MSCT斜矢状位重组图像观察颈动脉鞘周围淋巴结的价值

目的：探讨多层螺旋CT斜矢状位图像显示颈动脉鞘周围淋巴结的显示效果。方法：选择因颈部肿块或结节就诊的门诊患者39例,行颈部各项同性扫描及对比剂增强扫描,然后分别进行轴位、冠状位、双侧斜矢状位重建,观察双侧颈动脉鞘周围显示淋巴结的数目。最后在工作站多方位重组图像观察淋巴结的数目,比较三种图像观察淋巴结的数目的百分率。结果：冠状位图像观察到得淋巴结数目多于轴位图像,双侧斜矢状位图像多于冠状位及轴位图像。斜矢状位图像与颈动脉鞘内血管及胸锁乳突肌走行一致,并与颈动脉鞘周围淋巴结长轴平行,可以直观显示淋巴结及血管的长轴。结论：双侧斜矢状位不但显示颈动脉鞘周围淋巴结数目上明显优于其他图像,而且可以真实直观地反映淋巴结与周围血管及肌肉的关系,将有助于颈部淋巴结的定位、定量诊断和治疗后随访观察。     

多层螺旋CT对椎体后缘软骨结节的诊断

目的:探讨椎体后缘软骨结节在多层螺旋CT(MSCT)的表现及特点,提高对该病变的显示及诊断率。方法:25例椎体后缘软骨结节进行螺旋CT扫描、薄层重建后再进行轴位、矢状及冠状面重建,分析比较几种重建方法对椎体后缘软骨结节的显示效果。结果:轴位重建清晰显示腰椎体后缘骨质缺损、游离骨块及合并相应水平椎间盘突出情况;矢状位重建是对轴位重建的良好补充,并可以较好显示相应水平硬膜囊受压情况;冠状位重建对显示椎体后缘骨缺损及游离骨块也有一定帮助。结论:多层螺旋CT及多平面重建(MPR)在椎体后缘软骨结节的影像学诊断中具有重要意义。     

Die Diagnostik der Stadien T1 und T2 des Larynxkarzinoms mit dem Mehrschicht-Spiral-CT

The purpose of the study was to preoperatively investigate small laryngeal carcinomas using multi-slice spiral CT (MSCT) and subsequent multiplanar reconstructions (MPR) and to compare the results to the detailed spread found at surgery and histology. Nine patients with small (T1, T2) laryngeal cancer were investigated on a MSCT scanner (Siemens plus 4 Volume Zoom, Siemens). A 4 x 1 mm collimation, 120 kV, 200 mAs and a 0.5 seconds rotation time were used, allowing a coverage of the entire larynx in approximately 10 seconds within a single breathhold. Multiplanar reconstruction's (MPR) in sagittal and coronal plane were reconstructed in all patients and rated in consensus reading. In 8 of nine patients, the glottic spread was detected by MSCT, in one cause of a supraglottic tumor a glottic invasion was excluded. The infiltration of the anterior commissure, the infiltration into the subglottic space and the extension into the hypopharynx was correctly assessed in all patients. MSCT was not able to predict infiltration of the arythnoids in two patients. The use of multi-slice spiral CT for the preoperative assessment of small laryngeal tumors shows great promise. The detection or exclusion of subtle spread of these tumors into the supra- or subglottic space and along the glottic level was possible with high accuracy. As the examination time is short, artifacts are rare and multiplanar reconstructions gain in clinical importance.     

Magnetic resonance angiography of the neck vessels: imaging optimization

The neck vessels of 60 patients were studied by means of magnetic resonance angiography, with gradient-echo FISP sequences with short TR and TE and with a 25 degrees flip angle. To study arterial neck vessels, sequences were acquired on the coronal and on the sagittal planes, centered on the cricoid. The intracranial tract of the vertebral arteries required axial sequences centered under the floor of the sella turcica. Post-processing was obtained with the maximum intensity projection technique. The coronal and sagittal sequences were rotated on the axial plane from 0 degrees to 180 degrees with 15 degrees interval, while axial sequences were rotated on the sagittal plane from 0 degrees to 180 degrees with the same interval. TR, TE and flip angle values were very important for image quality: the thinner the volumes the more effective resolution power and vessel visualization. These volumes should not exceed 1.5 mm. Axial rotations of coronal sequences from -45 degrees to +45 degrees and of sagittal sequences from 60 degrees to 120 degrees were useful for diagnosis. The intracranial tract of the vertebral arteries was clearly depicted after axial sequences and after 75 degrees and 135 degrees sagittal rotations.     

