Perfusion of hepatocellular carcinomas measured by diffusion-derived vessel density biomarker: Higher hepatocellular carcinoma perfusion than earlier intravoxel incoherent motion reports

Diffusion-derived vessel density (DVDD) is a physiological surrogate of the area of microvessels per unit tissue area. DDVD is calculated according to DDVD(b0b2) = Sb0/ROIarea0 - Sb2/ROIarea2, where Sb0 and Sb2 refer to the liver signal when b is 0 or 2 s/mm2. Pathohistological studies and contrast-enhanced CT/MRI data showed higher blood volume in hepatocellular carcinoma (HCC) relative to native liver tissue. With intravoxel incoherent motion (IVIM) imaging, most authors paradoxically reported a decreased perfusion fraction of HCC relative to the adjacent liver. This study applied DDVD to assess the perfusion of HCC. MRI was performed with a 3.0-T magnet. Diffusion-weighted images with b-values of 0 and 2 s/mm2 were acquired in 72 HCC patients. Thirty-two patients had microvascular invasion (MVI(+)) and 40 patients did not have microvascular invasion (MVI(-)). Fifty-eight patients had Edmondson-Steiner grade I or II HCC, and 14 patients had Edmondson-Steiner grade III or IV HCC. DDVD measurement was conducted on the axial slice that showed the largest HCC size. DDVD(b0b2) T/L = HCC DDVD(b0b2)/liver DDVD(b0b2). DDVD(b0b2) T/L median (95% confidence interval) of all HCCs was 2.942 (2.419-3.522), of MVI(-) HCCs was 2.699 (2.030-3.522), of MVI(+) HCCs was 2.988 (2.423-3.990), of Edmondson-Steiner grade I/II HCCs was 2.873 (2.277-3.465), and of Edmondson-Steiner grade III/IV HCCs was 3.403 (2.008-4.485). DDVD(b0b2) T/L approximately agrees with contrast agent dynamically enhanced CT/MRI literature data, whereas it differs from earlier IVIM study results, where HCC perfusion fraction was paradoxically lower relative to native liver tissue. A weak trend was noted with MIV(+) HCCs had a higher DDVD(b0b2) T/L than that of MVI(-) HCCs, and a weak trend was noted with the poorly differentiated group of HCCs (Edmondson-Steiner grade III and IV) had a higher DDVD(b0b2) T/L than that of the better differentiated group of HCCs (Edmondson-Steiner grade I and II).

Repeatability and reproducibility comparisons of liver IVIM imaging with free-breathing or respiratory-triggered sequences

For liver intravoxel incoherent motion (IVIM) data acquisition, respiratory-triggering (RT) MRI is commonly used, and there are strong motivations to shorten the scan duration. For the same scan duration, more b values or higher numbers of excitations can be allowed for free-breathing (FB) imaging than for RT. We studied whether FB can be used to replace RT when careful IVIM image acquisition and image processing are conducted. MRI data of 22 healthy participants were acquired using a 3.0 T scanner. Diffusion imaging was based on a single-shot spin-echo-type echo-planar sequence and 16 b values of 0, 2, 4, 7, 10, 15, 20, 30, 46, 60, 72, 100, 150, 200, 400, and 600 s/mm2 . Each subject attended two scan sessions with an interval of 10-20 days. For each scan session, a subject was scanned twice, first with RT and then with FB. The mean image acquisition time was 5.4 min for FB and 10.8 min for RT. IVIM parameters were calculated with bi-exponential model segmented fitting with a threshold b value of 60 s/mm2 , and fitting started from b = 2 s/mm2 . There was no statistically significant difference between IVIM parameters measured with FB imaging or RT imaging. Perfusion fraction ICC (intraclass correlation coefficient) for FB imaging and RT imaging in the same scan session was 0.824. For perfusion fraction, wSD (within-subject standard deviation), BA (Bland-Altman) difference, BA 95% limit, and ICC were 0.022, 0.0001, -0.0635~0.0637, and 0.687 for FB and 0.031, 0.0122, -0.0723~0.0967, and 0.611 for RT. For Dslow (×10-3  s/mm2 ), wSD, BA difference, BA 95% limit, and ICC were 0.057, 0.0268, -0.1258~0.1793, and 0.471 for FB and 0.073, -0.0078, -0.2170-0.2014, and <0.4 for RT. The Dfast coefficient of variation was 0.20 for FB imaging and 0.28 for RT imaging. All reproducibility indicators slightly favored FB imaging.

