Diffusion-weighted whole-body imaging with background body signal suppression/T2-weighted image fusion of gastrointestinal cancers

Abstract

Abstract. Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) yields positive results for cancer against the surrounding tissues. The combination of DWIBS and T2-weighted images (DWIBS/T2) in the diagnosis of gastrointestinal tract cancers was retrospectively analyzed in the present study. Patients were subjected to magnetic resonance imaging after cancer was diagnosed through specimens obtained via biopsy or endoscopic mucosal resection. Sixteen patients were assessed between July, 2012 and June, 2013 and the correlation between detection with DWIBS/T2 and T staging was analyzed. Regarding patients who underwent surgery, the correlation between detection with DWIBS/T2 and the diameter or depth of invasion was analyzed. All cancers that had advanced to >T2 stage were detectable by DWIBS/T2, whereas all cancers staged as <T1 were not (P<0.0001). Tumors that were undetected by DWIBS/T2 had a mean diameter of 1.53±0.25 cm, whereas those detected had a mean diameter of 3.63±1.88 cm; however, the difference was not statistically significant (P= 0.1053). Cancers invading beyond the muscularis propria were detectable by DWIBS/T2, while those which had not invaded the mucosa were not (P= 0.0476). In conclusion, DWIBS/T2 was able to positively identify gastrointestinal tract cancers at an advanced stage (>T2) or invading beyond the muscularis propria. IntroductionEndoscopy is the gold standard for diagnosing cancers of the gastrointestinal tract, including the esophagus, stomach, colon and rectum (1,2). However, endoscopy is not suitable for evaluating the depth of invasion and extent of cancer, as it only allows observation of the lumen. Endoscopic ultrasonography (EUS) and contrast-enhanced computed tomography (CE-CT) are performed to assess the structure of the primary lesion, the depth of invasion into the surrounding tissues and distant metastasis (3,4). Assessing the depth of invasion may occasionally be difficult due to the weak contrast of the cancer against the surrounding tissues. Therefore, an imaging modality with a strong signal and contrast would facilitate the assessment of the depth of tumor invasion.Magnetic resonance imaging (MRI) is not as popular as CT due to blurring and low spatial resolution (5). However, MRI may be a promising method if a strong soft tissue contrast in the abdomen can be achieved. Diffusion-weighted wholebody imaging with background body signal suppression (DWIBS) images are acquired using multiple-signal averaging, pre-pulse fat suppression and heavy diffusion weighting during free breathing (6). DWIBS is based on diffusion-weighted imaging (DWI) that visualizes and assesses the random movement of water at the molecular level (Brownian motion) (7,8). An advantage of DWIBS is that it provides a strong contrast of cancerous against surrounding non-cancerous tissues, which is useful for the detection, staging and monitoring of the response to therapy (9). A major limitation of DWIBS is that anatomical analysis may be difficult at times (10,11).

Comparison of DWIBS/T2 image fusion and PET/CT for the diagnosis of cancer in the abdominal cavity

“…A major issue with adenomyomatosis of the gallbladder is differentiating it from gallbladder cancer (27). Our previous study has already reported that IPMN was negative on DWBIBS/T2 (28). The present study confirmed these negative results with PET/CT imaging.…”

Diagnostic performance of diffusion‐weighted imaging for differentiating benign and malignant gallbladder lesions: A systematic review and meta‐analysis

“…After removing 39 duplicates, we reviewed 131 titles and abstracts and excluded 118 studies for the following reasons: nonhuman studies (n = 3), case reports/letters/editorials/conference abstracts (n = 54), review articles/guidelines/consensus statements (n = 29), and studies outside the field of interest (n = 32). After reviewing the full text of 13 eligible articles, we excluded four for the following reasons: studies outside the field of interest (n = 3) and those with overlapping study populations (n = 2) . Ultimately, eight studies evaluating the diagnostic performance of DWI for GB lesions, including 557 patients, were included.…”

Diffusion-weighted whole-body magnetic resonance imaging with background body signal suppression/T2 image fusion for the diagnosis of acute cholecystitis

“…Images obtained from DWIBS are fused with their corresponding T2-weighted images using a workstation (13)(14)(15). DWIBS and T2-weighted image fusion (DWIBS/T2) enables anatomical evaluation of the positive signals obtained from DWIBS (16). Therefore, the present study retrospectively analyzed images obtained by DWIBS/T2 from patients with acute cholecystitis to determine how useful this technique is in the management of the disease.…”