脑CT灌注成像对轻型颅脑损伤预后的评估价值

目的 探讨脑CT灌注成像技术对轻型颅脑损伤(mTBI)患者预后的评估价值。方法 收集2020-01至2022-01联勤保障部队第908医院轻型颅脑损伤患者34例,行头颅64排CT平扫及脑CT灌注成像检查,脑创伤后1个月对患者进行随访及Rivermead脑震荡症状问卷评分(RPQ)作为预后评估指标。结果 30例(88.2%)发现脑灌注异常,12例(35.3%)出现脑震荡后综合征(PCS)阳性(RPQ>14分),4例(11.8%)未见异常灌注改变。30例灌注异常患者中PCS阳性11例(36.7%),4例无灌注异常患者PCS阳性中仅1例(25.0%)。灌注异常区域主要表现为额叶或颞叶局灶性低灌注改变。结论 脑CT灌注成像有助于了解mTBI患者血流动力学变化情况,对评价病情严重程度,及时纠正脑微循环异常具有重要意义。     

脑CT灌注成像及其在颅脑肿瘤诊断中的应用

灌注成像作为一种能反映组织血液动力学状况的功能性成像方法，在全身各脏器疾病尤其是急性缺血性脑血管病诊断中的应用进展迅速。初步研究证明，利用CT灌注成像可定量地反映脑肿瘤的血管化程度和血流灌注状况，对于推断肿瘤的分级和预后，鉴别肿瘤复发与放射性坏死，观察疗效、指导治疗方案的制订及引导活检等有较大的临床应用价值。     

SPECT脑灌注显像对颅脑损伤的诊断价值

ＳＰＥＣＴ脑灌注可显示颅脑损伤的形态改变，又可提供其病理生理学信息，对颅脑损伤的诊断，疗效观察，预后推测等具有一定临床价值，本文综述了ＳＰＥＣＴ脑灌注显颅脑损伤的临床应用及共与ＣＴ，ＭＲＩ的对比研究。     

创伤性颅脑损伤CT灌注成像的临床应用

目的探讨CT灌注成像(CTP)在创伤性颅脑损伤中应用的可能性,评估其对预后的判断价值。方法回顾性分析17例创伤性颅脑损伤病人CT灌注参数及图像,并与头颅CT平扫进行比较。结果 17例中CT平扫见创伤组织及周围脑实质低密度灶13例;CT灌注参数显示脑组织低灌注11例(64.7%),术区及挫伤脑组织高灌注4例(23.5%),2例未见明显脑组织灌注异常。低灌注者预后不良。结论对创伤性颅脑损伤行CT灌注有助于了解颅脑损伤后局部脑组织血流灌注情况,对预后判断提供帮助;在创伤性颅脑损伤的治疗中不仅注意脑低灌注,还应注意高灌注的存在。     

兔肝缺血再灌注损伤CT灌注及其病理对照

目的：探索CT灌注成像在兔肝脏缺血再灌注损伤（I/R）模型中的应用。方法：新西兰大白兔随机分成4组（正常对照组及I/R 6h、12h、24h组,每组5只）。I/R模型采用无创性动脉夹结扎肝左叶血供60min后,恢复血供。各组分别采用iCT行全肝灌注成像;在灌注图上测量肝动脉灌注量（HAP）、门静脉灌注量（HPP）、总灌注量（TLP）及肝动脉灌注指数（HPI）;同时行组织病理学检查。结果：与正常组对比,24h组HAP显著下降（P〈0.01）;各I/R组中HPP、TLP明显低于正常组（P〈0.05）;而在I/R 6h、12h组中,HPI显著高于对照组（P〈0.05）。镜下表现肝窦红细胞淤积,肝细胞核固缩凋亡,肝窦解离,在24h组出现局灶性坏死。结论：CT灌注成像能够动态准确反应肝I/R后微循环灌注量的变化情况。     

多层CT脑灌注成像在早期脑梗死诊断中的初步应用

目的：探讨CT灌注成像在早期脑梗死诊断中的初步应用和诊断价值。方法：对8例疑有脑梗死的患者行常规CT平扫和CT脑灌注检查，发病时间为l一24h，3例患者同时行MRI检查。结果：8例脑梗死患者CT平扫均未见异常，3例CT脑灌注后见大面积脑梗死灶，其中l例发病仅lh，MRI T2W及DWI未见异常信号，6d后CT复查证实；另2例MRI T1、T2加权阴性，DWI呈异常高信号。其余5例CT平扫和脑灌注成像均未见异常，3—7d后CT复查，其中2例为脑干梗死，2例为左侧基底节区、放射冠区小范围梗死和腔隙性脑梗死，l例未见异常。结论：CT脑灌注成像最早可在出现症状40min后显示脑梗死病灶，超早期诊断的特异性好，异常灌注区以脑血流(CBF)、对比剂平均通过时间(MTT)、对比剂峰值时间(TTP)最敏感，CT脑灌注使患者得到早期诊断和治疗，改善预后。但对脑干或其它部位小的脑梗死灶，CT脑灌注的价值不大。     

