Dynamic Volume CT Research Articles

Retracted: Application and Value of Dynamic Volume CT Multiparameter Imaging in the Diagnosis of Traumatic High-Flow Penile Abnormal Erection

Retracted: Application and Value of Dynamic Volume CT Multiparameter Imaging in the Diagnosis of Traumatic High-Flow Penile Abnormal Erection

Noninvasive assessment of foot perfusion in cholesterol-fed rabbits using dynamic volume perfusion CT with an upslope method

To evaluate the feasibility of dynamic foot volume CT with the upslope method and to demonstrate macrovascular reactivity and microvascular perfusion during cuff-induced reactive hyperemia state in cholesterol-fed rabbits. 30 New Zealand male rabbits were divided into 2 groups: dietary hypercholesterolemia (n = 10) and normal diet control (n = 20). To measure for macrovascular reactivity, perfusion parameters of the left posterior tibial artery was measured at baseline and at reactive hyperemia state. For the evaluation of microvascular perfusion, color-coded perfusion map of the plantar dermis was generated for perfusion CT scan by an in-house developed dedicated analysis software based on upslope method. Dermal perfusion values were measured and analyzed before and after cuff-induced reactive hyperemia. Foot dynamic volume CT with the upslope method demonstrated significant impairment of both macrovascular reactivity and microvascular perfusion in cholesterol-fed rabbits without significant macrovascular lesions during cuff-induced reactive hyperemia (CRH) state. Arterial time-to-peak of cholesterol-fed rabbits failed to show acceleration while chow-fed rabbits showed significant decrease in time. Microvascular perfusion calculated by perfusion value (P < 0.01) and perfusion ratio (P = .014) showed decreased microvascular perfusion in cholesterol-fed rabbits compared to chow-fed rabbits during CRH state. Post-CT pathologic examination revealed decreased endothelial cell density in cholesterol-fed rabbits (P < 0.001). Foot perfusion CT using upslope method provides perfusion parameters for large arteries and a perfusion map of the foot during cuff-induced reactive hyperemia in cholesterol-fed rabbits. It may be a useful tool to assess microvascular reactivity in patients with peripheral artery disease but no apparent macrovascular lesions.

Application and Value of Dynamic Volume CT Multiparameter Imaging in the Diagnosis of Traumatic High-Flow Penile Abnormal Erection

Objective. To explore the clinical application of dynamic volume CT multiparameter imaging in the observation of penile hemodynamics in patients with abnormal vascular erections. Methods. 90 patients with suspected vascular abnormal erections treated in our hospital from January 2016 to January 2020 were included in the study, and 40 patients with psychologically abnormal erections were selected for the control. The corpus cavernosum injection vasoactive drug test (ICI) and dynamic volume CT and Doppler ultrasound were used to test the hemodynamics of the corpus cavernosum of all selected patients and to analyze the changes of penile length, circumference, systolic peak flow rate, diastolic peak flow rate, and blood flow resistance index in different types of penile erection disorder patients before and after ICI test. Results. Among the 90 patients with suspected vascular abnormal erection, 34 patients had arterial abnormal erection, 25 patients had venous abnormal erection, and 31 patients had mixed vascular abnormal erection. In patients with arterial abnormal erection and mixed vascular abnormal erection, penile cavernous body diameter, PSV, and abnormal erection V are smaller than those in patients with venous abnormal erection and psychological abnormal erection, while arterial abnormal erection and psychological abnormal erection are obviously higher in RI than venous abnormal erection and mixed vascular abnormal erection, and the difference is statistically significant ( P &lt; 0.05 ). Before the ICI test, there was no significant difference in the penis circumference and length between the four groups of patients with arterial abnormal erection, venous abnormal erection, mixed vascular abnormal erection, and psychological abnormal erection ( P &gt; 0.05 ); after the ICI test, patients with arterial abnormal erections had significantly shorter penis perimeter and penis length than those with venous abnormal erections, mixed vascular abnormal erections, and psychological abnormal erections ( P &lt; 0.05 ). Conclusion. Dynamic volume CT can clearly reflect the penile hemodynamic state of patients with vascular abnormal erections, provide a powerful diagnostic basis for accurately and effectively determining the classification of vascular abnormal erections, and be worthy of popularization and clinical use.