Magnetic Resonance Deep Learning Radiomic Model Based on Distinct Metastatic Vascular Patterns for Evaluating Recurrence-Free Survival in Hepatocellular Carcinoma

BACKGROUND

The metastatic vascular patterns of hepatocellular carcinoma (HCC) are mainly microvascular invasion (MVI) and vessels encapsulating tumor clusters (VETC). However, most existing VETC-related radiological studies still focus on the prediction of VETC status.

PURPOSE

This study aimed to build and compare VETC-MVI related models (clinical, radiomics, and deep learning) associated with recurrence-free survival of HCC patients.

STUDY TYPE

Retrospective.

POPULATION

398 HCC patients (349 male, 49 female; median age 51.7 years, and age range: 22-80 years) who underwent resection from five hospitals in China. The patients were randomly divided into training cohort (n = 358) and test cohort (n = 40).

FIELD STRENGTH/SEQUENCE

3-T, pre-contrast T1-weighted imaging spoiled gradient recalled echo (T1WI SPGR), T2-weighted imaging fast spin echo (T2WI FSE), and contrast enhanced arterial phase (AP), delay phase (DP).

ASSESSMENT

Two radiologists performed the segmentation of HCC on T1WI, T2WI, AP, and DP images, from which radiomic features were extracted. The RFS related clinical characteristics (VETC, MVI, Barcelona stage, tumor maximum diameter, and alpha fetoprotein) and radiomic features were used to build the clinical model, clinical-radiomic (CR) nomogram, deep learning model. The follow-up process was done 1 month after resection, and every 3 months subsequently. The RFS was defined as the date of resection to the date of recurrence confirmed by radiology or the last follow-up. Patients were followed up until December 31, 2022.

STATISTICAL TESTS

Univariate COX regression, least absolute shrinkage and selection operator (LASSO), Kaplan-Meier curves, log-rank test, C-index, and area under the curve (AUC). P < 0.05 was considered statistically significant.

RESULTS

The C-index of deep learning model achieved 0.830 in test cohort compared with CR nomogram (0.731), radiomic signature (0.707), and clinical model (0.702). The average RFS of the overall patients was 26.77 months (range 1-80 months).

DATA CONCLUSION

MR deep learning model based on VETC and MVI provides a potential tool for survival assessment.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 3.

Pelvic Ultrasound in Diagnosing and Evaluating the Efficacy of Gonadotropin-Releasing Hormone Agonist Therapy in Girls With Idiopathic Central Precocious Puberty

Background and Objective: Idiopathic central precocious puberty (ICPP) is characterized by early pubertal changes, the acceleration of growth velocity, and rapid bone maturation that often results in reduced adult height. Gonadotrophin-releasing hormone agonist (GnRHa) is currently considered to be an effective therapeutic agent. At present, GnRH stimulation test is adopted as a gold standard for the diagnosis of ICPP and the efficacy evaluation of GnRHa therapy. However, it is difficult to operate in practice due to the cumbersome procedures and multiple blood samples required. This study was conducted to establish the value of pelvic ultrasound in diagnosing ICPP and evaluating the efficacy of GnRHa therapy.

