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雙源CT診斷肺動脈吊帶畸形一例

MDCT Evaluation of Anatomic Variants of Middle Turbinate and Nasal Septum

目的：采用高分辨多排螺旋CT研究鼻中隔和中鼻甲解剖變異，并評價它們對前組鼻副竇引流通道的影響。方法：回顧分析60例行鼻腔和副鼻竇高分辨多排螺旋CT檢查患者的圖像資料。 其中男35例，女25例，平均年齡42歲。所有受試者均采用16排螺旋CT機行高分辨容積掃描，層面從硬腭至額竇上緣，準直0.75~1 mm，橫斷、冠狀和矢狀重建，層厚及層距均為1 mm。分別觀察和統計鼻中隔和中鼻甲解剖變異的類型和發生率，并評價其與前組鼻副竇引流通道的關系。結果：60例中，共發現鼻中隔變異45例(75%)，其中鼻隔偏曲45例(單向偏曲31例，雙向偏曲14例)；犁骨軟骨結合部畸形5例(肥大2例，脫位3例)；鼻隔刺16例。中鼻甲變異共43例(71.7%)，其中反曲15例；氣化9例；雙側不對稱20例(46.5%)。不對稱中鼻甲中，增大一側多見于鼻隔偏移方向的對側，多數伴有不同程度的鉤突移位和篩漏斗或鼻道狹窄。結論：鼻腔和中鼻甲不對稱與鼻中隔偏曲關系密切，后者是導致前組鼻副竇引流通道中的關鍵部位--中鼻道和篩漏斗狹窄的重要原因。

迭代重建技術降低踝關節內固定金屬偽影的價值

目的 探討迭代重建（iterative reconstruction，IR）技術在踝關節金屬內固定術后數字化斷層融合（digital radiographic tomosynthesis，DTS）檢查中的臨床應用價值。 方法 2014 年 10 月—2015 年 6 月采用 DTS 技術檢查踝關節金屬內固定術后復查患者 30 例，每例患者的原始數據分別采用 IR 算法和濾波反投影（filter back projection，FBP）算法進行重建。重建后圖像根據圖像噪聲、內固定金屬周圍骨質清晰度和失真度，以 3 分法對圖像質量進行主觀評價，數值越高圖像越清晰；測量螺釘偽影長度、螺釘與骨質結合程度作為客觀數據評價，數據值越小圖像質量越好。 結果 圖像噪聲、內固定周圍骨質清晰度和失真度的主觀評分：采用 IR 算法重建的圖像中，優片 26 例（86.7%），良片 4 例（13.0%）；采用 FBP 算法重建的圖像中，優片 3 例（10.0%），良片 27 例（90.0%）；兩種算法重建圖像優質率差異有統計學意義（χ2=21.043，P<0.001）。兩種算法重建圖像均無螺釘偽影。IR 算法重建圖像螺釘與骨質結合緊密，間隙度為 0 mm；FBP 算法重建圖像螺釘與骨質結合間隙度為 0.2～0.3 mm，系金屬硬化束偽影。 結論 DTS 掃描 IR 技術能有效降低踝關節內固定金屬偽影，圖像質量明顯優于 FBP 重建圖像，踝關節金屬內固定 DTS 檢查 IR 技術有較高的臨床應用價值。

