cancer in the absence of a mass lesion and underscore the importance of considering cancer progression in patients with bowel obstruction, even when there is no obvious mass lesion and/or only minor retroperitoneal findings. Progression along the retromesenteric plane may be the key pathway via which progressive bladder cancer results in duodenal obstruction without or with a minor mass lesion.


Assuntos
Obstrução Duodenal/diagnóstico por imagem , Obstrução Duodenal/etiologia , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/patologia , Idoso , Progressão da Doença , Obstrução Duodenal/cirurgia , Evolução Fatal , Humanos , Imageamento por Ressonância Magnética , Masculino , Invasividade Neoplásica , Espaço Retroperitoneal/diagnóstico por imagem , Espaço Retroperitoneal/patologia , Tomografia Computadorizada por Raios X , Neoplasias da Bexiga Urinária/cirurgia
15.
Radiol Phys Technol ; 11(3): 294-302, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30014182

RESUMO

We evaluated quantitation accuracy of the specific binding ratio (SBR) and specific uptake ratio (SUR) of dopamine transporter for various correction methods by using a novel three-dimensional striatum digital brain (3D-SDB) phantom comprised of segments containing the striatum, ventricle, brain parenchyma, and skull bone extracted from T2-weighted MR images. A process image was reconstructed by projection data sets with blurring, scatter, and attenuation from 3D-SDB phantom data. A 3D-iterative reconstruction algorithm was used without correction (OSEM), or with scatter (SC), attenuation (AC), AC + SC (ACSC), AC + resolution recovery (RR; ACRR), SC + RR (SCRR), AC + SC + RR (ACSCRR), AC + SC + RR + partial volume (PVC; ACSCRRP), and AC + SC + RR + PVC + ventricle (ACSCRRPV). Data were then quantified using SBR and SUR. Differences between measured and true SBR values were (in order): ACSCRR < ACSC < ACRR < AC < SCRR < SC < OSEM: the maximal error was 45.3%. The trend of differences between measured and true SUR values was similar to that of SBR; maximal error was 65%. The ACSCRR-corrected SUR, which was closer to the true value, was underestimated by 30.4%. However, the ACSCRRP-corrected SUR was underestimated by a maximum of 22.5%. The SUR in the ACSCRRPV was underestimated by 6.2%. The accuracy of quantitation was improved using various types of compensation and correction. Accuracy improved more for the SUR when PVC and ventricle correction were added.


Assuntos
Imageamento Tridimensional , Neostriado/diagnóstico por imagem , Imagens de Fantasmas , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Tropanos
16.
Hepatol Res ; 48(12): 1055-1063, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29882287

RESUMO

AIM: In cases of symptomatic giant hepatic cysts, appropriate treatment is required to relieve symptoms. Ethanol, minocycline hydrochloride, and ethanolamine oleate have been conventionally used for ultrasound (US)-guided sclerotherapy. However, liquid sclerosing agents could mix with the residual fluid in the cyst and reduce their sclerotic effects. We carried out US-guided microfoam sclerotherapy using polidocanol for three patients and evaluated its efficacy and safety. METHODS: Between May 2016 and March 2017, three female patients with symptomatic giant hepatic cysts were referred to our hospital. All of them were prospectively included in this study. RESULTS: The maximum diameters of the hepatic cysts in the three patients were 92 × 89 × 86 mm, 155 × 119 × 140 mm, and 223 × 195 × 123 mm, respectively. Polidocanol microfoam was successfully administered through an 8.5-Fr pigtail catheter for all patients. One, two, and three microfoam sclerotherapy sessions were undertaken according to the initial cyst volume for cases 1, 2, and 3, respectively. The mean reduction rates of the cyst volume were 90.1% (85.5-98.9%) at 3 months, 96.3% (91.9-99.9%) at 6 months, and 99.5% (99.1-99.9%) at 9 months after treatment. No significant treatment-induced adverse effects were observed. CONCLUSION: Ultrasound-guided microfoam sclerotherapy using polidocanol could be an effective and safe method for the treatment of symptomatic giant liver cysts.

