Relative Computed Tomography (CT) Enhancement Value for the Assessment of Microvascular Architecture in Renal Cell Carcinoma.

BACKGROUND To investigate the correlation between the relative computed tomography (CT) enhancement value and the microvascular architecture in different pathologic subtypes of renal cell carcinoma (RCC). MATERIAL AND METHODS This retrospective study included 55 patients with pathologically confirmed RCC. Immunohistochemistry for CD34 was performed for all surgical specimens. Microvascular architecture parameters (density, area, diameter, and perimeter) for the microvessels and the microvessels with lumen were determined. The CT scan was performed during arterial phase or venous phase. The correlation of parameters on CT and tumor angiogenesis was investigated. RESULTS Density of microvessels showed a positive correlation with CT values of tumors, ratios of tumor to cortex, and differences of tumor and medulla, but no correlation with CT value ratio of tumor to aorta or tumor to medulla. CT parameters were positively correlated with microvascular parameters. However, no CT parameter differences between hypo-vascular clear cell RCC and papillary RCC was observed. Strikingly, the density and area of the microvessels were significantly higher in hypo-vascular clear cell RCC than that in papillary RCC, while the density of the microvessels with lumen in the cyst-present RCC was significantly higher than that in the cyst-absent RCC. The values (especially those of microvessels with lumen) of area density, diameter, and perimeter were higher in the capsule-absent RCC than in the capsule-present RCC. CONCLUSIONS The relative CT enhancement value of RCC was associated with vascular architecture parameters including density, area, and perimeter. Quantitative and semi-quantitative parameters on enhanced CT may shed some light on tumor vasculature and function as indicators of the biological behavior of RCC.

Synergistic Effects of Gold Nanocages in Hyperthermia and Radiotherapy Treatment.

Gold nanocages (GNCs) are a promising material that not only converts near infrared (NIR) light to heat for the ablation of tumors but also acts as a radiosensitizer. The combination of hyperthermia and radiotherapy has a synergistic effect that can lead to significant tumor cell necrosis. In the current study, we synthesized GNCs that offered the combined effects of hyperthermia and radiotherapy. This combination strategy resulted in increased tumor cell apoptosis and significant tumor tissue necrosis. We propose that GNCs can be used for clinical treatment and to potentially overcome resistance to radiotherapy by clearly increasing the antitumor effect.

Morphological changes of the thoracic duct and accessory lymphatic channels in patients with chylothorax: detection with unenhanced magnetic resonance imaging.

OBJECTIVES: To characterise the imaging findings of patients with chylothorax and to identify the leak site using unenhanced MRI. METHODS: Seven patients with chylothorax and 30 healthy individuals (as the control group) underwent three-dimensional heavily and routine T2-weighted MRI. Morphological changes and diameters of the thoracic duct, chyloma display, and some dilated accessory lymph channels were evaluated and measured. The differences between patients and the control group were compared. The leak sites of the thoracic duct and parietal pleura were also identified. RESULTS: The patients had a higher display rate of the entire thoracic duct and some accessory lymphatic channels, enlarged diameters and tortuous configuration of the thoracic duct, and existence of chylomas compared with the control group (P < 0.05). Seven leaks of the thoracic duct in five patients and five leaks of the parietal pleura in four patients were identified. Close relationships between the leak of thoracic duct and the chylomas or the meshworks of tiny lymphatics were found (P < 0.05). CONCLUSION: Unenhanced MRI appears reliable in the detection of morphological changes of thoracic lymphatics and in the identification of chyloma and leak sites in patients with chylothorax, which helps appropriate treatment planning and follow-up.

[Value of 3T magnetic resonance dynamic contrast-enhanced and diffusion-weighted imaging in differential diagnosis of musculoskeletal tumors].

