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OBJECTIVE: This study aimed to compare diagnostic performance for tumor detection and for assessment of tumor aggressiveness in prostate cancer (PC) between amide proton transfer magnetic resonance imaging (MRI) with 3-dimensional acquisition (3DAPT) and diffusion-weighted imaging. METHODS: The subjects were 23 patients with 27 pathologically proven PCs who underwent 3T multiparametric MRI. With reference to the pathology findings, 2 readers in consensus identified the location of PC on multiparametric MRI and measured APT signal intensity (APT SI [%]) and mean apparent diffusion coefficient (ADC) of the benign region and each PC lesion. RESULTS: The mean ADC showed a significant difference between benign regions and PC lesions (0.74 ± 0.15 vs 1.37 ± 0.21, P < 0.001), whereas APT SI did not ( P = 0.091). Lesion APT SI was significantly higher and lesion ADC was significantly lower in PCs with Gleason group (GG) ≥3 than in PCs with GG ≤2 (3.37 ± 1.30 vs 1.78 ± 0.67, P < 0.001, and 0.71 ± 0.18 vs 0.79 ± 0.10, P = 0.038, respectively). The APT SI was significantly higher in GG3 than in GG1, in GG3 than in GG2, and in GG4 than in GG2 ( P = 0.009, P = 0.001, and P = 0.006, respectively). The area under the curve for separating tumor lesions and benign regions was 0.601 for 3DAPT and 0.983 for ADC ( P < 0.001). The area under the curve for separating tumors with GG ≤2 from tumors with GG ≥3 was 0.912 for 3DAPT and 0.734 for ADC ( P = 0.172). CONCLUSIONS: In patients with PC, it might be preferable to use ADC to discriminate benign from malignant tissue and use APT SI for assessment of tumor aggressiveness.
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Neoplasias da Próstata , Prótons , Masculino , Humanos , Imageamento por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Amidas , Estudos RetrospectivosRESUMO
Bladder cancer (BCa) is among the ten most frequent cancers globally. It is the tumor with the highest lifetime treatment-associated costs, and among the tumors with the heaviest impacts on postoperative quality of life. The purpose of this article is to review the current applications and future perspectives of the Vesical Imaging Reporting and Data System (VI-RADS). VI-RADS is a newly developed scoring system aimed at standardization of MRI acquisition, interpretation, and reporting for BCa. An insight will be given on the BCa natural history, current MRI applications for local BCa staging with assessment of muscle invasiveness, and clinical implications of the score for disease management. Future applications include risk stratification of nonmuscle invasive BCa, surveillance, and prediction and monitoring of therapy response. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.
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Neoplasias da Bexiga Urinária , Humanos , Qualidade de Vida , Projetos de Pesquisa , Neoplasias da Bexiga Urinária/diagnóstico por imagemRESUMO
OBJECTIVES: To evaluate the CT characteristics and detectability of carcinoma in situ (CIS) of the upper urinary tract. METHODS: Between January 2007 and March 2020, 28 patients (mean age: 73 years, 25 male and 3 female) with 29 pure CIS lesions of the upper urinary tract (i.e., without concomitant non-CIS lesion) who underwent nephroureterectomy were identified. The most recent CT scan performed before ureteroscopy, systemic neoadjuvant chemotherapy, or nephroureterectomy was selected for analysis. Twenty-eight patients without upper tract malignancy were selected as a control group. All images were evaluated for presence of upper urinary tract CIS using confidence levels ranging from 1 to 100 by two radiologists. The confidence level of 75 was used as a cutoff threshold for calculating sensitivity and specificity. RESULTS: The median interval between CT scan and nephroureterectomy was 96 days. The number of true-positive lesions (per-lesion sensitivity) was 41% (12/29) and 52% (15/29) by readers 1 and 2. The true-positive lesion appeared as wall thickening in 83% (10/12) by reader 1 and 80% (12/15) by reader 2, and as a mass in 17% (2/12) by reader 1 and 20% (3/15) by reader 2. All mass-forming lesions were located in the renal collecting system. The per-patient sensitivity and specificity were 42% and 100% in reader 1, and 54% and 96% in reader 2. CONCLUSIONS: The common abnormal finding of pure CIS in the upper urinary tract was wall thickening. Pure CIS could also appear as a mass-forming lesion when it is located in the renal collecting system. KEY POINTS: ⢠The common abnormal finding of pure CIS in the upper urinary tract is wall thickening. Gradually progressive urothelial wall thickening and/or worsening symptoms should raise the suspicion of CIS. ⢠Pure CIS in the upper urinary tract also appears as a mass-forming lesion when it is located in the renal collecting system. ⢠Hydronephrosis and fat stranding play an auxiliary role in detecting pure CIS in the upper urinary tract.
