Whole tumour quantitative measurement of first-pass perfusion of oesophageal squamous cell carcinoma using 64-row multidetector computed tomography: Correlation with microvessel density

Purpose

To assess correlations between whole tumour first-pass perfusion parameters obtained with 64-row multidetector computed tomography (MDCT), and microvessel density (MVD) in oesophageal squamous cell carcinoma.

Materials and Methods

Thirty-one consecutive patients with surgically confirmed oesophageal squamous cell carcinomas were enrolled into our study. All the patients underwent whole tumour first-pass perfusion scan with 64-row MDCT. Perfusion parameters, including perfusion (PF), peak enhanced density (PED), blood volume (BV), and time to peak (TTP) were measured using Philips perfusion software. Postoperative tumour specimens were assessed for MVD. Pearson correlation coefficient tests were performed to determine correlations between each perfusion parameter and MVD.

Results

Mean values for PF, PED, BV and TTP of the whole tumour were 28.85 ± 20.29 ml/min/ml, 23.16 ± 8.09 HU, 12.13 ± 5.21 ml/100 g, and 35.05 ± 13.85 s, respectively. Mean MVD in whole tumour at magnification (×200) was 15.75 ± 4.34 microvessel/tumour sample (vessels/0.723 mm²). PED and BV were correlated with MVD (r = 0.651 and r = 0.977, respectively, all p < 0.05). However, PF and TTP were not correlated with MVD (r = 0.070 and r = 0.100, respectively, all p > 0.05).

Conclusion

The BV value of first-pass perfusion CT could reflect MVD in oesophageal squamous cell carcinoma, and can be an indicator for evaluating the tumour angiogenesis.     

First-pass perfusion computed tomography: Initial experience in differentiating adrenal adenoma from metastasis

Objective

To differentiate adrenal adenoma from metastasis in patients using perfusion computed tomography (PCT) imaging.

Methods

Thirty-two patients with adrenal masses underwent first-pass PCT imaging. Of these patients, twenty-one were diagnosed with adrenal adenoma, and the others with metastases. Perfusion maps of blood volume (BV), blood flow (BF), mean transit time (MTT) and permeability surface-area production (PS) were generated with an Advantage Windows workstation using the CT perfusion 3.0 software (General Electric Medical Systems, Milwaukee, WI). Histopathologic sections immunostained for CD34 were quantitatively evaluated for microvessel density (MVD).

Results

The perfusion parameters such as BV, BF and PS were statistically significant different between the two groups, with adenomas showing higher mean BV (12.18 versus 3.86), BF (97.51 versus 45.99) and PS (21.73 versus 10.93) compared with metastases (p < 0.05). For BV, a cutoff point of 7.30 was found to have a sensitivity of 95.2% and a specificity of 100% to differentiate between adenoma and metastasis. The sensitivity and specificity were 81.0 and 80.0%, respectively, for BF with a cutoff point of 71.96; and 85.7 and 86.7%, respectively, for PS with a cutoff point of 12.70 to differentiate adenoma and metastasis. A comparison of MVD counts from adenomas with those from metastases showed a significant difference (p < 0.05). However, no significant differences were observed in the four perfusion parameters and MVD between lipid rich and lipid poor adenomas.

Conclusion

PCT may be useful for evaluating the neovascularization of adrenal masses and differentiating adenoma from metastasis on the basis of PCT parameters. Adenomas show higher BV, BF and PS compared with metastases. According our data, the optimal threshold BV is 7.30, resulting in a sensitivity of 95.2% and a specificity of 100% for the differentiation of adenoma from metastasis. Adrenal adenomas have similar hemodynamic profiles, which are apparently independent of the lipid content of an adenoma.     

Dynamic susceptibility contrast perfusion MR imaging in distinguishing malignant from benign head and neck tumors: A pilot study

Purpose

To preliminarily investigate the utility of dynamic susceptibility contrast perfusion MR imaging in distinguishing malignant from benign head and neck tumors.