Larynx and hypopharynx: MR imaging with surface coils

Forty patients with disorders of the larynx or hypopharynx were studied with magnetic resonance (MR) imaging. Axial, coronal, and sagittal sections, 4 mm thick, were obtained. Twenty-eight of the patients underwent computed tomography (CT) scanning; 17 underwent surgery, and specimens were obtained for organ sectioning. Correlation was made between these three studies as well as with clinical history, physical examination, and endoscopic photography. In 13 patients who underwent all three studies, the depiction of cartilage invasion, adenopathy, and intraorgan and extraorgan spread of disease was compared. MR consistently showed superior soft-tissue definition and extent of disease compared with CT. Neither CT nor MR was able to depict histologic detail or microscopic spread of disease. Both studies were also less effective in the postoperative or postirradiated neck. The use of direct coronal and sagittal imaging planes on MR allowed the visualization of intrinsic laryngeal musculature, which was important in the recognition of subtle tumor extension. For these reasons, surface coil MR imaging is currently the imaging study of choice at our institution for disorders of the larynx and hypopharynx.     

Magnetic resonance imaging of the larynx

Rarely does any radiologic imaging modality play a significant role in reaching a diagnosis of malignancy in the larynx and hypopharynx. These regions are so readily accessible to clinical examination that the combination of cytology and visual inspection usually strongly indicates the diagnosis of cancer. Therefore, the primary role of MR is the same as that of CT in imaging the larynx and hypopharynx: to define the extent of the disease. Compared to CT, MR consistently shows superior soft tissue definition. The use of direct coronal and sagittal scan planes allows the visualization of intrinsic laryngeal musculature in addition to better defining cranial caudal tumor extension. Thus, MR is now the imaging study of choice for the evaluation of cancer of the larynx. The role of MR can also be extended to replace CT scanning in the evaluation of the laryngeal airway and benign lesions of the larynx.     

Enhanced four-detector row computed tomography imaging of laryngeal and hypopharyngeal cancers

PURPOSE: Four-detector row computed tomography (4D CT) enables imaging of the larynx and hypopharynx with high temporal resolution and rapid reformatting of coronal planes. The aim of our study was to assess the usefulness of postcontrast biphasic 4D CT in diagnosing tumor extent. METHODS: Forty-seven patients with laryngeal or hypopharyngeal cancer were investigated using 4D CT. Two radiologists retrospectively evaluated transverse and reformatted coronal images in both the early and late phases. RESULTS: Images in the late phase were superior to those in the early phase in the conspicuity of the depicted lesions. The coronal images facilitated assessment of the craniocaudal extension of tumors and obliteration of the paraglottic space. The maximal diameter of tumors tended to be larger on the coronal image than on the transverse image. CONCLUSIONS: Images in the late phase were more informative than images in the early phase to demonstrate tumor extension. Reformatted coronal imaging was useful in evaluating craniocaudal extension.     

肝内胆管囊腺瘤的多层螺旋CT诊断

目的 探讨多层螺旋CT对肝胆管囊腺瘤的诊断价值. 资料与方法 3例肝内胆管囊腺瘤均经病理证实.使用16层螺旋CT扫描仪.2例行冠状面、矢状面最大信号强度投影(MIP),1例行容积再现(VR);增强扫描行动脉期、门静脉期及延迟期扫描. 结果 3例均为多房性囊性结构肿块,囊壁及多房分隔平扫呈稍低密度,囊内液性部分呈低密度,增强动脉期、门静脉期囊壁及多房分隔呈不同程度强化,2例延迟期强化,囊壁及多房分隔显示较平扫清楚;其中1例多房分隔较薄不规则,可见壁结节,增强后冠状及矢状面MIP像上清晰显示囊肿内下部分较完整的分隔及壁结节;1例囊壁及多房分隔光滑,局部增厚,增强后冠状及矢状面MIP图像清楚显示不同角度的多房分隔的形态,VR图像显示门脉左支血管腔明显受压、变细、移位;1例囊壁及多房分隔较厚不规则. 结论 肝内胆管囊腺瘤的多层螺旋CT具有一定的特征性表现,结合三维重组图像及动态增强扫描对诊断有重要价值.     

