Imaging features of dermatofibrosarcoma protuberans.

Aims: The study highlights diffusion-weighted imaging (DWI) and dynamic enhancement features of DFSP and characterizes unenhanced and enhanced computed tomography (CT) and magnetic resonance imaging (MRI) scans. Settings and Design: Image findings and clinical histories of 23 patients with DFSP were reviewed. Nine patients underwent CT before and after intravenous administration of contrast material. MRI was performed for 17 patients. CT and MRI findings were analyzed using location, size, edge, shape, infiltration sign, density and signal enhancement mode, and degree. Results: Patients showed 26 superficial and one deep lesion. Ten superficial lesions bulged onto the skin surface. Fourteen lesions were well-defined and 13 ill-defined. All lesions were nodular, with nine being multilobular. Thirteen showed infiltration to adjacent skin, fat, and fascia. Seven lesions on CT were iso- or hypo-dense to muscle without calcification. Contrast-enhanced CT showed inhomogeneous moderate and progressive enhancement in the arterial phase. Small tortuous vessels were seen in the arterial phase in one case. Sixteen tumors displayed signals that were similar to muscle by T1WI. Ten lesions were either hyper-intense to muscle or iso-intense to fat; the deep DFSP was hypo-intense by T2WI. All lesions were hyper-intense homogeneously or heterogeneously under fat-suppressed T2WI. Twelve superficial lesions showed high-intermediate signal, and one deep lesion showed low-intermediate signal with DWI. Seven cases showed low signal diffusion coefficient (ADC) images. Dynamic enhancement and signal intensity-time (SI-T) curves of four tumors showed rapid SI increases followed by steady or slightly rising SI. All lesions showed inhomogeneous, progressive enhancement in the arterial phase. Conclusions: This report is the first on dynamic curves and highlights DWI and T2WI features of DFSP. DFSP can be correctly diagnosed by combining a patient's clinical manifestations with imaging characteristics.

Application and mechanism of manganese-coated caramelization nanospheres for active targeting in hepatobiliary tumors.

Aim: To elucidate the MRI mechanisms of manganese oxide-coated carbohydration nanosphere (Mn@CNS) for active targeting in hepatobiliary tumors. Materials & methods: The cytotoxicity, internalization pathway, metabolism and excretion pathway of Mn@CNS were assessed by several cell types. The MRI of Mn@CNS was verified via rat models bearing hepatobiliary tumors. Results: Mn@CNS showed no obvious cytotoxicity. Mice macrophage and hepatocellular Mn content significantly differed between pre- and post-uptake levels (p < 0.01). The animal experiment revealed fine T1 imaging of hepatobiliary tumors with peak enhancement at 3 h. Mn@CNS was metabolized within the cells and excreted mainly via feces. Conclusion: Mn@CNS is safe, biodegradable, and may serve as a new strategy for active target imaging and treatment applications.

A comparison of ultra-high-resolution CT target scan versus conventional CT target reconstruction in the evaluation of ground-glass-nodule-like lung adenocarcinoma.

BACKGROUND: The aim of this study was to determine whether the clinical value of scanned computed tomography (CT) images is higher when using ultra-high-resolution CT (U-HRCT) target scanning than conventional CT target reconstruction scanning in the evaluation of ground-glass-nodule (GGN)-like lung adenocarcinoma. METHODS: A total of 91 consecutive patients with isolated GGN-like lung adenocarcinoma were included in this study from April 2017 to June 2018. U-HRCT and conventional CT scans were conducted in all enrolled patients. Two experienced thoracic radiologists independently assessed image quality and made diagnoses. Based on the pathological results, the accuracies of U-HRCT target scanning and conventional CT target reconstruction for detecting morphological features on CT, including spiculation of GGNs, bronchial vascular bundles, solid components in the nodules, burr, vacuole, air bronchial signs, and fissure distortion, were calculated. All statistical analyses were performed using SPSS 17.0 software. Enumeration data were tested using the Chi-square test. A P value of <0.05 was considered statistically significant. RESULTS: When both techniques were compared with the pathological findings, the detection rate for CT images obtained using U-HRCT target scanning and conventional CT target reconstruction with regard to the spiculation of GGNs, bronchial vascular bundles, and solid components in the nodules were 78% vs. 61.5%, 72.5% vs. 54.9%, 65.9% vs. 49.5%, respectively. The presence of the spiculation of GGNs, bronchial vascular bundles, and solid components in the nodules in U-HRCT target scanning was significantly higher than that in conventional CT target reconstruction (all P<0.05). However, no significant difference was observed between the two techniques with regard to the burr, vacuole, air bronchial signs, and fissure distortion (all P>0.05). CONCLUSIONS: When viewing GGNs, the detection rate was higher for U-HRCT target scanning than for conventional CT target reconstruction, and this improvement significantly enhanced the diagnostic accuracy of early lung adenocarcinoma.

