scholarly journals Assessment of the percentage of apparent diffusion coefficient value changes as an early indicator of the response of colorectal hepatic metastases to chemotherapy

Author(s):  
Nada Gamal El-Husseiny ◽  
Sayed Mohamed Mehana ◽  
Sherif Farouk El Zawawy

Abstract Background Colorectal cancer is considered one of the most common causes of cancer-related deaths worldwide. We aim to evaluate the efficacy of DWI-MRI in predicting response to chemotherapy in this cohort. The study included 30 lesions in 20 biopsy proven-colorectal cancer patients with hepatic metastasis larger than 1 cm. All patients underwent both triphasic CT with intravenous contrast, pre-chemotherapy MRI (axial T2 and DW sequences) which was repeated 21 days following chemotherapy. A follow-up CT was done 2 months later. The response of the lesions was evaluated using the RESCIST criteria. On MRI, the lesions corresponding to the ones chosen on CT were identified and the apparent diffusion coefficient (ADC) values of pre- and post-chemotherapy images were recorded and correlated with the CT results. Results In the study, 17 (56.7%) of the lesions showed response to chemotherapy while 13 (43.3%) were non-responding. There was no significant difference in pretreatment ADC values between responding and non-responding lesions (p = 0.14). The mean percentage increase in ADC values in responding lesions was 42% compared to 18% in non-responding lesions (p < 0.001). Lesions that showed less than 18% increase were all found to be non-responsive Conclusion DWI-MRI has an emerging role in early assessment of early treatment response that can be detected before morphological response for patients with hepatic metastasis from colorectal cancer. Based on our study, the use of 25 % as the cutoff point of percent difference in ADC for detection of non-responding lesions proved to be successful only 21 days after the 1st chemotherapy cycle.

Author(s):  
Anu Sarah Easo ◽  
Rajeev Anand ◽  
Mini Issac

Background: To determine whether diffusion-weighted imaging (DWI) with measurement of apparent diffusion coefficient (ADC) will help in differentiating endometrial cancer from normal endometrium and to determine whether the grades of endometrial cancer will show significant difference in ADC values.Methods: This is a retrospective study done in MOSC medical college hospital Kolencherry. on patients on whom preoperative MRI was done before hysterectomy. Cases from July 2017 to March 2021 were included. Study cases included 40 females with pathologically confirmed endometrial cancer and 30 females with pathologically proven normal endometrium in cases of uterine leiomyoma and cervical cancer. The exclusion criteria for the study were patients with endometrial cancer in whom surgery was not done within 2 weeks of MRI, patients who were treated with chemotherapy or radiotherapy before surgery, patients who had hydrometra or pyometra.Results: The mean ADC value (10−3 mm2/second) of endometrial cancer was 0.77±0.04, which was significantly lower (p<0.05) than that of normal endometrium (1.323±0.05). The ADC values of different grades of endometrial cancers did not show any statistically significant difference (p>0.05).Conclusions: Our study showed that ADC measurement can differentiate between normal endometrium and endometrial cancer. The ADC values of different grades of endometrial cancers did not show any statistically significant difference.  


Author(s):  
M. Horger ◽  
M. N. Vogel ◽  
R. Beschorner ◽  
U. Ernemann ◽  
J. Wörner ◽  
...  

Objective:To quantify and compare T2 signal and apparent diffusion coefficient (ADC) in pilocytic and pilomyxoid astrocytoma (PA and PMA) and correlate results with myxoid content.Methods:Echo-planar diffusion weighted images (DWI) and standard magnetic resonance imaging (MRI) findings were reviewed retrospectively in patients with PA (n=34) and PMA (n=8). Regions of interest (ROIs) were drawn on ADC maps within tumor parts with lowest ADC values. Apparent diffusion coefficient values in tumor were normalized to those in cerebrospinal fluid (ADC/CSF). The ratio of T2 signal intensity in solid tumor parts to CSF (T2/CSF) was registered. Myxoid matrix was histologically quantified retrospectively in 8 PMAs and 17 PAs and correlated with imaging findings.Results:Mean ADC/CSF for PA and PMA was 0.53±0.10 and 0.69±0.10 (p<0.01). Mean T2/CSF for PA and PMA was 0.78±0.19 and 0.93±0.09 (p<0.01). Mean proportion of myxoid tumor matrix in PA was 50% (range, 10-100%) and 93% (range, 90-100%) in PMA (p=0.004). Eight patients (32%; all PA) had less than 50% myxoid content and 17 (68%; 8 PA; 9 PMA) had more. There was positive correlation of ADC/CSF, T2/CSF and ADC (r2=0.61, 0.65 and 0.60 respectively) and significant difference between the groups with more and less than 50% myxoid content (p=0.01 for ADC/CSF and T2/CSF and p=0.02 for ADC).Conclusions:General imaging features of PA and PMA are non-specific, ADC values and T2 signal intensity are generally higher in the latter, reflecting the proportion of myxoid matrix in these tumors.