MR imaging of the thorax: a comparison of axial, coronal, and sagittal imaging planes

We performed direct multisection coronal and sagittal magnetic resonance (MR) images in addition to axial images to determine the value and limitations of coronal and sagittal planes compared with axial planes. Ninety-four MR examinations of the thorax were performed with a 0.3 T permanent magnet system (Fonar) by spin echo technique. The MR axial images were found superior to coronal in demonstrating prevascular adenopathy (one case), pretracheal nodes (nine cases), left paraaortic nodes (three cases), subcarinal nodes (three cases), and small pleural effusions (three cases). The coronal or sagittal planes were better to determine relationship of a mass at the lung apex (five cases) or an abnormality at the lung base (five cases). The anteroposterior displacement or compromise of great vessels and bronchi was best displayed on the axial plane whereas craniocaudal displacement of above structures was best seen on the coronal plane. The axial images were found most informative and we suggest that they be performed routinely. Coronal or sagittal planes may be added in selected cases.     

New scans from old: digital reformatting knee MRI

Purpose: To determine the accuracy of cartilage volume and bone areas measured from a 3D knee MRI sequence reformatted in different planes.Methods: MRI of 16 adult subjects (9 females, 7 males, age range 45–68 years) were acquired in the sagittal plane using a 3D T1-weighted fat suppressed spoiled gradient echo sequence. Medial and lateral tibial cartilage volumes were determined by processing images acquired in the sagittal plane and from the same image data reformatted in the coronal plane. Tibial plateau areas were determined by processing images acquired in the sagittal plane and reformatted in the axial plane.Results: Cartilage volumes calculated from the original sagittal acquisition and data reformatted into the coronal plane were similar. The average over- or under-estimation of the lateral and medial cartilage volume from the reformatted coronal scans compared to the sagittal sequences was 4.6% and 9.8% respectively. Similar medial and lateral tibial plateau areas were obtained when the sagittal data was reformatted in the axial plane. The average over- and under-estimate of lateral and medial tibial plateau areas from the reformatted axial scans compared to the originally acquired sagittal sequences was 6.5% and 6.8% respectively.Conclusion: Knee data acquired via MRI in one plane can be reformatted into different planes, providing comparable cartilage volumes and bone areas. As different planes through the knee may provide better visualization of different joint structures, this method may be useful clinically and as a research tool, while avoiding the cost associated with the prolonged scanning times associated with acquiring multiple planes.     

Imaging of head and neck tumors--methods: CT, spiral-CT, multislice-spiral-CT

Spiral-CT is standard for imaging neck tumors. In correspondence with other groups we routinely use spiral-CT with thin slices (3 mm), a pitch of 1.3-1.5 and an overlapping reconstruction increment (2-3 mm). In patients with dental fillings a short additional spiral parallel to the corpus of the mandible reduces artifacts behind the dental arches and improves the diagnostic value of CT. For the assessment of the base of the skull, the orbital floor, the palate and paranasal sinuses an additional examination in the coronal plane is helpful. Secondary coronal reconstructions of axial scans are helpful in the evaluation of the crossing of the midline by small tumors of the tongue base or palate. For an optimal vascular or tissue contrast a sufficient volume of contrast medium and a start delay greater than 70-80 s are necessary. In our opinion the best results can be achieved with a volume of 150 ml, a flow of 2.5 ml/s and a start delay of 80 s. Dynamic enhanced CT is only necessary in some special cases. There is clear indication for dynamic enhanced CT where a glomus tumor is suspected. Additional functional CT imaging during i-phonation and/or Valsalva's maneuver are of great importance to prove vocal cords mobility. Therefore, imaging during i-phonation is an elemental part of every thorough examination of the hypopharynx and larynx region. Multislice-spiral-CT allows almost isotropic imaging of the head and neck region and improves the assessment of tumor spread and lymph node metastases in arbitrary oblique planes. Thin structures (the base of the skull, the orbital floor, the hard palate) as well as the floor of the mouth can be evaluated sufficiently with multiplanar reformations. Usually, additional coronal scanning is not necessary with multislice-spiral-CT. Multislice-spiral-CT is especially advantageous in defining the critical relationships of tumor and lymph node metastases and for functional imaging of the hypopharynx and larynx not only in the transverse plane but also in the coronal plane.     

