Preoperative clinical and contrasted-enhanced CT features to predict perineural invasion in gallbladder carcinoma: focus on clinical T3-4 stage

PURPOSE

To investigate the utility of combining clinical and contrasted-enhanced tomography (CECT) parameters for the preoperative evaluation of perineural invasion (PNI) in gallbladder carcinoma (GBC).

METHODS

A total of 134 patients with GBC (male/female, 52/82; age, 64.4 ± 9.7 years) were divided into PNI-positive (n = 63) and PNI-negative groups (n = 71). Clinical characteristics (demographic information, liver function indicators and tumor markers) and CECT parameters (tumor type, tumor size, gallbladder stone, invasion of gallbladder neck/cystic duct, clinical T stage and N stage) were collected and compared between two groups. Binary logistic regression analysis, receiver operating characteristic curves analyses and Delong test were used in further statistical analyses in clinical T3-4 stage (cT3-4) GBC patients. Overall survival (OS) rates after surgery were compared between PNI-negative group and PNI-positive group of cT3-4 GBC patients.

RESULTS

The majority of GBC patients with PNI were classified as cT3-4 (61/63, 96.8%), while only 3.2% (2/63) of PNI-positive cases were identified at cT1-2. Among cT3-4 GBC, OS was significantly lower in the PNI-positive group than the PNI-negative group after surgery (HR,1.661; 95% CI, 1.044-2.643; P = 0.032). Gender and gallbladder neck/cystic duct invasion were independent predictive factors for cT3-4 GBC patients with PNI. A combination of gender and gallbladder neck/cystic duct invasion showed the best diagnostic performance than that of individual parameters (all P < 0.05).

CONCLUSIONS

Preoperative T staging using CECT enables the initial assessment of PNI status in GBC patients. A combination of gender and gallbladder neck/cystic duct invasion may effectively predict PNI in GBC, particularly in cT3-4 GBC.

Comparison Between Contrast-Enhanced Computed Tomography and Contrast-Enhanced Magnetic Resonance Imaging With Magnetic Resonance Cholangiopancreatography for Resectability Assessment in Extrahepatic Cholangiocarcinoma

OBJECTIVE

To compare the diagnostic performance and interobserver agreement between contrast-enhanced computed tomography (CECT) and contrast-enhanced magnetic resonance imaging (CE-MRI) with magnetic resonance cholangiopancreatography (MRCP) for evaluating the resectability in patients with extrahepatic cholangiocarcinoma (eCCA).

MATERIALS AND METHODS

This retrospective study included treatment-naïve patients with pathologically confirmed eCCA, who underwent both CECT and CE-MRI with MRCP using extracellular contrast media between January 2015 and December 2020. Among the 214 patients (146 males; mean age ± standard deviation, 68 ± 9 years) included, 121 (56.5%) had perihilar cholangiocarcinoma. R0 resection was achieved in 108 of the 153 (70.6%) patients who underwent curative-intent surgery. Four fellowship-trained radiologists independently reviewed the findings of both CECT and CE-MRI with MRCP to assess the local tumor extent and distant metastasis for determining resectability. The pooled area under the receiver operating characteristic curve (AUC), sensitivity, and specificity of CECT and CE-MRI with MRCP were compared using clinical, surgical, and pathological findings as reference standards. The interobserver agreement of resectability was evaluated using Fleiss kappa (κ).

RESULTS

No significant differences were observed between CECT and CE-MRI with MRCP in the pooled AUC (0.753 vs. 0.767), sensitivity (84.7% [366/432] vs. 90.3% [390/432]), and specificity (52.6% [223/424] vs. 51.4% [218/424]) (P > 0.05 for all). The AUC for determining resectability was higher when CECT and CE-MRI with MRCP were reviewed together than when CECT was reviewed alone in patients with discrepancies between the imaging modalities or with indeterminate resectability (0.798 [0.754-0.841] vs. 0.753 [0.697-0.808], P = 0.014). The interobserver agreement for overall resectability was fair for both CECT (κ = 0.323) and CE-MRI with MRCP (κ = 0.320), without a significant difference (P = 0.884).

CONCLUSION

CECT and CE-MRI with MRCP showed no significant differences in the diagnostic performance and interobserver agreement in determining the resectability in patients with eCCA.