Quantitative evaluation of upper urinary tract pump function in pigs with acute unilateral lower ureteral obstruction by 640-slice dynamic volume CT

BackgroundIt is a challenging problem to differentiate obstructive hydronephrosis from noninvasive evaluation of renal pelvis and ureteral motility in patients. The purpose of this study was to explore the value of 640-slice dynamic volume CT (DVCT) in the quantitative measurement of upper urinary tract (UUT) pump function after acute unilateral lower ureteral obstruction in pigs.MethodsIn this study, a perfusion pig model was constructed by constant pressure perfusion testing of the renal pelvis and left nephrostomy. The perfusion and pressure measuring devices were connected to create a state of no obstruction and acute obstruction of the lower part of the left ureter. After successful modelling, continuous dynamic volume scanning of the bilateral renal excretion phase was performed with 640-slice DVCT, and pump functions of the renal pelvis and part of the upper ureter were calculated and analysed. No obstruction or acute obstruction of the lower part of the left ureter was observed. Pump functions of the renal pelvis and part of the upper ureter were determined.ResultsThe results showed that after LUUT fistulostomy, the time difference between the average UUT volume and positive volume value increased gradually, and the calculated flow velocity decreased, which was significantly different from that of the RUUT. The volume difference of the LUUT increased significantly in mild obstruction. In the bilateral control, the volume change rate of the LUUT increased with mild obstruction and decreased with severe obstruction, and there was a significant difference between the left and right sides.ConclusionThe continuous dynamic volume scan and measurement of 640-slice DVCT can obtain five pump function datasets of UUT in pigs with acute lower ureteral obstruction.

Quantitative Assessment of Left Ventricular Function of Coronary Atherosclerotic Heart Disease with 640-Slice Dynamic Volume CT in Comparison to Echocardiography

Objective: The primary aim is to investigate the correlation between 640-slice dynamic volume computer tomography (DVCT) and echocardiography (ECHO) in the function of left ventricular (LV), and the value of DVCT in the evaluation of left coronary artery disease (LCA) and geometry and function of left ventricular, by measuring the difference of left ventricular function of coronary atherosclerotic heart disease with DVCT in comparison to ECHO. Materials and Methods: Sixty-three patients of coronary heart disease (CHD) with left coronary artery disease were selected, all of them were examined by DVCT coronary imaging and ECHO. On the basis of the American Society of Cardiovascular Computed Temography, the study applied the Coronary Artery Disease Report and Data System (CAD-RADS) to assess the left cornary artery. The end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF) and myocardial mass (MM) of function parameters of the left ventricle were counted. The function parameters of DVCT and ECHO were comparatively analyzed. Results: The results showed that there was a positive correlativity between the value of EDV, ESV, SV and EF which measured through DVCT and the ECHO (r = 0.69, 0.90, 0.60, 0.71 respectively, P &lt; 0.05 all). The differences of ESV, SV, EF between CAD-RADS 2 and 4, CAD-RADS 3 and 4 were significant (P &lt; 0.05). The differences of data of EDV and MM between CAD-RADS 2, 3 and 4 were statistically significant (P &lt; 0.05). Conclusion: Both DVCT coronary artery imaging and ECHO can accurately assess left ventricular function and have a high correlation. DVCT coronary artery imaging can assess CAD and analyze the function of left ventricular. EDV and MM change significantly in CAD-RADS 3, which providing important quantitative data for clinical diagnosis and treatment plan of coronary heart disease.