Material and methods

Seventy eight patients with head and neck masses underwent single shot dynamic susceptibility contrast T2*-weighted perfusion weighted MR imaging after bolus infusion of gadolinium-DTPA was administrated. The signal intensity time curve of the lesion was created. Dynamic susceptibility contrast percentage (DSC%) was calculated and correlated with pathological findings.

Results

The mean DSC% of malignant tumor (n = 40) was 39.3 ± 9.6% and of benign lesions (n = 38) was 24.3 ± 10.3%. There was a statistically significant difference of the DSC% between benign and malignant tumors (P = 0.001) and within benign tumors (P = 0.001). When DSC% of 30.7% was used as a threshold for differentiating malignant from benign tumors, the best results were obtained: accuracy of 84.6%, sensitivity of 80% and specificity of 89.2%.

Conclusion

Dynamic susceptibility contrast perfusion weighted MR imaging is a non-invasive imaging technique that can play a role in differentiation between malignant and benign head and neck tumors.     

The utility of high b-value DWI in evaluation of ischemic stroke at 3 T

Purpose

The utility of DWI with high b-value in ischemic stroke is still unsettled. The purpose of this study is to compare high b-value (3000) and standard b-value (1000) diffusion-weighted images in patients with ischemic stroke at 3 T.

Materials and methods

27 patients with acute stroke who were admitted to the hospital during the first 24 h after symptom onset were included in this study. All patients had a brain MRI study with stroke protocol including standard (b = 1000) DWI and high b-value (b = 3000) DWI sequences at 3 T MR scanner.Number and localization of the lesions were assessed MR signal intensities (SI), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), contrast ratio (CR) and apparent diffusion coefficient (ADC) values of the lesions and normal parenchyma on DWI with b = 1000 and b = 3000 sequences were measured.

Results

All patients with acute stroke revealed hyperintense lesions due to restricted diffusion on DWI with both b-values. However, lesions of restricted diffusion were more conspicuous in b = 3000 value DWI than b = 1000, and additional 4 ischemic lesions were detected on b = 3000 DWI. SNR, CNR, SI and also ADC values in both stroke area and normal parenchyma were lower at b = 3000 than the value at b = 1000. At b = 3000, CR was significantly greater than b = 1000 images.

Conclusions

Although quantitative analysis shows higher SI, SNR and CNR values with standard b-value (b = 1000) diffusion-weighted imaging, using higher b-value may still be beneficial in detecting additional subtle lesions in patients whose clinical findings are not correlated with standard b-value DWI in stroke.     

Hepatic perfusion changes in an experimental model of acute pancreatitis: Evaluation by perfusion CT

Purpose

It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT.

Materials and methods

Forty Sprague-Dawley rats of both genders with average weights of 250 g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student's t test was used for statistical analyses.

Results

In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p < 0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance.

Conclusion

The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes.     

Left anterior descending coronary artery myocardial bridging by multislice computed tomography: Correlation with clinical findings

Objective

To assess the relationship between left anterior descending (LAD) coronary artery myocardial bridging detected by 64-slice computed tomography (CT) and clinical findings.

Methods

221 consecutive patients were examined with coronary 64-slice CT angiography. 21 patients with coronary stenosis >50% were excluded. The length, depth, and luminal narrowing of LAD myocardial bridges during systole and diastole were measured. CT findings were compared with the treadmill ECG-stress test, and clinical symptoms.

Results

Myocardial bridges of the LAD were found in 23% of patients (51/221) (length, 14.9 ± 6.5 mm; depth, 2.6 ± 1.6 mm). A significant difference was noted between the LAD luminal diameter before the intramyocardial course and intramyocardially, for both diastole and systole (p < 0.001); with a higher diameter reduction of 27% for end-systole compared to end-diastole with 15% (p = 0.006). Systolic LAD intramyocardial luminal narrowing >50% was found in 3/25 (8%). 30/51 (59%) of bridges were “deep” (>2 mm myocardial depth), 21/51 (41%) were “superficial”. The prevalence of a positive ECG-stress tests for the anterior myocardial region was significantly higher in patients with LAD myocardial bridges (34/50; 68%) compared to those without (28/144; 19.4%) (p < 0.001). There was no difference between “superficial” and “deep” LAD myocardial bridges in regard to a positive treadmill ECG-stress test. Typical angina was rare with 6%.

