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1.
Oka K Yakushiji T Sato H Yorimitsu S Hayashida Y Yamashita Y Mizuta H 《Journal of magnetic resonance imaging : JMRI》2008,28(5):1195-1200
Purpose
To evaluate the potential of diffusion‐weighted imaging (DWI) in distinguishing chronic expanding hematomas (CEHs) from malignant soft tissue tumors.Materials and Methods
We performed conventional MRI and DWI of six CEHs and 31 malignant soft tissue tumors from 37 patients seen between May 2000 and November 2006. DWI was obtained with a single‐shot echo‐planar imaging (EPI) sequence using a 1.5T MR imager. The mean apparent diffusion coefficient (ADC) value was also calculated. We evaluated MRI findings of CEHs and compared ADC value of CEHs with malignant soft tissue tumors.Results
On conventional MRI, two of six CEHs were difficult to differentiate from malignant soft tissue tumors based on imaging findings. The mean ADC value of CEHs and malignant soft tissue tumors was 1.55 ± 0.121 × 10?3 mm2/sec and 0.92 ± 0.139 × 10?3 mm2/sec (mean ± SD), respectively. The mean ADC value of CEHs was significantly higher than that of malignant soft tissue tumors (P < 0.01). There was no overlap in the minimum ADC values among CEHs and malignant soft tissue tumors.Conclusion
DWI is useful for differentiating between CEHs and malignant soft tissue tumors. J. Magn. Reson. Imaging 2008;28:1195–1200. © 2008 Wiley‐Liss, Inc.2.
Polat Koşucu MD Celal Tekinbaş MD Muharrem Erol MD Ahmet Sari MD Halil Kavgaci MD Funda Öztuna MD Şafak Ersöz MD 《Journal of magnetic resonance imaging : JMRI》2009,30(2):292-297
Purpose
To prospectively determine whether the diffusion‐weighted magnetic resonance imaging is useful to distinguish between malignant and benign mediastinal lymph nodes.Materials and Methods
Thirty‐five patients (14 women, 21 men; mean age 52 years) with 91 lymph nodes in the mediastinum detected by computed tomography underwent 1.5 Tesla (T) diffusion‐weighted MR imaging before mediastinoscopy (n = 29) and mediastinotomy (n = 6). Diffusion‐weighted MR images were acquired with a b factor of 50, and 400 s/mm2 using single‐shot echo‐planar sequence.Results
Of the 35 patients, 18 had diagnosis of malignant tumor. Of the 18 patients with tumor, 8 had nonsmall cell carcinoma, and 10 had small cell carcinoma. Ninety‐one mediastinal lymph nodes were detected in the 35 untreated patients: 19 were pathologically diagnosed as metastatic lymph nodes, and 72 lymph nodes were diagnosed as nonmetastatic lymph nodes, including 50 sarcoidosis, 14 reactive lymphoid hyperplasia, and 8 necrotizing granulamatous lymphadenitis. The apparent diffusion coefficient (ADC) was significantly lower in metastatic lymph nodes (1.012 ± 0.025 × 10?3 mm2/s; P < 0.0005) than in benign lymph nodes (1.511 ± 0.075 × 10?3 mm2/s). On the ADC map, malignant nodes showed hyperintense (n = 2, 10.52%), hypointense (n = 14, 73.68%), and mixed intensity (n = 3; 15.78%), whereas benign nodes showed hyperintense (n = 57; 79.16%), hypointense (n = 3; 41.6%), isointense (n = 6; 8.33%), and mixed intensity (n = 6; 8.33%).Conclusion
Diffusion‐weighted MR with ADC value and signal intensity can be useful in differentiation of malignant and benign mediastinal lymph nodes. J. Magn. Reson. Imaging 2009;30:292–297. © 2009 Wiley‐Liss, Inc.3.