Preptin is a new predictor of coronary artery calcification

BackgroundWe aimed to assess whether an elevated preptin level is associated with coronary artery calcification (CAC). MethodsTwo hundred and twenty participants with suspected cardiovascular disease were recruited. CAC was measured using 320-row-detector dynamic volume CT, and the patients were divided into 2 groups: the non-CAC group (with an Agatston score = 0) and the CAC group (with an Agatston score > 0). ResultsThe serum preptin level was significantly elevated in the CAC group compared with the non-CAC group. In logistic regression analysis, preptin, as well as age, gender, hypertension history and history of β-blocker use, were independent predictors of a positive CAC score. The highest preptin quintile of patients had a higher CAC level compared with other quintiles. Binary logistic regression analyses showed that the highest preptin quintile had a 2.9-time increased odds ratio of an elevated CAC level than the other 4 quintile patients. ConclusionsThis study demonstrated that serum preptin was associated with coronary artery calcification.

Fat poor angiomyolipoma differentiation from renal cell carcinoma at 320-slice dynamic volume CT perfusion.

To compare various CT perfusion features of fat poor angiomyolipoma (AML) with those of size-matched renal cell carcinoma (RCC). One hundred and seventy-four patients [16 with fat poor AML (mean diameter, 3.1cm; range, 1.5-5.5cm) and 158 with RCC (mean diameter, 3.2cm; range, 2.4-5.4cm)] who had undergone 320-slice dynamic volume CT perfusion were evaluated. Equivalent blood volume (BV Equiv), permeability surface-area product (PS), and blood flow (BF) of tumor were measured and analyzed. Fat poor AML was compared with each subtype of RCC (132 clear cell, 9 papillary, and 17 chromophobe). Receiver operating characteristic (ROC) curve analysis was performed for the comparison of fat poor AML and RCC. ROC curve analysis was not performed for the papillary RCC subtype because of the small number of masses of this subtype. BV Equiv and BF were significantly lower in fat poor AML than in clear cell RCC (P<0.05 for both). Fat poor AML had higher BV Equiv, PS, and BF than papillary RCC (P<0.05 for all). PS and BF in fat poor AML significantly exceeded those in chromophobe RCC (P<0.05 for both). For differentiating fat poor AML from clear cell RCC, area under the ROC curve (AUC) of BV Equiv and BF were 0.82 and 0.69. Using the optimal threshold value, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 0.82, 0.81, 0.35, 0.97 for BV Equiv and 0.71, 0.75, 0.24, 0.96 for BF, respectively. For differentiating fat poor AML from chromophobe RCC, AUC of PS and BF were 0.77 and 0.79, respectively. The optimal sensitivity, specificity, PPV, and NPV were 0.77, 0.75, 0.75, 0.76 for PS and 0.71, 0.81, 0.72, 0.80 for BF, respectively. Fat poor AML and subtypes of RCCs demonstrate different perfusion features at 320-slice dynamic volume CT, allowing their differentiations with BV Equiv, PS, and BF being valuable perfusion parameters.

Diagnostic value of four-dimensional CT angiography in arterial erectile dysfunction using 320-detector row dynamic volume CT

The present study aims to evaluate the diagnostic value of four-dimensional CT angiography (4D-CTA) in the diagnosis of arterial erectile dysfunction (ED) using 320-detector row dynamic volume CT. Arterial ED patients attributed to arterial insufficiency were enrolled. To induce penile erection, an intracavernous injection (ICI) of corpus cavernosum with a vasoactive drug was administered. Patients were assigned into the erection hardness score (EHS) 1/2 group or EHS 3/4 group. Color duplex Doppler ultrasound (CDDU) was used to analyze blood flow spectrum. Each patient was examined using 4D-CTA. Receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of 4D-CTA in arterial ED. According to Irwin Goldstein, the EHS 3/4 group (n=38) had a shorter course of ED and low proportion with history of hypertension, hyperlipidemia, and diabetes than the EHS 1/2 group (n=35). The peak systolic velocity (PSV), end diastolic velocity (EDV), and resistant index (RI) in the EHS 3/4 group were lower than those of the EHS 1/2 group. 4D-CTA showed there were a total of 35 cases in the EHS 1/2 group (two cases missed) and 38 cases in the EHS 3/4 group (seven cases misdiagnosed). Using 4D-CTA to diagnose arterial ED, the area under the ROC curve yielded a value of 0.879, with a specificity of 93.9% and a sensitivity of 82.5%. These findings indicated that 4D-CTA using 320-detector row dynamic volume CT is a promising and reliable utility in diagnosing arterial ED.