2018 ◽  
Vol 10 (12) ◽  
pp. 359-364
Author(s):  
Andrew McPartlin ◽  
Lucy Kershaw ◽  
Alan McWilliam ◽  
Marcus Ben Taylor ◽  
Clare Hodgson ◽  
...  

Background: Changes in prostate cancer apparent diffusion coefficient (ADC) derived from diffusion-weighted magnetic resonance imaging (MRI) provide a noninvasive method for assessing radiotherapy response. This may be attenuated by neoadjuvant hormone therapy (NA-HT). We investigate ADC values measured before, during and after external beam radiotherapy (EBRT) following NA-HT. Methods: Patients with ⩾T2c biopsy-proven prostate cancer receiving 3 months of NA-HT plus definitive radiotherapy were prospectively identified. All underwent ADC-MRI scans in the week before EBRT, in the third week of EBRT and 8 weeks after its completion. Imaging was performed at 1.5 T. The tumour, peripheral zone (PZ) and central zone (CZ) of the prostate gland were identified and median ADC calculated for each region and time point. Results: Between September and December 2014, 15 patients were enrolled (median age 68.3, range 57–78) with a median Gleason score of 7 (6–9) and prostate-specific antigen (PSA) at diagnosis 14 (3–197) ng/ml. Median period of NA-HT prior to first imaging was 96 days (69–115). All patients completed treatment. Median follow up was 25 months (7–34), with one patient relapsing in this time. Thirteen patients completed all imaging as intended, one withdrew after one scan and another missed the final imaging. PZ and CZ could not be identified in one patient. Median tumour ADC before, during and post radiotherapy was 1.24 × 10−3 mm2/s (interquartile range 0.16 × 10−3 mm2/s), 1.31 × 10−3 mm2/s (0.22 × 10−3 mm2/s), then 1.32 × 10−3 mm2/s (0.13 × 10−3 mm2/s) respectively ( p > 0.05). There was no significant difference between median tumour and PZ or CZ ADC at any point. Gleason score did not correlate with ADC values. Conclusions: Differences in ADC parameters of normal and malignant tissue during EBRT appear attenuated by prior NA-HT. The use of changes in ADC as a predictive tool in this group may have limited utility.


QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
K A A Sabry ◽  
O F Kamel ◽  
A Y Ahmed ◽  
H M Abuzeid

Abstract Purpose to assess the role of Diffusion-weighted MRI in diagnosis of acute pancreatitis by measure the apparent diffusion coefficient (ADC) values detected by diffusion-weighted imaging (DWI) in acute pancreatitis and compare them with the control group Methods and Material sixteen patients with acute pancreatitis and sixteen normal controls underwent DWI with b values (0,200 & 800). Apparent diffusion coefficient (ADC) maps are generated from DWI and ADC values were calculated for pancreas and compared the results between the two groups Results The mean pancreatic ADC in the AP group (1.17 × 10(-3) mm(2)/s ± 0.2) was significantly lower than in the normal group (1.6 × 10(-3) mm(2)/s ± 0.32). There was no significant difference in mean ADCs between each of the pancreatic segments in the controls. A threshold ADC value of 1.38 × 10-3 mm(2)/s yielded a sensitivity of 93% and specificity of 87% for detecting acute pancreatitis. Pancreatic ADCs are significantly lower in patients with AP than normal controls. Conclusion MR diffusion imaging could be an important supportive tool in diagnosis of acute pancreatitis


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Prativa Sahoo ◽  
Russell C. Rockne ◽  
Alexander Jung ◽  
Pradeep K Gupta ◽  
Ram K. S. Rathore ◽  
...  

Purpose. It has been reported that diffusion-weighted imaging (DWI) with ultrahigh b-value increases the diagnostic power of prostate cancer. DWI with higher b-values is challenging as it commonly suffers from low signal-to-noise ratio (SNR), distortion, and longer scan time. The aim of our study was to develop a technique for quantification of apparent diffusion coefficient (ADC) for higher b-values from lower b-value DW images. Materials and Methods. Fifteen patients (7 malignant and 8 benign) were included in this study retrospectively with the institutional ethical committee approval. All images were acquired at a 3T MR scanner. The ADC values were calculated using a monoexponential model. Synthetic ADC (sADC) for higher b-value was computed using a log-linear model. Contrast ratio (CR) between prostate lesion and normal tissue on synthetic DWI (sDWI) was computed and compared with original DWI and ADC images. Results. No significant difference was observed between actual ADC and sADC for b-2000 in all prostate lesions. However, CR increased significantly (p=0.002, paired t-test) in sDWI as compared to DWI. Malignant lesions showed significantly lower sADC as compared to benign lesions (p=0.0116, independent t-test). Mean (±standard deviation) of sADC of malignant lesions was 0.601 ± 0.06 and for benign lesions was 0.92 ± 0.09 (10−3 mm2/s). Discussion/Conclusion. Our initial investigation suggests that the ADC values corresponding to higher b-value can be computed using log-linear relationship derived from lower b-values (b ≤ 1000). Our method might help clinicians to decide the optimal b-value for prostate lesion identification.


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