Preoperative diagnosis of metastatic lymph nodes by CT-histopathologic matching analysis in gastric adenocarcinoma using dual-layer spectral detector CT

OBJECTIVES

There still remain challenges to accurate diagnosis of lymph node (LN) involvement in gastric cancer (GC) on conventional CT. This study evaluated the quantitative data derived from dual-layer spectral detector CT (DLCT) for preoperative diagnosis of metastatic LNs compared to conventional CT images.

METHODS

Patients with adenocarcinoma scheduled for gastrectomy were enrolled in this prospective study from July, 2021, to February, 2022. Regional LNs were labeled on preoperative DLCT. The LNs were located and matched using carbon nanoparticle solution during surgery according to their locations and anatomic landmarks on preoperative images. The matched LNs were randomly split into training and validation cohorts in a ratio of 2:1. The DLCT quantitative parameters in the training cohort were investigated using logistic regression models to identify independent predictors of metastatic LNs, and these predictors were subsequently applied to the validation cohort. Receiver operating characteristic curves were compared between the DLCT parameters and conventional CT images.

RESULTS

Fifty-five patients were included in the study, with 267 successfully matched LNs (90 metastatic, 177 nonmetastatic). Independent predictors included arterial phase CT attenuation on 70-keV images, venous phase electron density, and clustered feature. These combination predictors had areas under the curve (AUC) of 0.855 and 0.907 in the training and validation cohorts, respectively. Compared to conventional CT criteria alone, the model had higher AUC and accuracy (0.741 vs. 0.907, 75.28% vs. 87.64%; p < 0.01) for LN diagnosis.

CONCLUSION

Incorporating DLCT parameters improved preoperative diagnosis of LN metastasis in GC, increasing the accuracy of clinical N stage.

CLINICAL RELEVANCE STATEMENT

Compared to conventional CT criteria, quantitative parameters from dual-layer spectral detector CT showed higher diagnostic efficacy for the preoperative diagnosis of lymph node metastases in gastric cancer, increasing the accuracy of clinical N stage.

KEY POINTS

• Quantitative parameters from dual-layer spectral detector CT are useful for the preoperative diagnosis of lymph node metastases in gastric adenocarcinoma, increasing the accuracy of clinical N stage. • The values for metastatic lymph nodes are higher than those of nonmetastatic ones. The arterial phase of CT attenuation on 70-keV images, venous phase of electron density, and clustered feature independently predicted lymph node metastases. • Prediction model had area under the curve of 0.907, sensitivity of 81.82%, specificity of 91.07%, and accuracy of 87.64% for the preoperative diagnosis of lymph node metastasis.

Inguinal lymphadenopathy as a predicting factor for ipsilateral primary limb amputation after a successful endovascular treatment

PURPOSE

To assess the correlation between inguinal lymph node characteristics and ipsilateral limb amputation rates in patients with ischemic foot ulcers after a successful endovascular treatment.

METHOD

A retrospective review of patients who were endovascularly treated for ischemic foot ulcers between January 2015 and May 2017. Technical success was defined as arterial recanalization with stenosis less than 30 % and ankle brachial index improvement by > 0.2 after 24 h. Unilateral lymph node size, contrast enhancement, necrosis, and perinodular fat stranding were assessed on pre-procedural CTA. Primary endpoints were amputation and sepsis within 12 months following treatment. The relationship between lymph node characteristics and limb amputation and septic shock were examined.

RESULTS

Endovascular treatment of 202 limbs in 202 patients (135 males; median age 72.8 years [42.2-93.7]) was technically successful. Forty-two (20.8 %) patients underwent amputation, six (3 %) patients had septic shock. There was a significant difference in lymph node sizes between the amputated and the non-amputated limbs (P = 0.000). Lymph node characteristics (size, enhancement, necrosis, and perinodular fat stranding) were significantly related to amputation (P < 0.001). Patients with perinodular fat stranding or increased node size were 5.940 and 1.109 times more likely to undergo limb amputation, respectively. Lymph node characteristics were also significantly related to septic shock (P < 0.05).

CONCLUSIONS

Certain lymph node characteristics are associated with amputation in patients with ischemic foot ulcers, after a technically successful endovascular treatment of the limb. Large lymph node size and perinodular fat stranding are predictive of limb amputation.