Perineural Invasion and Spread in Common Abdominopelvic Diseases: Imaging Diagnosis and Clinical Significance

Malignancies and other diseases may spread by multiple pathways, including direct extension, hematogenous spread, or via lymphatic vessels. A less-well-understood route is the peripheral nervous system, which is known as perineural spread (PNS). In addition to accounting for pain and other neurologic symptoms, PNS affects both disease prognosis and management. Although PNS is commonly discussed in relation to head and neck tumors, there is emerging data regarding PNS in abdominopelvic malignancies and other conditions such as endometriosis. Due to improved contrast and spatial resolution, perineural invasion, a finding heretofore diagnosed only at pathologic examination, can be detected at CT, MRI, and PET/CT. PNS most commonly manifests as abnormal soft-tissue attenuation extending along neural structures, and diagnosis of it is aided by optimizing imaging parameters, understanding pertinent anatomy, and becoming familiar with the typical neural pathways of spread that largely depend on the disease type and location. In the abdomen, the celiac plexus is a central structure that innervates the major abdominal organs and is the principal route of PNS in patients with pancreatic and biliary carcinomas. In the pelvis, the lumbosacral plexus and inferior hypogastric plexus are the central structures and principal routes of PNS in patients with pelvic malignancies. Although the imaging findings of PNS may be subtle, a radiologic diagnosis can have a substantial effect on patient care. Knowledge of anatomy and known routes of PNS and optimizing imaging parameters is of utmost importance in providing key information for prognosis and treatment planning. © RSNA, 2023 Supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

Association of CT Findings With Perineural Invasion in Gallbladder Cancer: Preliminary Assessment

Perineural invasion (PNI) indicates a worse prognosis for patients with gallbladder cancer (GBC). This preliminary retrospective study included 19 patients with GBC who under-went contrast-enhanced CT in the 4 weeks before undergoing surgical resection. GBC showed PNI on pathologic assessment in eight of 19 patients. On CT, wall thickening morphology had sensitivity of 75.0% and specificity of 81.8% for PNI; soft-tissue stranding around the celiac plexus had sensitivity of 62.5% and specificity of 100.0% for PNI.

CT-Based Radiomics Analysis for Noninvasive Prediction of Perineural Invasion of Perihilar Cholangiocarcinoma

Purpose

The study aimed to construct and evaluate a CT-Based radiomics model for noninvasive detecting perineural invasion (PNI) of perihilar cholangiocarcinoma (pCCA) preoperatively.

Materials and Methods

From February 2012 to October 2021, a total of 161 patients with pCCA who underwent resection were retrospectively enrolled in this study. Patients were allocated into the training cohort and the validation cohort according to the diagnostic time. Venous phase images of contrast-enhanced CT were used for radiomics analysis. The intraclass correlation efficient (ICC), the correlation analysis, and the least absolute shrinkage and selection operator (LASSO) regression were applied to select radiomics features and built radiomics signature. Logistic regression analyses were performed to establish a clinical model, a radiomics model, and a combined model. The performance of the predictive models was measured by area under the receiver operating characteristic curve (AUC), and pairwise ROC comparisons between models were tested using the Delong method. Finally, the model with the best performance was presented as a nomogram, and its calibration and clinical usefulness were assessed.

Results

Finally, 15 radiomics features were selected to build a radiomics signature, and three models were developed through logistic regression. In the training cohort, the combined model showed a higher predictive capability (AUC = 0.950) than the radiomics model and the clinical model (AUC: radiomics = 0.914, clinical = 0.756). However, in the validation cohort, the AUC of the radiomics model (AUC = 0.885) was significantly higher than the other two models (AUC: combined = 0.791, clinical = 0.567). After comprehensive consideration, the radiomics model was chosen to develop the nomogram. The calibration curve and decision curve analysis (DCA) suggested that the nomogram had a good consistency and clinical utility.

Conclusion

We developed a CT-based radiomics model with good performance to noninvasively predict PNI of pCCA preoperatively.

Preliminary study of perineural invasion in patients with hilar cholangiocarcinoma by computed tomography imaging

OBJECTIVES

To explore the characteristics of hepatic plexuses and celiac ganglia, and their relationships with hilar cholangiocarcinoma (HCCA) perineural invasion (PNI) by computed tomography (CT) imaging preliminarily.