OBJECTIVE: To evaluate the value of magnetic resonance dynamic contrast-enhanced (MR-DCE) and magnetic resonance diffusion-weighted imaging (MR-DWI) in the differentiation of benign and malignant musculoskeletal tumors. METHODS: Sixty-three patients with pathologically confirmed musculoskeletal tumors were examined with MR-DCE and MR-DWI. Using single shot spin echo planar imaging sequence and different b values of 400, 600, 800 and 1000 s/mm(2), we obtained the apparent diffusion coefficient (ADC) of the lesions. ADC values were measured before and after MR-DCE, with a b value of 600 s/mm(2). The 3D fast acquired multiple phase enhanced fast spoiled gradient recalled echo sequence was obtained for multi-slice of the entire lesion. The time-signal intensity curve (TIC), dynamic contrast-enhanced parameters, maximum slope of increase (MSI), positive enhancement integral, signal enhancement ratio, and time to peak (T(peak)) were also recorded. RESULTS: ADC showed no significant difference between benign and malignant tumors when the b value was 400, 600, 800, or 1000 s/mm(2), and it was not significantly different between benign and malignant tumors in both pre-MR-DCE and post-MR-DCE with b value of 600 s/mm(2). TIC were classified into four types type1 showed rapid progression and gradual drainage; type2 showed rapid progression but had no or slight progression; type 3 showed gradual progression; and type 4 had no or slight progression. Most lesions of type1 or type2 were malignant, whereas most lesions of type 3 or type 4 were benign. When using type1 and type 2 as the standards of malignancy, the diagnostic sensitivity and specificity was 87.23% and 50.00%, respectively. The types of TIC showed significant difference between benign and malignant musculoskeletal tumors(χ(2)=17.009,P=0.001). When using MSI 366.62 ± 174.84 as the standard of malignancy, the diagnostic sensitivity and specificity was 86.78% and 78.67%, respectively. When using T(peak)≤70s as the standard of malignancy, the diagnostic sensitivity and specificity was 82.89%and 85.78%, respectively. Positive enhancement integral and signal enhancement ratio showed no significant difference between benign and malignant musculoskeletal tumors. CONCLUSIONS: TIC, MSI and T(peak) of MR-DCE are valuable in differentiating benign from malignant musculoskeletal tumors. T(peak) has the highest diagnostic specificity, and TIC has the highest diagnostic sensitivity. The mean ADC value are no significant difference between benign and malignant tumors.

[Application value of 3T 1H-magnetic resonance spectroscopy in diagnosing tumors of bone and soft tissue].

OBJECTIVE: To study benign and malignant bone and soft tissue tumors with 1H-magnetic resonance spectroscopy (1H-MRS) at 3 Tesla MR scanner and assess the value of 1H-MRS in diagnosing bone and soft tissue tumors and distinguishing benign from malignant tumors. METHODS; Totally 49 patients with clinically and pathologically confirmed bone and soft tissue tumors were enrolled in this study. 1H-MRS was performed before treatment with point-resolved spectroscopy sequence. The imaging characteristics of 1H-MRS for bone and soft tissue tumors were observed and the possible differences between benign and malignant tumors was compared. Since spectra were directly found under single-voxel proton MRS brain examination, the peak height of choline containing compounds (Cho) opposite to the creatine (Cr) and the Cho peak were observed, and then the malignancies of the tumors were judged. Cho/Cr value was calculated and used to distinguishing benign tumors from malignancies. RESULTS: 1H-MRS spectra of bone and soft tissue tumors were different from those of the normal muscles, and such difference also existed between benign and malignant tumors. The Cho peak disappeared or was extremely low among benign tumors. The Cho/Cr values of malignant tumors and benign tumors were 3.13 +/- 0.9 and 1.34 +/- 1.02, respectively (P = 0.02). Using 1.79 as the threshold value, the Cho/Cr value had sensitivity, specificity, and accuracy of 94%, 80%, and 90%, respectively, in diagnosing malignancies. CONCLUSIONS: The increased Cho level, as measured by 1H-MRS, is related with the bone and soft tissue malignant tumor. Cho/Cr value is useful in distinguishing benign tumors from malignancies. 1H-MRS can be an important supplement to the conventional magnetic resonance imaging.

