Helical CT evaluation of the preoperative staging of gastric cancer in the remnant stomach. AJR Am J Roentgenol. 2009;192:902-908. [PMID: 19304693 DOI: 10.2214/AJR.07.3520]

Efficacy of multi-slice spiral computed tomography in evaluating gastric cancer recurrence after endoscopic submucosal dissection

BACKGROUND

Recurrence is the major challenge facing endoscopic submucosal dissection (ESD)-based treatment therapies for early gastric cancer (EGC). Urgent development of simple and easy surveillance approaches will enhance clinical treatment of the disease.

AIM

To explore the role of computed tomography (CT) recurrence in evaluating EGC after ESD treatment.

METHODS

We retrospectively recruited patients from our endoscopy department, between January 2002 and December 2015, and analyzed their basic characteristics, including symptoms, CT results, and results of endoscopy with biopsy, among others.

RESULTS

Among a total of 2150 patients EGC patients surveyed, 1362 met our inclusion and exclusion criteria and were therefore enrolled in our study. The cohort's sensitivity of CT for recurrent GC and specificity were 44.22% and 43.86%, respectively, with negative and positive predictive values of 40.15% (275/685) and 48.01% (325/677), respectively. The area under the curve of arterial and venous CT values for recurrent EGC were 0.545, and 0.604, respectively. Receiver operating characteristic curve revealed no statistically significant differences between arterial and venous CT values for recurrent EGC.

CONCLUSION

Enhanced CT has superior diagnostic efficacy, but less accuracy, compared to gold standard techniques in patients with recurrent EGC.

Accuracy of preoperative staging of gastric stump cancer

BACKGROUND

In this study, the accuracy of preoperative staging for gastric stump cancer, which has not been thoroughly investigated since the condition is rare, was investigated using computed tomography and gastroscopic imaging.

METHODS

Between February 1994 and April 2018, 49 patients with gastric stump cancer, following subtotal or total gastrectomy, were reviewed retrospectively. Preoperative diagnoses of clinical T and clinical N categories were compared with post-operative pathological diagnoses (pT and pN categories). Positive predictive values, accuracy, sensitivity and specificity were also evaluated.

RESULTS

The overall accuracy of T staging was 40.8%. The positive predictive value for cT3/T4 was 96.3%, whereas the positive predictive value for cT1/T2 was 72.7%. The overall accuracy for N staging was 61.2%. The positive predictive value of lymph node positive patients was 73.3%. The positive predictive value and sensitivity of over stage II were 96.6% and 84.8%, respectively.

CONCLUSIONS

The accuracy of preoperative diagnosis using both computed tomography and gastroscopy imaging may be feasible for T3/T4 advanced gastric stump cancer, whereas diagnosing T1/2 gastric stump cancer must be carefully considered due to high misdiagnosis rates, relating to depth.

Preprocedural fasting for contrast-enhanced CT: when experience meets evidence

Traditional preparatory fasting policy prior to iodinated contrast media (ICM) assisted contrast-enhanced CT (CECT) examinations lacks methodologically acceptable evidence. Considering the possible negative effects of preprocedural fasting, the latest European Society of Urogenital Radiology guidelines V10.0 and American Committee of Radiology 2021 guidelines clearly state that preprocedural fasting is not recommended prior to routine intravenous ICM administration. This comprehensive and detailed Review presents the current global dietary preparation policies, potential harm of excessive fasting, and a systematical and well-bedded description of practice advancements of dietary preparation. The evidences revealed that there has been no single instance of vomiting-associated aspiration pneumonia due to the undemanding implementation of preparatory fasting prior to CECT yet. Non-fasting would not increase the incidence of emetic symptoms and the risk of aspiration pneumonia. Not every patient should undergo all CECT examinations without preparatory fasting. There is still much more refinement to be done on the preparatory fasting policy. Changes in traditional preparatory fasting policy will make positive and significant implications on clinical practice. This Review aims to provide operational guidance and suggestions for practitioners and policymakers, motivate efficient, reasonable, safe and normative ICM usage, and achieve optimal patient clinical benefits and high-quality radiological care practices.

Assessment of gastric wall structure using ultra-high-resolution computed tomography

PURPOSE

To evaluate the image quality of ultra-high-resolution CT (U-HRCT) in the comparison among four different reconstruction methods, focusing on the gastric wall structure, and to compare the conspicuity of a three-layered structure of the gastric wall between conventional HRCT (C-HRCT) and U-HRCT.

METHOD

Our retrospective study included 48 patients who underwent contrast-enhanced U-HRCT. Quantitative analyses were performed to compare image noise of U-HRCT between deep-learning reconstruction (DLR) and other three methods (filtered back projection: FBP, hybrid iterative reconstruction: Hybrid-IR, and Model-based iterative reconstruction: MBIR). The mean overall image quality scores were also compared between the DLR and other three methods. In addition, the mean conspicuity scores for the three-layered structure of the gastric wall at five regions were compared between C-HRCT and U-HRCT.