Comprehensive assessment of cavernosography with 320-row dynamic volume CT versus conventional cavernosography in erectile dysfunction patients caused by venous leakage.

The present study aims to investigate and compare the diagnostic and prognostic value of cavernosography with 320-row dynamic volume computed tomography (DVCT) versus conventional cavernosography in men with erectile dysfunction (ED) caused by venous leakage. A total of 174 patients diagnosed with ED were enrolled and received cavernosography with 320-row DVCT (DVCT group) and conventional cavernosography scans (control group) respectively. The diagnosis, complications, and prognosis of patients were evaluated. The DVCT group provided high-resolution images with less processing and testing time, as well as lowered radiological agent and contrast agent compared with the control group. In the DVCT group, 89 patients who were diagnosed with venous ED had six various venous leakage, namely superficial venous leakage, profundus venous leakage, the mixed type, cavernosal venous leakage, crural venous leakage, and also venous leakage between the penis and urethra cavernosum (9, 21, 32, 6, 18, and 3 cases respectively). Similarly, 74 patients out of the 81 who suffered from venous ED were classified to have superficial venous leakage (11), profundus venous leakage (14), the mixed type venous leakage (26), and middle venous leakage (23). Six out of 25 patients in the DVCT group, had improvements in ED while the remaining 19 achieved full erectile function recovery with no penile fibrosis and erectile pain. Cavernosography with 320-row DVCT is a reliable system that can be used to diagnose ED caused by venous leakage. This is especially useful in accurately determining the type of venous and allows for a better prognosis and direction of treatment.

Additive value of 320-section low-dose dynamic volume CT in relation to 3-T MRI for the preoperative evaluation of brain tumors.

To assess whether 320-section low-dose dynamic volume computed tomography (320-LDVCT) with adaptive iterative dose reduction (AIDR) adds value to 3-T MRI for the preoperative evaluation of brain tumors. The study population was comprised of 16 consecutive patients with brain tumors who, in addition to preoperative 3-T MRI, underwent 320-LDVCT with AIDR. Two radiologists independently evaluated the CT and MRI studies; one measured the relative cerebral blood volume (rCBV) in the tumor and contralateral brain on CT and MR perfusion maps. Interobserver agreement was assessed by κ statistics. In 3 of 16 patients (19%), 320-LDVCT added diagnostic value to 3-T MRI studies with respect to the visualization of feeders (κ=0.77), and in 12 (75%) it helped the delineation of venous structures (κ=0.71) and the relationship between the tumor and adjacent vessels (κ=0.85). The average standardized rCBV value was 12.2±2.40 (range 0.7-36.6) on MR and 8.80±2.77 (range 0.8-38.0) on CT perfusion studies; the correlation between these values was very strong (r=0.92, p<0.0001). According to the neurosurgeons, 320-LDVCT added helpful information for surgery in 4 patients (25%). The 320-LDVCT can add value to 3-T MRI for the tumor feeders and relationship between the tumor and adjacent vessels.

GW26-e3541 Diagnostic accuracy of 320-slice dynamic volume computed tomography angiography for detection of coronary artery stenosis in patients with atrial fibrillation

To evaluate the diagnostic accuracy of 320-slice dynamic volume CT angiography (CTA) in assessment of coronary artery stenosis in patients with atrial fibrillation (AF) compared with selective coronary angiography (SCA). Seventy-two patients (49males, 63.9±12.5 years) with persistent AF were

The primary study of low-dose pancreas perfusion by 640- slice helical CT: a whole-organ perfusion.