Conclusion

LAD myocardial bridges are common findings and can possibly explain a positive exercise ECG-stress test for anterior myocardial ischemia. Intramyocardial LAD segments show mild-to-moderate luminal narrowing at rest, which is higher during end-systolic phase.     

Measurement of canine pancreatic perfusion using dynamic computed tomography: Influence of input-output vessels on deconvolution and maximum slope methods

Objective

We investigated whether the prerequisite of the maximum slope and deconvolution methods are satisfied in pancreatic perfusion CT and whether the measured parameters between these algorithms are correlated.

Methods

We examined nine beagles injected with iohexol (200 mgI kg⁻¹) at 5.0 ml s⁻¹. The abdominal aorta and splenic and celiac arteries were selected as the input arteries and the splenic vein, the output veins. For the maximum slope method, we determined the arterial contrast volume of each artery by measuring the area under the curve (AUC) and compared the peak enhancement time in the pancreas with the contrast appearance time in the splenic vein. For the deconvolution method, the artery-to-vein collection rate of contrast medium was calculated. We calculated the pancreatic tissue blood flow (TBF), tissue blood volume (TBV), and mean transit time (MTT) using both algorithms and investigated their correlation based on vessel selection.

Results

The artery AUC significantly decreased as it neared the pancreas (P < 0.01). In all cases, the peak time of the pancreas (11.5 ± 1.6) was shorter than the appearance time (14.1 ± 1.6) in the splenic vein. The splenic artery-vein combination exhibited the highest collection rate (91.1%) and was the only combination that was significantly correlated between TBF, TBV, and MTT in both algorithms.

Conclusion

Selection of a vessel nearest to the pancreas is considered as a more appropriate prerequisite. Therefore, vessel selection is important in comparison of the semi-quantitative parameters obtained by different algorithms.     

Measurement of ventilation- and perfusion-mediated cooling during laser ablation in ex vivo human lung tumors

Purpose

Perfusion-mediated tissue cooling has often been described in the literature for thermal ablation therapies of liver tumors. The objective of this study was to investigate the cooling effects of both perfusion and ventilation during laser ablation of lung malignancies.

Materials and methods

An ex vivo lung model was used to maintain near physiological conditions for the specimens. Fourteen human lung lobes containing only primary lung tumors (non-small cell lung cancer) were used. Laser ablation was carried out using a Nd:YAG laser with a wavelength of 1064 nm and laser fibers with 30 mm diffusing tips. Continuous invasive temperature measurement in 10 mm distance from the laser fiber was performed. Laser power was increased at 2 W increments starting at 10 W up to a maximum power of 12-20 W until a temperature plateau around 60 °C was reached at one sensor. Ventilation and perfusion were discontinued for 6 min each to assess their effects on temperature development.

Results

The experiments lead to 25 usable temperature profiles. A significant temperature increase was observed for both discontinued ventilation and perfusion. In 6 min without perfusion, the temperature rose about 5.5 °C (mean value, P < 0.05); without ventilation it increased about 7.0 °C (mean value, P < 0.05).

Conclusion

Ventilation- and perfusion-mediated tissue cooling are significant influencing factors on temperature development during thermal ablation. They should be taken into account during the planning and preparation of minimally invasive lung tumor treatment in order to achieve complete ablation.     

Functional imaging in the assessment of myocardial infarction: MR imaging vs. MDCT vs. SPECT

Purpose

To intraindividually compare magnetic resonance (MR) imaging, ECG-gated multi-detector spiral computed tomography (MDCT) and gated single photon emission computed tomography (SPECT) for the evaluation of global and regional myocardial function and the identification of myocardial perfusion abnormalities.

Materials and methods

Nine patients (8 men; 55.1 ± 8.9 years) with a history of myocardial infarction (MI) were included in this retrospective study. All patients had undergone segmented k-space steady state free precession MR imaging, ^99mTc-MIBI gated myocardial perfusion SPECT and contrast enhanced ECG-gated 16-MDCT. Ventricular volumes and ejection fraction (EF) were calculated. Left ventricular (LV) wall motion at rest was analyzed. For SPECT and arterial phase MDCT perfusion abnormalities were assessed. Data was compared with Lin's concordance-correlation coefficient (ρ_c), Bland-Altman plots and kappa statistics.