RESULTS

The mean noise of U-HRCT with DLR was significantly lower than that with the other three methods (P < 0.001). The mean overall image quality scores with DLR images were significantly higher than those with the other three methods (P < 0.001). Regarding the comparison between C-HRCT and U-HRCT, the mean conspicuity scores for the three-layered structure of the gastric wall on U-HRCT were significantly better than those on C-HRCT in the fornix (5 [5-5] vs. 3.5 [3-4], P < 0.001), body (4 [3.25-5] vs. 4 [3-4], P = 0.039), angle (5 [4-5] vs. 3 [2-4], P < 0.001), and antral posterior (4 [3.25-5] vs. 2 [2-4], P < 0.001), except for antral anterior (4 [3-5] vs. 3 [3-4], P = 0.230) CONCLUSION: U-HRCT using DLR improved the image noise and overall image quality of the gastric wall as well as the conspicuity of the three-layered structure, suggesting its utility for the evaluation of the anatomical details of the gastric wall structure.

Performance of a machine learning-based decision model to help clinicians decide the extent of lymphadenectomy (D1 vs. D2) in gastric cancer before surgical resection

BACKGROUND

Controversy still exists on the optimal surgical resection for potentially curable gastric cancer (GC). Use of radiologic evaluation and machine learning algorithms might predict extent of lymphadenectomy to limit unnecessary surgical treatment. We purposed to design a machine learning-based clinical decision-support model for predicting extent of lymphadenectomy (D1 vs. D2) in local advanced GC.

METHODS

Clinicoradiologic features available from routine clinical assignments in 557 patients with GCs were retrospectively interpreted by an expert panel blinded to all histopathologic information. All patients underwent surgery using standard D2 resection. Decision models were developed with a logistic regression (LR), support vector machine (SVM) and auto-encoder (AE) algorithm in 371 training and tested in 186 test data, respectively. The primary end point was to measure diagnostic performance of decision model and a Japanese gastric cancer treatment guideline version 4th (JPN 4th) criteria for discriminate D1 (pT1 + pN0) versus D2 (≥ pT1 + ≥ pN1) lymphadenectomy.

RESULTS

The decision model with AE analysis produced highest area under ROC curve (train: 0.965, 95% confidence interval (CI) 0.948-0.978; test: 0.946, 95% CI 0.925-0.978), followed by SVM (train: 0.925, 95% CI 0.902-0.944; test: 0.942, 95% CI 0.922-0.973) and LR (train: 0.886, 95% CI 0.858-0.910; test: 0.891, 95% CI 0.891-0.952). By this improvement, overtreatment was reduced from 21.7% (121/557) by treat-all pattern, to 15.1% (84/557) by JPN 4th criteria, and to 0.7-0.9% (4-5/557) by the new approach.

CONCLUSIONS

The decision model with machine learning analysis demonstrates high accuracy for identifying patients who are candidates for D1 versus D2 resection. Its approximate 14-20% improvements in overtreatment compared to treat-all pattern and JPN 4th criteria potentially increase the number of patients with local advanced GCs who can safely avoid unnecessary lymphadenectomy.

Preoperative Gross Classification of Gastric Adenocarcinoma: Comparison of Double Contrast-Enhanced Ultrasound and Multi-Detector Row CT

The aim of this study was to compare the accuracy of multi-detector computed tomography (MDCT) with double contrast-enhanced ultrasound (DCEUS), in which intravenous microbubbles are used alongside oral contrast-enhanced ultrasound, in determining the gross classification of patients with gastric carcinoma (GC). Altogether, 239 patients with GC proved by histology after endoscopic biopsy were included in this study. DCEUS and MDCT were performed pre-operatively. The diagnostic accuracies of DCEUS and MDCT in determining the gross classification were calculated and compared. The overall accuracy of DCEUS in determining the gross appearance of GC was higher than that of MDCT (84.9% vs. 79.9%, p < 0.001). There was no significant difference in accuracy between DCEUS and MDCT for Borrmann I and IV classifications of advanced gastric cancer (χ(2), p = 0.323 for Borrmann type I, p = 0.141 for Borrmann type IV). The accuracy of DCEUS for early GC and Borrmann II and III classifications of GC was higher than that of MDCT (χ(2), p = 0.000 for all). DCEUS may be regarded as a valuable complementary tool to MDCT in determining the gross appearance of gastric adenocarcinoma pre-operatively.

Added value of diffusion-weighted MR imaging to T2-weighted and dynamic contrast-enhanced MR imaging in T staging of gastric cancer

OBJECTIVE

To assess the utilization of diffusion-weighted (DW) magnetic resonance (MR) imaging in T staging of gastric cancer prospectively.