Materials and Methods: One hundred and twenty-two girls with ICPP (ICPP group) were enrolled in the study. Pelvic ultrasound and levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were examined before and after GnRHa therapy for 3 months. Eighty normal prepubertal girls were enrolled as the control group. The difference in pelvic ultrasound parameters between the ICPP group before GnRHa therapy and the control group was compared by independent-sample t-test, while paired t-test for ICPP group before and after GnRHa therapy. Receiver operating characteristic (ROC) curve was used to explore the optimal pelvic ultrasound parameters for diagnosing ICPP. Pearson correlation analysis was performed between the pelvic ultrasound parameters and serum sexual hormone level.

Results: The pelvic ultrasound parameters (length of the uterine body, anteroposterior diameter of the uterine body, transverse diameter of the uterine body, volume of the uterine body, uterine body-cervix ratio, length of the ovary, transverse diameter of the ovary, anteroposterior diameter of the ovary, volume of the ovary, number of increased follicles and maximum diameter of the follicle) in the ICPP group before GnRHa therapy were significantly larger than those of the control group (P < 0.05). All the above pelvic ultrasound parameters in the ICPP group were significantly decreased after GnRHa therapy compared with those before treatment (P < 0.05). The volume of the uterine body had the largest area under the ROC curve in differentiating between patients with ICCP and the control group. Pelvic ultrasound parameters were significantly correlated with serum sexual hormone levels (P < 0.05).

Conclusion: This study indicates pelvic ultrasound is a simple and reliable tool to diagnose ICPP and evaluates the efficacy of GnRHa therapy by dynamically observing the morphology of internal genitalia. The volume of uterine body was the best ultrasound parameter to distinguish patients with ICPP from normal girls.

[Radiographic and masticatory physiologic evaluation after conservative treatment of condylar fractures in children and adolescents]

OBJECTIVE

To evaluate the developmental and functional outcome of condylar fractures in children and adolescents after conservative treatment.

METHODS

Eight children and adolescents with unilateral condylar fracture, aged 5-13 were included. A removable occlusal splint, the thickness of which was determined according to the age, the developmental stage of the dentition, the level of the fracture and the degree of dislocation, worn for 1-3 months, and the patients were asked to perform functional exercises. The patients were followed up by clinical observation, panoramic radiograph, temporomandibular joint(TMJ ) cone beam computed tomography(CBCT), and surface electromyography(sEMG) of masticatory muscles (superficial masseter, anterior temporalis, and anterior digastric muscles). Ramus height and body length of mandible were measured on panoramic radiograph. The patients were asked to return for follow-up visits at 1, 3, and 6 months after treatment, and then once a year. The patients underwent clinical examination at each follow-up visit, and radiological examinations at 6 months and then annually.

RESULTS

All the patients showed clinically satisfactory results. CBCT showed smooth and continuous cortex. Panoramic X-ray revealed that the ramus height was shorter in the fractured side than in the contralateral side, while body length was longer. The mean asymmetry index(AI,x±s) for ramus height and body length were (3.29±2.68)% and (4.01 ± 2.54)%. sEMG showed either hypertension or hypotension in the masticatory muscles of the fractured side and asymmetries were obvious. The mean AI for sEMG activity of the anterior temporalis, masseter, and anterior digastric muscle were masseter: (15.0 ± 16.9)%; anterior temporalis: (21.5 ± 15.9)%; anterior digastric muscles: (11.9 ± 10.7)%.

CONCLUSIONS

Conservative treatment of condylar fracture in children and adolescents had clinically satisfactory results, while mandibular development was slightly interrupted. Asymmetries of EMG activities of masticatory muscles were obvious. EMG could objectively reveal the functional recovery of condylar fracture in children.

Benign pericardial schwannoma in a Chinese woman: a case report

Background

Intrathoracic schwannomas are most frequently located in the posterior mediastinum. A Chinese woman presented with a benign pericardial schwannoma in the pretracheal space and aortopulmonary window, a location which has not been described previously in the literature.