Results

For EF, there was an excellent concordance and correlation (ρ_c = 0.99) between SPECT (EF = 41.7 ± 10.4%), MDCT (EF = 42.2 ± 11.1%), and MR imaging (EF = 41.9 ± 11.4%). Considering MR imaging as standard of reference, MDCT (κ = 0.86) is superior to SPECT (κ = 0.51) for the assessment of the regional wall motion at rest. There was a good agreement between SPECT and MDCT regarding the detection of perfusion abnormalities (κ = 0.62).

Conclusion

MDCT, MR imaging, and SPECT allow for the reliable assessment of global and regional left ventricular function in patients with a history of MI. MDCT also allows to some extent for the detection of perfusion abnormalities. With its potential to assess both, the coronary arteries as well as the myocardium, MDCT a promising modality for the comprehensive diagnostic work-up in patients with suspected myocardial ischemia.     

Improved visualization of delayed perfusion in lung MRI

Introduction

The investigation of pulmonary perfusion by three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was proposed recently. Subtraction images are generated for clinical evaluation, but temporal information is lost and perfusion defects might therefore be masked in this process. The aim of this study is to demonstrate a simple analysis strategy and classification for 3D-DCE-MRI perfusion datasets in the lung without omitting the temporal information.

Materials and methods

Pulmonary perfusion measurements were performed in patients with different lung diseases using a 1.5 T MR-scanner with a time-resolved 3D-GRE pulse sequence. 25 3D-volumes were acquired after iv-injection of 0.1 mmol/kg KG Gadolinium-DTPA. Three parameters were determined for each pixel: (1) peak enhancement S_n,max normalized to the arterial input function to detect regions of reduced perfusion; (2) time between arterial peak enhancement in the large pulmonary artery and tissue peak enhancement τ to visualize regions with delayed bolus onset; and (3) ratio R = S_n,max/τ was calculated to visualize impaired perfusion, irrespectively of whether related to reduced or delayed perfusion.

Results

A manual selection of peak perfusion images is not required. Five different types of perfusion can be found: (1) normal perfusion; (2) delayed non-reduced perfusion; (3) reduced non-delayed perfusion; (4) reduced and delayed perfusion; and (5) no perfusion. Types II and IV could not be seen in subtraction images since the temporal information is necessary for this purpose.

Conclusions

The analysis strategy in this study allows for a simple and observer-independent visualization and classification of impaired perfusion in dynamic contrast-enhanced pulmonary perfusion MRI by using the temporal information of the datasets.     

State-of-the-art radiological techniques improve the assessment of postoperative lung function in patients with non-small cell lung cancer

Purpose

The purpose of this study was to compare predictive capabilities for postoperative lung function in non-small cell lung cancer (NSCLC) patients of the state-of-the-art radiological methods including perfusion MRI, quantitative CT and SPECT/CT with that of anatomical method (i.e. qualitative CT) and traditional nuclear medicine methods such as planar imaging and SPECT.

Materials and methods

Perfusion MRI, CT, nuclear medicine study and measurements of %FEV₁ before and after lung resection were performed for 229 NSCLC patients (125 men and 104 women). For perfusion MRI, postoperative %FEV₁ (po%FEV₁) was predicted from semi-quantitatively assessed blood volumes within total and resected lungs, for quantitative CT, it was predicted from the functional lung volumes within total and resected lungs, for qualitative CT, from the number of segments of total and resected lungs, and for nuclear medicine studies, from uptakes within total and resected lungs. All SPECTs were automatically co-registered with CTs for preparation of SPECT/CTs. Predicted po%FEV₁s were then correlated with actual po%FEV₁s, which were measured %FEV₁s after operation. The limits of agreement were also evaluated.