To discuss the feasibility of low-dose whole-pancreas imaging utilizing 640-slice dynamic volume CT.80 patients (40 cases of normal pancreas and 40 patients supposed of having pancreatic carcinoma or focal pancreatic space-occupying lesions were mainly refered) referred for CT pancreas perfusion were enrolled in the study. 80 patients randomly assigned to 3 groups: Group ① (whole sequence). Group ② (odd number sequence). Group ③ (even number group)(Compared to ①, the scanning times and effective radiate dose of ② and ③ decreased about 50% respectively). The head, body, tail of each normal pancreas without any pancreatic disease, lesion and lesion-surrounding areas of each pancreatic cancer were selected as ROI, and tissue peak, blood flow are measured.According to pathology and clinical materials, 27 patients were diagnosed as pancreatic cancer; 40 patients were diagnosed as normal pancreas. The tissue peak and blood flow of the head, body, tail of normal pancreas without any pancreatic disease are 109.63 ± 16.60 and 131.90 ± 41.61, 104.38 ± 19.39 and 127.78 ± 42.52, 104.55 ± 15. 44 and 123.50 ± 33.44 respectively. The tissue peak and blood flow of pancreatic cancer is 59.59 ± 18.20 and 60.00 ± 15.36. For and between each group, there is no significant statistical difference for the tissue peak and blood flow of normal areas of the head, body, tail of normal pancreas. There is statistical difference for the tissue peak and blood flow of lesion and lesion-surrounding areas of pancreatic cancer in each group. However, there is no statistical difference for the tissue peak and blood flow of normal and diseasing areas between 3 groups.Low-dose whole-pancreas perfusion with 640-slice dynamic volume CT is feasible.

Whole-brain 320-detector row dynamic volume CT perfusion detected crossed cerebellar diaschisis after spontaneous intracerebral hemorrhage.

The purpose of this study was to evaluate the value of 320-detector row CT used to detect crossed cerebellar diaschisis (CCD) in patients with unilateral supratentorial spontaneous intracerebral hemorrhage (SICH). We investigated 62 of 156 patients with unilateral supratentorial SICH using 320-detector row CT scanning. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT), and time to peak (rTTP) levels were measured in different regions of interest (ROIs) that were manually outlined on computed tomography perfusion (CTP) for the cerebrum, including normal-appearing brain tissue that surrounded the perilesional low-density area (NA) and the perihematomal low-density area (PA) in all patients and the cerebellum (ipsilateral and contralateral) in CCD-positive patients. Of 62 cases, a total of 14 met the criteria for CCD due to cerebellar perfusion asymmetry on CTP maps. In the quantitative analysis, significant differences were found in the perfusion parameters between the contralateral and ipsilateral cerebellum in CCD-positive cases. No significant differences were found between the CCD-positive group and the CCD-negative group according to the hematoma volume, NIHSS scores, and cerebral perfusion abnormality (each P > 0.05). The correlation analysis of the degree of NA, PA perfusion abnormality, and the degree of CCD severity showed negative and significant linear correlations (R, -0.66∼-0.56; P < 0.05). 320-detector row CT is a robust and practicable method for the comprehensive primary imaging work-up of CCD in unilateral supratentorial SICH patients.

Study of 320-Slice Dynamic Volume CT Perfusion in Different Pathologic Types of Kidney Tumor: Preliminary Results

ObjectiveTo investigate microcirculatory differences between pathologic types of kidney tumor using 320-slice dynamic volume CT perfusion.MethodsPerfusion imaging with 320-slice dynamic volume CT was prospectively performed in 85 patients with pathologically proven clear cell renal cell carcinoma (RCC) (n = 66), papillary RCC (n = 7), chromophobe RCC (n = 5), angiomyolipoma (AML) with minimal fat (n = 7), or RCC (n = 78). Equivalent blood volume (Equiv BV), permeability surface-area product (PS; clearance/unit volume = permeability), and blood flow (BF) of tumor and normal renal cortex were measured and analyzed. Effective radiation dose was calculated.ResultsThere was a significant difference in all three parameters between tumor and normal renal cortex (P<0.001). Equiv BV was significantly different between RCC and AML with minimal fat (P = 0.038) and between clear cell RCC and AML with minimal fat (P<0.001). Mean Equiv BV and BF were significantly higher in clear cell RCC than in papillary RCC (P<0.001 for both) and mean Equiv BV was higher in clear cell RCC than in chromophobe RCC (P<0.001). The effective radiation dose of the CT perfusion protocol was 18.5 mSv.ConclusionPerfusion imaging using 320-slice dynamic volume CT can be used to evaluate hemodynamic features of the whole kidney and kidney tumors, which may be useful in the differential diagnosis of these four pathologic types of kidney tumor.

