Comparison of peritoneal tumor imaging using conventional MR imaging and diffusion-weighted MR imaging with different b values

doi:10.1016/j.ejrad.2010.06.004

European Journal of Radiology

Volume 80, Issue 2, November 2011, Pages 224-228

https://doi.org/10.1016/j.ejrad.2010.06.004 Get rights and content

Abstract

Purpose

The aim of this study was to evaluate the utility of DW MRI with two different b values in identifying peritoneal tumors in oncology patients.

Materials and methods

Nineteen patients with known malignancy underwent abdominal and pelvic MRI before surgery. MRI included free-breathing DWI with b values of 400 and 800 s/mm², T1-weighted fat-suppressed spoiled gradient-echo, T2-weighted fat-saturated turbo spin-echo, and 5-min delayed gadolinium-enhanced imaging. Two observers reviewed images for peritoneal tumors at ten anatomic sites within consensus. The results of laparatomy and histopathological evaluation were compared with MRI results. Sensitivity, specificity, and accuracy of identifying peritoneal metastases were calculated for conventional MRI, combined DWI with a b value of 400 s/mm² and conventional MRI, and combined DWI with a b value of 800 s/mm² and conventional MRI by consensus of two observers.

Results

One-hundred and twenty-five peritoneal metastasis sites were confirmed by surgical and histopathological findings. Conventional MRI alone identified 72 peritoneal metastases (sensitivity, 0.58; specificity, 0.87; accuracy, 0.67). Combined DWI with a b value of 400 s/mm² and conventional MRI revealed 106 peritoneal metastases (sensitivity, 0.85; specificity, 0.88; accuracy, 0.85). Finally, combined DWI with a b value of 800 s/mm² and conventional MRI revealed 103 peritoneal metastases (sensitivity, 0.83; specificity, 0.94; accuracy, 0.86).

Conclusion

DWI with a high b value provides complementary information that can improve the detection of peritoneal tumors when combined with conventional MRI. We recommend combined MRI and DWI with a high b value for increasing the sensitivity and accuracy of the preoperative detection of peritoneal tumors.

Introduction

The peritoneum is a serous sac made of a thin mesothelial membrane that lines the abdominal and pelvic cavities [1], [2], and it is divided into the visceral peritoneum and the parietal peritoneum [1].

Primary tumors of the peritoneum are rare, whereas metastatic disease is the most commonly encountered neoplastic process involving the peritoneum [1]. The most common locations of peritoneal metastases are the pouch of Douglas, ileocecal region, right paracolic gutter, sigmoid mesocolon, greater omentum, and right subdiaphragmatic parietal peritoneum [3].

Treatment protocols (medical treatment or surgery) are determined by the location and spread of peritoneal tumors, and a planned surgical approach reduces the extent of exploration and anesthesia time. Therefore, imaging modalities that identify and localize tumors are very important. Various imaging modalities, such as computed tomography (CT), ultrasonography (US) and magnetic resonance imaging (MRI) are used to detect peritoneal tumors [4]. Ultrasonography is recognized as a cumbersome, operator-dependent, time consuming technique when careful evaluation of structural identification of disease is required [4]. CT is undoubtedly the most used imaging modality in the evaluation of peritoneal tumors. It is non-invasive but carries the risk associated with radiation. Furthermore, CT examinations of the abdomen and pelvis are insensitive to small volumes (<5 mm) of diffuse peritoneal seeding. However, CT can be helpful when larger volume peritoneal tumors are present [5]. MRI of the abdomen is noninvasive, non-ionizing, and capable of providing multiplanar images. However, compared with CT scan time, MR image acquisition time is somewhat longer and more influenced by respiratory movement artifacts, its spatial resolution is lower, and clinicians find it harder to interpret [4].

Recently, diffusion-weighted imaging (DWI) of the abdomen and pelvis, which has a widespread usage for diagnostic aid, has been shown to provide a new contrast mechanism to evaluate patients with abdominal pathologies and solid abdominal and pelvic organs [6]. Recent studies have shown that adding DWI to routine MRI examination increases diagnostic accuracy [7], [8], [9], [10], [11], [12], [13], [14], [15], [16]. Most solid tumors show restricted diffusion due to the high cellularity and a significant number of cell membranes per unit volume, which results in the restriction of water movement in a corresponding high signal intensity on DW images [17], [18], [19]. Thus, we considered the use of DWI for the evaluation of peritoneal tumors. We hypothesized that adding DW MRI to conventional MRI would improve the specificity and sensitivity for identifying peritoneal tumors in the abdomen.

In this study, the aim was to evaluate the utility of DW MRI with two different b values in identifying peritoneal tumors in oncology patients.

