Perfusion scanning

About: Perfusion scanning is a research topic. Over the lifetime, 9496 publications have been published within this topic receiving 223860 citations. The topic is also known as: perfusion imaging.

Prospective comparison of MR lung perfusion and lung scintigraphy.

Abstract: This study attempted to assess the accuracy and potential of lung magnetic resonance (MR) perfusion imaging compared with perfusion scintigraphy in the evaluation of patients with suspected lung perfusion defects The technique, which uses an inversion recovery turbo-FLASH sequence with ultra-short TE (14 msec), was tested in 24 patients suspected clinically of having acute pulmonary embolism (n 5 19) and in patients with severe pulmonary emphysema (n 5 5) Perfusion lung scintigraphy was performed within 48 hours prior to the MRI examination in both groups of patients The dynamic study was acquired in the coronal plane and consisted of 10 images of 6 slices (a total of 60 images per series) Gadopentetate dimeglumine (01 mmol/kg) was manually injected as a compact bolus during the acquisition of the first image Three senior radiologists reviewed all unprocessed two-dimensional coronal sections They were blinded to clinical data and other imaging modalities For the three observers, the average sensitivity and specificity of MR were 69% and 91%, respectively The overall agreement between MR and scintigraphy appears to be good, with a good correlation between the two modalities (kappa 5 063) However, the data showed variability depending on the location of the perfusion defect, with higher accuracy in the upper lobes The agreement between MR perfusion and scintigraphy appears to be moderate in the left inferior lobe (kappa 5 048) The data showed an overall good interobsever agreement (kappa 5 066) MR perfusion of the lung is a promising technique in detecting lung perfusion defects J Magn Reson Imaging 1999;9:61‐68 r 1999 Wiley-Liss, Inc

MR and CT Imaging for the Evaluation of Pulmonary Hypertension

Abstract: Imaging plays a central role in the diagnosis and management of all forms of pulmonary hypertension (PH). Although Doppler echocardiography is essential for the evaluation of PH, its ability to optimally evaluate the right ventricle and pulmonary vasculature is limited by its 2-dimensional planar capabilities. Magnetic resonance and computed tomography are capable of determining the etiology and pathophysiology of PH, and can be very useful in the management of these patients. Exciting new techniques such as right ventricle tissue characterization with T1 mapping, 4-dimensional flow of the right ventricle and pulmonary arteries, and computed tomography lung perfusion imaging are paving the way for a new era of imaging in PH. These imaging modalities complement echocardiography and invasive hemodynamic testing and may be useful as surrogate endpoints for early phase PH clinical trials. Here we discuss the role of magnetic resonance imaging and computed tomography in the diagnosis and management of PH, including current uses and novel research applications, and we discuss the role of value-based imaging in PH.

CT perfusion predicts secondary cerebral infarction after aneurysmal subarachnoid hemorrhage

Abstract: Objective: To prospectively assess the diagnostic accuracy of CT perfusion (CTP) and transcranial Doppler sonography (TCD) for the prediction of secondary cerebral infarction (SCI) after aneurysmal subarachnoid hemorrhage (SAH). Methods: During 2 weeks after SAH, 38 consecutive patients completed an average of 3.5 CT/CTP and 10.7 TCD examinations at regular intervals as required by the study protocol. SCI was defined as delayed infarction on native CT between 3 and 14 days after SAH and developed in n = 14 patients (n = 24 without SCI). Analysis was based on examination dates before SCI. Common measures of diagnostic accuracy were calculated for qualitative CTP (visual color-map ratings from two blinded observers) and TCD assessments (mean flow velocity >120 cm/s in anterior, middle, and posterior cerebral artery territories). Quantitative measures, which for CTP were obtained from cortical a priori regions of interest corresponding to the vascular territories, were analyzed by binary logistic regression. Results: Time of prediction for SCI by CTP was at a median of 3 days (range 2 to 5 days) before manifestation of complete infarction on native CT. Visual assessment of time-to-peak (TTP) color maps performed best for the prediction of SCI with 0.93 sensitivity (95% CI: 0.7 to 1.0) and 0.67 specificity (95% CI: 0.53 to 0.7). On quantitative analysis, the odds ratio (OR) for 1 second of side-to-side delay in TTP was 1.4 ( p = 0.01, Wald χ 2 = 8.57, CI: 1.07 to 1.82). Daily TCD measures were not significantly related to SCI at any time before complete infarction on native CT. Conclusions: Time to peak as indicated by CT perfusion is a sensitive and early predictor of secondary cerebral infarction.

Measurement of human pancreatic perfusion using dynamic computed tomography with perfusion imaging

Abstract: Absolute quantification of pancreatic perfusion in man has been extremely difficult to date. This paper describes a relatively simple application of dynamic computed tomography to provide perfusion imaging of the human pancreas. Values for perfusion in eight normal pancreases ranged between 1.25 and 1.66 ml min" 1 ml" 1 (mean: 1.52 ml min" 1 ml" 1 ). Increased perfusion values were present in a patient with an islet cell tumour (overall perfusion 2.11 ml min" 1 ml" 1 ) and a patient with Wilson's disease (3.43 ml min" 1 ml" 1 ). Pancreatic perfusion was reduced in a patient with diabetes (0.60 ml min" 1 ml" 1 ) and in a failing pancreatic transplant (0.97 ml min" 1 ml" 1 ). The combination of functional information and good spatial detail afforded by computed tomography (CT) perfusion imaging means the technique is well suited for the evaluation of the human pancreas. It is currently the only technique which allows non-invasive absolute quantification of pancreatic perfusion.