Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

Purpose

To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium (³He)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT).

Materials and methods

Twenty-seven subjects, 22 with established emphysema and 5 with preclinical emphysema defined by PFT criteria, were examined with HP ³He-MRI and MSCT. Mean age was 55 (±12) years, 18 female and 9 male. Mean ADC from ³He-MRI was compared with emphysema index (EI), 15th percentile and mean lung density (MLD) values from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test.

Results

Mean ADC and standard deviation values were 0.392 ± 0.119 cm²/s for the established emphysema group and 0.216 ± 0.046 for the pre-clinical emphysema group. MSCT values for the established emphysema group and pre-clinical emphysema group were: EI (%) 11 ± 12 and 0.4 ± 0.6, respectively; 15th percentile (Hounsfield Units (HU)), −956 ± 25 and −933 ± 13, respectively and MLD (HU) −877 ± 20 and −863 ± 15, respectively. Correlations between mean ADC and EI and 15th percentile were both r = 0.90 and for MLD r = 0.59. There was higher correlation between mean ADC and %predicted DLCO (r = 0.90) than between EI and %predicted DLCO (r = 0.76).

Conclusion

HP ³He-MRI correlates well with density measurements from MSCT and agrees better than MSCT with %predicted DLCO which is the PFT most related to emphysema.     

Percutaneous mechanical thrombectomy combined with catheter-directed thrombolysis in the treatment of symptomatic lower extremity deep venous thrombosis

Purpose

To evaluate the efficacy of percutaneous mechanical thrombectomy (PMT) combined with catheter-directed thrombolysis (CDT) in the treatment of massive symptomatic lower limb deep venous thrombosis (DVT).

Materials and methods

One hundred and three clinically confirmed DVT patients were discharged from our institution. Sixteen patients with massive lower limb DVT were included in this retrospective study. After prophylactic placement of inferior vena cava filters (IVCFs), percutaneous mechanical thrombectomy (ATD, n = 10; Straub, n = 6) and catheter-directed thrombolysis were performed in all patients. Complementary therapy included percutaneous transluminal venous angioplasty (PTA, n = 3) and stent placement (n = 1). The doses of thrombolytic agents, length of hospital stay, peri-procedure complications and discharge status were reviewed. Oral anticoagulation was continued for at least 6 months during follow-up.

Results

The average hospital stay was 7 days. The technical success rate (complete and partial lysis of clot) was 89%, the other 11% patients only achieved less than 50% clot lysis. The mean dose of urokinase was 3.3 million IU. There were no significant differences of clinical outcome between the ATD and Straub catheter group. The only major complication was an elderly male who experienced a fatal intracranial hemorrhage while still in the hospital (0.97%, 1/103). Minor complications consisted of three instances of subcutaneous bleeding. No transfusions were required. Vascular patency was achieved in 12 limbs during follow-up. No pulmonary emboli occurred. There is one recurrent DVT 4.5 months after the treatment.

Conclusions

Percutaneous mechanical thrombectomy combined with catheter-directed thrombolysis is an effective and safe method for the treatment of symptomatic DVT. A randomized prospective study is warranted.     

Imaging manifestation of conventional and contrast-enhanced ultrasonography in percutaneous microwave ablation for the treatment of uterine fibroids

Objectives

To evaluate the image changes and the relationship between conventional ultrasonography and contrast-enhanced ultrasound (CEUS) in the perioperative period of microwave (MW) ablation for uterine fibroids; to guide clinical ablation therapy and evaluate the efficacy of MW.

Methods

Twenty-nine patients with 31 uterine fibroids were recruited in this study. All patients received conventional ultrasound as well as CEUS examination before, immediately after and 12–24 h after MW, in order to detect variations of echo and characteristics of blood supply. t-Tests were used to compare the hyperecho area on gray-scale ultrasound to immediately after ablation non-enhanced CEUS measurements, as well as to compare the immediately after ablation non-enhanced CEUS measurements to the 12–24 h after ablation measurements.