Results

All predicted po%FEV₁s showed good correlation with actual po%FEV₁s (0.83 ≤ r ≤ 0.88, p < 0.0001). Perfusion MRI, quantitative CT and SPECT/CT demonstrated better correlation than other methods. The limits of agreement of perfusion MRI (4.4 ± 14.2%), quantitative CT (4.7 ± 14.2%) and SPECT/CT (5.1 ± 14.7%) were less than those of qualitative CT (6.0 ± 17.4%), planar imaging (5.8 ± 18.2%), and SPECT (5.5 ± 16.8%).

Conclusions

State-of-the-art radiological methods can predict postoperative lung function in NSCLC patients more accurately than traditional methods.     

Dual-energy CT angiography of chronic thromboembolic disease: Can it help recognize links between the severity of pulmonary arterial obstruction and perfusion defects?

Purpose

To evaluate whether dual-energy CT angiography (DE-CTA) could identify links between morphologic and functional abnormalities in chronic pulmonary thromboembolism (CPTE).

Materials and methods

Seventeen consecutive patients with CPTE without underlying cardio-respiratory disease were investigated with DE-CTA. Two series of images were generated: (a) transverse diagnostic scans (i.e., contiguous 1-mm thick averaged images from both tubes), and (b) perfusion scans (i.e., images of the iodine content within the microcirculation; 4-mm thick MIPs). Two radiologists evaluated by consensus the presence of: (a) pulmonary vascular features of CPTE and abnormally dilated systemic arteries on diagnostic CT scans, and (b) perfusion defects of embolic type on perfusion scans.

Results

Diagnostic examinations showed a total of 166 pulmonary arteries (166/833; 19.9%) with features of CPTE, more frequent at the level of peripheral than central arteries (8.94 vs 0.82; p < 0.0001), including severe stenosis with partial (97/166; 58.4%) or complete (20/166; 12.0%) obstruction, webs and bands (37/166; 22.3%), partial filling defects without stenosis (7/166; 4.2%), focal stenosis (4/166; 2.4%) and abrupt vessel narrowing (1/166; 0.6%). Perfusion examinations showed 39 perfusion defects in 8 patients (median number: 4.9; range: 1-11). The most severe pulmonary arterial features of CPTE were seen with a significantly higher frequency in segments with perfusion defects than in segments with normal perfusion (p < 0.0001). Enlarged systemic arteries were observed with a significantly higher frequency ipsilateral to lungs with perfusion defects (9/12; 75%) compared with lungs without perfusion defects (5/22; 22.7%) (p = 0.004).

Conclusion

Dual-energy CTA demonstrates links between the severity of pulmonary arterial obstruction and perfusion impairment, influenced by the degree of development of the systemic collateral supply.     

CT-guided percutaneous lung biopsy: comparison of conventional CT fluoroscopy to CT fluoroscopy with electromagnetic navigation system in 60 consecutive patients

Purpose

To determine if use of an electromagnetic navigation system (EMN) decreases radiation dose and procedure time of CT fluoroscopy guided lung biopsy in lesions smaller than 2.5 cm.

Materials/methods

86 consecutive patients with small lung masses (<2.5 cm) were approached. 60 consented and were randomized to undergo biopsy with CT fluoroscopy (CTF) (34 patients) or EMN (26 patients). Technical failure required conversion to CTF in 8/26 EMN patients; 18 patients completed biopsy with EMN. Numerous biopsy parameters were compared as described below.

Results

Average fluoroscopy time using CTF was 28.2 s compared to 35.0 s for EMN (p = 0.1). Average radiation dose was 117 mGy using CTF and 123 mGy for EMN (p = 0.7). Average number of needle repositions was 3.7 for CTF and 4.4 for EMN (p = 0.4). Average procedure time was 15 min for CTF and 20 min for EMN (p = 0.01). There were 7 pneumothoracesin the CTF group and 6 pneumothoraces in the EMN group (p = 0.7). One pneumothorax in the CTF group and 3 pneumothoraces in the EMN group required chest tube placement (p = 0.1). One pneumothorax patient in each group required hospital admission. Diagnostic specimens were obtained in 31/34 patients in the CTF group and 22/26 patients in the EMN group (p = 0.4).