MATERIALS AND METHODS

Sixty-five HCCA patients (55 with PNI) between December 2014 and February 2019 were included in this retrospective study. The CT values of hepatic plexuses in Region 1 (the fat tissue around proper hepatic artery), in Region 2 (the fat tissue around common hepatic artery), and in Region 3 (the fat tissue around celiac trunk), and the CT values and diameters of celiac ganglia were measured on the preoperative CT images. Mann-Whitney U test was used to compare the measurements between PNI group and Non-PNI group. ROC curve was performed to analyze the sensitivity, specificity and optimal threshold of the measurements in discriminating HCCA PNI.

RESULTS

The CT values of hepatic plexuses in PNI group were significantly higher than those in Non-PNI group (all P < 0.05). The CT values of right celiac ganglia were significantly higher in PNI group than those in Non-PNI group (P = 0.007). There were no significant differences between two groups in other measurements (all P > 0.05). The CT values of hepatic plexuses in Region 1 showed the highest sensitivity (90.9%) and the CT values of right celiac ganglia demonstrated the highest specificity (80.0%).

CONCLUSIONS

The increases of CT values of hepatic plexuses around proper hepatic artery may be used as an indicator of PNI in patients with HCCA and may facilitate treatment planning in considering its early recurrence after surgery and poor prognosis.

Respiratory- and cardiac-triggered three-dimensional sheath inked rapid acquisition with refocused echoes imaging (SHINKEI) of the abdomen for magnetic resonance neurography of the celiac plexus

The visualisation of the celiac plexus using respiratory- and cardiac-triggered three-dimensional (3D) sheath inked rapid acquisition with refocused echoes imaging (SHINKEI) was evaluated. After ethical approval and written informed consent, eight volunteers (age 27 ± 5 years, mean ± standard deviation) were scanned at 1.5 and 3 T. Displacement of the celiac ganglia due to aortic pulsatility was studied on axial single-slice breath-hold balanced turbo field-echo cine sequences in five volunteers and found to be 3.0 ± 0.5 mm (left) and 3.1 ± 0.4 mm (right). Respiratory- and cardiac-triggered 3D SHINKEI images were compared to respiratory- and cardiac-triggered fat-suppressed 3D T2-weighted turbo spin-echo and respiratory-triggered 3D SHINKEI in all volunteers. Visibility of the celiac ganglia was rated by three radiologists as visible or non-visible. On 3D SHINKEI with double-triggering at 1.5 T, the left and right ganglia were seen by all observers in 7/8 and 8/8 volunteers, respectively. At 3 T, this was the case for 6/8 and 7/8 volunteers, respectively. The nerve-to-muscle signal ratio increased from 1.9 ± 0.5 on fat-suppressed 3D T2-weighted turbo spin-echo to 4.7 ± 0.8 with 3D SHINKEI. Anatomical validation was performed in a human cadaver. An expert in anatomy confirmed that the hyperintense structure visible on ex vivo 3D SHINKEI scans was the celiac plexus. In conclusion, double-triggering allowed visualisation of the celiac plexus using 3D SHINKEI at both 1.5 T and 3 T.

Differentiating Nutrient Artery Canals of the Femur versus Fracture Lines in Patients with Total Hip Arthroplasty on Plain Radiographs

BACKGROUND

Nutrient artery canals of the femur are often visible on plain radiographs as radiolucent lines which may mimic fracture lines. The purpose of this study was to distinguish nutrient artery canals from fracture lines on plain radiographs.

MATERIALS AND METHODS

Ninety-three patients (102 hips) with an average age of 65.6 years were included in the study. We retrospectively analyzed nutrient artery canals of the femur on pre and postoperative anteroposterior (AP) and cross-table lateral (CTL) hip radiographs in patients with cementless total hip arthroplasty. The shape, number, location, direction of obliquity, length of nutrient artery canal, and the distance between the tip of the greater trochanter and the proximal end of the nutrient artery canal were measured.

RESULTS

Nutrient artery canals were determined in 54 hips (53.0%) on preoperative radiographs. The numbers of nutrient artery canals were entirely found to be one for each hip. The nutrient artery canals of the femur were the most frequently seen in the cortex on CTL radiographs with 32 hips (31.4%), whereas nutrient artery canals were not seen at all in the cortex on AP radiographs. All nutrient artery canals in the cortex on CTL radiographs coursed upward obliquely. Comparing to fracture lines, nutrient artery canals show less radiolucency, smaller diameter, and blunted ends in both the cortex and medullary cavity, show sclerotic walls in the cortex and have the less straight course in the medullary cavity.

CONCLUSIONS

Based on the results of this study, there are clearly distinguishable differences between nutrient artery canals of the femur and fracture lines on plain radiographs.