Results

Immediately after ablation, the average hyperecho area in gray-scale was 82.20 ± 72.32 cm³; the average non-enhancement area was 76.34 ± 70.63 cm³ by CEUS, showing a strong correlation (r = 0.997, P < 0.01) to the hyperecho area in gray-scale. The average non-enhancement area measured by CEUS immediately after ablation was 90.55 ± 74.41 cm³ and average 12–24 h after ablation was 98.29 ± 78.25 cm³; no statistically significant difference was detected between the two time points (P > 0.05).

Conclusions

Measurements made by hyperechoic range on gray-scale ultrasonography is strongly correlated to the no enhancement area by CEUS. The hyperechoic range on gray-scale image can represent the ablated area immediately after MW.     

比较肝动脉化疗栓塞联合经皮乙醇注射与联合冷循环微波刀治疗原发性肝癌的疗效

目的比较肝动脉化疗栓塞（TACE）联合经皮乙醇注射（PEI）与TACE联合冷循环微波刀术（PMCT）治疗原发性肝癌的效果。 方法150例患者接受TACE联合PEI,160例患者接受TACE联合PMCT治疗。术后4周复查动态增强CT,观察疗效。 结果TACE+PEI或TACE+PMCT后1个月,肿瘤一次消融率分别为70.00%和87.67%,TACE+PMCT组的疗效要优于TACE+PEI组（P<0.05）。 结论TACE+PMCT是原发性肝癌的有效治疗方法,是单纯TACE疗效不佳者的理想选择。     

Evaluation of contrast medium enhancement and [(18)F]-FDG uptake of liver metastasis in PET/CT prior to therapy

Objective

To evaluate the contrast medium enhancement and [¹⁸F]-FDG uptake of liver metastases in patients suffering from colon or breast carcinoma prior to therapy.

Material and methods

PET/CT (Philips Gemini) with 200 MBq [¹⁸F]-FDG and contrast medium was performed in 50 patients with colon and 39 patients with breast carcinoma. Lesions were characterized with the presence or the absence of a rim enhancement. The area size, the HU_mean, HU_max, SUV_mean, SUV_max of the lesion and of the liver were determined. The standard uptake values (SUVs) were correlated with the tumor markers CEA and CA 15-3.

Results

The lesions of colon carcinoma had HU_mean-values of 70.7 ± 19.2 and of breast carcinoma 88.1 ± 21.7 (p < 0.0001). In breast cancer the SUV_mean was 3.9 ± 1.3 versus 4.4 ± 1.9 in colon carcinoma (p = 0.0182). Lesion of colon carcinoma with rim enhancement had a significantly higher SUV_mean (4.4 ± 1.5 versus 3.6 ± 1.2; p = 0.001) and SUV_max (6.7 ± 2.6 versus 5.1 ± 2.1; p = 0.000) than lesions without a rim enhancement. A good correlation between tumor markers and SUVs_max could be found in both tumor groups; r = 0.83 (p < 0.01) for colon carcinoma and r = 0.82 (p < 0.01) for breast carcinoma.

Conclusions

The rim enhancement of the lesions in colon carcinoma indicate a significantly higher SUV.     

Comparison of multislice computed tomography with intravascular ultrasound for detection and characterization of coronary artery plaques: a systematic review

Purpose

Multislice computed tomography (MSCT) is a novel non-invasive test for detection and analysis of coronary artery plaques. A systematic review was conducted of the literature to compare MSCT with IVUS as the reference standard for assessing coronary artery plaques.

Materials and methods

We performed a literature search in the online database MEDLINE, which was accessed at http://www.pubmed.gov on 9th April 2008.