Value of Multi-slice CT in Assessing the Features of Carotid Artery Plaques

目的　探討多層螺旋CT在評價頸動脈斑塊特征中的價值。 方法　回顧性分析2011年7月－10月132例行CT頸部血管造影患者的影像資料。對頸動脈斑塊特征進行評價，重建方法包括多層面重建、容積再現技術、最大密度投影及曲面重建。 結果　132例患者中，80例檢出頸動脈斑塊，最常出現鈣化斑塊的部位為海綿竇段和床突上段，右側海綿竇段52例（65.0%）、左側海綿竇段49例（61.3%），右床突上段37例（46.3%）、左側床突上段30例（37.5%）。最常出現軟斑塊的部位為雙側頸總動脈，均為12例（15.0%）。最常出現混合斑塊的部位為頸總動脈，右側頸總動脈9例（11.3%）、左側頸總動脈12例（15.0%）。頸動脈最容易輕度狹窄294處（294/1 440，20.4%），中、重度狹窄少見，分別為8處（8/1 440，0.5%）和6處（6/1 440，0.4%）。頸部動脈血管斑塊最易出現鈣化，總計249處（249/1 440，17.3%），其次是軟斑塊和混合斑塊，均為39處（39/1 440，2.7%）。 結論　多層螺旋CT可準確評價頸動脈斑塊特征。

Assessment of Low-Dose Radiation in Coronary Artery Imaging by 64-Slices Multi-detector CT

【摘要】　目的　評價64層螺旋CT低劑量冠狀動脈血管成像的價值。　方法　2009年1-6月157例患者隨機分為3組，常規劑量組（A組）管電流量采用1 000 mAs，兩個低劑量組（B、C組）分別采用800、600 mAs。對3組的圖像質量、噪聲、CT劑量指數（CTDI）、劑量長度乘積（DLP）和有效劑量（ED）進行評估。　結果　A、B、C組圖像噪聲分別為20.50±3.23、23.02±3.05和26.28±2.58，組間差異均無統計學意義（Pgt;0.05）；A、B、C組的CTDI分別為（58.7±0.23）、（46.98±2.27）、（35.28±3.56） mGy，DLP分別為（1 050.88±89.63）、（846.21±57.86）、（641.13±32.15） mGy?cm，ED分別為（14.78±2.56）、（11.85±1.87）、（8.98±1.15） mSv，B、C組的CTDI、DLP、ED均明顯低于常規劑量A組（Plt;0.05），C組的CTDI、DLP、ED均為3組中最低值。　結論　64層螺旋CT冠狀動脈血管檢查，采用600 mAs管電流量獲得的冠脈圖像既可滿足診斷需要，又可使患者接受的輻射劑量降低。【Abstract】　Objective　To evaluate the best tube current for low-dose radiation CT in coronary artery imaging by 64-slices multi-detector CT.　Methods　From January to June 2009, a total of 157 consecutive patients were randomly divided into 3 groups: group A (conventional group): 1 000 mAs; group B: 800 mAs; group C: 600 mAs. The image quality, noise, CT dose index (CTDI), dose length product (DLP) and effective dose (ED) in each group were measured and compared respectively.　Results　The image noise scores in group A, B, and C were (20.50±3.23), (23.02±3.05) and (26.28±2.58), respectively. There was no statistically significant difference among the three groups in the two indexes (Pgt;0.05). The CTDI in group A, B and C were (58.7±0.23), (46.98±2.27), and (35.28±3.56) mGy, respectively; the DLP in each were (1 050.88±89.63), (846.21±57.86), and (641.13±32.15) mGy?cm, respectively; the Ed were (14.78±2.56), (11.85±1.87), and (8.98±1.15) mSv, respectively. All of the differences among the three groups in CTDI, DLP and ED were statistically significant (Plt;0.05).　Conclusion　The image with 600 mAs as tube current in the coronary artery imaging of 64-slices multi-detector CT could fulfill the need of the diagnosis, and the radiation dose is apparently lower than the conventional scan.

