Acta Radiologica

It is clinically necessary to validate a new non-invasive and reliable imaging method to detect early chronic pancreatitis. Intravoxel incoherent motion magnetic resonance imaging (MRI) is useful for quantitative assessment in abdominal solid organs.

To investigate the usefulness of intravoxel incoherent motion MRI parameters in the diagnosis of chronic pancreatitis.

Sixty patients with early chronic pancreatitis (n = 44) and chronic pancreatitis (n = 16) were assessed with intravoxel incoherent motion imaging. For comparison, a control group of 71 individuals without chronic pancreatitis was also enrolled. The perfusion fraction (f), pseudo-diffusion coefficient (D*), true diffusion coefficient (D), and apparent diffusion coefficient of pancreatic parenchyma were calculated. These measurements were compared between the three groups. The diagnostic accuracy of imaging parameters was assessed.

The f values of the early chronic pancreatitis group and the chronic pancreatitis group were significantly lower than those of the control group (P < 0.001 and P < 0.001, respectively). The D* value of the chronic pancreatitis group was significantly lower than that of the early chronic pancreatitis group (P = 0.0025). The D values of the early chronic pancreatitis group and the chronic pancreatitis group were significantly higher than those of the control group (P = 0.001 and P = 0.001, respectively). The perfusion fraction showed the highest diagnostic performance with an Az value of 0.76 for discriminating the control group from the early chronic pancreatitis and chronic pancreatitis groups.

Intravoxel incoherent motion MRI parameters may reflect the minimal histological changes in early chronic pancreatitis.

Staging of rectal cancer with MRI has major impact on treatment choice and may be of importance in new cancer management strategies such as “wait-and-see” policy.

To assess the reproducibility of a software package recently developed at our department to measure volumes, apparent diffusion coefficient, and the skewness of apparent diffusion coefficient in lymph nodes and tumors in rectal cancer patients before and after chemoradiation treatment.

This study included 20 consecutive patients with biopsy-verified rectal cancer, in whom MRI staging had been performed both before and after chemoradiation treatment. The diffusion-weighted images were transferred to the software. The volume, apparent diffusion coefficient, and skewness were determined for 93 lymph nodes and 40 tumors. The volumes were compared with manual measurements of the volume of the same lymph nodes and tumors.

The agreement in semi-automatic measurements of lymph nodes was very good (ICC = 0.99), and in tumors good (ICC = 0.88). The agreement in manual measurements of lymph nodes was very good (ICC = 0.95) when all lymph nodes were included, but low (ICC = 0.52) if three outliers were excluded. Bland–Altman plots showed clear agreement between manual and semi-automatic measurements in the lymph nodes, but not in measurements of tumors. The values of apparent diffusion coefficient and skewness in tumors differed before and after treatment but did not differ in lymph nodes as a group.

The software package showed a high degree of reproducibility in measurements on lymph nodes but requires further development to improve the reproducibility of tumor measurements.

Hypovascular pancreatic neuroendocrine tumor is usually misdiagnosed as pancreatic ductal adenocarcinoma.

To investigate the value of texture analysis in differentiating hypovascular pancreatic neuroendocrine tumors from pancreatic ductal adenocarcinoma on contrast-enhanced computed tomography (CT) images.

Twenty-one patients with hypovascular pancreatic neuroendocrine tumors and 63 patients with pancreatic ductal adenocarcinomas were included in this study. All patients underwent preoperative unenhanced and dynamic contrast-enhanced CT examinations. Two radiologists independently and manually contoured the region of interest of each lesion using texture analysis software on pancreatic parenchymal and portal phase CT images. Multivariate logistic regression analysis was performed to identify significant features to differentiate hypovascular pancreatic neuroendocrine tumors from pancreatic ductal adenocarcinomas. Receiver operating characteristic curve analysis was performed to ascertain diagnostic ability.

The following CT texture features were obtained to differentiate hypovascular pancreatic neuroendocrine tumors from pancreatic ductal adenocarcinomas: RMS (root mean square) (odds ratio [OR] = 0.50, P<0.001), Quantile50 (OR = 1.83, P<0.001), and sumAverage (OR = 0.92, P=0.007) in parenchymal images and “contrast” in portal phase images (OR = 6.08, P<0.001). The areas under the curves were 0.76 for RMS (sensitivity = 0.75, specificity = 0.67), 0.73 for Quantile50 (sensitivity = 0.60, specificity = 0.77), 0.70 for sumAverage (sensitivity = 0.65, specificity = 0.82), 0.85 for the combined texture features (sensitivity = 0.77, specificity = 0.85).