Section snippets

Patients

Nineteen patients with known malignancy (12 men, 7 women, mean ± SD age: 64 ± 6 years, range: 46–82 years) were involved in this study. Written informed consent was acquired from all patients. This retrospective study was approved by the institutional review board. The study group consisted of patients with confirmed diagnoses of ovarian cancer (n = 3), colon cancer (n = 7), esophageal cancer (n = 3), gastric cancer (n = 4) and pancreatic cancer (n = 2). All patients had abdominal and pelvic MRI examinations

Results

For each of 19 patients, peritoneal metastasis was confirmed upon surgical and histopathological evaluation.

Metastatic lesion findings for all patients from three imaging sessions are shown in Table 1. One hundred and twenty-five peritoneal metastasis sites were confirmed by surgical and histopathological findings, and 65 sites showed no tumor involvement. Table 2 shows the consensus interpretation by two observers of imaging results for each peritoneal metastasis site.

Table 1, Table 2 show

Discussion

DW MR imaging detects abnormalities on the basis of tumor cellularity. With this new technique, information is extracted from diffusion of water molecules in tissues, and this technique produces different contrasts than conventional MR imaging sequences. Therefore, DW MR imaging enables the characterization of tissues at the microscopic level and utilizes a mechanism that is different from T1 and T2 relaxation [21]. Tumors are more cellular than the tissue from which they originate and, thus,

Conclusion

Using DWI with a high b value provides increased specificity that can improve imaging of peritoneal tumors when added to conventional MRI. We recommend combined MR and DW imaging with high b values for increased sensitivity and accuracy of preoperative imaging of peritoneal tumors.

Conflict of interest

None.

References (21)

K.M. Elsayes et al.
MRI of the peritoneum: spectrum of abnormalities
AJR Am J Roentgenol
(2006)
J.C. Healy et al.
The peritoneum, mesenteries and omenta: normal anatomy and pathological processes
Eur Radiol
(1998)
C.K. Chou et al.
MRI demonstration of peritoneal implants
Abdom Imaging
(1994)
S. González-Moreno et al.
Imaging of peritoneal cacinomatosis
Cancer J
(2009)
A. Archer et al.
Radiology of peritoneal carcinomatosis
Cancer Treat Res
(1996)
M. Matsuki et al.
Diffusion-weighted MR imaging for urinary bladder carsinoma: initial results
Eur Radiol
(2007)
R. Brammer et al.
Diffusion tensor imaging using single-shot SENSE-EPI
Magn Reson Med
(2002)
P. Murtz et al.
Abdomen: diffusion-weighted MR imaging with pulse-triggered single-shot sequences
Radiology
(2002)
L.C. Chow et al.
Single breath-hold diffusion-weighted imaging of the abdomen
J Magn Reson Imaging
(2003)
T. Takahara et al.
Diffusion weighted whole body imaging with background body signal supression (DWIBS): technical improvement using free breathing, STIR and high resolution 3D display
Radiat Med
(2004)

There are more references available in the full text version of this article.

Cited by (57)