[Evaluation of blood oxygen level in hepatocellular carcinoma with noninvasive magnetic resonance multi-echo R2* technique and its clinical significance].

OBJECTIVE: To probe the relationship of clinical and pathological features of hepatocellular carcinoma (HCC) with the blood oxygen level by the technique of noninvasive magnetic resonance multi-echo R2*. METHODS: Multi-echo R2* sequence was carried out pre-operatively in a total of 46 patients with pathologically proved HCC. The T2* and R2* values of HCC, liver, spleen and paraspinous muscle on T2* and R2* maps and the ratios of HCC to liver (H/L), spleen (H/S) and muscle (H/M) were calculated. Different groups were defined according to such clinical parameters as the serum AFP level, lesion dimension, Edmondson's grade, ascites, capsula, liver cirrhosis, intrahepatic daughter foci or tumor-emboli in portal vein respectively. The differences in T2* and R2* values and the ratios between different groups were analyzed. RESULTS: In contrast with T2* value, the R2* value of HCC was less than that of liver or spleen (P < 0.05). Difference in R2* ratio of H/M (0.81 +/- 0.26 vs. 1.23 +/- 0.39) was found between positive and negative groups of AFP (P = 0.047, t = 2.248). And so was the same difference (0.83 +/- 0.24 vs. 1.23 +/- 0.43) between the lesions with or without capsula (P = 0.046, t = 2.257). The R2* ratio of H/S in hepatic cirrhosis group (1.01 +/- 0.58) was higher than that in noncirrhosis one (0.53 +/- 0.17) (P = 0.035, t = 2.247) whereas the T2* ratio of H/S was reversed (1.42 +/- 0.92 vs. 2.64 +/- 1.15) (P = 0.036, t = 2.230). The differences in T2* ratio of H/M in the group with or without intrahepatic daughter foci (1.18 +/- 0.47 vs. 2.24 +/- 1.71) (P = 0.048, t = 2.115), and in T2* value in the group with or without tumor-emboli in portal vein (27.24 +/- 11.90 ms vs. 46.70 +/- 38.40 ms) (P = 0.049, t = 2.046) were shown to be significant. However, no differences in MR parameters between other groups were observed (P > 0.05). CONCLUSION: The blood oxygen level parameters, R2* and T2* values and the ratios are related to some clinical and pathological features of HCC. And the blood oxygen level is affected by multiple factors.

Morphological features and clinical feasibility of thoracic duct: detection with nonenhanced magnetic resonance imaging at 3.0 T.

PURPOSE: To evaluate the detection of the thoracic duct using nonenhanced magnetic resonance imaging (MRI) and to determine the influence of some related disorders on the lymphatic duct. MATERIALS AND METHODS: Highly fluid-sensitive sequence and fat-suppressed T2-weighted imaging (FS-T2WI) were performed in a total of 139 cases. The axial and coronal images were used to locate the thoracic duct and the measurement and evaluation of its dimensions were performed using a 3D maximum intensity projection (MIP) reconstruction image. The differences in the dimensions among control, portal hypertension, and common bile duct obstruction groups were compared using one-way analysis of variance. RESULTS: The cisterna chyli was shown in 91% of cases on FS-T2WI, while the thoracic duct appeared in 70% of the MIP images. The common configuration of the cisterna chyli was tubular or saccular in 73%. Eighty thoracic ducts had a slight turn declining to the left at the level of T8-10. There was a significant difference in the transverse diameter of the thoracic duct between the portal hypertension group and other groups (F = 5.638, P = 0.005). CONCLUSION: Nonenhanced MRI is feasible for locating and depicting the morphological features of the thoracic duct. Portal hypertension may influence the dimension of the thoracic duct.

[Changes of 3-tesla 31P-MR spectroscopy of bone and soft tissue tumors].