CT texture analysis may be helpful to differentiate hypovascular pancreatic neuroendocrine tumors from pancreatic ductal adenocarcinomas. The three combined texture features showed acceptable diagnostic performance.

Analysis of morphometric details of aortic coarctation and collateral circulation using computed tomography (CT) and its impact on clinical symptoms is a perspective which is missing in the published literature.

To perform CT-based qualitative and quantitative evaluation of aortic coarctation and collateral circulation with reference to clinical symptoms.

The study comprised 2022 patients who underwent CT angiography. If aortic coarctation was seen, the patients underwent evaluation of its anatomy and associated clinical symptoms.

Aortic coarctation was found in 33 patients. Follow-up (median 2476 days; range 1692–3543) was performed in 31 (94%) individuals. In this group (median age 42 years; range 30–52.5 years), median stenosis at the site of coarctation was 70% (range 58–85%) of the lumen area, with 17 (55%) patients presenting with significant (≥70%) stenosis. Patients with significant stenosis had a greater right and left internal mammary artery diameter (P = 0.0070 and P = 0.0114, respectively) than those with mild stenosis. Patients with significant coarctation stenosis revealed hypertension and headache more commonly than those with mild stenosis (17 vs. 9, P = 0.01 and 10 vs. 2, P = 0.02), respectively. In patients who underwent intervention, a decrease in prevalence of hypertension (19 vs. 0, P = 0.008) and headache (12 vs. 3, P = 0.010) were observed in the follow-up.

CT enables quantitative and qualitative evaluation of aortic coarctation anatomy, including stenosis at the site of coarctation, and collateral circulation. In adult patients with aortic coarctation, the prevalence of hypertension and headache is related to the degree of stenosis at the site of coarctation and decreases after intervention.

Bifurcated self-expanding metallic stents have mainly been primarily used for the treatment of airway disease around the main carina, but few studies have reported the use of small bifurcated stents to treat malignant bronchial fistula or severe stenosis around the upper left carina.

We aimed to determine the safety, feasibility, and efficacy of small metallic bifurcated stent placement in the upper left carina.

Twenty-two patients with malignant bronchial disease were treated with small bifurcated stents. All bifurcated stents were custom-designed according to the measurement of CT measurements and placed under local anesthesia with fluoroscopic guidance. Clinical outcomes and CT imaging data were retrospectively analyzed.

A total of 27 stents were used in 22 patients, with two stents removed immediately after placement due to stent insufficient dilation and failure of sealing fistula. Twenty patients underwent successful treatment, with a technical success of 90.9%. Thirteen complications were found in 9 (40.9%) patients. Five patients underwent successful stent removal due to failure of sealing fistula (n = 2) or because they were effectively cured (n = 3) during the follow-up period. Ten patients died of cancer, one patient died of chronic renal failure, and one died of myocardial infarction. The one-, three-, and five-year survival rates were 48.0%, 40.0%, and 32.0%, respectively. The median survival was 12.7 months.

Small bifurcated self-expanding metallic stents are a safe and effective treatment option for malignant bronchial fistula or severe stenosis around the upper left carina, but complications are relatively high. Further prospective studies are needed to evaluate alternative treatment options.

Although several studies have examined the value of thyroid nodule size as a malignancy predictor, the results are conflicting.

To investigate the relationship between nodule size and malignancy risk and to evaluate the impact of nodule size on the false-negative rate of fine needle aspiration or core needle biopsy according to the histological type of thyroid cancer.

From January 2013 to December 2013, 3970 thyroid nodules that underwent ultrasound-guided fine needle aspiration or core needle biopsy were retrospectively reviewed. We assessed the relationship between nodule size and malignancy risk according to histological type of thyroid cancer. In addition, we compared the false-negative rate by thyroid nodule size category.

Of 3970 thyroid nodules, 1170 nodules were malignant. For papillary thyroid carcinoma, nodule size was inversely related to malignancy risk, whereas in nodules of follicular carcinoma and follicular variant papillary thyroid carcinoma, nodule size was positively related to malignancy risk (P < 0.001). The false-negative rate tended to increase as nodule size increased (P = 0.002) for all nodules and the overall false-negative rate was 2.3%.

Overall, nodule size does not correlate with risk of malignancy, but the relationship between nodule size and malignancy risk depends on the histological type of thyroid cancer.

Preoperative accurate characterization of parotid gland tumors in different histologic types is crucial. T2 mapping has been proven to be useful for improving the accuracy of tumor characterization.