Delayed Contrast Enhancement in Magnetic Resonance Imaging and Vascular Morphology of Primary Diffuse Large B-Cell Lymphoma (DLBCL) of the Central Nervous System (CNS): A Retrospective Study.

BACKGROUND This study aimed to compare the magnetic resonance imaging (MRI) findings of primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system (CNS) with delayed contrast enhancement and histological microvessel density (MVD). T1-weighted and T2-weighted contrast-enhanced and non-enhanced brain imaging were used. CNS lymphoma tissue was evaluated using primary antibodies to endothelial cells and smooth muscle cells, and histochemical staining for reticulin fibers and basement membrane, which allowed quantification of the MVD. MATERIAL AND METHODS Twenty-one patients with histologically confirmed primary DLBCL of the CNS underwent pre-contrast-enhanced and postcontrast-enhanced MRI. Histology of the CNS lymphoma tissue included immunohistochemical staining with antibodies to CD34 for vascular endothelial cells and alpha smooth muscle actin (ASMA) for vascular smooth muscle cells, and histochemical staining included periodic acid-Schiff (PAS) and silver staining for reticulin fibers to evaluate microvessel density (MVD). RESULTS In primary DLBCL of the CNS, a positive correlation was found between the degree of necrosis and the size of the lymphoma (r=0.546, P=0.01). Delayed imaging enhancement was significantly correlated with the number of mature vessels, MVD, basement membrane, and reticulin fibers (r=0.593, 0.466, 0.446 and 0.497, respectively). Standardized ß regression coefficient analysis showed that the MVD, PAS-positive structures, the number of mature vessels, and reticulin fibers, were significantly associated with delayed enhancement on MRI (ß values, 0.425, 0.409, 0.295, and 0.188, respectively). CONCLUSIONS In primary DLBCL of the CNS, delayed imaging enhancement on MRI may be due to reduced neovascularization and vascular infiltration by lymphoma cells.

Apparent Diffusion Coefficient to Subdivide Breast Imaging Reporting and Data System Magnetic Resonance Imaging (BI-RADS-MRI) Category 4 Lesions.

BACKGROUND This study aims to subdivide BI-RADS-MRI (Breast Imaging Reporting and Data System Magnetic Resonance Imaging) Category 4 lesions and to evaluate the role of Fischer's scoring system, apparent diffusion coefficient (ADC), and Fischer's + ADC in differential diagnosis of breast lesions. MATERIAL AND METHODS This study retrospectively analyzed the data of 143 patients (150 breast lesions), who were diagnosed by biopsy, and received dynamic contrast enhancement and diffusion-weighted imaging. The diagnostic efficacies of ADC, Fischer's scoring system, and the Fischer's + ADC were analyzed by the receiver operating characteristics curve. The area under the curve (AUC) was calculated. Fischer's scoring system and the Fischer's + ADC were used to subdivide BI-RADS Category 4 breast lesions. RESULTS ADC value was negatively correlated with the tumor grade. The AUC of Fischer's + ADC (0.949) was significantly higher than that of ADC (0.855) and Fischer's (0.912) (P=0.0008 and 0.001, respectively). Scored by Fischer's scoring system, Category 4 and 5 indicated a likely malignant threshold with sensitivity and specificity of 98.70% and 65.75%, respectively. Scored by the Fischer's + ADC method, Category 4B and 4C indicated a likely malignant threshold with sensitivity of 97.40% and specificity of 82.19%. Kappa values were 0.63 (ADC), 0.65 (Fischer's), and 0.80 (Fischer's + ADC), respectively. The positive predictive value of BI-RADS 4A, 4B, and 4C were 7.69%, 52.38% and 89.29%, respectively. CONCLUSIONS Fischer's scoring system combined with ADC could reasonably subdivide Category 4 breast lesions with high specificity and sensitivity.