OBJECTIVE: To study the characteristic changes of 31P-MR spectroscopy of bone and soft tissue tumors. METHODS: 41 patients were examined by phosphorus surface coil of 3 tesla MR machine, including 18 benign tumor foci and 28 malignant foci, and adjacent normal muscles. The areas under the peaks of various metabolites in the spectra were measured, including phosphomonoester (PME), inorganic phosphours (Pi), phosphodiester (PDE), phosphocreatine (Pcr), adenosine triphosphate (ATP) gamma, alpha, beta. The ratios of the metabolites to beta-ATP, NTP and Pcr were calculated. Intracellular pH was calculated according to the chemical shift change of Pi relative to Pcr. RESULTS: The ratios of Pcr/PME and PME/NTP in benign and malignant tumor groups were significantly different from those of the normal group (P<0.05). Between benign and malignant tumor groups, the ratios of PME/beta-ATP and PME/NTP were significantly different (P<0.05). CONCLUSION: Pcr/PME and PME/NTP are potential diagnostic indexes of bone and soft tissue tumors. PME/beta-ATP and PME/NTP are potential indexes of differential diagnosis of bone and soft tissue tumors.

[Angiogenesis and its maturation of hepatocellular carcinoma and its correlation with the deoxyhemoglobin parameters R2 * and T2 * values by using noninvasive magnetic resonance imaging].

OBJECTIVE: To explore the angiogenesis and its maturation of hepatocellular carcinoma (HCC) and its correlation with deoxyhemoglobin parameters R2 * and T2 * values and the lesion/muscle R2*, T2 * ratio by using noninvasive magnetic resonance imaging (MRI). METHODS: T2 *, R2 * values and the lesion/muscle R2 *, T2 * ratio in tumor periphery and center were calculated via series T2 * images in a total of 31 patients with surgically and pathologically confirmed HCC. After surgery, all sections were obtained from the specimen periphery in accordance with the MR analyzed areas. Continuous slices of each lesion were stained with hematoxylin-eosin (HE), and immunohistochemical staining was performed in vascular endothelial growth factor (VEGF), Flk-1, proliferating cell nuclear antigen (PCNA), CD34, and alpha smooth muscle actin (SMA). The expressions of VEGF, Flk-1, and PCNA index (PI) were evaluated. According to CD34 and SMA, some vascular parameters, including number, mean vessel area, total vessel area, circumference, diameter, distance between adjacent vessels, and variety index of microvessel and mature vessel, were calculated with a computed analysis system. The amounts of arterioles and veinlets, mature vessel index, and mean perfused fraction (mPF) were also recorded. All vessel parameters were compared with the calculated values of MRI. RESULTS: R2 * value or lesion/muscle R2 * ratio decreased and T2 * value or the lesion/muscle T2 * ratio increased in HCC when compared with hepatic parenchyma (P < 0.05); however, those values between lesion periphery and center and among different pathological grades were not significantly different (P > 0.05). T2 * value and the lesion/muscle T2 * ratio significantly decreased when the expression of VEGF was positive (P < 0.05). T2 * value was negatively correlated with microvessel amount (P = 0.047, r = - 0.639), while T2 * value and the lesion/muscle T2 * ratio were positively correlated with mPF (P = 0.040, r = 0.655; P = 0.048, r = 0.40, respectively). R2 * value was also positively correlated with mean area (P = 0.028, r = 0.688), total area (P = 0.021, r = 0.712) or circumference (P = 0.037, r = 0.663) of microvessel, and negatively correlated with mPF (P = 0.024, r = - 0.702). Meanwhile, the lesion/muscle R2 * ratio was positively correlated with mean area (P = 0.043, r = 0.647) and circumference (P = 0.026, r = 0.694) of microvessels. CONCLUSION: R2 * or T2 * value may be influenced by the variation of deoxyhemoglobin caused by the heterogeneity of angiogenesis.

[Diagnosis of solid-pseudopapillary tumor of the pancreas and the value of post-processing in the surgery by spiral CT].

