scholarly journals Role of diffusion weighted MR imaging in diagnosis of acute pancreatitis

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

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.  


2020 ◽  
Vol 14 (3) ◽  
pp. 312-319 ◽  
Author(s):  
Hirohito Kanamoto ◽  
Masaki Norimoto ◽  
Yawara Eguchi ◽  
Yasuhiro Oikawa ◽  
Sumihisa Orita ◽  
...  

Study Design: Observational study.Purpose: To evaluate healthy volunteers and patients with spinal canal lesions using apparent diffusion coefficient (ADC) maps with diffusion-weighted imaging.Overview of Literature: Decompression surgery for lumbar spinal stenosis (LSS) is selected on the basis of subjective assessment and cross-sectional magnetic resonance imaging (MRI). However, there is no objective standard for this procedure.Methods: We performed 3T MRI in 10 healthy volunteers and 13 patients with LSS. The ADC values in the spinal canal were evaluated at 46 vertebrae (L4/5 and L5/S1 for each participant), and the reduced and conventional fields of view were compared.Results: The ADC values were 2.72±0.12 at L4/5 in healthy volunteers, 2.76±0.19 at L5/S1 in healthy volunteers, 1.77±0.58 at L4/5 in patients with LSS, and 2.35±0.29 at L5/S1 in patients with LSS. The ADC value at L4/5 in patients with LSS was significantly lower than that at L5/S1 in patients with LSS and that at L4/5 and L5/S1 in healthy volunteers (<i>p</i> <0.05). With an ADC cutoff value of 2.46 to identify LSS, this approach provided an area under the curve of 0.81, sensitivity of 0.92, and specificity of 0.76 (<i>p</i> <0.05).Conclusions: Preoperative examination using ADC maps permits visualization and quantification of spinal canal lesions, thus proving the utility of ADC maps in the selection of decompression surgery for LSS.


2019 ◽  
Vol 1 (3) ◽  
pp. 212-216
Author(s):  
Punam Bajaj ◽  
Chiara Iacconi ◽  
David D Dershaw ◽  
Elizabeth A Morris

Abstract Objective Fibrosis from chest irradiation could lower the apparent diffusion coefficient (ADC) of breast tissue. ADC values of normal breast tissue in high-risk women who underwent mantle radiation before age 30 years were compared with a screening control group matched for breast fibroglandular tissue (FGT). Methods In this retrospective study, we reviewed 21 women with a history of mantle radiation who underwent breast MRI examinations between 2008 and 2013, and 20 nonirradiated patients (control group) imaged during the same period with matching FGT and similar age. The women were dichotomized into low FGT (10/20, 50%) and high-FGT (10/20, 50%) groups, based on BI-RADS descriptors. All MRI examinations included diffusion-weighted imaging (DWI) (b = 0, 1000); ADC maps were generated and evaluated on PACS workstations by two radiologists in agreement. Region of interest markers were placed on ADC maps in visualized breast tissue in the retroareolar region of each breast. The ADC value was averaged for the right and left breast in each patient included in the study. The Wilcoxon signed-rank test was used to compare the ADC values in the irradiated patients and the matched control patients. Results The median breast ADC was lower in the irradiated group (1.32 × 10-3mm2/sec) than in the control group (1.62 × 10-3mm2/sec; P = 0.0089). Low FGT in the irradiated group had a lower median ADC (1.25 × 10-3mm2/sec) than it did in the control group (1.53 × 10-3mm2/sec). Irradiated high-FGT breasts had a median ADC (1.52 × 10-3mm2/sec), as compared with nonirradiated control patients with high FGT (1.82 × 10-3mm2/sec). Conclusion Previously irradiated breasts have lower ADC values than do nonirradiated breasts.


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.


2015 ◽  
Vol 123 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Ping Zheng ◽  
Bin He ◽  
Yijun Guo ◽  
Jingsong Zeng ◽  
Wusong Tong

OBJECT The relationship between microstructural abnormality in patients with traumatic brain injury (TBI) and hormone-secreting status remains unknown. In this study, the authors aimed to identify the role of the apparent diffusion coefficient (ADC) using a diffusion-weighted imaging (DWI) technique and to evaluate the association of such changes with hypopituitarism in patients with TBI. METHODS Diffusion-weighted images were obtained in 164 consecutive patients with TBI within 2 weeks after injury to generate the pituitary ADC as a measure of microstructural change. Patients with TBI were further grouped into those with and those without hypopituitarism based on the secretion status of pituitary hormones at 6 months postinjury. Thirty healthy individuals were enrolled in the study and underwent MRI examinations for comparison. Mean ADC values were compared between this control group, the patients with TBI and hypopituitarism, and the patients with TBI without hypopituitarism; correlational studies were also performed. Neurological outcome was assessed with the Glasgow Outcome Scale (GOS) for all TBI patients 6 months postinjury. RESULTS In the TBI group, 84 patients had hypopituitarism and 80 had normal pituitary function. The pituitary ADC in TBI patients was significantly less than that in controls (1.83 ± 0.16 vs 4.13 ± 0.33, p < 0.01). Furthermore, the mean ADC was much lower in TBI patients with hypopituitarism than in those without pituitary dysfunction (1.32 ± 0.09 vs 2.28 ± 0.17, p < 0.05). There was also a significant difference in ADC values between patients with hyperprolactinemia and those with normal prolactin levels (p < 0.05). Additionally, the receiver operating characteristic curve analysis showed that the pituitary ADC could predict hypopituitarism with a sensitivity of 90.0% and a specificity of 90.1% at the level of 1.720 (ADC value). Finally, the ADC value was positively correlated with neurological outcome at 6 months following TBI (r = 0.602, p < 0.05). CONCLUSIONS Use of DWI demonstrated that the pituitary ADC is correlated with hormone-secreting status in TBI patients. The authors suggest that pituitary ADC may be a useful biomarker to predict pituitary function in patients with TBI.