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Carcinoma in Situ , Carcinoma de Células de Transição , Neoplasias Urológicas , Idoso , Carcinoma in Situ/cirurgia , Feminino , Humanos , Masculino , Nefroureterectomia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Neoplasias Urológicas/diagnóstico por imagemRESUMO
OBJECTIVES: Image quality (IQ) of diffusion-weighted imaging (DWI) with single-shot echo-planar imaging (ssEPI) suffers from low signal-to-noise ratio (SNR) in high b-value acquisitions. Compressed SENSE (C-SENSE), which combines SENSE with compressed sensing, enables SNR to be improved by reducing noise. The aim of this study was to compare IQ and prostate cancer (PC) detectability between DWI with ssEPI using SENSE (EPIS) and using C-SENSE (EPICS). MATERIALS AND METHODS: Twenty-five patients with pathologically proven PC underwent multi-parametric magnetic resonance imaging at 3T. DW images acquired with EPIS and EPICS were assessed for the following: lesion conspicuity (LC), SNR, contrast-to-noise ratio (CNR), mean and standard deviation (SD) of apparent diffusion coefficient (ADC) of lesion (lADCm and lADCsd), coefficient of variation of lesion ADC (lADCcv), and mean ADC of benign prostate (bADCm). RESULTS: LC were comparable between EPIS and EPICS (p > 0.050), and SNR and CNR were significantly higher in EPICS than EPIS (p = 0.001 and p < 0.001). In both EPIS and EPICS, lADCm was significantly lower than bADCm (p < 0.001). In addition, lADCcv was significantly lower in EPICS than in EPIS (p < 0.001). CONCLUSION: Compared with EPIS, EPICS has improved IQ and comparable diagnostic performance in PC.
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Imagem Ecoplanar , Neoplasias da Próstata , Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Humanos , Imageamento por Ressonância Magnética , Masculino , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Reprodutibilidade dos Testes , Razão Sinal-RuídoRESUMO
BACKGROUND: Biparametric MRI (bpMRI) without dynamic contrast-enhanced MRI (DCE-MRI) results in an elimination of adverse events, shortened examination time, and reduced costs, compared to multiparametric MRI (mpMRI). The ability of bpMRI to detect clinically significant prostate cancer (csPC) with the Prostate Imaging and Reporting Data System version 2.1 (PI-RADS v2.1) compared to standard mpMRI has not been studied extensively. PURPOSE: To compare the interobserver reliability and diagnostic performance for detecting csPC of bpMRI and mpMRI using PI-RADS v2.1. STUDY TYPE: Retrospective. POPULATION: In all, 103 patients with elevated prostate-specific antigen (PSA) levels who underwent mpMRI and subsequent MRI-ultrasonography fusion-guided prostate-targeted biopsy (MRGB) with or without prostatectomy. FIELD STRENGTH/SEQUENCES: T2 -weighted imaging (T2 WI), diffusion-weighted imaging (DWI), and DCE-MRI at 3T. ASSESSMENT: Three readers independently assessed each suspected PC lesion, assigning a score of 1-5 for T2 WI, a score of 1-5 for DWI, and positive and negative for DCE-MRI according to PI-RADS v2.1 and determined the overall PI-RADS assessment category of bpMRI (T2 WI and DWI) and mpMRI (T2 WI, DWI, and DCE-MRI). The reference standard was MRGB or prostatectomy-derived histopathology. STATISTICAL TESTING: Statistical analysis was performed using the kappa statistic and McNemar and Delong tests. RESULTS: Of the 165 suspected PC lesions in 103 patients, 81 were diagnosed with csPC and 84 with benign conditions. Interobserver variability of PI-RADS assessment category showed good agreement for bpMRI (kappa value = 0.642) and mpMRI (kappa value = 0.644). For three readers, the diagnostic sensitivity was significantly higher for mpMRI than for bpMRI (P < 0.001 to P = 0.016, respectively), whereas diagnostic specificity was significantly higher for bpMRI than for mpMRI (P < 0.001 each). For three readers, the area under the receiver operating characteristic curve (AUC) was higher for bpMRI than for mpMRI; however, the difference was significant only for Reader 1 and Reader 3 (Reader 1: 0.823 vs. 0.785, P = 0.035; Reader 2: 0.852 vs. 0.829, P = 0.099; and Reader 3: 0.828 vs. 0.773, P = 0.002). DATA CONCLUSION: For detecting csPC using PI-RADS v2.1, the interobserver reliability and diagnostic performance of bpMRI was comparable with those of mpMRI. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 2.