METHODS

Fifty-one patients underwent T2-weighted (T2W), contrast-enhanced (CE) and DW MR imaging. Two radiologists independently interpreted the images for T staging of the tumors.

RESULTS

The overall accuracy of T staging in pT1-4 gastric cancers by T2W+CE+DW (88.2%) was significantly higher than that by T2W+CE and T2W+DW (both 76.5%, P=.031).

CONCLUSION

DW adds useful information to T2W and CE MR imaging in T staging of gastric cancer.

Value of 64-slice spiral CT triple-phase enhanced scanning for preoperative evaluation of lymph node dissection in patients with gastric cancer

AIM: To analyze the value of 64-slice spiral computed tomography (CT) triple-phase enhanced scanning for preoperative evaluation of lymph node dissection in patients with gastric cancer.

METHODS: Thirty-eight patients with gastric cancer underwent preoperative 64-slice spiral CT triple-phase enhanced scanning to comprehend the anatomic distribution of the celiac trunk, its three branches and their tributaries (common hepatic artery, right hepatic artery, left hepatic artery, splenic artery, and left gastric artery) through volume rendering and three dimensional vascular imaging. The lymph nodes were detected using group orientation method, and N staging was performed to compare with postoperative pathological results.

RESULTS: Surgical results verified that 64-slice spiral CT triple-phase enhanced scanning through volume rendering and three dimensional vascular imaging had an accuracy rate of 100% in preoperative evaluation of the distribution of the celiac trunk, its three branches and their tributaries. Compared to postoperative pathological results, the accuracy rate was 92.1% (35/38) in evaluating perigastric lymph node metastasis, and 71.4% (5/7), 62.5% (5/8), 81.82% (9/11), 75% (6/8), 25% (1/4) and 68.42% (26/38) in preoperatively evaluating stages N0-N3b and N gastric cancer, respectively.

CONCLUSION: Preoperative 64-slice spiral CT triple-phase enhanced scanning is an objective way to assess the distribution of the celiac artery trunk and related tributaries in patients with gastric cancer, and it allows to reliably judge whether there is perigastric lymph node metastasis and can guide intraoperative lymph node dissection and reduce intraoperative injury to the artery.

CT features and quantification of the characteristics of adrenocortical carcinomas on unenhanced and contrast-enhanced studies

AIM

To describe the morphological and contrast-agent washout characteristics of adrenocortical carcinomas (ACCs) on computed tomography (CT).

MATERIALS AND METHODS

Forty-one patients with histopathologically proven ACCs were retrospectively evaluated. The morphological characteristics of the ACCs were documented and compared with surgical and histopathological findings. The percentage of contrast agent enhancement washout (PEW) and relative PEW (RPEW) were calculated for 17 patients who had the combination of unenhanced, portal venous, and 15 min delayed phase images.

RESULTS

Characteristic imaging findings of ACCs included large size (38 of 41 tumours were >6 cm), well-defined margin with a thin enhancing rim (25 patients), and central stellate area of low attenuation on contrast-enhanced CT images (21 patients). Tumour extension into the inferior vena cava (IVC) with associated thrombus was identified on CT in six (14.6%) patients. Of 17 tumours evaluated, 12 (71%) had a PEW value of ≤60%, and 14 (82%) had an RPEW value of ≤40%.

CONCLUSION

Large size, a well-defined margin with a thin enhancing rim, central low attenuation, and a predilection for extension into the IVC are typical morphological characteristics of ACC on CT. The contrast-washout characteristics of ACCs, in concordance with their malignant nature, share those of non-adenomas rather than adenomas.

Double contrast-enhanced ultrasonography evaluation of preoperative Lauren classification of advanced gastric carcinoma

INTRODUCTION

The clinical value of double contrast-enhanced ultrasonography (DCUS) in determining the Lauren classification of advanced gastric carcinoma needed investigation.

MATERIAL AND METHODS

Fifty-eight patients with gastric cancer proved by endoscopic biopsy underwent preoperative DCUS examination in which an oral contrast agent was combined with an intravenous agent, and the findings were compared with the postoperative pathological findings using haematoxylin-eosin and Alcian Blue-Periodic Acid Schiff (AB-PAS) staining.

RESULTS

Of 58 patients, 34 (59%) were the intestinal type and 24 (41%) the diffuse type on pathological examination of resected specimens. Among intestinal type patients, 30 (88%) showed homogeneous vascular enhancement and 4 (12%) heterogeneous enhancement with the "sandwich" pattern in 2 patients (50%) and "barrier" pattern in 2 patients (50%). In the diffuse type, 22 of 24 patients (92%) enhanced heterogeneously, with stippled and peripheral enhancement in 9 (41%), the "sandwich" pattern in 8 (36%) and "barrier" pattern in 5 (23%). Two of 24 patients (8%) with the diffuse type enhanced homogeneously. The proportion of heterogeneous enhancement was significantly different between the 2 subtypes of tumour (p = 0.0001). The sensitivity and specificity of heterogeneous enhancement in diagnosing the diffuse type of advanced gastric cancer were 92% and 88%, respectively. Youden's index was 0.8.