Results

The search identified 14 studies with 340 patients (mean age 59 ± 5 years). The systematic review revealed a sensitivity of MSCT on the lesion level (n = 1779 coronary plaques) on the order of 90% (range from 87 to 92%) in comparison to IVUS. Per-segment analysis (n = 356) yielded a lower sensitivity of 81-86%. In the per-vessel analysis (n = 90), MSCT had a better sensitivity and specificity for the RCA (83-89% and 92-100%) and the LAD (83-87% and 93%) than for the LCX (71-85% and 77-89%), and on the vessel level and the cross-section analysis MSCT was more sensitive for calcified plaques than for non-calcified plaque. It is noteworthy that most studies provide only incomplete data on technical and methodological parameters such as radiation exposure and patient characteristics.

Conclusion

MSCT is an accurate and reliable test for detection of coronary artery plaques in comparison to IVUS with limitations in regards to the LCX and non-calcified plaques. Studies published thus far are limited by the sample sizes and methodological quality issues.     

MRI estimation of total renal volume demonstrates significant association with healthy donor weight

Purpose

The purpose of this study was to correlate total renal volume (TRV) calculations, obtained through the voxel-count method and ellipsoid formula with various physical characteristics.

Materials and methods

MRI reports and physical examination from 210 healthy kidney donors (420 kidneys), on whom renal volumes were obtained using the voxel-count method, were retrospectively reviewed. These values along with ones obtained through a more traditional method (ellipsoid formula) were correlated with subject height, body weight, body mass index (BMI), and age.

Results

TRV correlated strongly with body weight (r = 0.7) and to a lesser degree with height, age, or BMI (r = 0.5, −0.2, 0.3, respectively). The left kidney volume was greater than the right, on average (p < 0.001). The ellipsoid formula method over-estimated renal volume by 17% on average which was significant (p < 0.001).

Conclusions

Body weight was the physical characteristic which demonstrated the strongest correlation with renal volume in healthy subjects. Given this finding, a formula was derived for estimating the TRV for a given patient based on the his or her weight: TRV = 2.96 × weight (kg) + 113 ± 64.     

Percutaneous excisional biopsy of clinically benign breast lesions with vacuum-assisted system: comparison of three devices

Purpose

The aim of this study was to compare three devices in percutaneous excisional biopsy of clinically benign breast lesions in terms of complete excision rate, duration of procedure and complications.

Materials and methods

In a retrospective study from March 2005 to May 2009, 983 lesions underwent ultrasound-guided excisional biopsy with three vacuum-assisted systems, respectively. The lesions were category 3 lesions as determined by ultrasound imaging according to Breast Imaging Reporting and Data System (BI-RADS) (n = 951) or had been confirmed as benign by a previous core needle biopsy (n = 32). The completely excision rate, duration of procedure and complications (hematoma, pain and ecchymosis) were recorded.

Results

99.7% (980/983) lesions were demonstrated to be benign by pathology after percutaneous excisional biopsy. The overall complete excision rate was 94.8% (932/983). In lesions whose largest diameter equal to or larger than 1.5 cm, the complete excision rates of EnCor^® group (97.8%, 348/356) and Mammotome^® group (97.2%, 139/143) were significantly higher than that of Vacora^® group (91.9%, 445/484) (P < 0.05). The EnCor^® group (6.6 ± 6.5 min) had a significant less duration than Mammotome^® (10.6 ± 9.3 min) and Vacora^® group (25.6 ± 23.3 min) (P < 0.05). Hematoma occurred more in EnCor^® group and Mammotome^® group than in Vacora^® group (P < 0.05).

Conclusions

All these three vacuum-assisted systems are highly successful for excisional biopsy of benign breast lesions.     

Features of time-intensity curve parameters of colorectal adenocarcinomas evaluated by double-contrast enhanced ultrasonography: initial observation

Purpose

This study is to investigate the value of double contrast-enhanced ultrasonography (DCEU) in assessing microcirculation of colorectal adenocarcinomas and to describe the perfusion features of the tumours.

Material and methods

DCEUS was performed in 42 patients with adenocarcinoma. The time–intensity curve parameters (arrival time (AT), time-to-peak (TTP), peak intensity (PI) and area under the curve (AUC)) within the tumours were extracted. The parameters were compared among the tumours with different CEUS features and stages.