Conclusions

EMN was not statistically different than CTF for fluoroscopy time, radiation dose, number of needle repositions, incidence of pneumothorax, need for chest tube, or diagnostic yield. Procedure time was increased with EMN.     

Perfusion CT in cirrhotic patients with early stage hepatocellular carcinoma: Assessment of tumor-related vascularization

Purpose

To assess the value of CT-perfusion in determining the quantitative vascularization features of early hepatocellular carcinoma (HCC) in cirrhotic patients.

Materials and methods

A total of 35 cirrhotic patients with single histologically proven HCC not exceeding 3 cm in diameter underwent conventional triple-phase multidetector computed tomography (MDCT) examination. All patients were also examined with CT-perfusion (CTp) technique after i.v. injection of 50 mL of iodinated contrast. Data were analyzed using a dedicated software which generated a quantitative map of liver parenchyma perfusion. The following parameters were assessed: hepatic perfusion (HP); blood volume (BV); arterial perfusion (AP); time to peak (TTP) and hepatic perfusion index (HPI). Univariate Wilcoxon signed rank test was used for statistical analysis.

Results

In the 35 HCCs evaluated, the following quantitative data were obtained: HP (mL/s/100 g): median = 47.0 (1^stqt = 35.5; 3^stqt = 61.2); BV (mL/100 mg): median = 22.5 (1^stqt = 18.4; 3^stqt = 27.7); AP (mL/min): median = 42.9 (1^stqt = 35.8; 3^stqt = 55.6); HPI(%): median = 75.3 (1^stqt = 63.1; 3^stqt = 100); TTP(s): median = 18.7 (1^stqt = 16.8; 3^stqt = 24.5). Perfusion values calculated in cirrhotic liver parenchyma were HP: median = 10.3 (1^stqt = 9.1; 3^stqt = 13.2); BV: median = 11.7 (1^stqt = 9.6; 3^stqt = 15.5); AP: median = 10.4 (1^stqt = 8.6; 3^stqt = 11.3); HPI: median = 17.5 (1^stqt = 14.3; 3^stqt = 19.7); TTP: median = 44.6 (1^stqt = 40.3; 3^stqt = 50.1). HP, BV, HPI and AP were found to be significantly higher in HCC lesion than in liver parenchyma (p < 0.001), while TTP was significantly lower (p < 0.001).

Conclusion

CT-perfusion technique allows obtaining quantitative information about tumor-related vascularization of early HCC, in patients with liver cirrhosis.     

Dynamic volume perfusion CT in patients with lung cancer: Baseline perfusion characteristics of different histological subtypes

Objective

To evaluate dynamic volume perfusion CT (dVPCT) tumor baseline characteristics of three different subtypes of lung cancer in untreated patients.

Materials and methods

173 consecutive patients (131 men, 42 women; mean age 61 ± 10 years) with newly diagnosed lung cancer underwent dVPCT prior to biopsy. Tumor permeability, blood flow (BF), blood volume (BV) and mean transit time (MTT) were quantitatively assessed as well as tumor diameter and volume. Tumor subtypes were histologically determined and compared concerning their dVPCT results. dVPCT results were correlated to tumor diameter and volume.

Results

Histology revealed adenocarcinoma in 88, squamous cell carcinoma in 54 and small cell lung cancer (SCLC) in 31 patients. Tumor permeability was significantly differing between adenocarcinoma, squamous cell carcinoma and SCLC (all p < 0.05). Tumor BF and BV were higher in adenocarcinomathan in SCLC (p = 0.001 and p = 0.0002 respectively). BV was also higher in squamous cell carcinoma compared to SCLC (p = 0.01). MTT was not differing between tumor subtypes. Regarding all tumors, tumor diameter did not correlate with any of the dVPCT parameters, whereas tumor volume was negatively associated with permeability, BF and BV (r = −0.22, −0.24, −0.24, all p < 0.05). In squamous cell carcinoma, tumor diameter und volume correlated with BV (r = 0.53 and r = −0.40, all p < 0.05). In SCLC, tumor diameter und volume correlated with MTT (r = 0.46 and r = 0.39, all p < 0.05). In adenocarcinoma, no association between morphological and functional tumor characteristics was observed.