CT灌注成像在脑内缺血性疾病中的初步应用

目的 评价ＣＴ灌注成像在脑内缺血性疾病的作用。方法 对２４例缺血性中风发作２小时至２个月的患者及１０例开颅术后的患者行常规ＣＴ扫描及ＣＴ灌注成像,２８例进行ＭＲＩ检查,６例行ＤＳＡ检查及单光子发射计算机体层成像（ｓｉｎｇｌｅ ｐｈｏｔｏｎｅｍｉｓｓｉｏｎ ｃｏｍｐｕｔｅｄ ｔｏｍｏｇｒａｐｈｙ,ＳＰＥＣＴ）。结果 ３４例患者ＣＴ扫共检出３０个缺血及梗死灶,ＣＴ灌注成像共检出４１个病灶,均经随访Ｃ     

脑梗死前期脑局部低灌注的CT灌注成像表现及分期

目的 探讨脑梗死前期动态CT灌注成像分期的应用价值。方法 对32例临床诊断为脑局部缺血患者作了CT灌注成像和局部脑血流量(regional cerebral blood flow，rCBF)、局部脑血容量(regional cerebral blood volume，rCBV)、平均通过时间(mean transit time，MTF)和最大峰值时间(time-to-peak，TTP)比值(病侧／健侧)测量。根据影像学表现进行脑梗死前期的分期，包括Ⅰ1期：TTP延长，MTT、rCBF和rCBV正常；Ⅱ2期：TTP和MTT延长，rCBF正常，rCBV正常或轻度升高；Ⅱ1期：TTP、MTT延长以及rCBF下降，rCBV基本正常或轻度下降；Ⅱ2期：TTP、MTT延长，rCBF和rCBV下降。结果 Ⅰ1期4例，CT灌注成像见脑局部TTP延长，MTT、rCBF和rCBV正常。rCBF、rCBV、MTT和TTP平均比值分别为1．00、1．00、1．00和1．30。Ⅰ2期13例，表现为脑局部TTP和MTT延长，rCBF和rCBV正常(8／13)或rCBV轻度增高(5／13)。rCBF、rCBV、MTT和TTP平均比值分别为1．00、1．03、1．38和1．30。Ⅱ1期8例，CT灌注成像见TTP、MTT延长以及rCBF下降，rCBV正常(3／8)或轻度下降(5／8)。rCBF、rCBV、MTT和TTP平均比值分别为0．56、0．94、1．49和1．47。Ⅱ2期4例，表现为脑局部区域TTP、MTT延长，rCBF和rCBV下降。rCBF、rCBV、MTT和TTP平均比值分别为0．42、0．59、1．57和1．55。3例CT灌注参数图未见异常区域。结论 动态CT灌注成像可以清楚地显示脑梗死前期的血流动力学异常，并可根据各种参数的比值及相互关系提供相关的脑血流动力学的功能信息。脑梗死前期的影像学分期可以区分低灌注所致脑局部微循环的病理生理学状态，具有重要的临床应用价值。     

CT diagnosis in acute cerebral ischemia

The advent of new MRI techniques such as perfusion- (PWI) and diffusion- (DWI) weighted imaging has improved diagnostic imaging in stroke. However, CT scanners are more widely available and less expensive than MRI scanners and are often located in the emergency departments even of smaller community hospitals. Topic of this article is CT-based diagnosis of patients with hyperacute ischemic stroke. In hyperacute stroke, a multiparametric CT protocol allows a comprehensive diagnosis by combining non-contrast enhanced CT (NECT), perfusion CT (PCT), and CT angiography (CTA). PCT can render important information about the hypoperfused brain tissue, CTA provides further important information about the vessel status. When stroke MRI is not available, multiparametric stroke CT can give nearly equivalent information, and can help to identify patients for thrombolytic therapy.     

Perfusion measurements of the brain: using dynamic CT for the quantitative assessment of cerebral ischemia in acute stroke

Objective: Perfusion CT has been successfully used as a functional imaging technique for the differential diagnosis of patients with hyperacute stroke. We investigated to what extent this technique can also be used for the quantitative assessment of cerebral ischemia. Methods and material: We studied linearity, spatial resolution and noise behaviour of cerebral blood flow (CBF) determination with computer simulations and phantom measurements. Statistical ROI based analysis of CBF images of a subset of 38 patients from a controlled clinical stroke study with currently more than 75 patients was done to check the power of relative cerebral blood flow (rCBF) values to predict definite infarction and ischemic penumbra. Classification was performed using follow-up CT and MR data. Results: Absolute CBF values were systematically underestimated, the degree depended on the cardiac output of the patients. Phantom measurements and simulations indicated very good linearity allowing reliable calculation of rCBF values. Infarct and penumbra areas in 19 patients receiving standard heparin therapy had mean rCBF values of 0.19 and 0.62, respectively. The corresponding values for 19 patients receiving local intraarterial fibrinolysis were 0.18 and 0.57. The difference between infarct and penumbra values was highly significant (P<0.0001) in both groups. No penumbra area was found with an rCBF value of less than 0.20. While in the heparin group only 25% of all areas with an rCBF between 0.20 and 0.35 survived, in the fibrinolytic group 61% of these areas could be saved (P<0.05). Conclusion: Perfusion CT is a fast and practical technique for routine clinical application. It provides substantial and important additional information for the selection of the optimal treatment strategy for patients with hyperacute stroke. Relative values of cerebral blood flow discriminate very well between areas of reversible and irreversible ischemia; an rCBF value of 0.20 appears to be a definite lower limit for brain tissue to survive an ischemic injury.     