17.
Radiol Phys Technol ; 11(2): 219-227, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29700797

RESUMO

This study aimed to evaluate the effect of ventricular enlargement on the specific binding ratio (SBR) and to validate the cerebrospinal fluid (CSF)-Mask algorithm for quantitative SBR assessment of 123I-FP-CIT single-photon emission computed tomography (SPECT) images with the use of a 3D-striatum digital brain (SDB) phantom. Ventricular enlargement was simulated by three-dimensional extensions in a 3D-SDB phantom comprising segments representing the striatum, ventricle, brain parenchyma, and skull bone. The Evans Index (EI) was measured in 3D-SDB phantom images of an enlarged ventricle. Projection data sets were generated from the 3D-SDB phantoms with blurring, scatter, and attenuation. Images were reconstructed using the ordered subset expectation maximization (OSEM) algorithm and corrected for attenuation, scatter, and resolution recovery. We bundled DaTView (Southampton method) with the CSF-Mask processing software for SBR. We assessed SBR with the use of various coefficients (f factor) of the CSF-Mask. Specific binding ratios of 1, 2, 3, 4, and 5 corresponded to SDB phantom simulations with true values. Measured SBRs > 50% that were underestimated with EI increased compared with the true SBR and this trend was outstanding at low SBR. The CSF-Mask improved 20% underestimates and brought the measured SBR closer to the true values at an f factor of 1.0 despite an increase in EI. We connected the linear regression function (y = - 3.53x + 1.95; r = 0.95) with the EI and f factor using root-mean-square error. Processing with CSF-Mask generates accurate quantitative SBR from dopamine transporter SPECT images of patients with ventricular enlargement.


Assuntos
Ventrículos Cerebrais/diagnóstico por imagem , Ventrículos Cerebrais/patologia , Processamento de Imagem Assistida por Computador , Neostriado/diagnóstico por imagem , Imagens de Fantasmas , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Tropanos/metabolismo , Neostriado/metabolismo , Distribuição Normal , Tamanho do Órgão
18.
Korean J Radiol ; 19(1): 32-39, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29353997

RESUMO

Objective: To selectively visualize the left gastric vein (LGV) with hepatopetal flow information by non-contrast-enhanced magnetic resonance angiography under a hypothesis that change in the LGV flow direction can predict the development of esophageal varices; and to optimize the acquisition protocol in healthy subjects. Materials and Methods: Respiratory-gated three-dimensional balanced steady-state free-precession scans were conducted on 31 healthy subjects using two methods (A and B) for visualizing the LGV with hepatopetal flow. In method A, two time-spatial labeling inversion pulses (Time-SLIP) were placed on the whole abdomen and the area from the gastric fornix to the upper body, excluding the LGV area. In method B, nonselective inversion recovery pulse was used and one Time-SLIP was placed on the esophagogastric junction. The detectability and consistency of LGV were evaluated using the two methods and ultrasonography (US). Results: Left gastric veins by method A, B, and US were detected in 30 (97%), 24 (77%), and 23 (74%) subjects, respectively. LGV flow by US was hepatopetal in 22 subjects and stagnant in one subject. All hepatopetal LGVs by US coincided with the visualized vessels in both methods. One subject with non-visualized LGV in method A showed stagnant LGV by US. Conclusion: Hepatopetal LGV could be selectively visualized by method A in healthy subjects.