Results

The mean values of AT, TTP, PI and AUC of the colorectal adenocarcinomas were 13.68 ± 13.36 s, 32.61 ± 19.56 s, 19.82 ± 16.54 dB and 271.10 ± 159.19 dB s, respectively. In the adenocarcinomas with necrosis, the mean values of AUC was significantly lower than that of the adenocarcinomas without (231.10 ± 219.27 dB s, 278.10 ± 123.20 dB s, p = 0.004). In the adenocarcinomas with necrosis, the AUC and PI of the non-necrotic part were significantly higher than that of the necrotic part (p = 0.007, 0.0025, respectively). AUC increased progressively in the subgroups of T2, T3 and T4 and the difference of AUC between T2 and T4 subgroup was significant (p = 0.008).

Conclusions

Double contrast-enhanced ultrasonography is a valuable technique for quantifying tumour vascularity of colorectal adenocarcinomas. AUC was significantly different in the subgroups of different T stage. AUC and PI could reflect the different perfusion status of tumours with or without necrosis.     

Motion characterization of aortic wall and intimal flap by ECG-gated CT in patients with chronic B-dissection

Rationale and objectives

To evaluate whether dynamic computed tomography (CT)-imaging can provide functional vessel information in patients with chronic aortic dissection type Stanford-B (ADB).

Materials and methods

In 32 patients, ECG-gated CT-angiography images were obtained. Cross-sectional area change and wall distensibility were investigated by semiautomatic vessel area segmentation at the end of aortic arch. Significance of distensibility differences was tested with regard to the aortic diameter, and the oscillation of the intimal flap was analyzed.

Results

The aorta could be segmented successfully in all patients. These were separated into three subgroups: (A) 6 patients with an aortic diameter <4 cm and without a visible intimal flap, (B) 9 patients with an aortic diameter <4 cm, and (C) 17 individuals with an aortic diameter ≥4 cm; (B) and (C) having a visible intimal flap. Differences in distensibility between the subgroups were not significant. Overall mean distensibility was D_tot = (1.3 ± 0.6) × 10⁻⁵ Pa⁻¹. Analysis of intimal flap oscillation showed a pulsatile short axis diameter decrease of the true lumen of up to 29%.

Conclusion

Dynamic, ECG-gated CT-angiography can demonstrate pulsatile changes in aortic area and a highly variable motion of the intimal flap. Aortic distensibility appears independent of diameter or presence of a intimal flap. Follow-up studies may show correlation with possible complications.     

Uterine artery embolization (UAE) for diffuse leiomyomatosis of the uterus: clinical and imaging results

Purpose

The aim of the current study was to evaluate the efficacy of uterine artery embolization (UAE) in the management of diffuse uterine leiomyomatosis with mid-term follow-up.

Materials and methods

All patients who underwent UAE between 2008 and 2010 for symptomatic fibroids were analyzed. Among 360 cases, a total of 7 patients with diffuse uterine leiomyomatosis diagnosed based on MRI were included in this retrospective study. Patient ages ranged from 29 to 38 (mean 32.7) years. The median follow-up period was 16 (range; 6–31) months. The embolic agent was non-spherical polyvinyl alcohol particles. All patients underwent follow-up MRI at 3 months after UAE. Uterine volumes were calculated using MRI. Menorrhagia symptom changes were assessed at mid-term follow-up.

Results

There were no technical failures to catheterize the uterine artery and no adverse events requiring therapy after UAE. Contrast-enhanced MRI showed complete necrosis of the leiomyomatous nodules in 5 patients (71%) 3 months after embolization. Two patients (28%) showed mostly leiomyomatous nodules that were necrotized, some of which were still viable. All 7 patients with menorrhagia had improvement of symptoms at the mid-term follow-up. The initial mean uterine volume was 601.30 ± 533.92 cm³ and was decreased to a mean of 278.81 ± 202.70 cm³ at 3 months follow-up, for a mean uterus volume reduction rate of 50.1% (p < 0.05). One patient became pregnant 5 months after UAE treatment.