Meniscal tears: role of axial MRI alone and in combination with other imaging planes

OBJECTIVE: The purpose of this study was to determine the reliability of standard axial MR images alone in the diagnosis of meniscal tears of the knee and in combination with other imaging planes. MATERIALS AND METHODS: Sixty-two patients (55 men, seven women; age range, 23-68 years) with a prior MRI examination who underwent arthroscopic surgery of the knee during a 1-year period were included in the study group. Images were independently reviewed for identification of meniscal tears by two musculoskeletal radiologists blinded to arthroscopic findings. Sequences for meniscal evaluation included axial fat-saturated fast spin-echo proton density, coronal fat-saturated fast spin-echo proton density, and sagittal fast spin-echo proton density with 4- to 5-mm slice thicknesses. Imaging groups for evaluation were axial, coronal, sagittal, axial and sagittal, axial and coronal, and coronal and sagittal. Observers reported a confidence level for the presence or absence of meniscal tear in all imaging groups based on a 5-point scale. Statistical analysis considered medial and lateral menisci separately. RESULTS: Forty patients had medial meniscal tears, and 16 had lateral meniscal tears at arthroscopy. For medial and lateral meniscal tears, the accuracy (79% and 71%, respectively) of imaging in the axial plane was comparable to other imaging groups but the mean confidence levels (2.82 and 3.00, respectively) were low. In one patient, the axial plane alone correctly showed that no tear was present. No statistically significant difference was observed between imaging plane groups of both menisci in the diagnosis of meniscal tears (p > 0.05). The axial plane increased the accuracy of sagittal and coronal planes of lateral meniscus when combined. CONCLUSION: In standard knee MRI examinations, the axial imaging plane may be valuable for the detection and characterization of meniscal tears.     

Accelerating image acquisition in 64-MDCT: the influence of scan parameters on image resolution and quality in a phantom study

Computed tomographic (CT) image resolution and quality were evaluated utilizing varying scan protocols with accelerated image acquisition. A resolution phantom with hole diameters from 0.2 to 1.0 mm was scanned in axial, coronal, and sagittal plane using a 64-slice multidetector CT with varying scan parameters. No relevant differences in image resolution and quality were detected between the fastest scan protocol, with the shortest rotation time and highest pitch, and the slowest protocol. Accelerated CT protocols resulted in diagnostic images with adequate resolution and quality.     

Head and neck MR imaging in the pediatric patient

Magnetic resonance (MR) imaging studies of the head and neck (excluding the brain) were obtained in 49 children believed to have lesions of the head and neck. Seven children had normal images; in the remaining 42, lesions were divided into four categories: midline lesions, lesions of symmetric paired structures, facial lesions, and nasopharyngeal and oropharyngeal lesions. All entities were well delineated by MR imaging. The imaging planes and sequences chosen depended on the suspected abnormality. Midline lesions were best imaged in the sagittal plane, lesions of paired structures and the face in the axial or coronal planes, and nasopharyngeal and oropharyngeal lesions in the axial or sagittal planes. Intracranial extension of head and neck neoplasms was best evaluated in the coronal plane. Surface coils provided better resolution and were thus more useful in evaluating small superficial lesions; head or body coils were more useful in defining the extent of large lesions. T2-weighted images provided better differentiation between normal and tumor tissue in patients with head and neck neoplasms.     

Routine isotropic computed tomography scanning of chest: value of coronal and sagittal reformations

OBJECTIVE: We sought to evaluate the usefulness of coronal and sagittal reformations from isotropic chest computed tomography (CT) examinations. METHODS: A total of 30 chest CT examinations were reconstructed into 2 sets of axial source images: 0.9-mm slice width with 0.45-mm reconstruction interval (isotropic) and 4-mm slices with 3-mm reconstruction interval. The isotropic dataset was reformatted into coronal and sagittal stacks with 4-mm slices. Three readers reviewed the image sets with 4-mm slice widths. Coronal and sagittal reformations were compared at the same sitting to axial images for depiction of anatomy and disease in the aorta, pulmonary arteries, hilar regions, mediastinum, lung parenchyma, pleura, diaphragm, thoracic spine, ribs, and trachea. A 5-point scale was used to determine whether nonaxial reformations showed anatomy and disease significantly better, somewhat better, same, somewhat worse or significantly worse than equivalent thickness axial source images. A 3-point scale was used to score if nonaxial image sets showed no, some, or significant additional information compared with the axial plane regarding the main diagnosis. RESULTS: There was better visualization of the hilar regions, diaphragm, spine, and trachea on the coronal reformations compared with source axial images (P < 0.05). Sagittal reformations scored better than axial source images for aorta, pleura, diaphragm, spine, and ribs (P < 0.05). The coronal and sagittal series showed significant additional information in 11% and 9% of patients, respectively. CONCLUSION: Radiologists should consider the use of one or both of coronal and sagittal planes in addition to the axial series in routine interpretation of chest CT.     