Image noise-based dose adaptation in dynamic volume CT of the heart: dose and image quality optimisation in comparison with BMI-based dose adaptation

To compare the image quality and radiation dose using image-noise (IN)-based determination of X-ray tube settings compared with a body mass index (BMI)-based protocol during CT coronary angiography (CTCA). Two hundred consecutive patients referred for CTCA to our institution were divided into two groups: BMI-based, 100 patients had CTCA with the X-ray tube current adjusted to the patient's BMI while maintaining a fixed tube potential of 120kV; IN-based, 100 patients underwent imaging with the X-ray tube current and voltage adjusted to the IN measured within the mid-left ventricle on a pre-acquisition trans-axial image. Two independent cardiac radiologists performed blinded image quality assessment with quantification of the IN and signal-to-noise ratio (SNR) from the mid-LV and qualitative assessment using a three-point score. Radiation dose (CTDI and DLP) was recorded from the console. Results showed: IN (HU): BMI-based, 30.1 ± 9.9; IN-based, 33.1 ± 6.7; 32% variation reduction (P = 0.001); SNR: BMI-based, 18.6 ± 7.1; IN-based, 15.4 ± 3.7; 48% variation reduction (P < 0.0001). Visual scores: BMI-based, 2.3 ± 0.6; IN-based, 2.2 ± 0.5 (P = 0.54). Radiation dose: CTDI (mGy), BMI-based, 22.68 ± 8.9; IN-based, 17.16 ± 7.6; 24.3% reduction (P < 0.001); DLP (mGy.cm), BMI-based, 309.3 ± 127.5; IN-based, 230.6 ± 105.5; 25.4% reduction (P < 0.001). Image-noise-based stratification of X-ray tube parameters for CTCA results in 32% improvement in image quality and 25% reduction in radiation dose compared with a BMI-based protocol. • Image quality and radiation dose are closely related in CT coronary angiography. • So too are the image quality, radiation dose and body mass index (BMI). • An image-noise-based CTCA protocol reduces the radiation dose by 25%. • It improves inter-patient image homogeneity by 32%.

Differentiation of malignant and benign pulmonary nodules with first-pass dual-input perfusion CT

To assess diagnostic performance of dual-input CT perfusion for distinguishing malignant from benign solitary pulmonary nodules (SPNs). Fifty-six consecutive subjects with SPNs underwent contrast-enhanced 320-row multidetector dynamic volume CT. The dual-input maximum slope CT perfusion analysis was employed to calculate the pulmonary flow (PF), bronchial flow (BF), and perfusion index [Formula: see text]. Differences in perfusion parameters between malignant and benign tumours were assessed with histopathological diagnosis as the gold standard. Diagnostic value of the perfusion parameters was calculated using the receiver-operating characteristic (ROC) curve analysis. Amongst 56 SPNs, statistically significant differences in all three perfusion parameters were revealed between malignant and benign tumours. The PI demonstrated the biggest difference between malignancy and benignancy: 0.30 ± 0.07 vs. 0.51 ± 0.13 , P < 0.001. The area under the PI ROC curve was 0.92, the largest of the three perfusion parameters, producing a sensitivity of 0.95, specificity of 0.83, positive likelihood ratio (+LR) of 5.59, and negative likelihood ratio (-LR) of 0.06 in identifying malignancy. The PI derived from the dual-input maximum slope CT perfusion analysis is a valuable biomarker for identifying malignancy in SPNs. PI may be potentially useful for lung cancer treatment planning and forecasting the therapeutic effect of radiotherapy treatment. • Modern CT equipment offers assessment of vascular parameters of solitary pulmonary nodules (SPNs) • Dual vascular supply was investigated to differentiate malignant from benign SPNs. • Different dual vascular supply patterns were found in malignant and benign SPNs. • The perfusion index is a useful biomarker for differentiate malignancy from benignancy.