Conclusion

UAE was a highly effective treatment for diffuse uterine leiomyomatosis with mid-term durability and may be a valuable alternative to hysterectomy.     

Multipolar radiofrequency ablation using internally cooled electrodes in ex vivo bovine liver: correlation between volume of coagulation and amount of applied energy

Purpose

To evaluate the relationship between applied energy and volume of coagulation induced by multipolar radiofrequency (RF) ablation.

Methods and materials

Multipolar RF ablations (n = 80) were performed in ex vivo bovine liver. Three bipolar applicators with two electrodes located on each applicator shaft were placed in a triangular array. The power-output (75–225 W) and the distance between the different applicators (2, 3, 4, 5 cm) were systematically varied. The volume of confluent white coagulation and the amount of applied energy were assessed. Based on our experimental data the relationship between the volume of coagulation and applied energy was assessed by nonlinear regression analysis. The variability explained by the model was determined by the parameter r².

Results

The volume of coagulation increases with higher amounts of applied energy. The maximum amount of energy was applied at a power-output of 75 W and an applicator distance of 5 cm. The corresponding maximum volume of coagulation was 324 cm³ and required an application of 453 kJ. The relationship between amount of applied energy (E) and volume (V) of coagulation can be described by the function, V = 4.39E^0.7 (r² = 0.88). By approximation the volume of coagulation can be calculated by the linear function V = 0.61E + 40.7 (r² = 0.87).

Conclusion

Ex vivo the relationship between volume of coagulation and amount of applied energy can be described by mathematical modeling. The amount of applied energy correlates to the volume of coagulation and may be a useful parameter to monitor multipolar RF ablation.     

IVIM-DWI of transplanted kidneys: Reduced diffusion and perfusion dependent on cold ischemia time

Purpose

To evaluate the effect of cold ischemia time (CIT) of renal allografts on diffusion and perfusion using intravoxel incoherent motion (IVIM) derived parameters.

Material and methods

A total of 37 patients with renal allografts (CIT: 27 <15 h, 10 ≥15 h) and 30 individuals with healthy kidneys were examined at 1.5 T using a single-shot echo-planar diffusion-weighted pulse sequence with nine b-values ranging from 0 to 800 s/mm². ADC, perfusion fraction f, and the diffusion coefficient D were calculated using the IVIM model. Parameters of allografts stratified by CIT were compared with healthy kidney groups using the Mann–Whitney U test for unpaired data. We computed the Spearman correlation coefficient for correlation with creatinine values.

Results

ADC, D, and f of transplanted kidneys were significantly lower than in the healthy controls. The long-CIT group showed significantly lower diffusion parameters compared with the short-CIT group [mean ± SD]: ADC: 1.63 ± 0.14 μm²/ms, f: 11.90 ± 5.22%, D: 1.55 ± 0.25 μm²/ms versus ADC: 1.79 ± 0.13 μm²/ms, f: 16.12  ± 3.43%, D: 1.73 ± 0.14 μm²/ms, P_ADC, _f, _D < 0.05.

Conclusion

Our results suggest that diffusion parameters, especially the ADC, depend on the CIT of the kidney allograft. Potentially, this stands for functional changes in renal allografts. Diffusion-weighted imaging could be used for follow-up examinations. Thus, diffusion parameters may help guide therapy in patients with delayed graft function.     

Triple-rule-out dual-source CT angiography of patients with acute chest pain: Dose reduction potential of 100kV scanning

Purpose

To investigate the dose reduction potential of low kV triple-rule-out dual-source CT angiography (TRO-CTA) in non-obese (BMI ≤ 25 kg/m²) patients with acute chest pain.