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.

Specific imaging characteristic of solitary necrotic nodule of the liver: Marked peripheral rim-like enhancement with internal hypointensity on longer delayed MRI.

OBJECTIVES: To obtain specific imaging findings of solitary necrotic nodule of the liver (SNNL) using longer delayed contrast-enhanced MRI and compare them with those of three mimic hepatic diseases. METHODS: Sixteen patients with SNNL underwent plain and contrast-enhanced triphasic CT and multiphasic MRI with delayed time prolonged to 2 h after contrast bolus injection. Twenty-three patients with mimic lesions including seven with eight HCCs, five with five iCCs and 11 with metastatic lesions served as the control group. Those patients also received plain and multiphasic contrast-enhanced MRI. Imaging features of lesions such as peripheral wash-out time were evaluated. RESULTS: Among the 16 SNNLs, with a prolonged delayed MRI time, the enhancement degree of tumour periphery increased gradually. When it was up to 1 h, all lesions represented moderate/marked peripheral enhancement with internal hypointensity. However, the peripheral wash-out in seven HCCs (87.5%) and all metastatic lesions except three appeared at 10 or 15 min, one iCC (20%) at 30 min and the other lesions at 1 h. CONCLUSIONS: Longer MRI with a delayed time of 1-2 h may be useful in diagnosis SNNL, revealing the specific imaging characteristic of SNNL as pronounced peripheral enhancement with internal hypointensity. KEY POINTS: • Longer delayed MRI plays an important role in the diagnosis of SNNL. • Characteristic imaging feature of SNNL is pronounced peripheral enhancement with internal hypointensity. • Periphery wash-out time can differentiate SNNL from mimic diseases. • Imaging findings of SNNL on routine CT and MRI are unspecific.

Topological Organization of Metabolic Brain Networks in Pre-Chemotherapy Cancer with Depression: A Resting-State PET Study.

This study aimed to investigate the metabolic brain network and its relationship with depression symptoms using 18F-fluorodeoxyglucose positron emission tomography data in 78 pre-chemotherapy cancer patients with depression and 80 matched healthy subjects. Functional and structural imbalance or disruption of brain networks frequently occur following chemotherapy in cancer patients. However, few studies have focused on the topological organization of the metabolic brain network in cancer with depression, especially those without chemotherapy. The nodal and global parameters of the metabolic brain network were computed for cancer patients and healthy subjects. Significant decreases in metabolism were found in the frontal and temporal gyri in cancer patients compared with healthy subjects. Negative correlations between depression and metabolism were found predominantly in the inferior frontal and cuneus regions, whereas positive correlations were observed in several regions, primarily including the insula, hippocampus, amygdala, and middle temporal gyri. Furthermore, a higher clustering efficiency, longer path length, and fewer hubs were found in cancer patients compared with healthy subjects. The topological organization of the whole-brain metabolic networks may be disrupted in cancer. Finally, the present findings may provide a new avenue for exploring the neurobiological mechanism, which plays a key role in lessening the depression effects in pre-chemotherapy cancer patients.

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.

Palliation of malignant esophageal obstruction and fistulas with covered self expandable metallic stents: assessment of a simple fluroscopic method.