Sachiko Yuen MD PhD Kei Yamada MD PhD Mariko Goto MD PhD Kaori Nishida MD Akiko Takahata MD PhD Tsunehiko Nishimura MD PhD 《Journal of magnetic resonance imaging : JMRI》2009,29(5):1080-1084
Purpose
To investigate the effect of gadolinium (Gd)‐DTPA on the apparent diffusion coefficient (ADC) of breast carcinoma and to analyze the relationship between pre/postcontrast ADC and the degree of contrast enhancement.Materials and Methods
Nineteen histopathologically confirmed breast carcinomas (mean size = 22 mm) were analyzed. Their ADCs before and after contrast administration were measured. The contrast‐to‐noise ratios (CNRs) of the tumors were measured on fat‐suppressed 3D T1‐weighted images in precontrast, early, and late postcontrast phases. These results were correlated with the measured ADC values.Results
A significant decrease in the measured ADC was noted after contrast administration (?23%, P = 0.01). Lesions with relatively high ADC before contrast (>1.3 × 10?3 mm2/sec; n = 12) demonstrated a larger degree of ADC reduction (mean 34%) than lesions with low ADC (≤1.3 × 10?3 mm2/sec; n = 7) (mean 4.5%). When an early postcontrast image was used as a surrogate marker of malignant potential, we found a significant inverse correlation with postcontrast ADC (γ = ?0.57, P = 0.02).Conclusion
Postcontrast ADC exhibited lower values than precontrast ADC, which is thought to reflect suppression of the microperfusion‐induced effect on diffusion‐weighted imaging. Postcontrast ADC may be a better indicator than precontrast ADC to reflect malignant potential of tumors. J. Magn. Reson. Imaging 2009;29:1080–1084. © 2009 Wiley‐Liss, Inc.4.
Toshitake Yakushiji PhD Kiyoshi Oka MD Hiro Sato MD Shigeta Yorimitsu MD Toru Fujimoto PhD Yasuyuki Yamashita PhD Hiroshi Mizuta PhD 《Journal of magnetic resonance imaging : JMRI》2009,29(4):895-900
Purpose
To detect differences in magnetic resonance imaging (MRI) between chondroblastic osteosarcoma and the other types of osteosarcomas or chondrosarcomas using gadolinium‐enhanced versus diffusion‐weighted sequences.Materials and Methods
Contrast‐enhanced MRI and diffusion‐weighted imaging (DWI) were performed in five chondroblastic osteosarcoma (CO) cases, 17 other types of osteosarcomas (OS), and 18 chondrosarcomas (CS). DWI was obtained with a single‐shot echo‐planar imaging (EPI) sequence using a 1.5T MR imager. The apparent diffusion coefficients (ADCs) of the minimum and maximum values were also obtained. The contrast‐enhancement pattern was evaluated and minimum‐maximum ADC value of CO was compared with other types of OS and CS.Results
Both CO and CS showed a similar enhancement pattern; both showed septonodular and peripheral rim enhancement. The minimum ADC value of CO (1.24 ± 0.10 × 10?3mm2/sec) was significantly higher than that of other types of OS (0.84 ± 0.15 × 10?3mm2/sec) and was significantly lower than that of CS (1.64 ± 0.20 × 10?3mm2/sec). In addition, the maximum ADC value of CO (2.28 ± 0.20 × 10?3mm2/sec) was significantly higher than that of other types of OS (1.33 ± 0.26 × 10?3mm2/sec).Conclusion
DWI appears to be more useful for differentiating between chondroblastic osteosarcoma and chondrosarcoma or other types of osteosarcoma than Gd‐enhanced MRI. J. Magn. Reson. Imaging 2009;29:895–900. © 2009 Wiley‐Liss, Inc.5.
Gulnur Erdem MD Tamer Erdem MD Hakki Muammer Karakas MD Deniz Yakar Mutlu MD Ahmet Kemal Fırat MD Ibrahim Sahin MD Alpay Alkan MD 《Journal of magnetic resonance imaging : JMRI》2010,31(1):94-100
Purpose:
To reveal the possible role of diffusion‐weighted images (DWI) in the differential diagnosis of benign and malignant thyroid nodules by comparing the results of fine‐needle aspiration cytology (FNAC).Materials and Methods:
In an 18‐month period (December 2005 to May 2007), 27 cases with benign thyroid nodules with a total of 52 benign nodules, nine cases with thyroid gland malignancy, and 24 healthy control cases were included in the study. Cases that were indicated to undergo to FNAC examination and sent by a clinician for biopsy to the radiology unit were included in the study to assess the cytopathologic confirmation of the clinic, ultrasonographic, and magnetic resonance imaging (MRI) findings.Results:
The mean apparent diffusion coefficient (ADC) values of thyroid nodules were 2745.3 ± 601.1 × 10?6 mm2/s (1605–3899 × 10?6mm2/s) in the benign group and 695.2 ± 312.5 × 10?6mm2/s (165–1330 × 10?6mm2/s) in the malignant group. Normal thyroid tissues had mean ADC values of 1344.1 ± 276.4 × 10?6 mm2/s (1015–1764 × 10?6mm2/s). The ADC values of three subgroups were significantly different (P = 0.0001). A reduced ADC was observed in most types of malignant tumors due to the consequent decrease of the extracellular extravascular space.Conclusion:
Our preliminary results showed that ADC values of nodules may provide useful data about the nature of a thyroid nodule. J. Magn. Reson. Imaging 2010;31:94–100. © 2009 Wiley‐Liss, Inc.6.