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Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias da Próstata , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
BACKGROUND. The Vesical Imaging Reporting and Data System (VI-RADS), based on multiparametric MRI (mpMRI), was developed to provide accurate information for the diagnosis of muscle-invasive bladder cancer (MIBC). OBJECTIVE. The purpose of our study was to evaluate the interobserver agreement and diagnostic performance of VI-RADS among readers with different levels of experience. METHODS. This retrospective study included 91 consecutive patients who underwent mpMRI before transurethral resection of bladder tumor (TURBT) from July 2010 through August 2018. After attending a training session, seven radiologists (five radiologists experienced in bladder MRI and two inexperienced radiologists) reviewed and scored all MRI examinations according to VI-RADS. The interobserver agreement was assessed by kappa statistics. ROC analysis was used to evaluate the diagnostic performance for MIBC. AUCs were estimated. RESULTS. Among 91 patients (72 men and 19 women; mean age ± SD, 73.2 ± 10.2 years), 48 (52.7%) had MIBC and 43 (47.3%) had non-muscle-invasive bladder cancer. Sixty-eight patients were treated with TURBT, and 23 were treated with radical cystectomy. Interobserver agreement was moderate to substantial (κ = 0.60-0.80) among the experienced readers, substantial (κ = 0.67) between the two inexperienced readers, and moderate to substantial (κ = 0.55-0.75) between the experienced and inexperienced readers. The pooled AUC was 0.88 (range, 0.82-0.91) for experienced readers and 0.84 (range, 0.83-0.85) for inexperienced readers, and 0.87 for all readers. Using a VI-RADS score of 4 or greater as the cutoff value for MIBC, the pooled sensitivity and specificity were 74.1% (range, 66.0-80.9%) and 94.1% (range, 88.6-97.7%) for experienced readers and 63.9% (range, 59.6-68.1%) and 86.4% (range, 84.1-88.6%) for inexperienced readers. Using a VI-RADS score of 3 or greater as the cutoff value, the pooled sensitivity and specificity were 83.4% (range, 80.9-85.1%) and 77.3% (range, 61.4-88.6%) for experienced readers and 82.0% (range, 80.9-83.0%) and 73.9% (range, 72.7-75.0%) for inexperienced readers. CONCLUSION. We observed moderate to substantial interobserver agreement and a pooled AUC of 0.87 among radiologists of different levels of expertise using VI-RADS. CLINICAL IMPACT. VI-RADS could help determine the depth and range of excision in TURBT, decreasing the risk of complications and enhancing the accuracy of pathologic diagnosis.
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Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética Multiparamétrica/métodos , Sistemas de Informação em Radiologia/normas , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Estudos Retrospectivos , Sensibilidade e Especificidade , Bexiga Urinária/diagnóstico por imagemRESUMO
OBJECTIVE. The purpose of this article is to review the natural history and management of bladder cancer, with insight into MRI applications for the assessment of muscle invasiveness of bladder cancer using the newly developed Vesical Imaging Reporting and Data System (VI-RADS) score. CONCLUSION. Multiparametric MRI and the VI-RADS score have been consistently validated across several different institutions as appropriate tools for local staging of bladder cancer and have been proven to contribute to the diagnostic workup and management of urinary bladder cancer.