Conclusions

dVPCT parameters are only partially related to tumor diameter and volume and are significantly differing between lung cancer subtypes.     

Co-registered perfusion SPECT/CT: Utility for prediction of improved postoperative outcome in lung volume reduction surgery candidates

Purpose

To directly compare the capabilities of perfusion scan, SPECT, co-registered SPECT/CT, and quantitatively and qualitatively assessed MDCT (i.e. quantitative CT and qualitative CT) for predicting postoperative clinical outcome for lung volume reduction surgery (LVRS) candidates.

Materials and methods

Twenty-five consecutive candidates (19 men and six women, age range: 42-72 years) for LVRS underwent preoperative CT and perfusion scan with SPECT. Clinical outcome of LVRS for all subjects was also assessed by determining the difference between pre- and postoperative forced expiratory volume in 1 s (FEV₁) and 6-min walking distance (6MWD). All SPECT examinations were performed on a SPECT scanner, and co-registered to thin-section CT by using commercially available software. On planar imaging, SPECT and SPECT/CT, upper versus lower zone or lobe ratios (U/Ls) were calculated from regional uptakes between upper and lower lung fields in the operated lung. On quantitatively assessed CT, U/L for all subjects was assessed from regional functional lung volumes. On qualitatively assessed CT, planar imaging, SPECT and co-registered SPECT/CT, U/Ls were assessed with a 4-point visual scoring system. To compare capabilities of predicting clinical outcome, each U/L was statistically correlated with the corresponding clinical outcome.

Results

Significantly fair or moderate correlations were observed between quantitatively and qualitatively assessed U/Ls obtained with all four methods and clinical outcomes (−0.60 ≤ r ≤ −0.42, p < 0.05).

Conclusion

Co-registered perfusion SPECT/CT has better correlation with clinical outcome in LVRS candidates than do planar imaging, SPECT or qualitatively assessed CT, and is at least as valid as quantitatively assessed CT.     

Early and late-onset acute GvHD following hematopoietic cell transplantation: CT features of gastrointestinal involvement with clinical and pathological correlation

Objective

With the introduction of non-myeloablative hematopoietic cell transplantation, acute graft-versus-host-disease (GvHD) is frequently observed beyond the traditional 100 days cut-off.The aim of this study was to describe and compare CT features of gastrointestinal early and late-onset GvHD and to correlate findings with clinical and pathology grading.

Subjects and methods

Abdominal CT scans were obtained in 20 patients with early and 15 with late-onset GvHD. Examinations were assessed for intestinal and extraintestinal abnormalities and findings compared between the two subgroups of GvHD. Distinct CT abnormalities as well as a CT-score integrating multiple pathologies were correlated with gut, clinical or pathology grading.

Results

Frequent intestinal abnormalities included wall thickening, abnormal enhancement, and excessive fluid-filling (94%, 89%, and 94%). 86% of patients showed concomitant small and large bowel involvement. A discontinuous distribution was observed in 54%. Bile tract abnormality was the most common extra-intestinal finding (74%).The distribution of pathologies was equal between subgroups of early or late-onset disease.Wall thickening and mucosal attenuation in non-enhanced scans were significantly related to clinical and pathology scores (P ≤ 0.018). Number of abnormal segments, small bowel dilatation, engorgement of the vasa recta, mesenteric fat stranding and ascites were linked to clinical grading (P ≤ 0.019). A CT-score integrating multiple abnormalities was correlated to gut, overall clinical and pathology grading (r = 0.64, 0.57, 0.50).

Conclusion

CT morphology of acute GvHD is independent of its time of onset and, thus, facilitates differential diagnosis of late-onset acute GvHD. Correlation of CT morphology with clinical and pathological grading is important in terms of prognosis and may help guiding the therapeutic approach.     