Christina Schraml MD Nina F. Schwenzer MD Stephan Clasen MD Hans‐Joerg Rempp MD Petros Martirosian MS Claus D. Claussen MD Philippe L. Pereira MD 《Journal of magnetic resonance imaging : JMRI》2009,29(6):1308-1316
Purpose
To evaluate diffusion alterations after hepatic radiofrequency (RF) ablation using a navigator respiratory‐triggered diffusion‐weighted imaging (NRT‐DWI) sequence with regard to potential diagnostic information for detection of local tumor progression (LTP).Materials and Methods
One hundred forty‐eight consecutive follow‐up magnetic resonance (MR) examinations of 54 patients after hepatic RF ablation were reviewed. Apparent diffusion coefficient (ADC) values of ablation zones and liver parenchyma were assessed using a single‐shot echoplanar imaging sequence with the NRT technique. ADC values of ablation zones and adjacent signal alterations identified in NRT‐DWI were analyzed with regard to LTP.Results
Mean ADC values of ablation zones (119.9 ± 30.5 × 10?5 mm2/sec) and liver (106.3 ± 21.2 × 10?5 mm2/sec) differed significantly (P = 0.0003). No evident changes in ablations' ADC values over time could be identified. ADC values obtained from the entire ablation zone did not significantly differ regarding the presence of LTP. In 58 examinations, hyperintense areas in the periphery of the ablation zone were detected on the NRT‐DWI. Corresponding ADC values were significantly lower in patients with LTP (102.1 ± 22.4 versus 130.8 ± 47.6 × 10?5 mm2/sec; P = 0.0124).Conclusion
NRT‐DWI is useful in the follow‐up imaging after RF ablation. ADC‐based evaluation of signal alterations adjacent to the ablation zone may contribute to the identification of LTP and nontumoral posttreatment tissue changes. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.7.
Sung Hun Kim MD Eun Suk Cha MD Hyeon Sook Kim MD Bong Joo Kang MD Jae Jeong Choi MD Ji Han Jung MD Yong Gyu Park PhD Young Jin Suh MD 《Journal of magnetic resonance imaging : JMRI》2009,30(3):615-620
Purpose
To evaluate the role of diffusion‐weighted imaging (DWI) in the detection of breast cancers, and to correlate the apparent diffusion coefficient (ADC) value with prognostic factors.Materials and Methods
Sixty‐seven women with invasive cancer underwent breast MRI. Histological specimens were analyzed for tumor size and grade, and expression of estrogen receptors (ER), progesterone receptors, c‐erbB‐2, p53, Ki‐67, and epidermal growth factor receptors. The computed mean ADC values of breast cancer and normal breast parenchyma were compared. Relationships between the ADC values and prognostic factors were determined using Wilcoxon signed rank test and Kruskal‐Wallis test.Results
DWI detected breast cancer as a hyperintense area in 62 patients (92.5 %). A statistically significant difference in the mean ADC values of breast cancer (1.09 ± 0.27 × 10?5 mm2/s) and normal parenchyma (1.59 ± 0.27 × 10?5 mm2/s) was detected (P < 0.0001). There were no correlations between the ADC value and prognostic factors. However, the median ADC value was lower in the ER‐positive group than the ER negative group, and this difference was marginally significant (1.09 × 10?5 mm2/s versus 1.15 × 10?5 mm2/s, P = 0.053).Conclusion
The ADC value was a helpful parameter in detecting malignant breast tumors, but ADC value could not predict patient prognosis. J. Magn. Reson. Imaging 2009;30:615–620. © 2009 Wiley‐Liss, Inc.8.