Feasibility of using two-dimensional axial computed tomography in pretreatment decision making for patients with early gastric cancer

Computed tomography (CT) is widely used in the pretreatment period of early gastric cancer (EGC). Only few studies have reported low accuracy of CT imaging for T and N staging in patients with EGC. However, owing to the limited number of studies, the value of CT imaging for EGC staging is not well known. Thus, we conducted a retrospective cross-sectional study regarding the associations among submucosal invasion, lymph node metastasis, and CT findings.The medical records of patients with EGC who had surgery or endoscopic resection were reviewed in a single center from January 2011 to December 2016. We evaluated the histological type, invasion depth, and lymph node (LN) metastasis on the basis of two-dimensional CT findings.We enrolled 1544 patients. Submucosal (SM) invasion was related to tumor size, histological type, and wall thickening or enhancement on CT images. Deep SM invasion (>500 μm) was also related to tumor size, poorly differentiated type, and abnormal CT findings (wall thickening, enhancement, and central depression). Among the patients with LN reactive positivity (0.5-1 cm), those who were female and had a tumor invasion of >1000 μm showed a higher prevalence of LN metastasis. The false-negative LN group had a higher prevalence of large tumors (>3 cm), poor differentiation, and SM invasion than the true-negative group.Wall thickening, enhancement, and central depression on CT images might be related to SM invasion. Patients with any positive CT findings needs more attention when performing ESD.

Intra-Arterial DSA and Duplex-Doppler Ultrasonography in Detection of Vascularized Inguinal Lymp Node

Twenty-three patients with ischemic disease of the legs referred for routine preoperative angiography were examined with intra-arterial DSA and high resolution ultrasonography with duplex-Doppler to detect inguinal lymph nodes. None of the patients had evidence of malignant or lymphomatous disease and only 3 had skin ulceration on the foot. DSA detected nodes in 9 patients (39%). In 3 cases the nodes were highly vascularized. Ultrasonography detected lymph nodes in 16 patients (70%). In all but 2 nodes a high velocity arterial flow was recorded. It is concluded that DSA and particularly duplex-Doppler ultrasonography are sensitive methods to detect vascularized lymph nodes and that such nodes are found in many patients with no evidence of malignancy or infection.

Enhancement characteristics of retroperitoneal lymphomatous lymph nodes

BACKGROUND

Previous studies of CT enhancement of lymphomatous lymph nodes (LLN) of the neck and the mediastinum showed that the LLN had lower enhancement values than normal lymph nodes.

PURPOSE

To elucidate the contrast medium enhancement curves of LLN in the retroperitoneum by comparing the curves of LLN with those of normal lymph nodes, to test whether differences between these curves could be of diagnostic value, and to compare the present enhancement curves of LLN of the retroperitoneum with the curves of LLN of the neck and the mediastinum from previous similar investigations.

MATERIAL AND METHODS

Twenty-eight consecutive patients with LLN of the retroperitoneum (three with Hodgkin's lymphoma [HL]) and 21 control patients with sarcomas and thus presumably normal retroperitoneal nodes underwent dynamic CT examinations. The previous, similar investigation of lymph nodes of the neck comprised 28 patients with LLN and the investigation of mediastinal lymph nodes comprised 24 patients with LLN.

RESULTS

The enhancement curves of the retroperitoneal LLN had significantly lower attenuation than those of the retroperitoneal control nodes. A combination of peak contrast value and time to peak adjusted to total body weight yielded a diagnostic accuracy which at the best showed a sensitivity of 90.5% with a specificity of 82.6%. The LLN of the retroperitoneum had higher attenuation values than corresponding nodes of the mediastinum but no significant difference was found between LLN of the retroperitoneum and LLN of the neck in previous similar investigations.

CONCLUSION

The comparison of enhancement curves of retroperitoneal LLN with retroperitoneal control nodes showed a marked similarity with and substantiates our previous findings in lymph nodes of the neck and of the mediastinum. The best diagnostic accuracy was achieved by combining the parameters peak contrast value and time to peak and adjusting these values to the body weight. Peak enhancement of the retroperitoneal LLN was higher and arrived earlier than that of the mediastinal nodes from the previous investigation.

Gastric cancer staging with dual energy spectral CT imaging

Purpose

To evaluate the clinical utility of dual energy spectral CT (DEsCT) in staging and characterizing gastric cancers.