PURPOSE: To introduce a convenient, quick and effective way to place self-expandable metal stents (SEMSs) to relieve dysphagia and fistula caused by esophageal carcinoma. MATERIALS AND METHODS: A consecutive series of 36 patients (25 men, 11 women), aged 38-82 years (median, 52.7 years) underwent stent placement using a 7F long sheath of 55 cm and fully covered SEMS under local anesthesia with fluoroscopic control. RESULTS: Stent placement was successful in all patients. Swallowing improved from mean dysphagia score 3.44 ± 0.50 to score 0.69 ± 0.71 (P = 0.000). There were no clinically significant complications during and after the deployment of stents. Migration was noted in 4 patients. Restenting was needed in 3 patients. Removal was needed in 2 patients. Mean survival following stenting was 134.14 d. CONCLUSIONS: SEMSs provide rapid, safe and effective relief of dysphagia and fistula. Using the 7F long sheath of 55 cm could make the procedure easy, quick and safe.

Evaluation of astrocytoma cell proliferation using diffusion-weighted imaging: correlation with expression of proliferating cell nuclear antigen.

The purpose of this study was to analyze if there is a significant correlation between the results of diffusion-weighted imaging (DWI) and the expression of proliferating cell nuclear antigen (PCNA) in astrocytomas. The DWI scans of 19 different-grade astrocytomas were obtained on a 3 T magnetic resonance scanner. The average regional apparent diffusion coefficients (ADC) were measured. The positive expression of PCNA was determined immunohistochemically by using streptavidin-peroxidase complex staining, and was quantified by calculating its calibrated opacity density (COD) using an image analysis system. The average regional ADC and PCNA COD of low grade and high grade astrocytomas were compared. Correlations between regional ADC and PCNA COD were analyzed. The average regional ADC of high grade astrocytomas was significantly (t = 10.169, P = 0.000) less (0.687 ± 0.225 × 10-3 mm2/s) than that of low grade astrocytomas (1.572 ± 0.333 × 10-3 mm2/s). The PCNA COD (0.343 ± 0.052) of high grade astrocytomas was significantly (t=-7.858, P=0.000) greater than that (0.194 ± 0.012) of low grade astrocytomas. There were strong negative correlations between regional ADC and PCNA COD (r = -0.801, P = 0.000). The results demonstrated that DWI is helpful in evaluating cell proliferation and preoperatively grading astrocytomas by measuring regional ADC.

Preoperative evaluation of collateral venous anastomoses in meningioma involving cerebral venous sinus by susceptibility weighted imaging.

Precise preoperative identification of the collateral venous anastomoses is critical for proper surgical management of patients with meningioma involving sinus. This study was to assess the feasibility of susceptibility weighted imaging (SWI) to delineate the collateral venous anastomoses before surgery. Twenty-five patients with meningiomas that were involved in sinuses underwent surgery and the collateral anastomoses were evaluated with SWI and phase-contrast magnetic resonance venography (MRV) before surgery. The results obtained with SWI were compared with those obtained with MRV. Intraoperative findings were used as the gold standard. By surgery, a total of 98 collateral anastomotic veins were identified in the 25 patients. SWI depicted 85 collateral anastomotic veins close to the meningioma with a sensitivity of 87%, whereas MRV showed 57 collateral anastomotic veins with a sensitivity of 58%. The detectability of collateral anastomotic veins in SWI images was superior to MRV. The results suggest that SWI is superior to MRV and could provide more reliable information on the collateral venous anastomoses in patients with meningioma.

Improving depiction of temporal bone anatomy with low-radiation dose CT by an integrated circuit detector in pediatric patients: a preliminary study.

The purpose of this study was to determine the performance of low-dose computed tomography (CT) scanning with integrated circuit (IC) detector in defining fine structures of temporal bone in children by comparing with the conventional detector. The study was performed with the approval of our institutional review board and the patients' anonymity was maintained. A total of 86 children<3 years of age underwent imaging of temporal bone with low-dose CT (80 kV/150 mAs) equipped with either IC detector or conventional discrete circuit (DC) detector. The image noise was measured for quantitative analysis. Thirty-five structures of temporal bone were further assessed and rated by 2 radiologists for qualitative analysis. κ Statistics were performed to determine the agreement reached between the 2 radiologists on each image. Mann-Whitney U test was used to determine the difference in image quality between the 2 detector systems. Objective analysis showed that the image noise was significantly lower (P<0.001) with the IC detector than with the DC detector. The κ values for qualitative assessment of the 35 fine anatomical structures revealed high interobserver agreement. The delineation for 30 of the 35 landmarks (86%) with the IC detector was superior to that with the conventional DC detector (P<0.05) although there were no differences in the delineation of the remaining 5 structures (P>0.05). The low-dose CT images acquired with the IC detector provide better depiction of fine osseous structures of temporal bone than that with the conventional DC detector.