Application of 320-detector dynamic volume CT angiography in evaluating preoperative and postoperative intracranial aneurysms

Application of 320-detector dynamic volume CT angiography in evaluating preoperative and postoperative intracranial aneurysms

Initial study of optimal reconstruction windows in 320-detector row CT coronary angiography

Objective To investigate the optimal reconstruction windows for coronary angiography using 320-detector row dynamic volume CT (DVCT) and evaluate their effects on image quality,radiation dose and diagnostic accuracy.Methods From 77 patients [mean heart rate (70 + 13) bpm,range:46-102 bmp] were scanned with retrospective ECG-gating 320-detector row DVCT.The relationship between heart rate and optimal reconstruction windows was analyzed.From 53 patients [mean heart rate ( 75 ±11 ) bpm,range:57-114 bpm] were scanned with prospective ECG-gating 320-detector row DVCT.The effects of prospective ECG-gating on image quality,radiation dose and diagnostic accuracy were evaluated.Friedman test was performed for image quality scores in random groups.Linear regression and Spearman correlation were performed to test bivariate data.Results The proportion of systolic duration in the cardiac cycle increased significantly with higher heart rate (r =0.78,P ＜0.01 ).The image quality in systolic and diastolic phases were significantly influenced by heart rate ( r =0.38,0.82 ; P ＜ 0.01 ).According to the regression analysis of image quality score in different heart rate groups,the optimal reconstruction windows were determined as followed:when heart rate was ＜ 70 bpm,the optimal reconstruction windows should be preset at 65％-80％ ; 70 to 80 bpm,70％-85％ ; 81 to 90 bpm,70％-90％ ; ＞90 bpm,35％-50％.Compared with retrospective ECG-gating,prospective ECG-gating which preset reconstruction windows according to the phases mentioned above,could decrease radiation dose [(6.1 ± 3.8 )vs (12.4 ± 7.0) mSv],without deteriorating the image quality (t =6.5,P ＜ 0.01 ).However,in higher heart rate,the radiation dose of prospective ECG-gating DVCT was still higher ( r =0.64,P ＜ 0.01 ).Conclusions DVCT can provide high image quality in a wide range of heart rate with prospective ECG gating.It is still recommended to control heart rate strictly since the radiation dose increases significantly in high heart rate. Key words: Coronary angiography; Image quality; Tomography, X-ray computed; Radiation dose

Evaluation of CT coronary artery angiography with 320-row detector CT in a high-risk population

The aim of this article was to prospectively evaluate the accuracy and radiation dose of 320-detector row dynamic volume CT (DVCT) for the detection of coronary artery disease (CAD) in a high-risk population. 60 patients with a high risk of CAD underwent DVCT without preceding heart rate control and also underwent invasive coronary angiography (ICA), which served as the standard reference. On a per segment analysis, overall sensitivity was 95.3%, specificity was 97.6%, positive predictive value was 90.6%, negative predictive value was 98.8% and Youden index was 0.93. In both heart rate subgroups, diagnostic accuracy for the assessment of coronary artery stenosis was similar. The accuracy of the subgroup with an Agatston score ≥100 was lower than that for patients with an Agatston score <100. However, the difference between DVCT and ICA results was not significant (p=0.08). The mean estimated effective dose of CT was 12.5 ± 9.4 mSv. In those patients with heart rates less than 70 beats per minute (bpm), the mean radiation exposure of DVCT was 5.2 ± 0.9 mSv. The effective radiation dose was significantly lower than that of ICA (14.1 ± 5.9 mSv) (p<0.001). When the heart rate was >70 bpm, a significantly higher dose was delivered to patients with DVCT (22.6 ± 5.2 mSv, p<0.001) than with ICA (15.0 ± 5.3 mSv, p<0.001). DVCT reliably provides high diagnostic accuracy without heart rate/rhythm control. However, from a dosimetric point of view, it is recommended that heart rate should be controlled to <70 bpm to decrease radiation dose.

320-row CT scanning: reduction in tube current parallels reduction in radiation exposure?

320-row CT scanning: reduction in tube current parallels reduction in radiation exposure?