Savannah C. Partridge PhD Wendy B. DeMartini MD Brenda F. Kurland PhD Peter R. Eby MD Steven W. White BS Constance D. Lehman MD PhD 《Journal of magnetic resonance imaging : JMRI》2010,31(3):562-570
Purpose:
To investigate the diagnostic performance of diffusion‐weighted imaging (DWI) for mammographically and clinically occult breast lesions.Materials and Methods:
The study included 91 women with 118 breast lesions (91 benign, 12 ductal carcinoma in situ [DCIS], 15 invasive carcinoma) initially detected on dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) and assigned BI‐RADS category 3, 4, or 5. DWI was acquired with b = 0 and 600 s/mm2. Lesion visibility was assessed on DWI. Apparent diffusion coefficient (ADC) values were compared between malignancies, benign lesions, and normal (no abnormal enhancement on DCE‐MRI) breast tissue, and the diagnostic performance of DWI was assessed based on ADC thresholding.Results:
Twenty‐four of 27 (89%) malignant and 74/91 (81%) benign lesions were hyperintense on the b = 600 s/mm2 diffusion‐weighted images. Both DCIS (1.33 ± 0.19 × 10?3 mm2/s) and invasive carcinomas (1.30 ± 0.27 × 10?3mm2/s) were lower in ADC than benign lesions (1.71 ± 0.43 × 10?3mm2/s; P < 0.001), and each lesion type was lower in ADC than normal tissue (1.90 ± 0.38 × 10?3mm2/s, P ≤ 0.001). Receiver operating curve (ROC) analysis showed an area under the curve (AUC) of 0.77, and sensitivity = 96%, specificity = 55%, positive predictive value (PPV) = 39%, and negative predictive value (NPV) = 98% for an ADC threshold of 1.60 × 10?3mm2/s.Conclusion:
Many mammographically and clinically occult breast carcinomas were visibly hyperintense on diffusion‐weighted images, and ADC enabled differentiation from benign lesions. Further studies evaluating DWI while blinded to DCE‐MRI are necessary to assess the potential of DWI as a noncontrast breast screening technique. J. Magn. Reson. Imaging 2010;1:562–570. © 2010 Wiley‐Liss, Inc.9.
Frank H. Miller MD Nancy Hammond MD Aheed J. Siddiqi MD Sagar Shroff BS Gaurav Khatri MD Yi Wang MD Laura B. Merrick BA Paul Nikolaidis MD 《Journal of magnetic resonance imaging : JMRI》2010,32(1):138-147
Purpose:
To evaluate apparent diffusion coefficient (ADC) values for characterization of a variety of focal liver lesions and specifically for differentiation of solid benign lesions (focal nodular hyperplasia [FNH] and adenomas) from solid malignant neoplasms (metastases and hepatocellular carcinoma [HCC]) in a large case series.Materials and Methods:
A total of 542 lesions in 382 patients were evaluated. ADC values were measured in 166 hemangiomas, 112 hepatomas, 107 metastases, 95 cysts, 10 abscesses, 43 FNH, and nine adenomas. ADCs of 1.5 and 1.6 (×10?3 mm2/second) were selected as threshold values to separate benign and malignant lesions. Sensitivity, specificity, positive, and negative predictive values (PPV, NPV) were calculated. Comparisons were carried out with studentized range test.Results:
There was high interobserver agreement in ADC measurements for all lesion types. The mean ADCs for cysts was 3.40 (×10 ?3 mm2/second), hemangiomas 2.26, FNH 1.79, adenomas 1.49, abscesses 1.97, HCC 1.53, and metastases 1.50. The mean ADC for benign lesions was 2.50 and for malignant lesions was 1.52. Cysts were easily distinguished from other lesions. There was, however, overlap between solid benign and malignant lesions.Conclusion:
Benign lesions have higher mean ADC values than malignant lesions. However, ADC values of solid benign lesions (FNH and adenomas) are similar to malignant lesions (metastases, HCC) limiting the value of diffusion weighted imaging (DWI) for differentiating solid liver masses. J. Magn. Reson. Imaging 2010;32:138–147. © 2010 Wiley‐Liss, Inc.10.
Sato Eida DDS PhD Misa Sumi DDS PhD Takashi Nakamura DDS PhD 《Journal of magnetic resonance imaging : JMRI》2010,31(3):673-679
Purpose:
To evaluate the stepwise approach in differentiating between benign and malignant salivary gland tumors using time‐intensity curves (TICs) and apparent diffusion coefficients (ADCs).Materials and Methods:
TICs and ADCs were analyzed on the tumor‐by‐tumor (overall) and pixel‐by‐pixel (TIC and ADC maps) bases in patients with benign (n = 52) or malignant (n = 18) salivary gland tumor. TICs were categorized into Types 1 (<20% increment ratio), 2 (≥20% increment ratio and >120 sec peak time), 3 (≥20% increment ratio, ≤120 sec peak time, and <30% washout ratio), or 4 (≥20% increment ratio, ≤120 sec peak time, and ≥30% washout ratio). ADCs were classified as extremely low (<0.6 × 10?3 mm2/sec), low (<1.2), intermediate (<1.8), or high (≥1.8).Results:
Malignant tumors had small (<30%) areas with Type 1 TIC with one of the following magnetic resonance imaging (MRI) characteristics: Type 3 overall TIC patterns, Type 4 overall TIC patterns and extremely low (<0.60 × 10?3 mm2/sec) overall ADCs, or Type 2 overall TIC patterns and large (>40%) areas with low or extremely low ADCs.Conclusion:
We propose a stepwise approach by using multiparametric MRI techniques as an effective tool for differentiating between benign and malignant salivary gland tumors J. Magn. Reson. Imaging 2010;31:673–679. © 2010 Wiley‐Liss, Inc.11.