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Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Meios de Contraste , Humanos , Interpretação de Imagem Assistida por Computador , Invasividade Neoplásica , Estadiamento de Neoplasias , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/terapiaRESUMO
OBJECTIVE: The purpose of this article was to determine whether imaging features on contrast-enhanced CT can differentiate benign from metastatic adrenal masses in patients with renal cell carcinoma (RCC). MATERIALS AND METHODS: Between January 2008 and January 2014, 135 patients with untreated RCC were found to have 163 adrenal masses (102 benign and 61 metastatic) on contrast-enhanced CT including the corticomedullary phase (66 benign and 42 metastatic) or nephrographic phase (56 benign and 33 metastatic) or both. Imaging features of renal and adrenal masses were recorded, including T and N staging components of renal masses, internal texture, CT attenuation values, and attenuation differences between renal and adrenal masses. Logistic regression diagnostic models to differentiate benign from metastatic adrenal mass were constructed using independently significant imaging parameters in the respective corticomedullary and nephrographic phases (corticomedullary phase model and nephrographic phase model). Diagnostic performance of the models was evaluated by ROC analysis. RESULTS: Statistically significant variables for the models were regional lymphadenopathy, perirenal or renal sinus fat invasion (corticomedullary phase model only), adrenal mass size, CT attenuation value of adrenal mass, and absolute value of attenuation difference between renal and adrenal masses. Both models had excellent diagnostic performance; the AUC and optimal sensitivity and specificity for the diagnosis of metastasis were 0.991, 100%, and 92.4%, respectively, in the corticomedullary phase model and 0.947, 81.8%, and 96.4%, respectively, in the nephrographic phase model. CONCLUSION: Differentiation between benign and metastatic adrenal masses in patients with RCC can be achieved accurately by combining multiple imaging features on contrast-enhanced CT.
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Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/secundário , Carcinoma de Células Renais/diagnóstico por imagem , Carcinoma de Células Renais/secundário , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/patologia , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por ComputadorRESUMO
OBJECTIVE: The objective of our study was to compare the diagnostic performance of nephrographic phase only, excretory phase only, and both nephrographic and excretory phases of CT urography (CTU) for the detection of upper tract urothelial carcinoma. MATERIALS AND METHODS: Forty-nine consecutive patients with pathologically proven upper tract urothelial carcinoma who underwent a single-bolus CTU examination were evaluated. Forty-nine control patients with normal findings on two CTU examinations performed at a 1-year interval were included. Two radiologists independently reviewed the 98 CTU examinations at three different sessions (nephrographic phase only, excretory phase only, and both nephrographic and excretory phases simultaneously) and rated the likelihood of the presence of a urothelial carcinoma in each segment of the renal collecting system and ureter using a 5-point scale. Sensitivity, specificity, and AUC of ROC curve were calculated per segment and per patient. RESULTS: A total of 314 segments, 56 of which contained tumors, were evaluated. In the per-segment analysis for reviewers 1 and 2, the sensitivity, specificity, and AUC, respectively, were as follows: 88%, 98%, and 0.95 and 84%, 97%, and 0.94 for the nephrographic phase; 79%, 98%, and 0.91 and 89%, 98%, and 0.95 for the excretory phase; and 88%, 99%, and 0.95 and 89%, 99%, and 0.96 for the combined nephrographic and excretory phases. The AUC of the combined nephrographic and excretory phases was significantly higher than that of the nephrographic phase (per-patient analysis, reviewer 2) and that of excretory phase (per-segment analysis, reviewer 1) but was not significantly different in any other comparisons. CONCLUSION: The nephrographic and excretory phases are complementary for the detection of upper tract urothelial carcinoma.