The BUMPy road of peritoneal metastases in ovarian cancer
2022, Diagnostic and Interventional Imaging
Citation Excerpt :
T2-weighted and contrast-enhanced T1-weighted MRI sequences yield the same sensitivity than CT in the detection of peritoneal deposits, however with delayed post-contrast imaging, oral contrast agents and diffusion-weighted imaging (DWI), there is improved accuracy with sensitivities of MRI surpassing that of CT [17,24–28]. The sensitivity and specificity of MRI with DWI are as high as 90% and 95.5%, respectively for peritoneal implant detection [25,29-37] (Table 2). Despite these promising results, most reports to date are single-center studies with small sample sizes.
Ovarian cancer is the most common cause of death due to gynecologic malignancies, with more than 70% of patients presenting with advanced stage disease at the time of diagnosis. The extent and distribution of tumor guide primary treatment selection and clinical management. While primary cytoreductive surgery with complete tumor resection improves survival, patients with extensive peritoneal disease may benefit from neoadjuvant chemotherapy first to reduce tumor burden followed by interval cytoreductive surgery. Imaging plays an essential role in triaging patients including selecting patients who may benefit from neoadjuvant chemotherapy before cytoreductive surgery. Interestingly, there are no universally established criteria to predict resectability and local practices depend on local guidelines and surgeon preferences. Nevertheless, certain anatomical tumor locations are known to be difficult to resect and are associated with suboptimal cytoreduction or require special surgical considerations. This review discusses the recent advances in the initial management of patients with ovarian cancer, a practical approach to the assessment and communication of peritoneal metastases locations on CT and MRI. It also explores recent advances in genomics profiling and radiomics that may influence the initial management of these patients.
Diffusion-weighted MRI and PET/CT reproducibility in epithelial ovarian cancers during neoadjuvant chemotherapy
2021, Diagnostic and Interventional Imaging
To investigate the reproducibility of diffusion-weighted (DW) MRI and ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG)-Positron emission tomography/CT (PET/CT) in monitoring response to neoadjuvant chemotherapy in epithelial ovarian cancer.
Ten women (median age, 67 years; range: 41.8–77.3 years) with stage IIIC-IV epithelial ovarian cancers were included in this prospective trial (NCT02792959) between 2014 and 2016. All underwent initial laparoscopic staging, four cycles of carboplatine-paclitaxel-based chemotherapy and interval debulking surgery. PET/CT and DW-MRI were performed at baseline (C0), after one cycle (C1) and before surgery (C4). Two nuclear physicians and two radiologists assessed five anatomic sites for the presence of ≥ 1 lesion. Target lesions in each site were defined and their apparent diffusion coefficient (ADC), maximal standardized uptake value (SUV-max), SUV-mean, SUL-peak, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were monitored (i.e., 10 patients × 5 sites × 3 time-points). Their relative early and late changes were calculated. Intra/inter-observer reproducibilities of qualitative and quantitative analysis were estimated with Kappa and intra-class correlation coefficients (ICCs).
For both modalities, inter- and intra-observer agreement percentages were excellent for initial staging but declined later for DW-MRI, leading to lower Kappa values for inter- and intra-observer variability (0.949 and 1 at C0, vs. 0.633 and 0.643 at C4, respectively) while Kappa values remained > 0.8 for PET/CT. Inter- and intra-observer ICCs were > 0.75 for SUV-max, SUL-peak, SUV-mean and their change regardless the time-point. ADC showed lower ICCs (range: 0.013–0.811). ANOVA found significant influences of the evaluation time, the measurement used (ADC, SUV-max, SUV-mean, SUV-max, SUL-peak, MTV or TLG) and their interaction on ICC values (P = 0.0023, P< 0.0001 and P =0.0028, respectively).
While both modalities demonstrated high reproducibility at baseline, only SUV-max, SUL-peak, SUV-mean and their changes maintained high reproducibility during chemotherapy.
Diffusion-weighted magnetic resonance imaging in peritoneal carcinomatosis from suspected ovarian cancer: Diagnostic performance in correlation with surgical findings
2019, European Journal of Radiology
Ovarian cancer (OC) is the commonest cause of death by gynaecological cancer in developed countries.
Peritoneal carcinomatosis (PC) complete debulking without residual disease of >1 cm is the best prognostic predictor in advanced OC.
PC is assessed with Computed tomography (CT). CT accuracy and cytoreduction success predictive ability are limited. PET/CT is not an imaging standard for PC.
PC shows high signal foci in Diffusion-weighted magnetic resonance imaging (DWI MRI).
We assessed the diagnostic performance (DP) and tumour burden correlation of Whole body DWI with background suppression MRI (WB-DWIBS/MRI) in PC of suspected OC using the Peritoneal Cancer Index (PCI), referring to cytoreduction surgery as the standard reference.
Fifty patients with suspicion of disseminated OC underwent cytoreduction and WB-DWIBS/MRI. The PCI scores tumour burden (0–3) in 13 anatomical regions (global range of 0–39). Two radiologists (Rad1/Rad2) assessed the PCI preoperatively and with surgical findings.
We evaluated regional and global DP, the interobserver agreement (Cohen´s kappa coefficient), statistical differences (McNemar test) and tumour burden (Pearson’s test).
72% (36/50) were epithelial OC and 78% (39/50) achieved complete cytoreduction. Global-PCI correlation was 0.762 (Rad1) with DP: Sensitivity 0.84, specificity 0.89, accuracy 0.89, and kappa 0.41.
Average global-PCI was 7. The pelvis and right hypochondrium showed the highest positive rate and DP, while the intestinal regions presented the lowest. Previous studies reported higher sensitivity than CT or PET/CT, although only a few used the PCI.