Assuntos
Angiografia por Ressonância Magnética/métodos , Veia Porta/diagnóstico por imagem , Adulto , Velocidade do Fluxo Sanguíneo , Feminino , Voluntários Saudáveis , Frequência Cardíaca , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Estômago/irrigação sanguínea , Ultrassonografia
19.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 73(10): 1018-1027, 2017.
Artigo em Japonês | MEDLINE | ID: mdl-29057773

RESUMO

PURPOSE: This study aimed at developing the realistic striatal digital brain (SDB) phantom and to assess specific binding ratio (SBR) for ventricular effect in the 123I-FP-CIT SPECT imaging. METHODS: SDB phantom was constructed in to four segments (striatum, ventricle, brain parenchyma, and skull bone) using Percentile method and other image processing in the T2-weighted MR images. The reference image was converted into 128×128 matrixes to align MR images with SPECT images. The process image was reconstructed with projection data sets generated from reference images additive blurring, attenuation, scatter, and statically noise. The SDB phantom was evaluated to find the accuracy of calculated SBR and to find the effect of SBR with/without ventricular counts with the reference and process images. RESULTS: We developed and investigated the utility of the SDB phantom in the 123I-FP-CIT SPECT clinical study. The true value of SBR was just marched to calculate SBR from reference and process images. The SBR was underestimated 58.0% with ventricular counts in reference image, however, was underestimated 162% with ventricular counts in process images. CONCLUSION: The SDB phantom provides an extremely convenient tool for discovering basic properties of 123I-FP-CIT SPECT clinical study image. It was suggested that the SBR was susceptible to ventricle.


Assuntos
Encéfalo/diagnóstico por imagem , Imagens de Fantasmas , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Humanos , Tropanos , Adulto Jovem
20.
Magn Reson Imaging ; 43: 42-47, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28688951

RESUMO

PURPOSE: To evaluate images of non-contrast-enhanced 3D MR portography within a breath-hold (BH) using compressed sensing (CS) compared to standard respiratory-triggered (RT) sequences. MATERIALS AND METHODS: Fifty-nine healthy volunteers underwent MR portography using two sequences of balanced steady-state free-precession (bSSFP) with time-spatial labeling inversion pulses (Time-SLIP): BH bSSFP-CS and RT bSSFP. Two radiologists independently scored the diagnostic acceptability to delineate the portal branches (MPV: main portal vein; RPV: right portal vein; LPV: left portal vein; RPPV: right posterior portal vein; and P4 and P8: portal branch of segment 4 and segment 8, respectively) and the overall image quality on a four-point scale. We assessed noninferiority of BH bSSFP-CS to RT bSSFP. For quantitative analysis, vessel-to-liver contrast (Cv-l) was calculated in MPV, RPV and LPV. RESULTS: BH bSSFP sequence was successfully performed with a 30-second acquisition time. The diagnostic acceptability scores of BH bSSFP-CS compared with RT bSSFP were statistically noninferior: MPV (95% CI for score difference of Reader 1 and Reader 2, respectively: [-0.16, 0.06], [-0.05, 0.02]), RPV ([-0.00, 0.11], [-0.01, 0.08]), LPV ([-0.03, 0.10], [-0.10, 0.03]), RPPV ([-0.03, 0.10], [-0.05, 0.05]), P4 ([-0.13, 0.34], [-0.28, 0.21]) and P8 ([-0.21, 0.11], [-0.25, -0.02]). However, the overall image quality of BH bSSFP-CS did not show noninferiority ([-0.61, -0.24], [-0.54, -0.17]). Cv-l values were significantly lower in BH bSSFP-CS (P<0.001). CONCLUSION: CS enabled non-contrast-enhanced 3D bSSFP MR portography to be performed within a BH while maintaining noninferior diagnostic acceptability compared to standard RT bSSFP MR portography.


Assuntos
Suspensão da Respiração , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética , Portografia , Aceleração , Adulto , Meios de Contraste , Coleta de Dados , Compressão de Dados , Feminino , Voluntários Saudáveis , Humanos , Processamento de Imagem Assistida por Computador , Fígado , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Veia Porta/diagnóstico por imagem , Estudos Prospectivos , Reprodutibilidade dos Testes , Adulto Jovem
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