Materials and methods

Sixty consecutive patients were randomly assigned to two different retrospectively ECG-gated TRO-CTA protocols in this prospective trial: Thirty patients were examined with a 120-kV standard protocol (320 reference mAs with automatic tube current modulation, automatically adapted pitch and ECG-pulsing) and served as the control group (group 1), an otherwise identical 100 kV protocol was used in the other thirty patients (group 2) for a radiation dose reduction. Subjective image quality was assessed on a 5 point scale (1: excellent, 5: non-diagnostic) by two blinded observers. Quantitative image analysis assessed vascular attenuation, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in different vascular segments. The effective dose was calculated from the dose length product (DLP) using a conversion coefficient of 0.017 mSv mGy⁻¹ cm⁻¹.

Results

There was no significant difference of age, BMI, heart rate, pitch or scan length between both patient groups. Subjective image quality was rated similar in both groups (group 1: 1.2 ± 0.4, group 2: average score = 1.3 ± 0.5). Vessel attenuation was significantly higher in group 2 than in group 1 (ascending aorta: 456 ± 83 HU vs. 370 ± 78 HU, p < 0.001; pulmonary artery: 468 ± 118 HU vs. 411 ± 91 HU, p = 0.03; left coronary artery: 437 ± 110 HU vs. 348 ± 89 HU, p < 0.001), however, there was no significant difference in SNR (13.2 ± 7.6 vs. 14.5 ± 7.5, p = 0.49) or CNR (13.8 ± 6.6 vs. 15.9 ± 7.7, p = 0.25). The effective radiation dose of the 100 kV protocol was significantly lower (9.6 ± 3.2 mSv vs. 18.1 ± 9.4 mSv, p < 0.0001).

Conclusion

TRO-CTA with 100 kV is feasible in non-obese patients and results in diagnostic image quality and significantly reduced radiation dose.     

The evaluation of anti-angiogenic treatment effects for implanted rabbit VX2 breast tumors using functional multi-slice spiral computed tomography (f-MSCT)

Objective

Investigate the benefit of functional multi-slice spiral computed tomography (f-MSCT) perfusion imaging in the non-invasive assessment of targeted anti-angiogenesis therapy on an implanted rabbit VX2 breast tumor model.

Method

69 female pure New Zealand white rabbits were randomly assigned to one of the 4 groups and received treatment accordingly: control (saline), Endostar, neoadjuvant chemotherapy (Cyclophosphamide, Epirubicin and 5-Fluorouracil, CEF), combination therapy (Endostar and CEF). After 2 weeks of treatment, f-MSCT perfusion scannings were performed for all rabbits and information about blood flow (BF), blood volume (BV), mean transit time (MTT) and surface permeability (SP) was collected. After perfusion imaging, tumor tissues were sampled for immunohistochemistry and the Western blot test of VEGF protein expression.

Results

(1) The VEGF expression level, measured by immunohistochemistry and Western blot, decreased by treatment group (control > Endostar > CEF > combination therapy). The same was true for the mean BF, BV, MTT and PS, which decreased from the control group to the combination therapy group gradually. The mean MTT level increased in reverse order from the control to the combination therapy group. The difference between any 2 groups on these measures was statistically significant (P < 0.05). (2) There was moderate positive correlation between VEGF expression and BE, BV, or PS level (P < 0.05) and a negative correlation between VEGF expression and MTT level for all 4 groups (P < 0.05).

Conclusion

Therefore, f-MSCT can be used as a non-invasive approach to evaluate the effect of anti-angiogenic therapy for implanted rabbit VX2 breast tumors.     

Dual-energy CT-cholangiography in potential donors for living-related liver transplantation: improved biliary visualization by intravenous morphine co-medication

Purpose

To prospectively evaluate whether intravenous morphine co-medication improves bile duct visualization of dual-energy CT-cholangiography.

Materials and methods

Forty potential donors for living-related liver transplantation underwent CT-cholangiography with infusion of a hepatobiliary contrast agent over 40 min. Twenty minutes after the beginning of the contrast agent infusion, either normal saline (n = 20 patients; control group [CG]) or morphine sulfate (n = 20 patients; morphine group [MG]) was injected. Forty-five minutes after initiation of the contrast agent, a dual-energy CT acquisition of the liver was performed. Applying dual-energy post-processing, pure iodine images were generated. Primary study goals were determination of bile duct diameters and visualization scores (on a scale of 0 to 3: 0—not visualized; 3—excellent visualization).