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Carcinoma/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Urografia/métodos , Neoplasias Urológicas/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC , Estudos Retrospectivos , UrotélioRESUMO
OBJECTIVE: The objective of this study was to characterize MRI findings of inverted urothelial papilloma of the bladder. MATERIALS AND METHODS: Data pertaining to 16 patients with 18 pathologically proven inverted urothelial papillomas of the bladder who had undergone MRI were retrospectively collected from seven institutions. The shape and surface characteristics of the tumors were evaluated using T2-weighted MR images. In addition, the signal intensity of inverted urothelial papillomas was visually assessed on T1-weighted, T2-weighted, and DW images and on early and delayed phase contrast-enhanced images. RESULTS: The shape of the 18 inverted urothelial papillomas of the bladder was classified as polypoid with a stalk for 16 tumors (89%) and polypoid without a stalk for two tumors (11%). All stalks were surrounded by urine in the bladder. A total of 15 of the tumor surfaces (83%) were nonpapillary and three (17%) were papillary. All 12 of the inverted urothelial papillomas for which evaluable T1-weighted images were available were isointense with the bladder wall. The lesions had a slightly higher signal intensity than the bladder wall in 15 of the patients (83%) and showed isointensity with the bladder wall in three patients (17%). A total of three patients (17%) had tiny hyperintense foci noted on T2-weighted images. All 16 of the inverted urothelial papillomas examined by DWI had very high signal intensity. All 13 of the lesions for which early phase images were obtained using dynamic contrast-enhanced MRI showed strong enhancement. When compared with early phase images, delayed phase images of the same 13 lesions showed that enhancement was stronger in two lesions (15%), similar in six lesions (46%), and weaker in five lesions (38%). CONCLUSION: On MRI, the typical appearance of inverted urothelial papillomas of the bladder is a polypoid shape with a nonpapillary surface and a thin short stalk surrounded by urine. Cystic foci are also occasionally seen within the tumor.
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Imageamento por Ressonância Magnética/métodos , Papiloma Invertido/diagnóstico , Neoplasias da Bexiga Urinária/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Cistoscopia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/instrumentação , Masculino , Pessoa de Meia-Idade , Papiloma Invertido/patologia , Estudos Retrospectivos , Neoplasias da Bexiga Urinária/patologiaRESUMO
PURPOSE: To investigate the usefulness of MRI for detection of sarcomatoid renal cell carcinoma (SRCC) components within RCC and differentiation from other renal tumors. METHODS: Two observers independently interpreted T2-weighted images of 10 patients with pathologically confirmed RCCs with SRCC and 131 with non-SRCC renal tumors, with special reference to conspicuously low signal intensity (SI) areas (T2LIA) compared to the renal cortex. SRCC probability was classified as (1) definitely non-SRCC, no T2LIA; (2) probably non-SRCC, <1 cm T2LIA; (3) low probability of SRCC, homogeneous tumor with 1-3 cm T2LIA; (4) probably SRCC, heterogeneous tumor with 1-3 cm T2LIA; and (5) definitely SRCC, >3 cm T2LIA, multiple >1 cm T2LIAs, or showing disruption of the pseudocapsule. The observers used chemical shift imaging to exclude the area representing hemorrhage or hemosiderin deposition from T2LIA. Scores of 4/5 were regarded as positive for evaluating the accuracy and area under the receiver operating characteristic curve. The SI ratio of the lowest SI in the tumor to that of the renal cortex in the 1 and ≥2 score groups was compared using Mann-Whitney's U test. RESULTS: Sensitivity, specificity, accuracy, and positive and negative predictive values were 90%, 95%, 94%, 56%, and 99%, respectively, and area under the receiver operating characteristic curve was 0.93. The mean SI ratio of the lowest SI in the tumor to that of the renal cortex was significantly lower in the ≥2 score group (0.58) than in the 1 score group (1.36). CONCLUSIONS: MRI predicted RCC with SRCC with a moderate positive predictive value and a high negative predictive value.