Evaluation of angiogenesis in colorectal carcinoma with multidetector-row CT multislice perfusion imaging

To evaluate the correlation between 64 multidetector-row CT (64MDCT) perfusion imaging in colorectal carcinoma and microvessel density (MVD) and vascular endothelial growth factor (VEGF), 64MDCT perfusion imaging was performed in 33 patients with pathologically verified colorectal carcinoma. These images were analyzed with perfusion functional software, and time-density curves (TDC) were created for the region of interest (ROI) encompassing the tumor, the target artery and vein. The individual perfusion maps generated indicated blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability-surface area product (PS). MVD and VEGF were evaluated by immunohistochemical staining with anti-CD34 and anti-VEGF, respectively. Correlations between MVD or VEGF with CT perfusion parameters and clinicopathological factors (Dukes’ stages, invasion depth, and lymph node and liver metastasis) were also investigated. MVD in the colorectal carcinoma was 22.61 ± 9.01 per ×200 field. The scores obtained for VEGF expression were 4.15 ± 1.09. VEGF staining was positive in 25 of 29 tumors (86.2%). There was no significant correlation between the presence of MVD, VEGF expression and clinicopathological factors (P > 0.05). There was also no correlation between MVD, VEGF expression, and any dynamic CT parameters (P > 0.05). The BV and MTT were significantly higher in tumors demonstrating serous coat invasion than in those without it (t = −2.63, −2.24, P = 0.0137, 0.0331, respectively). BV was also significantly correlated with tumor size (r = 0.41, P = 0.02). Neither BF nor PS was correlated with clinicopathological factors. In conclusion, 64MDCT perfusion imaging, MVD, and VEGF may reflect angiogenic activity, but no significant correlation among these factors.     

The thickness of the A1 pulleys reflects the disability of hand mobility in scleroderma. A pilot study using high-frequency ultrasound

Background

Hand involvement in scleroderma is a serious concern. Clinical tests to asses hand dysfunction are based on the experience of the clinician.

Objective

To asses if utrasonographic (US) measurement of A1 pulley thickness may be used as an indicator of hand mobility in scleroderma.

Materials and methods

Institutional review board approval and patient informed consent was obtained. Twenty-eight patients affected suffering from scleroderma and 40 healthy controls were prospectively evaluated by two blinded radiologists with US, with a transducer operating at 17 MHz. A1 pulley thickness was measured and correlated with the Hand Mobility in Scleroderma Test (HAMIS) and disease duration.

Results

The thickness of the A1 pulley was greater in sclerodermic patients than in controls (p < 0.05). Intra and inter-observer agreement were better for ultrasound (0.94;0.88) than for HAMIS tests (0.71;0.70). A good correlation between pulley thickness, hand mobility and disease duration was found (r = 0.78, p < 0.018; r = 0.54, p < 0.05).

Conclusion

A1 pulley thickness measured on ultrasound correlates with hand mobility and disease duration. Ultrasound is an useful tool to evaluate hand disability in scleroderma.     

Imaging parameter effects in apparent diffusion coefficient determination of magnetic resonance imaging

Purpose

Although an apparent diffusion coefficient (ADC) value is often used for differential diagnosis of tumours, it varies with scanning parameters. The present study was performed to investigate the influence of imaging parameters, i.e., b value, repetition time (TR) and echo time (TE), on ADC value.

Methods

The phantoms were scanned using diffusion weighted imaging (DWI) with changing b values (b = 0-3000 s/mm²), TR and TE to determine the influence on ADC. Moreover, ADC of the brain in normal volunteers was determined with varying b values (b = 0-1000 s/mm²).

Results

Diffusion decay curves were obtained by biexponential fitting in all phantoms. The points where fast and slow components of the biexponential decay crossed were called turning points. The b values of turning points that crossed from the biexponential curve were different in each phantom. The b values of turning points depended on ADC of fast diffusion component. When ADC is calculated using two b values of front and back for the turning point, the ADC value may be different. Therefore, it was necessary to perform calculations by b value until the turning point to obtain the ADC value of the fast component. In addition, b ≥ 100 was recommended to avoid the influence of perfusion by blood. Furthermore, the choice of long TR and short TE was effective for accurate measurement of ADC.

Conclusion

It is important to determine the turning point for measuring ADC.