Study on the Feasibility of Brain CT Perfusion with 70 kV Tube Voltage

ObjectiveTo investigate the influence of 70 kV low-dose CT perfusion technique on brain CT perfusion parameter maps and image quality. MethodsRetrospective analysis of all patients who underwent CT perfusion of brain between October 2013 and February 2014 was carried out. The patients were randomly divided into two groups according to diTherent CT examination dose: group A (80 kV, 200 mAs) and group B (70 kV, 200 mAs). All patients were scanned on a dual-source-CT (Siemens Definition Flash). Fifteen normal subjects without brain diseases in each group were selected to be studied. Region of interest (ROI) with an area of 80 mm2 was placed in the nucleus, putamen, thalamus, periventricular white matter of the frontal lobe and temporo-occipital area, and the parameters in the ROI including cerebral blood flow, cerebral blood volume, mean transit time and time to peak were detected. The carrierto-noise ratio and signal-to-noise ratio of thalamus and periventricular white matter of the frontal lobe were contrasted. The image quality of perfusion was assessed by two senior radiologists using 5 point system for blind assessment (5=best, 1=worst). The measurement of radiation dose was studied through effective dose, volume CT dose index (CTDIVOL) and dose length product (DLP). Statistical analysis was performed by independent sample t test. ResultsThere was no significant difference between group A and group B in brain CT perfusion parameters (P>0.05). There was no significant diTherence in image quality between the two groups in the objective and subjective assessment (P>0.05). In comparison with group A, the measured effective dose, CTDIVOL and DLP for group B decreased by 35%. ConclusionThere was no significant influence on the brain CT perfusion parameters and image quality using 70 kV tube voltage, and radiation dose is decreased obviously.

Influence of the abduction angle of the double upper limbs on liver non-enhanced CT image quality in patients with vehicle accident

ObjectivesTo investigate the influence of the abduction angle of the upper extremities on the image quality of non-enhanced CT scan and clinical value of the patients who cannot lift with double upper limbs by vehicle accident.Methods60 patients with double upper limbs that could not lift by vehicle accidents were required to receive liver non-enhanced CT scan, the patients were divided into 3 groups according to the abduction angle (group A, B, C), 20 cases in each group, another 20 cases with standard pose as the control group (group D). The CT value and standard deviation of the liver region of interest, the erector and the background air were measured, and the contrast to noise ratio of liver images, image noise value were calculated, together with the assessment of image quality and statistic analysis.ResultsThe liver non-enhanced CT scan were completed successfully. The image quality of group D was significantly better than A, B, C (Z=–10.753, P<0.05;Z=–11.645, P<0.05;Z=–12.281, P<0.05), respectively. Group C was better than A and B (Z=–8.502, P<0.05;Z=–4.068, P<0.05), respectively. Group B was better than A (Z=–5.885, P<0.05). The CNR of the four groups of images increased gradually, group A (0.09±0.77), group B (1.56±0.83), group C (2.51±0.87), group D (2.59±0.97), respectively. There were significant differences between four groups (F=36.323, P<0.05). The image noise decreased systematically, group A (14.84±2.94), group B (13.04±1.59), group C (11.60±1.72), group D (10.44±1.13), respectively. There were significant differences between four groups (H=426.755, P<0.05).ConclusionOn the premise of safety inspection, with the enlargement of angle of the upper limbs of patients who cannot lift with double upper limbs by vehicle accidents, the image noise decreased and image quality is improved with the increase of signal noise ratio.

In Vivo Anatomical Study of Inferior Attachment of Renal Fascia in Adult with Acute Pancreatitis as Shown on Multidetector Computed Tomography

This study aims to explore the inferior adhesion of the renal fascia (RF), and the inferior connectivity of the perirenal spaces (PS) with multidetector computed tomography (MDCT), and to investigate the diagnostic value of CT for showing this anatomy. From May to July 2012, eighty-two patients with acute pancreatitis presented in our hospital were enrolled into this study and underwent contrast-enhanced CT scans. All the image data were used to perform three dimensional reconstruction to show the inferior attachment of RF and the inferior connectivity of PS. The fusion of anterior renal fascia (ARF) and posterior renal fascia (PRF) next to the plane of iliac fossa were found on the left in 71.95% (59/82) cases, and on the right in 75.61% (62/82). In these cases, bilateral perirenal spaces, and anterior and posterior pararenal spaces were not found to be connected with each other. No fusion of ARF and PRF below the level of bilateral kidneys occurred on the left side in 28.05% (23/82) cases and on the right side in 24.39% (20/82). In these patients, the PS extended to the extraperitoneal space of the pelvic cavity and further to the inguinal region, and bilateral anterior and posterior pararenal spaces were not found to be connected with each other. Three-dimensional reconstruction on contrast-enhanced MDCT could be a valuable procedure for depicting inferior attachment of RF, and the inferior connectivity of PS.