A. Turan Ilica MD Hakan Artaş MD Asli Ayan MD Armağan Günal MD Ozdes Emer MD Zafer Kilbas MD Coskun Meric MD Mehmet Mahir Atasoy MD Ovsev Uzuner MD 《Journal of magnetic resonance imaging : JMRI》2013,37(5):1077-1082
Purpose:
To evaluate the role of diffusion‐weighted magnetic resonance imaging (DWMRI) in differentiating benign and malignant thyroid nodules using a 3 Tesla (T) MRI scanner.Materials and Methods:
Twenty‐eight nodules in 25 patients and 14 healthy control cases were included in the study. DWMRI was acquired with 6 b values with a 3T MRI scanner. The apparent diffusion coefficient (ADC) values of the nodules were calculated from reconstructed ADC map images and were compared with the final histopathological diagnoses.Results:
The mean ADC value of the benign nodules was 1548 ± 353.4 (×10?6 mm2/s), and the mean ADC of the malignant nodules was 814 ± 177.12 (×10?6 mm2/s). The normal thyroid tissue had a mean ADC value of 1323.43 ± 210.35 × 10?6 mm2/s (958–1689 × 10?6 mm2/s) in the healthy control group. The ADC values were significantly different among the three groups (P = 0.001). An ADC value of 905 × 10?6 mm2/s was determined to be the cutoff value for differentiating benign and malignant nodules, with 90% (55.5–98.3) sensitivity and 100% (81.3–100.0) specificity.Conclusion:
This study suggests that the ADC values of nodules measured with a 3T MRI scanner could help in differentiating benign thyroid nodules from malignant nodules. J. Magn. Reson. Imaging 2013;37:1077–1082. © 2012 Wiley Periodicals, Inc.12.
Jacob P. Hoogendam Wenche M. Klerkx MD PhD Gerard A.P. de Kort MD Shandra Bipat MD PhD Ronald P. Zweemer MD PhD Daisy M.D.S. Sie‐Go MD PhD René H.M. Verheijen MD PhD Willem P.T.M. Mali MD PhD Wouter B. Veldhuis MD PhD 《Journal of magnetic resonance imaging : JMRI》2010,32(2):376-382
Purpose:
To analyze the influence of different b‐value combinations on apparent diffusion coefficient (ADC)‐based differentiation of known malignant and benign tissue in cervical cancer patients.Materials and Methods:
A total of 35 patients with stage IB1, IB2, IIA cervical cancer underwent a 3.0T MRI scan prior to radical hysterectomy and pelvic lymph node dissection. Conventional T1‐ and T2‐weighted sequences and a diffusion‐weighted sequence (b = 0, 150, 500, 1000 seconds/mm2) were performed. Regions‐of‐interest (ROI) were drawn on ADC maps derived from five different b‐value combinations (0, 500; 0, 150, 500; 0, 1000; 0, 150, 500, 1000; 150, 500, 1000 seconds/mm2). The influence of the b‐value combination on ADC‐based differentiation of benign and malignant tissue was analyzed using receiver‐operating‐characteristics curves.Results:
For all b‐value combinations, ADCs were significantly lower (P < 0.001) in cervical malignancies (1.15 ± 0.21·10?3; 1.10 ± 0.21·10?3; 0.97 ± 0.18·10?3; 0.97 ± 0.23·10?3 and 0.85 ± 0.18·10?3 mm2/second respectively to the aforementioned b‐value combinations) than in benign cervix (2.08 ± 0.31·10?3; 2.00 ± 0.29·10?3; 1.62 ± 0.23·10?3; 1.54 ± 0.21·10?3 and 1.42 ± 0.22·10?3 mm2/second respectively). The diagnostic accuracy was high for all b‐value combinations and without statistical differences between the combinations.Conclusion:
ADC‐based differentiation of benign from malignant cervical tissue is independent of the tested b‐value combinations. The results support the inclusion and possible pooling of studies using different b‐value combinations in meta‐analyses on ADC‐based tissue differentiation in cervical cancer. J. Magn. Reson. Imaging 2010;32:376–382. © 2010 Wiley‐Liss, Inc.13.