Diagnosis of infantile myofibromatosis with pseudo-ulcerated plaque using prenatal ultrasound: A case report.

The present case report describes a case of infantile myofibromatosis (IM) with a pseudo-ulcerated plaque on the right side of the back of a fetus, detected in the 38th week of gestation using prenatal ultrasound. The fetus was examined weekly by ultrasound to measure the size of the mass. At birth, the scarlet mass was slightly elevated compared with the skin around it, with a cavity in the center. It appeared similar to an ulcerated plaque, but the surface of the mass was intact and smooth with a stratum lucidum. Thus, the mass was indicated to be a pseudo-ulcerated plaque. Three months later, the mass had grown larger and so was removed by surgery. The pathology of the mass was confirmed as IM. It is suggested that IM should be considered when a soft tissue tumor is presented by prenatal ultrasound.

Superiority of the modified Tönnis angle over the Tönnis angle in the radiographic diagnosis of acetabular dysplasia.

The aim of this study was to evaluate the limitations of the Tönnis angle as one of the most commonly used parameters in the diagnosis of acetabular dysplasia, and to explore the feasibility of the modified Tönnis angle in the diagnosis of acetabular dysplasia. A total of 224 patients (120 females and 104 males) with 448 hips, aged between 15 and 83 years (median, 45.0 years), were selected for the measurement of the center-edge (CE) and Tönnis angles. To evaluate the relative position of the medial edge of the acetabular sourcil, a new parameter, known as the center-medial-edge (CME) angle, was designed. As an improvement of the Tönnis angle, a new angle preliminarily termed the modified Tönnis angle was created. In addition, the degree of clarity of the medial edge of the acetabular sourcil on radiograph was evaluated, and the hips were divided into the clear-edge and blurred-edge groups. The hips belonging to the blurred-edge group could not be used for Tönnis angle measurements. All measurements were performed digitally using the tool of the picture-archiving communication system. Among the 448 acetabular sourcils, 142 had a blurred medial edge (31.7%). The mean value of the CME angle was 37.94°, with a range of 21.76-63.99°. The 95% prediction interval of the modified Tönnis angle was estimated to be -6.39 to 11.73°. The correlation coefficients were -0.838 between the CE and Tönnis angles, 0.889 between the Tönnis and modified Tönnis angles and -0.905 between the CE and modified Tönnis angles. In conclusion, the modified Tönnis angle can substitute for the Tönnis angle without joint space narrowing and subluxation of the hip, particularly when the Tönnis angle cannot be measured due to a blurred medial edge of the acetabular sourcil on pelvic radiograph.

Application of 256-slice computed tomography with low radiation doses in neonates with hypoxic-ischemic encephalopathy.

Hypoxic-ischemic encephalopathy (HIE), an injury or disease with lack of oxygen in the brain, may occur at any stage in childhood but the exact mechanisms that cause HIE remain unknown. In this study, 150 newborns suspected of having neonatal HIE and scheduled for a brain CT scan were randomly assigned to three equally sized groups as follows: standard dose group (120 kV, 250 mAsec), low dose group 1 (120 kV, 150 mAsec) and low dose group 2 (120 kV, 50 mAsec). All other acquisition parameters were the same in all groups. The CT dose index (CTDI), dose length product (DLP) and the image noise were compared among the three groups. The image quality was evaluated by blinded readers. The DLP of low dose group 2 was 19.3% of that of the standard dose group without a significant difference (P>0.05). The image noise of the low dose group 1 was greater than that of the standard dose group with a significant difference (P<0.01). Low dose scanning is feasible in the screening of HIE in neonates and is beneficial in protecting newborns against unnecessary radiation damage.

[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.

[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.