Case presentation

A 50-year-old Chinese woman initially reported a cough associated with a small amount of sputum. Contrast-enhanced computed tomography (CT) subsequently revealed a 9 × 11 cm² lobulated mass with sharp margins that presented as a capsule with heterogeneous enhancement and punctate calcification. Complete surgical resection was performed using a thoracotomy approach. The resected intrapericardial tumor was a firm, large mass with lobulation. Capsulation prevented infiltration of the mass into adjacent organs. Pathological examination verified that the tumor was a benign pericardial schwannoma.

Conclusion

This is the first reported case of a benign pericardial schwannoma located in the pretracheal space and aortopulmonary window. While a contrast-enhanced CT scan was able to differentiate this pericardial schwannoma from other middle mediastinal tumors, the exact diagnosis and plan for treatment depended on a pathological examination. For similar cases involving pericardial schwannomas, complete surgical resection is recommended, particularly for the prevention of life-threatening cardiopulmonary complications.

[Magnetic resonance myocardial perfusion imaging for evaluating myocardial viability after myocardial infarction]

OBJECTIVE

To assess the value of magnetic resonance (MR) myocardial perfusion imaging (MRMPI) in evaluating the myocardial viability in patients with myocardial infarction.

METHODS

MRMPI was performed in 51 patients with myocardial infarction using a 1.5 T MR scanner. All the patients were examined using IR-turbo FLASH sequence during the first-pass and delayed phase 5-30 min after injection of 0.1 mmol/kg Gd-DTPA at the rate of 4 ml/s. The short axis images were acquired during the first-pass, and both the short axis and long axis images were obtained during the delayed phase. The left ventricular wall on the short-axis slice was divided into 8 segments. A correlative study of the results of the rest and stress (99m)Tc single photon emission computed tomography (SPECT) was carried out in 21 patients.

RESULTS

In the 51 patients with myocardial infarction, 42(82.3%) showed hypoperfusion during the first-pass imaging and 50(98%) had delayed hyperenhancement. In the 21 patients receiving SPECT, 48 nonviable segments was detected among the 168 segments scanned by (99m)TcSPECT, and MRMPI showed delayed hyperenhancement in all the infracted areas. Of the 120 viable segments detected by rest and stress (99m)Tc SPECT, 97 segments (80.8%) were found to be free of delayed hyperenhancement by MRMPI. With the rest and stress (99m)Tc SPECT as the reference, the sensitivity and the specificity of MRMPI were 100.0% and 80.8%, respectively.

CONCLUSION

MRMPI allows effective identification of the myocardial viability and nonviability as well as the severity and extent of the myocardial infraction.

[Study on the three dimensional hepatic virtual operation based on the data of 64-slice helical CT scanning]

OBJECTIVE

To study the surgery plan and simulation effect of the three dimensional (3D) hepatic virtual operation based on the data of 64-slice helical CT scanning and to probe the feasibility of the virtual operation based on the FreeForm Modeling System.

METHODS

The volunteer liver was scanned to collect two dimensional (2D) DICOM data of 64-slice helical CT scanning and the 3D hepatic and intrahepatic vessels model were reconstructed by MIMICS software. The reconstructed liver, the intrahepatic vessels model and the artificial tumor models were output into the FreeForm Modeling System in the STL format. The device PHANTOM with the characterization of dynamo-feedback was applied to make the operation on the 3D hepatic.

RESULTS

The spatial relationship between the tumour and the intrahepatic vessels were clearly observed by rotation and enlargement of the target. According to the operation principle, the left lobe of liver resection was simulated by manipulating the device PHANToM. Through the liver transparence surface, the intrahepatic vessels were easily distinguished. The operation procedure was accord with the clinic hepatic surgery. Meanwhile, during the operation, by adjusting the incision objective intensity, the dynamo-feedback intensity was definitely touched.