Results

Bile duct visualization scores for second-order and third-order branch ducts were significantly higher in the MG compared to the CG (2.9 ± 0.1 versus 2.6 ± 0.2 [P < 0.001] and 2.7 ± 0.3 versus 2.1 ± 0.6 [P < 0.01], respectively). Bile duct diameters for the common duct and main ducts were significantly higher in the MG compared to the CG (5.9 ± 1.3 mm versus 4.9 ± 1.3 mm [P < 0.05] and 3.7 ± 1.3 mm versus 2.6 ± 0.5 mm [P < 0.01], respectively).

Conclusion

Intravenous morphine co-medication significantly improved biliary visualization on dual-energy CT-cholangiography in potential donors for living-related liver transplantation.     

Radiofrequency ablation of the liver abutting stomach: in vivo comparison of gastric injury before and after intragastric saline administration in a porcine model

Purpose

To compare the in vivo gastric injury observed during radiofrequency (RF) ablation of the liver abutting the stomach before and after the intragastric administration of chilled saline.

Materials and methods

Twenty RF ablation zones were created in the livers of 10 pigs with a 1-cm-exposed active tip of an internally cooled electrode under ultrasound guidance for 10 min. Ten RF ablation zones were created before (non-saline group) and after (saline group) the intragastric administration of approximately 1000 mL of chilled saline, and 20 RF ablation zones were made in the posterior part of the left lobe abutting the stomach. The frequency and severity of the thermal injury observed in the stomach of the two groups were compared histologically.

Results

All the resected gastric specimens showed thermal injuries of varying degrees of severity. The largest diameter of the gastric injury was significantly smaller in the saline group (mean 1.5 cm; range 1.3-1.8 cm) than in the non-saline group (mean 2.1 cm; range 1.8-2.4 cm) (p = 0.000). The saline group showed significantly less thermal injury to the muscular layer of the gastric wall by the histopathology (p = 0.033).

Conclusions

The intragastric administration of chilled saline might be a useful technique for reducing the severity of gastric injury during RF ablation of the liver abutting the stomach.     

Thyroid size change by CT monitoring after sorafenib or sunitinib treatment in patients with renal cell carcinoma: comparison with thyroid function

Objective

Hypothyroidism is a common complication in patients receiving tyrosine kinase inhibitors. We evaluated the relationship between thyroid size evident on CT and thyroid function in patients with advanced renal cell carcinoma (RCC) receiving tyrosine kinase inhibitors.

Materials and methods

Forty-two patients with metastatic RCC receiving tyrosine kinase inhibitors (sorafenib n = 25; sunitinib n = 17) and, followed-up for ≥12 months were eligible. Patients who had ever shown an elevated thyroid-stimulating hormone (TSH) level of >10 mU/l were defined as having “hypothyroidism”. CT scans were performed before, and 3, 6, 9, and 12 months after the start of treatment. The area of the thyroid in the maximum section at each examination was measured and compared with that before treatment. Using repeated-measures ANOVA, differences in thyroid size were compared over time between patients with and without “hypothyroidism”, in relation to the type of drug employed.

Results

Twenty-one patients (sorafenib 9, sunitinib 12) developed “hypothyroidism” 95 ± 88 days (range 12–315 days) after the start of treatment. In such patients, the thyroid was reduced in size to 89 ± 16% after 3 months, 81 ± 21% after 6 months, 71 ± 21% after 9 months and 68 ± 21% after 12 months, whereas the patients without “hypothyroidism” maintained a thyroid size of 90 ± 12% even after 12 months (p = 0.0030). Among the patients with “hypothyroidism”, those treated with sunitinib tended to show greater thyroid size reduction than those with sorafenib (59 ± 23% vs. 79 ± 13%, after 12 months).