Oka K Yakushiji T Sato H Fujimoto T Hirai T Yamashita Y Mizuta H 《Journal of magnetic resonance imaging : JMRI》2011,33(1):189-193
Purpose
To evaluate the usefulness of diffusion‐weighted imaging (DWI) for differentiating between desmoid tumors and malignant soft tissue tumors.Materials and Methods
Conventional MRI and DWI were performed for 8 desmoid tumors and 74 malignant soft tissue tumors. DWI was obtained with a single‐shot echo‐planar imaging sequence using a 1.5 Tesla (T) MR imager. DW images were acquired with motion‐probing gradient pulses applied along three directions (x, y, and z axes) with three b‐factors (0, 500, and 1000 s/mm2). Two observers blinded to clinical information measured three regions of interest within the solid tumor and selected a minimum apparent diffusion coefficient () in each lesion. The mean ADC of desmoid tumors was calculated and compared with that of malignant soft tissue tumors using the Mann‐Whitney U test.Results
The mean ADC of desmoid tumors and malignant soft tissue tumors was 1.36 ± 0.48 × 10−3 mm2/s and 0.88 ± 0.20 × 10−3 mm2/s (mean ± SD), respectively. The mean ADC of the desmoid tumors was significantly higher than that of malignant soft tissue tumors (P < 0.01).Conclusion
DWI is considered to be useful for differentiating between desmoid tumors and malignant soft tissue tumors. In the future, further investigation in a large series is necessary. J. Magn. Reson. Imaging 2011;33:189–193. © 2010 Wiley‐Liss, Inc.14.
Koc Z Erbay G Ulusan S Seydaoglu G Aka-Bolat F 《Journal of magnetic resonance imaging : JMRI》2012,35(3):650-659
Purpose:
To explore the optimal b value in diffusion‐weighted (DW)‐MRI for differentiation of benign and malignant gynecological lesions.Materials and Methods:
Consecutive 58 patients (66 lesions) with pathologically confirmed diagnosis of gynecological disease were included in the study. Routine pelvic MRI sequences were used for defining the lesions and reviewed independently for benignity/ malignity. Single‐shot echoplanar imaging (SH‐EPI) DW‐MRI with eight b values and nine apparent diffusion coefficient (ADC) maps were obtained. The lesions were analyzed qualitatively on DW‐MRI for benignity/malignity on a five‐point‐scale and quantitatively by measurement of apparent diffusion coefficient (ADC) values. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of ADC values for differentiating between benign and malignant lesions. Pathology results were the reference standard.Results:
Differentiation between benign and malignant gynecological lesions using visual scoring was found to be successful with b values of 600, 800, or 1000 s/mm2. The mean ADC values of malignant lesions were significantly lower than those of benign lesions for all b value (P < 0.005). The ADCs with b = 0 and 600, 0 and 1000 s/mm2, 0, 600, 800 and 1000 s/mm2, and all b values were more effective for distinguishing malignant from benign gynecological lesions (Az = 0.851, 0.847, 0.848, 0.849, respectively). Using ADC with b = 0, 600, 800, and 1000 s/mm2, a threshold value of 1.20 × 10?3 mm2/s permitted this distinction with a sensitivity of 83%, a specificity of 81%.Conclusion:
DW‐MRI is an important method, and the optimal b values are between 600 and 1000 s/mm2 for differentiation between benign and malignant gynecological lesions. J. Magn. Reson. Imaging 2012;35:650‐659. © 2011 Wiley Periodicals, Inc.15.