To evaluate the ability of T2 mapping imaging in the characterization of parotid gland tumors.

T2 mapping imaging was scanned in 74 patients (56 benign, 18 malignant) with pathologically confirmed parotid gland tumors. Mean T2 relaxation time was calculated and compared between benign and malignant group, and among malignant tumors, Warthin’s tumors, and pleomorphic adenomas. Independent-samples t test, one-way analysis of variance test, and receiver operating characteristic curve analyses were used for statistical analyses.

The malignant group showed significantly lower T2 relaxation times than the benign group (P = 0.001). Using a relaxation time of 91.5 ms as the cut-off value, optimal diagnostic performance could be achieved (area under the curve [AUC] 0.679, sensitivity 46.4%, specificity 94.4%). Pleomorphic adenomas showed significantly higher T2 relaxation times than malignant tumors (P = 0.003) and Warthin’s tumors (P = 0.001). However, no significant difference was found on the T2 relaxation times between Warthin’s tumors and malignant tumors (P = 0.435). Optimal diagnostic performance could be achieved (AUC 0.783, sensitivity 58.1%, specificity 94.4%), when setting a T2 value of 92.0 ms as the threshold value for differentiating pleomorphic adenomas from malignant tumors. Meanwhile, optimal AUC, sensitivity, and specificity were 0.892, 87.1%, and 83.3%, respectively, when setting a T2 value of 80.5 ms as the threshold value for differentiating pleomorphic adenomas from Warthin’s tumors.

T2 mapping imaging could serve as an incremental imaging biomarker for characterizing parotid gland tumors.

In clinical practice, we have often observed contrast material spreading into the epidural space during lumbar facet joint injection. However, the exact incidence of epidural spread and contrast pattern have not been reported.

To evaluate the incidence and pattern of epidural spread in lumbar facet joint injection.

One hundred consecutive patients (38 men, 62 women; mean age 68 years; age range 20–88 years) who underwent lumbar facet joint injection at two sites between April 2014 and June 2014 were investigated in this prospective study. Initial oblique, final anteroposterior, and lateral fluoroscopic images were obtained and evaluated for the presence of epidural spread and its contrast pattern (based on direction and extent) with the consensus of three radiologists. The relationship between epidural spread and its potential predictors was analyzed using the chi-squared test, Fisher’s exact test, and the t-test.

The incidence of epidural spread during lumbar facet joint injection was 64.6% (n=64) in 99 patients and 49.5% (n=95) in 192 procedures; ventral spread occurred in 29.2% and foraminal spread in 18.8%. When epidural spread occurred, the most commonly identified distributions were unilateral (73.7%), dorsal (92.6%), and cephalad (92.6%). Epidural spread increased significantly in the caudocephalic direction (P < 0.0001), in men (relative risk [RR]=1.478), in the adjacency of posterior fusion level (RR=1.545), in patients with spondylolisthesis (RR=1.454), and when there was no other leakage (RR=0.334).

Epidural spread occurred at about half the number of lumbar facet joint injections and showed a contrast pattern similar to that seen with the interlaminar approach.

Articular cartilage injury and meniscal tear are usually combined with anterior cruciate ligament injury.

We investigated the incidence of cartilage injury and traumatic meniscal tear according to the type of combined anterior cruciate ligament tear (both-bundle versus selective bundle tear).

This retrospective study included 103 patients diagnosed with anterior cruciate ligament tear after knee joint magnetic resonance imaging and who underwent knee joint arthroscopy. Two radiologists evaluated articular cartilage injuries and meniscal tear independently. We used the chi-square test to analyze the association between type of anterior cruciate ligament bundle tear and presence of cartilage or meniscal injury in each reader.

Cartilage injury presented a significantly higher prevalence in both-bundle tear than did selective bundle tear in reader 1 (P = 0.004). In reader 2, both-bundle tear had a tendency for higher risk of cartilage injury, but this was not statistically significant (P = 0.178). In meniscal injury, there was a statistically significant increase in the risk of associated meniscal injury in both-bundle tear versus selective bundle anterior cruciate ligament injury (P = 0.019 and 0.021). The risk of accompanying traumatic meniscal lesion was significantly higher in both-bundle tear (P = 0.036 and 0.018).

The incidence of accompanying meniscal injury, especially traumatic tears, is higher in both-bundle anterior cruciate ligament tear than in selective bundle tear. There was no significant difference in incidence of cartilage injury between both-bundle tear and selective bundle tear, although one of two readers showed a higher incidence in both-bundle tear.