Materials and Methods

96 patients suspected of gastric cancers underwent dual-phasic scans (arterial phase (AP) and portal venous phase (PP)) with DEsCT mode. Three types of images were reconstructed for analysis: conventional polychromatic images, material-decomposition images, and monochromatic image sets with photon energies from 40 to 140 keV. The polychromatic and monochromatic images were compared in TNM staging. The iodine concentrations in the lesions and lymph nodes were measured on the iodine-based material-decomposition images. These values were further normalized against that in aorta and the normalized iodine concentration (nIC) values were statistically compared. Results were correlated with pathological findings.

Results

The overall accuracies for T, N and M staging were (81.2%, 80.0%, and 98.9%) and (73.9%, 75.0%, and 98.9%) determined with the monochromatic images and the conventional kVp images, respectively. The improvement of the accuracy in N-staging using the keV images was statistically significant (p<0.05). The nIC values between the differentiated and undifferentiated carcinoma and between metastatic and non-metastatic lymph nodes were significantly different both in AP (p = 0.02, respectively) and PP (p = 0.01, respectively). Among metastatic lymph nodes, nIC of the signet-ring cell carcinoma were significantly different from the adenocarcinoma (p = 0.02) and mucinous adenocarcinoma (p = 0.01) in PP.

Conclusion

The monochromatic images obtained with DEsCT may be used to improve the N-staging accuracy. Quantitative iodine concentration measurements may be helpful for differentiating between differentiated and undifferentiated gastric carcinoma, and between metastatic and non-metastatic lymph nodes.

Enhancement characteristics of lymphomatous lymph nodes of the mediastinum

BACKGROUND

Previous studies of CT enhancement of lymphomatous lymph nodes (LLN) of the neck showed that the LLN had lower enhancement values than normal lymph nodes.

PURPOSE

To elucidate the contrast medium enhancement curves of LLN in the mediastinum by comparing the curves of LLN with those of normal lymph nodes, and to compare the present enhancement curves of LLN of the mediastinum with the curves of LLN of the neck from a previous similar investigation.

MATERIAL AND METHODS

Twenty-four consecutive patients with LLN in the mediastinum (9 with Hodgkin's lymphoma [HL]) and 23 control patients with sarcomas and thus presumably normal mediastinal nodes underwent dynamic CT examinations. The previous, similar investigation of lymph nodes of the neck comprised 28 patients with LLN and 20 control patients.

RESULTS

The enhancement curves of the mediastinal LLN had significantly lower values than those of the mediastinal control nodes. The LLN of the mediastinum had lower mean peak contrast values than the corresponding nodes of the neck from a previous investigation.

CONCLUSION

The comparison of enhancement curves of mediastinal LLN with mediastinal control nodes showed a marked similarity with and substantiates our previous findings in lymph nodes of the neck.

Determining gastric cancer resectability by dynamic MDCT

PURPOSE

Multi-detector row CT (MDCT) has been widely used to detect primary lesions and to evaluate TNM staging. In this study we evaluated the accuracy of dynamic MDCT in the preoperative determination of the resectability of gastric cancer.

METHODS

MDCT was used to image 350 cases of gastric cancer diagnosed by biopsy before surgery. MDCT findings regarding TNM staging and resectability were correlated with surgical and pathological findings.

RESULTS

The accuracy of MDCT for staging gastric cancer was high, especially for tumour stage T1 (94.3%), lymph node stage N2 (87.3%), and for predicting distant metastases (>96.6%). When resectability was considered to be the outcome, the total accuracy of MDCT was 87.4%, sensitivity was 89.7% and specificity was 76.7%. Results showed high sensitivity for identifying peritoneal seeding (90.0%) and for predicting liver metastasis (80.0%).

CONCLUSION

Dynamic enhanced MDCT is useful for TNM staging of gastric cancers and for predicting tumour respectability preoperatively.

Preoperative diagnosis of gastric tumors by three-dimensional multidetector row ct and double contrast barium meal study: correlation with surgical and histologic results

BACKGROUND/PURPOSE

Recent three-dimensional multidetector row computed tomography (3D MDCT) can provide detailed images of a gastric tumor, including its general contour, location and depth. We therefore evaluated the efficacy of MDCT in the differential diagnosis and staging of gastric tumors in patients prepared for surgery.