Jing Ren MD Yi Huan MD PhD Fang Li MD He Wang MD PhD YaLi Ge MB YingJuan Chang MM Hong Yin MD PhD LiJun Sun MD PhD 《Journal of magnetic resonance imaging : JMRI》2009,30(2):351-356
Purpose
To retrospectively determine the diffusion‐weighted imaging (DWI) characteristics and apparent diffusion coefficient (ADC) values of prostate carcinoma (PCa) with urinary bladder invasion, and to compare the accuracy of T2‐weighted MRI alone and T2 combined with DWI for predicting urinary bladder invasion.Materials and Methods
Sixty‐eight patients with proven PCa were diagnosed with urinary bladder invasion after conventional magnetic resonance imaging (MRI) and DWI (b value = 750 sec/mm2) examinations. All the 68 cases underwent cystoscopy examination. DWI appearances of all urinary bladder invasion and a normal urinary bladder wall were analyzed, and their ADC values were measured. T2 images alone and then T2 images combined with DWI were scored for the likelihood of urinary bladder invasion on the basis of radiologists' written reports. The area under the receiver operating characteristic curve (AUC) was used to assess accuracy. Statistical significance was inferred at P < 0.05.Results
After cystoscopy examination, 45 (66%) of 68 cases were pathologically proven urinary bladder invasion. The mean ADCs for urinary bladder invasion and normal urinary bladder wall were (0.963 ± 0.155) × 10?3mm2/sec and (1.517 ± 0.103) × 10?3mm2/sec, respectively. The ADC values of urinary bladder invasion were significantly lower than those of normal urinary bladder wall (P = 0.000). The AUC for T2‐weighted imaging plus DW imaging (0.861) was significantly larger than that for T2‐weighted imaging alone (0.734) or for DW imaging alone (0.703) (P < 0.001).Conclusion
Urinary bladder invasion had lower ADC values compared with normal urinary bladder wall. T2 images plus DWI is significantly better than T2‐weighted imaging alone in the detection of urinary bladder invasion in patients with PCa. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.16.
Hesheng Wang MS Baowei Fei PhD EngD 《Journal of magnetic resonance imaging : JMRI》2010,32(2):409-417
Purpose:
To examine diffusion‐weighted MRI (DW‐MRI) for assessing the early tumor response to photodynamic therapy (PDT).Materials and Methods:
Subcutaneous tumor xenografts of human prostate cancer cells (CWR22) were initiated in athymic nude mice. A second‐generation photosensitizer, Pc 4, was delivered to each animal by a tail vein injection 48 h before laser illumination. A dedicated high‐field (9.4 Tesla) small animal MR scanner was used to acquire diffusion‐weighted MR images pre‐PDT and 24 h after the treatment. DW‐MRI and apparent diffusion coefficients (ADC) were analyzed for 24 treated and 5 control mice with photosensitizer only or laser light only. Tumor size, prostate specific antigen (PSA) level, and tumor histology were obtained at different time points to examine the treatment effect.Results:
Treated mice showed significant tumor size shrinkage and decrease of PSA level within 7 days after the treatment. The average ADC of the 24 treated tumors increased 24 h after PDT (P < 0.001) comparing with pre‐PDT. The average ADC was 0.511 ± 0.119 × 10?3 mm2/s pre‐PDT and 0.754 ± 0.181 × 10?3 mm2/s 24 h after the PDT. There is no significant difference in ADC values pre‐PDT and 24 h after PDT in the control tumors (P = 0.20).Conclusion:
The change of tumor ADC values measured by DW‐MRI may provide a noninvasive imaging marker for monitoring tumor response to Pc 4‐PDT as early as 24 h. J. Magn. Reson. Imaging 2010;32:409–417. © 2010 Wiley‐Liss, Inc.17.
Seong‐Eun Kim PhD Eun‐Kee Jeong PhD Xian‐Feng Shi MS Glen Morrell MD PhD Gerald S. Treiman MD Dennis L. Parker PhD 《Journal of magnetic resonance imaging : JMRI》2009,30(5):1068-1077
Purpose:
To determine if 2D single‐shot interleaved multislice inner volume diffusion‐weighted echo planar imaging (ss‐IMIV‐DWEPI) can be used to obtain quantitative diffusion measurements that can assist in the identification of plaque components in the cervical carotid artery.Materials and Methods:
The 2D ss‐DWEPI sequence was combined with interleaved multislice inner volume region localization to obtain diffusion weighted images with 1 mm in‐plane resolution and 2 mm slice thickness. Eleven subjects, six of whom have carotid plaque, were studied with this technique. The apparent diffusion coefficient (ADC) images were calculated using DW images with b = 10 s/mm2 and b = 300 s/mm2.Results:
The mean ADC measurement in normal vessel wall of the 11 subjects was 1.28 ± 0.09 × 10?3 mm2/s. Six of the 11 subjects had carotid plaque and ADC measurements in plaque ranged from 0.29 to 0.87 × 10?3 mm2/s. Of the 11 common carotid artery walls studied (33 images), at least partial visualization of the wall was obtained in all ADC images, more than 50% visualization in 82% (27/33 images), and full visualization in 18% (6/33 images).Conclusion:
2D ss‐IMIV‐DWEPI can perform diffusion‐weighted carotid magnetic resonance imaging (MRI) in vivo with reasonably high spatial resolution (1 × 1 × 2 mm3). ADC values of the carotid wall and plaque are consistent with similar values obtained from ex vivo endarterectomy specimens. The spread in ADC values obtained from plaque indicate that this technique could form a basis for plaque component identification in conjunction with other MRI/MRA techniques. J. Magn. Reson. Imaging 2009;30:1068–1077. © 2009 Wiley‐Liss, Inc.18.