Ankle ultrasound imaging could be an option with higher priority due to its lack of radiation, and cost- and time-effectiveness. However, previous studies regarding anterior tibiofibular ligament and calcaneofibular ligament injuries have shown varied results.

To evaluate the diagnostic performance of ankle ultrasound for anterior tibiofibular ligament and calcaneofibular ligament injuries.

PubMed and EMBASE databases were searched for diagnostic accuracy studies that used ultrasound for diagnosing anterior tibiofibular ligament and calcaneofibular ligament injuries. Bivariate and hierarchical summary receiver operating characteristic modeling were used to evaluate diagnostic performance. Subgroup analysis was performed using studies according to severity of the injury (complete and partial anterior tibiofibular ligament tear). We performed meta-regression analyses for heterogeneity exploration.

Ten articles involving a total of 380 patients were included. For anterior tibiofibular ligament injury, the summary sensitivity, summary specificity, and area under the hierarchical summary receiver operating characteristic curve (AUC) were 0.99, 0.92, and 0.99, respectively. For calcaneofibular ligament injury, the summary sensitivity, summary specificity, and AUC were 0.95, 0.99, and 0.95, respectively. In subgroup analysis, for complete anterior tibiofibular ligament tear, the summary sensitivity, summary specificity, and AUC were 0.96, 0.82, and 0.96, respectively. For partial anterior tibiofibular ligament tear, the summary sensitivity, summary specificity, and AUC were 0.90, 0.82, and 0.93, respectively. Among the various potential covariates, proportion of anterior tibiofibular ligament tear, ultrasound interpreter, and reference standard were associated with specificity heterogeneity.

Ankle ultrasound demonstrates high diagnostic performance in the diagnosis of anterior tibiofibular ligament and calcaneofibular ligament injuries. We recommend ultrasound performed by a musculoskeletal radiologist as a first-line diagnostic tool to diagnose anterior tibiofibular ligament and calcaneofibular ligament injuries.

Hybrid SPECT/CT systems allow the shortening of lead time for investigation of cancer patients, since a complementary CT for radiological characterization of focally increased isotope uptake of unclear origin in bone scintigraphy can be performed simultaneously. The use of low-dose CT (sub-mSv CT) reduces radiation dose compared to standard-dose CT and facilitates the application of complementary CT.

To test the feasibility of sub-mSv CT for the characterization of non-specific findings in the bone scintigraphy of oncological patients.

Nineteen oncological patients with a total of 50 findings of unclear origin on bone scintigraphy which required further correlation with morphologic data were included in the study. Each patient underwent two CT scan series consecutively: one low-dose CT and one standard-dose CT. The CT studies were randomized and each finding was rated by four blinded experienced radiologists. A shift in ratings between standard-dose and low-dose images were assessed using the Stuart–Maxwell chi-squared test. Inter-observer agreement and intra-observer agreement was assessed using Light’s kappa and Cohen’s kappa, respectively.

The mean effective dose of low-dose CT scans was 0.8 mSv compared to 4.2 mSv for the standard-dose CT scans. No statistically significant shift in ratings was observed (P = 0.62). There was no statistically significant difference in the inter-observer agreements: the values for the standard-dose and low-dose groups were 0.68 (95% confidence interval [CI] 0.57–0.79) and 0.60 (95% CI 0.47–0.72), respectively.

These results indicate that sub-mSv CT for characterization of non-specific findings in bone scintigraphy of oncological patients is feasible.

T2 mapping has been proven to be useful in tumor characterization. As to orbital masses, its diagnostic value needs to be investigated.

To evaluate the usefulness of T2 mapping in orbital masses and the ability of T2 relaxation time in differentiating malignant from benign orbital masses.

Forty-seven patients with solid orbital masses (33 benign and 14 malignant) who underwent T2 mapping examination for preoperative assessment were enrolled in the current study. T2 mapping was acquired using 16 TE values (range 12–192 ms; delta TE 12 ms). Mean T2 relaxation time was calculated based on the whole mass region of interest and compared between the malignant and benign groups using the unpaired t-test. Receiver operating characteristic curve analysis was adopted to calculate its diagnostic value.

Malignant orbital masses showed significantly lower T2 relaxation time than benign masses (76.4 ± 13.0 ms vs. 119.1 ± 20.4 ms; P < 0.001). If setting a T2 relaxation time of 89.5 ms as the threshold value, optimal differentiating performance could be achieved (area under the curve 0.936; sensitivity 100.0%; specificity 87.9%; accuracy 91.5%; positive predictive value 77.8%; negative predictive value 100%).