Bildanalyse bei der Mehrschicht-Spiral-CT der Lunge mit MPR- und MIP-Rekonstruktionen

PURPOSE: To test, whether axial, coronal and sagittal MIP and MPR reconstructions of diagnostic quality can be obtained from 1-mm collimation MSCT data of the chest for the evaluation of thoracic anatomy and pathology. MATERIALS AND METHODS: 1-mm collimation MSCT scans were obtained with a pitch of 6 in an acrylic phantom and in 20 patients. Axial images were reconstructed with 0.6-mm increment. Multiplanar reformations (MPRs) and sliding thin-slab maximum intensity projections (STS-MIPs) were reconstructed in axial, coronal and sagittal planes. Images were printed in lung windows and evaluated by three readers by using a standardized evaluation scheme. RESULTS: Overall, both methods allowed good visualization of anatomic structures. MIP was superior for visualization of the pulmonary arteries (p < 0.05) while central and peripheral bronchi and the lung parenchyma were better depicted on multiplanar reconstructions. A confident diagnosis of thoracic pathology was feasible using both modalities, however MIPs appeared less usefull for evaluation of gross parenchymal abnormalities, such as pneumonic infiltrates or fibrotic changes. No significant difference in the degree of motion artifacts were detected between both modalities. CONCLUSION: MSCT data sets are ideally suited for generating MPR and MIP reconstructions. While MIPs are superior for the evaluation of thoracic vessels, MPR is advantageous for visualizing central and peripheral bronchi and the pulmonary parenchyma.     

颌下腺螺旋CT影像分析

目的：探讨螺旋cT及后处理技术对正常人颌下腺影像的显示。方法：选择不同年龄健康志愿者80例,其中男40例,女40例,并按年龄进行分组,对其颌下腺行4层螺旋CT扫描,应用图像后处理软件测量颌下腺轴面、冠状面、矢状面最大截面积及左右径的大小、左右两腺体间的最近距离、两侧颌下腺后缘连线与颈椎前缘的距离以及腺体CT值,并进行统计学处理。结果：测量结果经统计学分析冠状面、矢状面最大截面积、最大径线及腺间距男女间有显著差异,其中冠状面面积及上下径有极显著性差异。不同年龄分组的冠状位面积、腺间距男女间无显著性差异。结论：螺旋CT及后处理技术能很好地显示颌下腺的影像解剖,并可测量出颌下腺各截面积及各径线长度、腺体CT值,为颌下腺的研究及相关疾病的诊断提供客观依据。     

多层螺旋CT在腹股沟区解剖中的应用

目的:探讨多层螺旋CT三维重建在腹股沟区解剖的应用.方法:回顾性分析20例行多层螺旋CT腹股沟区扫描的三维重建图像,观察在横断面、冠状面及矢状面上腹股沟韧带、腹壁下动脉、圆韧带或精索的显示情况.结果:20例病例中腹壁下动脉在3个轴面上均能显示,显示率100％.横断面不能很好的显示腹股沟韧带,圆韧带或精索的显示率为70％...     

多层螺旋CT后处理技术在喉癌分期中的应用

目的探讨16层螺旋CT各种后处理技术在喉癌术前分期中的应用。资料与方法37例拟诊喉癌患者术前行准直为0．625mm螺旋CT扫描,利用扫描获取的容积资料行薄层1mm冠状、矢状、轴位多平面重组（MPR）、仿真喉镜（CTVL）、容积再现（VR）重建肿块与颈部邻近血管关系以及喉腔透明显示（RSP）等多种后处理技术,综合对喉癌术前TNM作出评估,并将影像分期结果与手术病理结果对照,评价该方法的准确性。结果16层螺旋CT术前对喉TNM分期与临床最终手术病理结果对照,其中TI期符合率为50％,T2期为60％,T3期为75％,T4期为81．25％。总体分期符合率为72．9％。尤其是1mm薄层MPR图像可明显提高对前联合、喉旁间隙、声门下有无受累以及喉软骨微浸润的判断。结论16层螺旋CT0．625mm层厚各向同性容积扫描,各种后处理技术的综合应用,在喉癌术前临床评估中具有很高的实用价值,值得推广应用。     

Normal brachial plexus: MR imaging

Magnetic resonance (MR) imaging of the brachial plexus was performed in the axial, coronal, and sagittal planes in seven volunteers. Normal structures were delineated by comparison with axial and sagittal cadaver sections and with gross dissection. Differentiation of soft tissues with MR imaging enabled the brachial plexus to be defined from surrounding muscle and vascular structures. Multiplanar imaging demonstrated anatomic detail not previously demonstrated with other radiologic modalities and provided excellent delineation of the components of the brachial plexus from the ventral rami to the peripheral nerve branches.