Shigeru Kiryu MD DMSc Keiichi Dodanuki RT Hidemasa Takao MD Makoto Watanabe MD DMSc Yusuke Inoue MD DMSc Masakazu Takazoe MD Rikisaburo Sahara MD Kiyohito Unuma RT Kuni Ohtomo MD DMSc 《Journal of magnetic resonance imaging : JMRI》2009,29(4):880-886
Purpose
To investigate the application of free‐breathing diffusion‐weighted MR imaging (DWI) to the assessment of disease activity in Crohn's disease.Materials and Methods
Thirty‐one patients with Crohn's disease were investigated using free‐breathing DWI without special patient preparation or IV or intraluminal contrast agent. The bowel was divided into seven segments, and disease activity was assessed visually on DWI. For quantitative analysis, the apparent diffusion coefficient (ADC) was measured in each segment. The findings of a conventional barium study or surgery were regarded as the gold standard for evaluating the diagnostic ability of DWI to assess disease activity.Results
Upon visual assessment, the sensitivity, specificity, and accuracy for the detection of disease‐active segments were 86.0, 81.4, and 82.4%, respectively. In the quantitative assessment, the ADC value in the disease‐active area was lower than that in disease‐inactive area in small and large bowels (1.61 ± 0.44×10?3 mm2/s versus 2.56 ± 0.51 × 10?3 mm2/s in small bowel and 1.52 ± 0.43 × 10?3 mm2/s versus 2.31 ± 0.59 × 10?3 mm2/s in large bowel, respectively, P<0.001).Conclusion
Free‐breathing DWI is useful in the assessment of Crohn's disease. The accuracy of DWI is high in evaluating disease activity, especially in the small bowel, and the ADC may facilitate quantitative analysis of disease activity. J. Magn. Reson. Imaging 2009;29:880–886. © 2009 Wiley‐Liss, Inc.19.
Philipp Heusch MD Hans‐Jörg Wittsack PhD Patric Kröpil MD Dirk Blondin MD Michael Quentin MD Janina Klasen MD Gael Pentang MSc Gerald Antoch MD Rotem S. Lanzman MD 《Journal of magnetic resonance imaging : JMRI》2013,37(1):233-236
Purpose:
To evaluate the impact of renal blood flow on apparent diffusion coefficients (ADC) and fractional anisotropy (FA) using time‐resolved electrocardiogram (ECG)‐triggered diffusion‐tensor imaging (DTI) of the human kidneys.Materials and Methods:
DTI was performed in eight healthy volunteers (mean age 29.1 ± 3.2) using a single slice coronal echoplanar imaging (EPI) sequence (3 b‐values: 0, 50, and 300 s/mm2) at the timepoint of minimum (20 msec after R wave) and maximum renal blood flow (200 msec after R wave) at 3T. Following 2D motion correction, region of interest (ROI)‐based analysis of cortical and medullary ADC‐ and FA‐values was performed.Results:
ADC‐values of the renal cortex at maximum blood flow (2.6 ± 0.19 × 10?3 mm2/s) were significantly higher than at minimum blood flow (2.2 ± 0.11 × 10?3 mm2/s) (P < 0.001), while medullary ADC‐values did not differ significantly (maximum blood flow: 2.2 ± 0.18 × 10?3 mm2/s; minimum blood flow: 2.15 ± 0.14 × 10?3 mm2/s). FA‐values of the renal medulla were significantly greater at maximal blood (0.53 ± 0.05) than at minimal blood flow (0.47 ± 0.05) (P < 0.01). In contrast, cortical FA‐values were comparable at different timepoints of the cardiac cycle.Conclusion:
ADC‐values in the renal cortex as well as FA‐values in the renal medulla are influenced by renal blood flow. This impact has to be considered when interpreting renal ADC‐ and FA‐values. J. Magn. Reson. Imaging 2013;37:233–236. © 2012 Wiley Periodicals, Inc.20.
Hai Ying Zhou MS Xiao Ming Zhang MD Nan Lin Zeng Shun Hai Jian MS Wei Tang MS 《Journal of magnetic resonance imaging : JMRI》2012,36(6):1395-1401