T2 mapping and its derived T2 relaxation time could provide quantitative information and serve as a supplementary imaging marker for differentiating malignant from benign orbital masses.

Myoinvasion and tumor-type determines surgical planning in endometrial carcinoma.

To evaluate whole tumor diffusion tensor imaging histogram texture parameters in evaluating myoinvasion and tumor type in endometrial carcinoma.

Twenty-seven patients with endometrial carcinoma underwent diffusion tensor imaging on a 1.5-T MRI system using echo-planar imaging sequence with 0 and 700 s/mm² b values. Whole tumor histogram parameters were obtained from fractional anisotropy, mean diffusivity maps. Mann–Whitney U test and receiver operating characteristic curve analyses were used

The mean fractional anisotropy of tumors with no myoinvasion was significantly higher than tumors which underwent myoinvasion, suggesting higher anisotropy in tumors which did not invade the myometrium. Voxel-wise heterogeneity in distribution of fractional anisotropy and mean diffusivity was seen in the form of higher uniformity and lower entropy of tumors with superficial <50% myoinvasion versus >50% myoinvasion. Uniformity, entropy, and energy of voxel-wise fractional anisotropy distribution gave an area under the curve of 0.827, 0.821, and 0.796, respectively, in predicting the presence of deep myometrial invasion while energy, entropy, and uniformity of mean diffusivity distribution in tumor gave an area under the curve of 0.84, 0.815, and 0.809 respectively. Tumor type was predicted with an area under the curve of 0.747, 0.759, and 0.765 for the uniformity, energy, and entropy of voxel-wise fractional anisotropy distribution. A logistic regression combining all the important histogram parameters obtained 94% and 88% sensitivity and 88% and 80% specificity in predicting deep myoinvasion and tumor type, respectively.

Diffusion tensor histogram analysis can better characterize endometrial carcinomas and can be used as a quantitative marker of tumor behavior.

Magnetic resonance (MR) has been widely used in predicting the aggressiveness of endometrioid adenocarcinoma. However, the diagnostic value of the MR volume of the lesion has been controversial.

To determine whether the whole-lesion MR volume measurement could be used as a better predictor for evaluating the aggressiveness of endometrioid adenocarcinoma.

In this retrospective study, we include 357 patients with pathologically demonstrated endometrioid adenocarcinoma at our institution between 1 January 2013 and 31 December 2018. Whole-lesion MR volume was calculated on sagittal T2-weighted images with ITK-SNAP software on a personal computer.

According to the receiver operating characteristics curve analysis, whole-lesion MR volume has the competitive advantage in evaluating deep myometrial invasion compared with the frozen results, generating area under the curve (AUC) values of 0.751 vs. 0.834 (P = 0.0629, Z = 1.860). The AUC of tumor maximum diameter, simple tumor volume, and whole-lesion MR volume in predicting deep myometrial invasion was 63.8%, 67.6%, and 75.1%, respectively.

Whole-lesion MR volume is a good diagnostic tool for prediction of deep myometrial invasion, lymph node metastasis, and lymphovascular invasion. MR volumetry could reflect the aggressiveness of endometrioid adenocarcinoma more accurately than traditional lesion measurements.

Whirlpool sign on computed tomography (CT) is pathognomic of adnexal torsion.

To evaluate the visibility and common location of the whirlpool sign in adnexal torsion on CT.

This retrospective study included 143 consecutive patients who underwent preoperative CT imaging and subsequent surgically confirmed as adnexal torsion. Two readers independently recorded the presence and location of whirlpool sign in adnexal torsion on CT. Patients with and without whirlpool sign were compared with regard to the size of the adnexal mass and the degree of torsion.

Whirlpool sign was detected in 60 (42.0%) patients on the transverse CT plane and 79 (55.2%) patients on the coronal CT plane of 143 patients. The sign was significantly better detected on the coronal CT plane than on the transverse CT plane (P = 0.03). The most common location of the sign included the posterolateral aspect of the adnexal mass on the transverse CT plane (25/60, 41.7%, P = 0.04) and the upper-lateral aspect of the adnexal mass on the coronal CT plane (45/79, 60.0%, P < 0.001). The size of the adnexal mass with whirlpool sign was significantly larger than the mass without whirlpool sign on the transverse CT plane (median 9.6 vs. 8.6 cm, P = 0.03). No significant difference in the degree of torsion was found between patients with and without whirlpool sign on CT (P = 0.56–0.62).

Whirlpool sign of adnexal torsion is well detected at the upper-lateral aspect of adnexal mass on the coronal CT plane.