2018 ◽  
Vol 4 (2) ◽  
pp. 205511691881225 ◽  
Author(s):  
Toshiyuki Tanaka ◽  
Hideo Akiyoshi ◽  
Keiichiro Mie ◽  
Hidetaka Nishida

Objectives Most nasopharyngeal masses in cats are lymphomas or polyps. To our knowledge, there is no report of MRI findings, including diffusion-weighted imaging (DWI) or apparent diffusion coefficient (ADC) values, of nasopharyngeal lymphomas and nasopharyngeal polyps in cats. This study aimed to evaluate the MRI findings of nasopharyngeal lymphomas and nasopharyngeal polyps, including DWI and ADC values. Methods MRI examination was performed on two cats with a histologically confirmed nasopharyngeal polyp and one cat with lymphoma. The magnetic resonance scanning protocol included T2-weighted imaging (T2WI), T1-weighted imaging (T1WI) and DWI. An ADC map was created based on DWI. ADC values were then calculated. Results MRI of the nasopharyngeal polyps revealed well-defined masses with strong rim enhancement, mass-associated stalk-like structures and asymmetric tympanic bulla lesions. The polyps appeared hyperintense on T2WI, hypo- to isointense on T1WI, and of mixed intensity or hypointense on DWI. On the ADC map, the masses appeared hyperintense. The ADC values of the polyps were 2.07 × 10−3 mm2/s and 2.28 × 10−3 mm2/s. MRI examination of the nasopharyngeal lymphoma revealed a strongly enhancing heterogeneous lesion. The mass appeared mildly hyperintense on T2WI, isointense on T1WI and hyperintense on DWI. On the ADC map, the mass appeared hypointense. The ADC value of the mass was 0.46 ×10−3 mm2/s. The ADC values of the nasopharyngeal polyps were higher than the ADC value of the nasopharyngeal lymphoma. Conclusions and relevance Measurement of ADC values may be useful for differentiating between nasopharyngeal polyps and nasopharyngeal lymphomas.


Author(s):  
Preeti Mundhada ◽  
Sudarshan Rawat ◽  
Ullas Acharya ◽  
Dhananjay Raje

Abstract Aim To determine the role of diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) values in differentiating benign and malignant orbital masses. Materials and Methods After obtaining institutional ethical board approval and informed consent from all patients, an observational study was done for a period of 24 months in the radiology department of a tertiary care hospital in South India. Conventional magnetic resonance imaging and DWI using a 3T scanner was done for all patients with suspected orbital mass lesion. ADC value and clinicohistopathological correlation were studied for every patient. Chi-square test was used to compare the signal characteristics of DWI and ADC maps between benign and malignant lesions. A comparison of mean ADC values for benign and malignant masses was performed using Student’s t-test for independent samples. The cut-off value for ADC was obtained using the receiver operating characteristic (ROC) curve. Results Of 44 patients with orbital lesions, 70% were benign and 30% were malignant. There was a significant difference in the mean ADC values of benign and malignant orbital masses. Using ROC curve analysis, an optimal ADC threshold of 1.26 × 10−3 mm2/s was calculated for the prediction of malignancy with 100% sensitivity, 80.65% specificity, and 86.36% accuracy (95% confidence interval: 0.872, 1.00, p < 0.0001). Two ADC thresholds were used to characterize the orbital masses with more than 90% confidence. Conclusion Quantitative assessment of ADC is a useful noninvasive diagnostic tool for differentiating benign and malignant orbital masses. Malignant orbital lesions demonstrate significantly lower ADC values as compared with benign lesions.


Author(s):  
Alexey Surov ◽  
Hans-Jonas Meyer ◽  
Maciej Pech ◽  
Maciej Powerski ◽  
Jasan Omari ◽  
...  

Abstract Background Our aim was to provide data regarding use of diffusion-weighted imaging (DWI) for distinguishing metastatic and non-metastatic lymph nodes (LN) in rectal cancer. Methods MEDLINE library, EMBASE, and SCOPUS database were screened for associations between DWI and metastatic and non-metastatic LN in rectal cancer up to February 2021. Overall, 9 studies were included into the analysis. Number, mean value, and standard deviation of DWI parameters including apparent diffusion coefficient (ADC) values of metastatic and non-metastatic LN were extracted from the literature. The methodological quality of the studies was investigated according to the QUADAS-2 assessment. The meta-analysis was undertaken by using RevMan 5.3 software. DerSimonian, and Laird random-effects models with inverse-variance weights were used to account the heterogeneity between the studies. Mean DWI values including 95% confidence intervals were calculated for metastatic and non-metastatic LN. Results ADC values were reported for 1376 LN, 623 (45.3%) metastatic LN, and 754 (54.7%) non-metastatic LN. The calculated mean ADC value (× 10−3 mm2/s) of metastatic LN was 1.05, 95%CI (0.94, 1.15). The calculated mean ADC value of the non-metastatic LN was 1.17, 95%CI (1.01, 1.33). The calculated sensitivity and specificity were 0.81, 95%CI (0.74, 0.89) and 0.67, 95%CI (0.54, 0.79). Conclusion No reliable ADC threshold can be recommended for distinguishing of metastatic and non-metastatic LN in rectal cancer.


Sign in / Sign up

Export Citation Format

Share Document