CT for acute stage of closed head injury

Brain damage after head injury can be classified by its time course. Primary damage that includes acute subdural hematoma (SDH), acute epidural hematoma (EDH), and intraaxial lesions that include contusions, diffuse axonal injury (DAI), and intracranial hemorrhage (ICH), occurs at the moment of impact and is thought to be irreversible. Secondary damage that includes herniations, diffuse cerebral swelling, and secondary infarction and hemorrhage, evolves hours or days after injury as a consequence of systemic or intracranial complications. The duration and severity of secondary damage influence outcome. Head injury management is focused on preventing, detecting, and correcting such secondary damage. CT has been widely used for the neuromonitoring of head trauma. CT is the gold standard for the detection of intracranial abnormalities and is a safe method for survey. While MRI is more sensitive and accurate in diagnosing cerebral pathology, CT is considered the most critical imaging technique for the management of closed head-injured patients in the acute stage. In this article, we review the imaging findings and literature of various lesions of closed head injury in the acute stage.     

Is contrast-enhanced CT indicated in acute head injury?

Summary The authors discuss the value of intravenous contrast enhancement in CT scanning in acute head injury. In a series of seventy consecutive patients they conclude that no incremental information was obtained by performing contrast-enhanced CT scans in the acute phase of the head injury.     

亚低温对重型颅脑损伤后脑循环动力学的影响

目的 研究亚低温对重型颅脑损伤（ＳＨＩ）后脑循环动力学的影响及其临床意义。方法 ３６例ＳＨＩ患者,随机分为常规治疗组和亚低温组,各１８例。用脑循环动力学检测仪检测伤后０,１,３,７,１０,１４,２１ｄ的脑循环动力学指标（ＣＶＤＩ）,结合ＣＴ动态观察,分析两组ＣＶＤＩ变化规律、伤灶脑水肿大小和预后。结果 与正常组比较,常规治疗组伤后ＣＶＤＩ可划分为四个期,即低灌注期（０ｄ）、高灌注期（１￣３ｄ）、脑     

Prevalence of MR evidence of diffuse axonal injury in patients with mild head injury and normal head CT findings.

PURPOSETo assess the prevalence of MR evidence for diffuse axonal injury at 1.5 T in patients with normal head CT findings after mild head injury.METHODSTwenty consecutive patients with mild head injury (Glasgow Coma Scale, 13 to 15; no subsequent deterioration, loss of consciousness < 20 minutes) and normal head CT findings were examined with MR at 1.5 T. Pulse sequences included a conventional T2-weighted spin-echo sequence (2500-3000/30,80/1[repetition time/echo time/excitations]) and a T2*-weighted gradient-echo sequence (750/40/2, 10 degrees flip angle). Each sequence was read independently by two blinded readers.RESULTSThe readers agreed that abnormalities compatible with diffuse axonal injury were present in the white matter of 6 (30%) of 20 patients (95% confidence interval, 12% to 54%). Both readers agreed that foci of high signal intensity were present on the T2-weighted spin-echo sequence in 3 (15%) of the 20 cases (95% confidence interval, 3% to 38%) and that foci of hypointensity compatible with hemorrhagic shear injury were present on the T2*-weighted sequence in 4 (20%) of the 20 patients (95% confidence interval, 6% to 44%). Both types of abnormality were noted by the readers in one patient.CONCLUSIONSMR shows evidence of diffuse axonal injury in some patients with normal head CT findings after mild head injury. These lesions may represent the pathologic substrate underlying the postconcussion syndrome that occurs in many patients with moderate to severe head injury.     

Perfusion CT of head and neck cancer

We aim to review the technique and clinical applications of perfusion CT (PCT) of head and neck cancer. The clinical value of PCT in the head and neck includes detection of head and neck squamous cell carcinoma (HNSCC) as it allows differentiation of HNSCC from normal muscles, demarcation of tumor boundaries and tumor local extension, evaluation of metastatic cervical lymph nodes as well as determination of the viable tumor portions as target for imaging-guided biopsy. PCT has been used for prediction of treatment outcome, differentiation between post-therapeutic changes and tumor recurrence as well as monitoring patient after radiotherapy and/or chemotherapy. PCT has a role in cervical lymphoma as it may help in detection of response to chemotherapy and early diagnosis of relapsing tumors.