CONCLUSIONS

By using the FreeForm Modeling System,the hepatic operation procedure can be simulated ahead of time. The operation complication in the practical surgery can be anticipated and the individualization operation schema can be reasonable instituted.

[The value of three-dimensional 64-multi-slices helical computer tomography on the diagnosis of diseases of digestive system]

OBJECTIVE

To study the value of three-dimensional 64-slice helical computer tomography (64-MSCT) in diagnosis and surgical treatment on diseases of digestive system.

METHODS

From November 2005 to August 2006, 64-MSCT was performed on 102 patients suspected of digestive diseases to display foci of infection, hepatic conduit, biliary-pancreatic duct and portal venous system, followed by three-dimensional reconstruction of those targets. The reconstructed images as well as the data obtained from the reconstruction were compared with the surgical results.

RESULTS

Twenty-five of 27 patients with portal hypertension (PHT) showed blur-free imaging of main portal vein (MPV) while the other 2 cases showed congenital cavernous transformation or thrombogenesis of MPV. Compensatory circulation of portal venous system was displayed satisfactorily in 27 cases. The three-dimensionally reconstructed images of 34 cases of hepatocellular carcinoma (HCC) demonstrated no invasion of tumors into the tissues and blood vessels of 23 cases, visible invasion into portal vein and hepatic veins of 9 cases, tumor embolus in portal veins of 1 case, and arterio-venous fistula in only one case. The 3D imaging of biliary passages displayed total concretion, tumor and constrictive or dilated biliary-pancreatic duct and bile duct around amphi-obstruction, which complied with the operations research of calculus of bile duct in 25 cases, cholangiocarcinoma in 5 cases, and cancer of pancreas in 5 cases. Operations research in accordance with the 3D reconstructed imaging accorded with imaging diagnosis in respect of PHT, HCC and diseases of biliary-pancreatic system at the rates of 100%, 97% and 100%, respectively.

CONCLUSIONS

Three-dimensional 64-MSCT displays foci of infection and constructions of biliary-pancreatic duct and hepatic conduit stereoscopically.

Quantitative evaluation of diffusion-weighted magnetic resonance imaging of focal hepatic lesions

AIM: To explore the quantitative analysis of diffusion-weighted magnetic resonance imaging (DWMRI) in differential diagnosis of focal hepatic lesions.

METHODS: DWMRI was performed in 149 hepatic lesions, including hepatocellular carcinoma (34 cases), hepatic metastases (37 cases), cavernous hemangioma (42 cases), hepatic cyst (36 cases). Apparent diffusion coefficient (ADC) values were evaluated using four different b values in different sequences. The ratio of ADC values of lesion/liver in hepatocellular carcinoma and hepatic metastases was also calculated.

RESULTS: The mean ADC values of hepatic lesions were as follows: hepatocellular carcinoma (0.95 ± 0.11)×10^-3 mm²/s, hepatic metastasis (1.13 ± 0.21)×10^-3 mm²/s, cavernous hemangioma (1.86 ± 0.36)×10^-3 mm²/s, hepatic cyst (3.14 ± 0.31)×10^-3 mm²/s. The ratio of ADC values in lesion/liver in hepatocellular carcinoma was 0.91± 0.11, being significantly different from that in hepatic metastasis (1.21 ± 0.18, P < 0.05).

CONCLUSION: ADC values and quantitative analysis of focal hepatic lesions are of significant values in differential diagnosis of focal hepatic lesions.

Evaluation of diffusion weighted imaging of magnetic resonance imaging in small focal hepatic lesions: a quantitative study in 56 cases

BACKGROUND

Diffusion-weighted imaging (DWI) as a new technique of magnetic resonance imaging (MRI) is used to detect focal hepatic lesions. This study was designed to evaluate the significance of DWI to differentiate focal hepatic lesions less than 3 cm in diameter by the quantitation of apparent diffusion coefficient (ADC) values.