CONCLUSIONS

Double contrast-enhanced ultrasonography is a new and useful method to determine Lauren classification in patients with gastric carcinoma.

Hypervascular gastric masses: CT findings and clinical correlates

OBJECTIVE

This article focuses on masses that are hypervascular on IV contrast-enhanced CT.

CONCLUSION

The rising use of dual-phase IV contrast-enhanced CT will result in an increase in incidental detection of hypervascular gastric masses. Radiologists must be aware of the range of abnormalities that may appear as a hyperenhancing gastric mass because the differential diagnosis includes both benign and malignant lesions.

Diagnostic performance of 64-channel multidetector CT in the evaluation of gastric cancer: differentiation of mucosal cancer (T1a) from submucosal involvement (T1b and T2)

PURPOSE

To identify the computed tomographic (CT) findings in T1a and T1b cancers and to evaluate the diagnostic performance of multidetector CT with two-dimensional multiplanar reconstruction and three-dimensional CT gastrography for evaluating the preoperative staging of gastric cancer, with special emphasis on the differentiation between T1a and T1b cancers.

MATERIALS AND METHODS

The institutional review board approved this retrospective study. A total of 148 patients with gastric cancer (64 T1a, 36 T1b, and 48 T2) were included. To identify CT findings in T1a and T1b cancers, two radiologists in consensus interpreted the preoperative CT images of the 100 T1 cancers to determine the morphologic characteristics to be used as staging criteria on CT images. By using univariate and multiple logistic regression analyses, the diagnostic criteria to identify T1a and T1b cancers were developed. To evaluate the diagnostic performance of multidetector CT by using the criteria, two other blinded reviewers independently analyzed the CT images of all 148 patients to assess the T (classifying the depth of invasion as T1a, T1b, or T2) and N (classifying nodal involvement as absent or present) stage. CT staging was correlated with histopathologic results. Interobserver agreement was assessed by using weighted kappa statistics.

RESULTS

The detectability of T1b cancer was significantly higher than that of T1a cancer (P = .003). T1b cancer showed well-enhancing mucosal thickening more frequently than did T1a cancer (P = .002). By using the modified CT criteria, the overall accuracy values of T staging and N staging were 64.9% (96/148) and 79.1% (117/148) for reviewer 1 and 63.5% (94/148) and 83.8% (124/148) for reviewer 2, respectively. Weighted kappa values of T and N staging were 0.795 and 0.641, respectively.

CONCLUSION

On multidetector CT images, T1a cancer shows different imaging features than does T1b cancer regarding enhancing characteristics and detectability. Multidetector CT provides relatively valuable results of T and N staging, including differentiation between T1a, T1b, and T2 gastric cancers.

Gastric Adenocarcinoma: Is Computed Tomography (CT) Useful in Preoperative Staging?

BACKGROUND AND PURPOSE

Although multiple studies testing the accuracy of CT in the preoperative staging of gastric adenocarcinoma have been carried out, their results are controversial. Whilst some authors claim that CT is an accurate method for preoperatively staging gastric cancer, others have advocated the contrary. Because of this discrepancy we have retrospectively reviewed preoperative CT findings compared with histopathological results in patients with gastric adenocarcinoma.

PATIENTS AND METHODS

Seventy-two patients diagnosed with gastric cancer who underwent potentially curative surgery and preoperative staging CT of quality were included in the study. The size, gastric wall thickening, presence of lymphadenopathy, adjacent organ invasion and location of the gastric mass was recorded. Early tumors (T1 and T2) and more advanced tumors (T3 and T4) were grouped together. CT staging was correlated with the final histopathological stage (TNM). The global results were expressed as sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).

RESULTS

Seventy-two cases were included with fifty-five being male and a median age of 67 years (range 33-91). CT correctly identified the location of the tumor in 56 (53% antropyloric, 18% subcardial). Median time from CT scan to surgery was fourteen days (range 2-49). In T detection: T1/T2 and T3/T4 with sensitivity of 70% and 61%. Lymph node involvement: Sensitivity 49%. Overstaged in 47% Understaged in 75%. Specificity of 53%. Nine patients with colon-mesocolon (5 patients) and pancreas (4 patients) invasion. Sensitivity 44% and specificity 96%.

CONCLUSION

Spiral CT is not an accurate method in predicting preoperative stages in gastric cancer.