WB-DWIBS/MRI is reliable to depict, quantify and to predict complete cytoreductive surgery in OC PC.
Imaging for Peritoneal Metastases
2018, Surgical Oncology Clinics of North America
Citation Excerpt :
The increased conspicuity of these enhancing peritoneal tumors improved detection of small and microscopic tumors that are often missed on CT scans and PET. The addition of diffusion MRI further improves peritoneal tumor depiction because most tumors cause restricted diffusion, producing high signal on diffusion-weighted imaging (DWI)20–26 (Fig. 2). Limitations of MR for peritoneal tumor imaging include longer examination time, which is typically 30 to 45 minutes, and increased motion artifact in the uncooperative patient.
The emerging roles of functional imaging in ovarian cancer with peritoneal carcinomatosis
2018, Clinical Radiology
This article reviews the emerging roles of functional imaging in the assessment of peritoneal carcinomatosis in ovarian cancer, focusing on the use of diffusion-weighted magnetic resonance imaging (DW-MRI) and 2-[¹⁸F]-fluoro-2-deoxy-d-glucose positron-emission tomography combined with computed tomography (PET-CT), their advantages and shortcomings as well as the added-value over conventional imaging.
Magnetic Resonance Assessment of Peritoneal Carcinomatosis: Is There a True Benefit From Diffusion-Weighted Imaging?
2020, Current Problems in Diagnostic Radiology
Citation Excerpt :
We compared the diagnostic performance of conventional MRI and its combination with DWI, using b values of 500 and 1000 s/mm2 with ADC maps, for the detection of peritoneal metastasis. Our results agree with previous articles10,20,26,27 showing that combined conventional MRI and DWI is superior to conventional MRI alone in depicting peritoneal tumors. As a matter of facts, the sensitivity and AUC values were superior to those of conventional MRI for both observers and both b values when DWI was added to conventional MRI (Table 4).
To assess the added value of diffusion weighted imaging (DWI) with intermediate (500 s/mm²) and high (1000 s/mm²) b values when combined to conventional contrast-enhanced magnetic resonance imaging (MRI) in identifying peritoneal neoplastic involvement.
Twenty-four patients with peritoneal carcinomatosis from gastrointestinal or gynecological tumors were retrospectively evaluated. All patients underwent peritonectomy with hyperthermic intraoperative chemotherapy and 1.5 T MRI including DWI with 500 s/mm² and 1000 s/mm² b values within 1 month from surgery. Images were independently reviewed by 2 radiologists with different experience in abdominal MRI in 3 separate reading sessions, the first including conventional MR images alone (T2-weighted, T1-weighted pre- and post gadolinium injection), the second conventional MRI and DWI with a b value of 500 s/mm² (b 500-DWI), and the third conventional MRI and DWI with a b value of 1000 s/mm² (b 1000-DWI). Apparent diffusion coefficient maps were included in the DWI analyses. Peritoneal dissemination was assessed in 9 anatomical sites, including right and left subphrenic space, paracolic gutters, small bowel mesentery, greater omentum, gastric-bowel serosa, free peritoneal surfaces, rectosigmoid-colon mesentery, and pelvis. The presence or absence of peritoneal dissemination for each patient and for each site was scored using a 5-point confidence scale. Sensitivity, specificity, and area under the curve (AUC) for identifying per-site peritoneal implants were calculated for each reader at each reading session. Interobserver agreement was evaluated using kappa statistics.
For both readers, the sensitivity and AUC values resulting from combined interpretation of conventional MRI and DWI (both b500-DWI and b1000-DWI) were significantly higher than those of conventional MRI alone (P < 0.001). The added value of DWI was greater for the less experienced reader (sensitivity 0.55, specificity 0.73, AUC 0.64 on conventional MRI; sensitivity 0.75, specificity 0.72, AUC 0.74 on b500-DWI; sensitivity 0.87, specificity 0.72, AUC 0.80 on b1000-DWI) than for the more experienced reader (sensitivity 0.63, specificity 0.75, AUC 0.70 on conventional MRI; sensitivity 0.76, specificity 0.77, AUC 0.77 on b500-DWI; sensitivity 0.85, specificity 0.72, AUC 0.79 on b1000-DWI), although the differences between the 2 observers were not statistically significant. Interobserver agreement resulted to be fair (κ = 0.30) when dealing with conventional MRI alone. The addition of b500-DWI and b1000-DWI to conventional MRI allowed to reach a substantial agreement (κ = 0.75).
The combined interpretation of high b value DWI and conventional MRI provides increased sensitivity and diagnostic performance in detection of peritoneal carcinomatosis in oncologic patients.

View all citing articles on Scopus

View full text

Published by Elsevier Ireland Ltd.

Comparison of peritoneal tumor imaging using conventional MR imaging and diffusion-weighted MR imaging with different b values

Abstract

Purpose

Materials and methods

Results

Conclusion

Introduction

Section snippets

Patients

Results

Discussion

Conclusion

Conflict of interest

MRI of the peritoneum: spectrum of abnormalities

AJR Am J Roentgenol

The peritoneum, mesenteries and omenta: normal anatomy and pathological processes

Eur Radiol

MRI demonstration of peritoneal implants

Abdom Imaging

Imaging of peritoneal cacinomatosis

Cancer J

Radiology of peritoneal carcinomatosis

Cancer Treat Res

Diffusion-weighted MR imaging for urinary bladder carsinoma: initial results

Eur Radiol

Diffusion tensor imaging using single-shot SENSE-EPI

Magn Reson Med

Abdomen: diffusion-weighted MR imaging with pulse-triggered single-shot sequences

Radiology

Single breath-hold diffusion-weighted imaging of the abdomen

J Magn Reson Imaging

Diffusion weighted whole body imaging with background body signal supression (DWIBS): technical improvement using free breathing, STIR and high resolution 3D display

Radiat Med