Conclusion

Tyrosine kinase inhibitors cause an apparent thyroid size reduction in patients with “hypothyroidism”.     

Low dose dual-source CT angiography in infants with complex congenital heart disease: a randomized study

Objectives

To investigate the radiation dose and image quality of prospective ECG-triggering dual-source CT angiography in infants with complex congenital heart disease (CHD) in comparison with retrospective ECG-gated scanning.

Methods

Ninety-six infants less than 1 year old (60/36 male/female, age: 4.8 ± 2.7 months, weight: 5.8 ± 1.8 kg) with complex CHD were enrolled. Three image acquisition protocols were set: group 1: 80 kV, 100 mA, retrospective ECG-gated protocol; group 2: 80 kV, 100 mA, prospective ECG-triggering protocol with acquisition window of 380 ms; group 3: 80 kV, 100 mA, prospective ECG-triggering protocol with acquisition window of 200 ms. Patients were selected to any one of the protocols randomly. The signal-to-noise ratios (SNR) were calculated in the ascending aorta and the pulmonary artery trunk. Image quality was assessed by a five-point score. A score of <3 represents non-diagnostic. Effective radiation dose (ED) was calculated.

Results

Image quality score of groups 1, 2 and 3 were 4.1 ± 0.4, 4.0 ± 0.6 and 4.2 ± 0.6 (p = 0.224). SNR of ascending aorta and pulmonary artery trunk among them had no statistical difference (all p > 0.05). The average ED (median) of groups 1, 2 and 3 were 1.17 ± 0.07 mSv (1.25 mSv), 0.72 ± 0.24 mSv (0.78 mSv) and 0.48 ± 0.41 mSv (0.39 mSv). Any two of the three groups had significant differences (all p < 0.001).

Conclusion

Prospective ECG-triggering DSCT angiography associated with a significantly lower ED than retrospective protocol, while maintaining image quality for diagnosis. Prospective ECG-triggering DSCT angiography could be used as a very important second-line diagnostic tool in infants with complex CHD.     

Multikinase inhibitor sorafenib transiently promotes necrosis after radiofrequency ablation in rat liver but activates growth signals

Aim

To investigate the effects of sorafenib when combined with radiofrequency ablation treatment in liver tissue, the necrosis volume, tissue repair and hepatocellular growth signals were analyzed in rats. Radiofrequency ablation (RFA) is a widely applied treatment for hepatocellular carcinoma (HCC). Radiofrequency ablation is combined with the multi-tyrosinkinase-inhibitor sorafenib in ongoing clinical trials. Whether this combination treatment affects liver tissue repair is unknown.

Materials and methods

Male Sprague Dawley (SD) rats received RFA or sham puncture with concomitant sorafenib (5 mg/kg qd from day 2) or vehicle. Necrosis volume was calculated from resected specimens. Proliferation and micro vessel density were determined by Ki67 and CD31 immunofluorescence, respectively. mRNA expression of hepatocyte growth factor (HGF), epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) was quantified.

Results

While ablation size was identical in all treatment groups at day 1, sorafenib treated animals showed sustained necroses (219 ± 24 vs. 88 ± 52 mm³ in controls; P = 0.03), elevated alanine aminotransferase (ALT) and elevated glutamate dehydrogenase (GLDH) (76 ± 37 vs. 47 ± 58 mm³; P = 0.50) at day 3. By day 7 necrosis volumes equalized for the treatment groups. Ki67 and CD31 staining showed reduced proliferation and micro vessel density at days 1 and 3 following sorafenib. Growth factors HGF and EGF were significantly overexpressed in liver tissue after sorafenib.

Conclusion

Sorafenib initially promotes necrosis after RFA in liver tissue. The delay in tissue repair is overcome at day 7 presumably by transient compensatory overexpression of growth signals. Based on these data from animal studies further investigation of adjuvant sorafenib in humans is warranted.