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Carcinoma de Células Renais/diagnóstico , Neoplasias Renais/diagnóstico , Imageamento por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Rim/patologia , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Curva ROC , Sensibilidade e Especificidade , Adulto JovemRESUMO
The Vesical Imaging-Reporting and Data System (VI-RADS) is a standard magnetic resonance imaging (MRI) and diagnostic method for muscle-invasive bladder cancer that was published in 2018. Several studies have demonstrated that VI-RADS has high diagnostic power and reproducibility. However, reading VI-RADS requires a certain amount of expertise, and radiologists need to be aware of the various pitfalls. MRI of the bladder includes T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced imaging (DCEI). T2WI is excellent for understanding anatomy. DWI and DCEI show high contrast between the tumor and normal anatomical structures and are suitable for staging local tumors. Bladder tumors are classified into five categories according to their size and morphology and their positional relationship to the bladder wall based on the VI-RADS diagnostic criteria. If the T2WI, DWI, and DCEI categories are the same, the category is the VI-RADS category. If the categories do not match, the DWI category is the VI-RADS category. If image quality of DWI is not evaluable, the DCEI category is the final category. In many cases, DWI is dominant, but this does not mean that T2WI and DCEI can be omitted from the reading of the bladder. In this educational review, typical and atypical teaching cases are demonstrated, and how to resolve misdiagnosis and the limitations of VI-RADS are discussed. The most important aspect of VI-RADS reading is to practice multiparametric reading with a solid understanding of the characteristics and role of each sequence and an awareness of the various pitfalls.
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PURPOSE: To compare the image quality, inter-reader agreement, and diagnostic capability for muscle-invasive bladder cancer (MIBC) of the reconstructed images in sections orthogonal to the bladder tumor obtained by 3D Dynamic contrast-enhanced (DCE)-MRI using the Golden-angle Radial Sparse Parallel (GRASP) technique with the images directly captured using the Cartesian sampling. MATERIALS AND METHODS: This study involved 68 initial cases of bladder cancer examined with DCE-MRI (GRASP: n = 34, Cartesian: n = 34) at 3 Tesla. Four radiologists conducted qualitative evaluations (overall image quality, absence of motion artifact, absence of streak artifact, and tumor conspicuity) using a five-point Likert scale (5 = Excellent/None) and quantitative signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measurements. The areas under the receiver-operating characteristic curves (AUCs) for the Vesical Imaging-Reporting and Data System (VI-RADS) DCE score for MIBC assessment were calculated. Inter-reader agreement was also assessed. RESULTS: GRASP notably enhanced overall image quality (pooled score: GRASP 4 vs. Cartesian 3, P < 0.0001), tumor conspicuity (5 vs. 3, P < 0.05), SNR (Median 38.2 vs. 19.0, P < 0.0001), and CNR (7.9 vs. 6.0, P = 0.005), with fewer motion artifacts (5 vs. 3, P < 0.0001) and minor streak artifacts (5 vs. 5, P > 0.05). Although no significant differences were observed, the GRASP group tended to have higher AUCs for MIBC (pooled AUCs: 0.92 vs. 0.88) and showed a trend toward higher inter-reader agreement (pooled kappa-value: 0.70 vs. 0.63) compared to the Cartesian group. CONCLUSIONS: Using the GRASP for 3D DCE-MRI, the reconstructed images in sections orthogonal to the bladder tumor achieved higher image quality and improve the clinical work flow, compared to the images directly captured using the Cartesian. GRASP tended to have higher diagnostic ability for MIBC and showed a trend toward higher inter-reader agreement compared to the Cartesian.
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PURPOSE: This study aimed to assess whether short repetition time (TR) diffusion-weighted imaging (DWI) could improve diffusion contrast in patients with prostate cancer (PCa) compared with long TR (conventional) reference standard DWI. MATERIALS AND METHODS: Our Institutional Review Board approved this retrospective study and waived the need for informed consent. Twenty-five patients with suspected PCa underwent multiparametric magnetic resonance imaging (mp-MRI) using a 3.0-T system. DWI was performed with TR of 1850 ms (short) and 6000 ms (long) with b-values of 0, 1000, and 2000s/mm2. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), visual score, apparent diffusion coefficient (ADC), and diagnostic performance were compared between short and long TR DWI for both b-values. The statistical tests included paired t-test for SNR and CNR; Wilcoxon signed-rank test for VA; Pearson's correlation and Bland-Altman plot analysis for ADC; and McNemar test and receiver operating characteristic analysis and Delong test for diagnostic performance. RESULTS: Regarding b1000, CNR and visual score were significantly higher in short TR compared with long TR (P = .003 and P = .002, respectively), without significant difference in SNR (P = .21). Considering b2000, there was no significant difference in visual score between short and long TR (P = .07). However, SNR and CNR in long TR were higher (P = .01 and P = .04, respectively). ADC showed significant correlations, without apparent bias for ADC between short and long TR for both b-values. For diagnostic performance of DWI between short and long TR for both b-values, one out of five readers noted a significant difference, with the short TR for both b-values demonstrating superior performance. CONCLUSIONS: Our data showed that the short TR DWI1000 may provide better image quality than did the long TR DWI1000 and may improve visualization and diagnostic performance of PCa for readers.