METHODS

DWI using 1.5T MRI scanner unit was performed with a spin-echo single-shot echo planar imaging (EPI) in 56 cases of small focal hepatic lesions, including hepatocellular carcinoma (11), hepatic metastatic tumor (15), hepatic cavernous hemangioma (14), and hepatic cyst (16). The ADC values of these lesions were calculated respectively. The ratios of the ADC values of lesion/liver in hepatocellular carcinomas and hepatic metastatic tumors were also estimated.

RESULTS

The mean ADC values (mm2/s) were (0.93+/-0.06) x 10(-3) in hepatocellular carcinomas, (1.09+/-0.18) x 10(-3) in hepatic metastatic tumors, (1.95+/-0.38) x 10(-3) in hepatic cavernous hemangiomas, and (3.18+/-0.33) x 10(-3) in hepatic cysts. The ratios of ADC values of lesion/liver were 0.90+/-0.06 and 1.15+/-0.14 in hepatocellular carcinoma and hepatic metastatic tumors respectively, which were significantly different (P < 0.05).

CONCLUSION

The measurement of ADC values and the ratios of ADC values of lesion/liver are helpful in MR diagnosis and differentiation of focal hepatic lesions.

[Quantitative study of diffusion weighted imaging on magnetic resonance imaging in focal hepatic lesions less than 3 cm]

OBJECTIVE

To evaluate the characteristics of MR imaging of hepatic lesions using measurement of apparent diffusion coefficient (ADC) value of hepatic lesions on diffusion weighted imaging.

METHODS

MR diffusion weighted images were obtained in patients with 97 hepatic lesions (22 hepatocellular carcinomas, 21 metastatic tumors, 28 hemangiomas, 26 cysts). ADC values were evaluated with different sequences. The ADC ratio of lesion/liver was estimated.

RESULTS

Average ADC values of hepatic lesions were as follows: carcinomas (0.91 +/- 0.07) x 10(-3) mm(2)/s, metastatic tumors (1.13 +/- 0.27) x 10(-3) mm(2)/s, cavernous hemangiomas (1.94 +/- 0.37) x 10(-3) mm(2)/s, cysts (3.26 +/- 0.30) x 10(-3) mm(2)/s. The ADC ratio of lesion/liver was significantly different between primary carcinomas and metastatic tumors (P < 0.05).

CONCLUSION

Quantitative study in hepatic lesions using ADC values and the ADC ratio of lesion/liver, would improve the accuracy in diagnosing hepatic lesions.

[Dynamic evaluation of rabbit VX2 hepatic carcinoma with CT and MRI]

OBJECTIVE

To dynamically monitor the growth of rabbit VX2 hepatoma by CT and MRI, and to understand the CT and MRI features during different periods of tumor growth.

METHODS

The plain and dual-phase enhanced CT as well as the plain and enhanced MRI were performed in all the 10 rabbit VX2 hepatoma models (with 20 foci) at 1, 2 and 3 weeks after tumor implantation.

RESULTS

The detection rate of the VX2 tumors by CT and MRI was low at 1 week after implantation, but was raised to 100% after another week. The tumors were shown to be homogeneously hypointense by unenhanced CT. In arterial phase CT images, peripheral rim enhancement of all the tumors were observed, while the main bodies of the tumors remained hypointense. The nutrient arteries for the tumors stretching straight to the margins of the tumors were detected in 14 (70%) foci and arterial vessels in the tumors visualized in 9 (45%) lesions. On portal venous phase CT the tumors were also shown to be hypointense. The tumors were shown to be homogeneously hypointense in T1-weighted MR images and lightly hyperintense in T2-weighted images, with peripheral rim enhancement of the tumors after injection of the contrast agent. The intensity of most tumors became hetergenerous on plain CT and MRI at week 3 after implantation.

CONCLUSION

Rabbit VX2 hepatomas are hypovascular tumors the growth of which can be monitored by CT and MRI effectively.