OBJECTIVE: To study the CT manifestations of the solid-pseudopapillary tumor of the pancreas (SPTP) and to explore the value of post-processing in the surgery. METHODS: Clinical and CT features of 14 patients with SPTP proved pathologically were retrospectively analyzed. RESULTS: (1) 13 tumors were composed of different proportions of solid and cystic parts and 1 tumor was composed of solid part only. The solid portions demonstrated slight enhancement in the arterial phase and marked enhancement in the portal venous phase on post-contrast CT. The cystic portions appeared hypo-attenuation on both pre- and post-contrast CT images. Tumors were encapsulated and the capsule enhanced markedly with well-defined margins on post-contrast images. (2) Dilatation of the common bile duct or pancreatic duct wasn't seen in all of the cases and 1 case with the right adrenal ganglioneuroma. (3) 5 tumors located in the head of the pancreas, 3 of which with the superior mesenteric vein compression and displacement, in 2 cases the vessels were partially encapsulated by tumor. 6 tumors located in the tail of the pancreas, 3 of them with splenic hilum compression and multiple splenic vein tortuosity and dilatation, the veins drained into superior mesenteric vein anteriorly and posteriorly of the tumor. Splenic vein compression and posterior displacement occurred in 2 cases. In one case, there was no clear margin between the tumor and the splenic hilum. CONCLUSION: The SPTP has characteristic CT findings and correct diagnosis could be made by combining clinical features. The relationship of the lesions and surrounding structures could be revealed by the post-processing and was helpful for the operation.

Increased metabolite concentration in migraine rat model by proton MR spectroscopy in vivo and ex vivo.

PURPOSE: To investigate brain metabolite change in rat migraine model by proton magnetic resonance spectroscopy (1H-MRS) in vivo and ex vivo. METHODS: 18 Adult SD rats were enrolled in the study. After nitroglycerin administration, the migraine rat model was established according to ethology evaluation. 1H-MRS was performed at 3T MR scanner in vivo and 14.7T Bruker MR spectrometer ex vivo. Area of peak for different metabolite material was obtained and compared by using independent-T test. The significance level was set at p<0.05. RESULTS: In thalami of experimental group, areas of peak for Cho, Cr and Glu both in vivo and ex vivo were higher than in control group(p<0.05). In contrast, there was no statistical difference in cerebellum. CONCLUSION: The elevated Cho and Cr spectral pattern were found in rat migraine model. Neuron activity in thalamus is significantly changeable during attacks.

Metabolite concentration ratios in thalami of patients with migraine and trigeminal neuralgia measured with 1H-MRS.

OBJECTIVE: To investigate the metabolite concentration ratios including N-acetylaspartate (NAA), choline-containing compounds (Cho) and creatine plus phosphocreatine (Cr) in thalami of patients with migraine without aura, patients with trigeminal neuralgia and healthy comparison subjects using multi-voxel proton magnetic resonance spectroscopy (1H-MRS). METHODS: 1H-MRS was performed with a 3.0 T MR system on the thalamus bilaterally in 20 patients with migraine without aura, 16 patients with trigeminal neuralgia and 14 healthy control subjects. RESULTS: In the patients with trigeminal neuralgia, metabolite concentration ratios except for Cho/Cr in thalami were different from those of healthy subjects (p>0.05). In migraine group, only NAA/Cho is low in the left thalamus (p>0.05). Comparing the metabolite concentration ratios of affected and contralateral sides in migraine and trigeminal neuralgia groups, only NAA/Cr showed a significant difference (p>0.05). CONCLUSION: It was proved that migraine and trigeminal neuralgia seemed to be associated with an abnormal balance of the neural activity in the thalamus using 1H-MRS. There was some significant difference between metabolite concentration ratios in two diseases. 1H-MRS may serve as a useful non-invasive tool for evaluating thalamic neural activity and therapy effect in clinical performance of patients with migraine without aura.