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Imagem de Difusão por Ressonância Magnética , Neoplasias da Próstata , Humanos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Estudos Retrospectivos , Idoso , Pessoa de Meia-Idade , Razão Sinal-Ruído , Idoso de 80 Anos ou mais , Próstata/diagnóstico por imagem , Próstata/patologia , Aumento da Imagem/métodos , Sensibilidade e Especificidade , Reprodutibilidade dos TestesRESUMO
Diagnostic work-up and risk stratification in patients with bladder cancer before and after treatment must be refined to optimize management and improve outcomes. MRI has been suggested as a non-invasive technique for bladder cancer staging and assessment of response to systemic therapy. The Vesical Imaging-Reporting And Data System (VI-RADS) was developed to standardize bladder MRI image acquisition, interpretation and reporting and enables accurate prediction of muscle-wall invasion of bladder cancer. MRI is available in many centres but is not yet recommended as a first-line test for bladder cancer owing to a lack of high-quality evidence. Consensus-based evidence on the use of MRI-VI-RADS for bladder cancer care is needed to serve as a benchmark for formulating guidelines and research agendas until further evidence from randomized trials becomes available.
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Neoplasias da Bexiga Urinária , Bexiga Urinária , Humanos , Bexiga Urinária/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Projetos de Pesquisa , Consenso , Estudos RetrospectivosRESUMO
Treatment decisions for bladder cancer patients are mainly based on the depth of bladder wall invasion by the tumor. In this article, we review the conventional MRI and exhibit a recently emerged diffusion-weighted imaging (DWI) of urinary bladder cancer for T-staging. We discuss limitations of conventional MRI, scanning protocols of DWI, normal pelvic findings on DWI, determination of T-stage using DWI, and pitfalls of DWI. DWI provides high contrast between bladder cancer and background tissue because the cancer shows markedly high SI. DWI has high sensitivity for detecting the stalk seen in stage Ta or T1. An inflammatory change or fibrosis surrounding the tumor mimics the invasion of bladder cancer on T2-weighted imaging or enhanced MRI and could lead to over-staging, but DWI could differentiate them clearly because these benign changes do not show high SI on DWI. DWI is also useful for detecting ureteral, urethral, and prostatic extension by means of the urethra. DWI provides more accurate information on the extent of bladder cancer and contributes to determination of the treatment strategy.
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Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Neoplasias da Bexiga Urinária/patologia , Bexiga Urinária/patologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Estadiamento de NeoplasiasRESUMO
We present an adult case of segmental multicystic dysplastic kidney (SMCDK). The patient had a 10 × 6 cm oval-shaped mass consisting of a solid and multilocular cystic component at the right upper renal sinus. The solid component showed gradual and mild enhancement on dual-phase enhanced CT. Excretory-phase CT demonstrated the excretion of contrast medium into the septa and cysts. Dilation of the upper calices and renal pelvis and atretic renal pelvis in the mass were also clearly visualized in the excretory phase. The signal intensity of the solid component was slightly lower than that of the renal parenchyma on T2-weighted images and similar to that of the medulla on diffusion-weighted images. Right nephrectomy showed a multilocular cystic component within the renal sinus and some of the cysts contained blood. The renal pelvis of the upper moiety was blind, as suggested by CT. Microscopically, there were multiple non-communicating small cysts, as shown by CT, and the wall was lined with immature tubule-like cells. In addition, immature tubule-like cells were seen in the septa. Immature mesenchymal cells were seen around the cysts. The solid component mainly consisted of fibroconnective tissue with immature tubule-like cells. The pathological diagnosis was confirmed as SMCDK. Excretion of contrast media into the septum and cystic component might be a characteristic finding of SMCDK in addition to the finding of a multilocular cystic mass in the upper moiety with urinary tract abnormality.