The Application of 70 kV and Sonogram-affirmed Iterative Reconstruction Technique in CT Examination for Children with Congenital Heart Disease

ObjectiveTo evaluate the value of 70 kV and sonogram-affirmed iterative reconstruction technique in CT examination for children with congenital heart disease. MethodsThirty children with congenital heart disease who underwent CT scan between January and September 2014 were included in this study. According to the different tube voltage, they were randomly divided into group A (80 kV) and group B (70 kV), with fifteen in each. All the children were scanned on a dual-source-CT (Siemens Definition Flash). Group A used filtered back projection reconstruction. Group B used sonogram-affirmed iterative reconstruction. We measured and calculated the pulmonary artery signal-to-noise ratio at the level of main pulmonary artery window, the signal-to-noise ratio of the ascending aorta, noise ratio contrast between the pulmonary artery and erector spinae and between the ascending aorta and erector spinae. The image quality for congenital heart disease was assessed by two senior radiologists. The measurement of radiation dose included effective dose (ED), volume CT dose index (CTDIvol) and dose length product (DLP). ResultsThere were no significant differences between group A and B in terms of pulmonary artery signal-to-noise ratio (14.54±3.77, 11.23±2.52), the signal-to-noise ratio of the ascending aorta (14.76±3.41, 12.31±3.47), the noise ratio contrast between pulmonary artery and erector spinae (12.04±3.96, 9.18±3.76) and between the ascending aorta and erector spinae (12.47±4.59, 9.77±4.41) (P > 0.05). There was significant difference between group A and group B in CTDIvol[(0.53±0.09), (0.38±0.03) mGy], DLP[(12.93±1.79), (6.67±0.72) mGy·cm], and ED[(0.34±0.05), (0.17±0.02) mSv] (P < 0.05). ConclusionThe application of 70 kV and sonogram-affirmed iterative reconstruction technique in CT examination for children with congenital heart disease can significantly reduce the radiation dose without any influence on image quality.

Application of Single-dose Contrast-enhanced Magnetic Resonance in Carotid Arteriography

目的　探討常規注射速率下單倍劑量對比劑在頸部三維對比增強磁共振血管成像（3D-CEMRA）中的可行性及臨床應用價值。 方法　2011年8月－11月，連續納入30例臨床懷疑頸動脈或椎動脈狹窄并要求頸部磁共振血管成像檢查的患者，隨機分成A、B兩組（每組各15例）。使用西門子Magnetom Avanto 1.5 T磁共振成像儀及其配備的頸部線圈和頭部線圈進行CEMRA成像。A組使用雙倍劑量對比劑（0.2 mmol/kg），B組使用單倍劑量對比劑（0.1 mmol/kg）。用三維快速小角度激發序列進行頸部血管成像。由2位有豐富經驗的高年資醫生對兩組原始圖像的信噪比以及最大密度投影（MIP）圖像的質量進行評價，并對結果進行統計學分析和處理。 結果　A、B兩組的所頸動脈信噪比分別為189.95 ± 71.31、175.07 ± 68.61，差異無統計學意義（t=?0.566，P=0.576）；所得的MIP圖像質量均達到優良，差異無統計意義（χ2=0.180，P=0.671）。 結論　與雙倍劑量相比，單倍劑量對比劑獲得頸部血管的圖像清晰，能夠滿足臨床診斷要求。