METHODS

Seventy-nine patients with gastric tumors identified by gastric optical endoscopy were admitted for preoperative evaluation. All patients received double-contrast barium meal (DCBM) study and abdominal MDCT with 3D reconstruction before surgery. We compared the accuracy of MDCT with DCBM study in detecting and differentiating gastric tumors. In addition, the MDCT findings were correlated with surgical and pathologic results in gastric cancers for Borrmann type, T and N stages.

RESULTS

Among the 79 patients with gastric tumors, there were 24 cases of early gastric cancer, 40 cases of advanced gastric cancer, 12 cases of gastrointestinal stromal tumor, and three cases of gastric lymphoma. Both MDCT and DCBM were very accurate in picking up the lesions (100%). The diagnostic accuracies of MDCT and DCBM were similar (94% vs. 96%) in differentiating mucosal and submucosal lesions as well as classification of Borrmann type in advanced gastric cancer (70% vs. 63%). In 64 patients with gastric cancers, there was good correlation between MDCT images and pathology in 73% of T staging and 69% of N staging.

CONCLUSION

MDCT has a similar high accuracy in the preoperative diagnosis of different gastric tumors compared with DCBM and provides additional information including tumor depth, lymph node and hepatic metastasis. Therefore, MDCT may be used as a primary tool for preoperative tumor diagnosis and staging.

Comparison of results of computed tomography and radiography with histopathologic findings in tracheobronchial lymph nodes in dogs with primary lung tumors: 14 cases (1999–2002)

OBJECTIVE

To compare results of computed tomography (CT) and radiography with histopathologic findings in tracheobronchial lymph nodes (TBLNs) in dogs with primary lung tumors.

DESIGN

Retrospective case series.

ANIMALS

14 client-owned dogs.

PROCEDURES

Criteria for inclusion were diagnosis of primary lung tumor, use of thoracic radiography and CT, and histologic confirmation of TBLN status. Medical records were reviewed for signalment; history; and physical examination, clinicopathologic, radiographic, CT, surgical, and histopathologic findings.

RESULTS

Tracheobronchial lymphadenopathy was not identified via radiography in any dogs. Tracheobronchial lymphadenopathy was diagnosed in 5 dogs via CT. Six dogs had histologic confirmation of metastasis to TBLNs. Radiographic diagnosis yielded 6 false-negative and no false-positive results for tracheobronchial lymphadenopathy. Computed tomography yielded 1 false-negative and no false-positive results. Sensitivity of CT for correctly assessing TBLN status was 83%, and specificity was 100%. Positive predictive value was 100%, and negative predictive value was 89%. Dogs with lymphadenopathy via CT, histologic confirmation of TBLN metastasis, or primary tumors with a histologic grade > 1 had significantly shorter survival times than their counterparts.

CONCLUSIONS AND CLINICAL RELEVANCE

Results of CT evaluation of TBLN status were in agreement with histopathologic findings and more accurate than use of thoracic radiography for evaluating TBLNs in dogs with primary lung tumors. Computed tomography imaging should be considered as part of the staging process to more accurately assess the TBLNs in dogs with primary lung tumors.

Gastric cancer by multidetector row CT: preoperative staging

The role of computed tomography (CT) in the preoperative staging of gastric cancer, even if controversial, may be fundamental for evaluating the local extent and nodal involvement of the disease, especially in locally advanced cases. However, previous results of CT staging have not been satisfactory for predicting the invasive depth of the tumor or possible nodal metastases. Recently introduced multidetector row CT (MDCT) and three-dimensional (3D) imaging are expected to overcome the limitations in cancer staging by offering rapid and accurate information for space perception, detailed hemodynamics, and real-time 3D processing of volumetric data sets. In particular, virtual endoscopic imaging may be helpful for detecting early gastric cancer. In our experience, T and N stagings of gastric cancer were improved with 3D MDCT when using volume rendering and virtual endoscopic imaging compared with conventional axial two-dimensional (2D) CT (accuracy of T staging with 3D vs. 2D CT images, 84% vs. 77%; accuracy of N staging, 63% vs. 61% with 3D vs. 2D images, respectively). In particular, the detection rate of early gastric cancer was markedly increased up to 96% when using 3D MDCT. Therefore, we believe that 3D MDCT of the stomach may enhance the performance of CT in the preoperative evaluation of patients who have gastric cancer by offering easy early detection of lesions and accurate tumor staging through the 3D imaging process.