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Rim Displásico Multicístico/diagnóstico por imagem , Extravasamento de Materiais Terapêuticos e Diagnósticos/diagnóstico por imagem , Feminino , Humanos , Achados Incidentais , Pelve Renal/anormalidades , Pelve Renal/diagnóstico por imagem , Imageamento por Ressonância Magnética , Intensificação de Imagem Radiográfica , Adulto JovemRESUMO
BACKGROUND: The effects of a tin filter on virtual non-enhanced (VNE) images created by dual-energy CT have not been well evaluated. PURPOSE: To compare the accuracy of VNE images between those with and without a tin filter. MATERIAL AND METHODS: Two different types of columnar phantoms made of agarose gel were evaluated. Phantom A contained various concentrations of iodine (4.5-1590 HU at 120 kVp). Phantom B consisted of a central component (0, 10, 25, and 40 mgI/cm(3)) and a surrounding component (0, 50, 100, and 200 mgI/cm(3)) with variable iodine concentration. They were scanned by dual-source CT in conventional single-energy mode and dual-energy mode with and without a tin filter. CT values on each gel at the corresponding points were measured and the accuracy of iodine removal was evaluated. RESULTS: On VNE images, the CT number of the gel of Phantom A fell within the range between -15 and +15 HU under 626 and 881 HU at single-energy 120 kVp with and without a tin filter, respectively. With attenuation over these thresholds, iodine concentration of gels was underestimated with the tin filter but overestimated without it. For Phantom B, the mean CT numbers on VNE images in the central gel component surrounded by the gel with iodine concentrations of 0, 50, 100, and 200 mgI/cm(3) were in the range of -19-+6 HU and 21-100 HU with and without the tin filter, respectively. CONCLUSION: Both with and without a tin filter, iodine removal was accurate under a threshold of iodine concentration. Although a surrounding structure with higher attenuation decreased the accuracy, a tin filter improved the margin of error.
Assuntos
Iodo , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/instrumentação , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Estanho , Tomografia Computadorizada por Raios X/métodos , Processamento de Imagem Assistida por Computador/métodos , Imagens de Fantasmas , Reprodutibilidade dos Testes , SefaroseRESUMO
Catheterization of the right adrenal vein (rt.AdV) to obtain blood samples can often be difficult. The aim of the present study was to investigate whether blood sampling from the inferior vena cava (IVC) at its juncture with the rt.AdV can be an ancillary to sampling of blood directly from the rt.AdV. This study included 44 patients diagnosed with primary aldosteronism (PA) in whom AVS with adrenocorticotropic hormone (ACTH) was performed, resulting in a diagnosis of idiopathic hyperaldosteronism (IHA) (n = 24), and patients diagnosed with unilateral aldosterone-producing adenoma (APA) (n = 20; rt.APA = 8, lt.APA = 12). In addition to regular blood sampling, blood was also sampled from the IVC, as the substitute rt.AdV [S-rt.AdV]. Diagnostic performance with the conventional lateralized index (LI) and the modified LI using the S-rt.AdV were compared to examine the utility of the modified LI. The modified LI of the rt.APA (0.4 ± 0.4) was significantly lower than those of the IHA (1.4 ± 0.7) (p < 0.001) and the lt.APA (3.5 ± 2.0) (p < 0.001). The modified LI of the lt.APA was significantly higher than those of the IHA (p < 0.001) and rt.APA (p < 0.001). Likelihood ratios to diagnose rt.APA and lt.APA using the modified LI with threshold values of 0.3 and 3.1 were 27.0, and 18.6, respectively. The modified LI has the potential to be an ancillary method for rt.AdV sampling in cases in which rt.AdV sampling is difficult. Obtaining the modified LI is extremely simple, which might complement conventional AVS.