Multiplanar reformation

Fig. 2. Curved multiplanar reformation. Widening of azygos sytem of veins in a patient with left-sided SVC syndrome.

Fig. 9. Curved multiplanar reformation, CT. Pacemaker electrodes passing through single PLSVC into coronary sinus.

Fig. 16. Curved multiplanar reformation. L-R shunt between right inferior pnilmonary vein (white arrow) and SVC via cardiac veins (black arrow)...

For all multislice CT protocols, the reconstructed slice thickness for liver and pelvic scans should be 3-5 mm in all orientations. Thinner slices contain more noise and are less suitable for primary image interpretation. Thin slices are mostly acquired to generate multiplanar reformations with a comparable spatial resolution. 

For examinations on a multislice scanner, thin slices should be used to compute high-quality multiplanar reformations. However, for interpretation of the source images, the reconstruction slice thickness should not be less than 3-5 mm, regardless of the slice orientation. 

Caoli EM, Paulson EK (2000) CT of small bowel obstruction another perspective using multiplanar reformations. AJR Am J Roentgenol 174 993-998... 

Table 13.1. Specific advantages of multiplanar reformation, shaded surface display, and color-coded 3D reformations...

Multiplanar reformation (MPR) Delineates structures that maybe overlooked with axial slices (often due to partial volume effects)... 

Keberle M, Sandstede J, Hoppe F, Fischer M, Hahn D (2003) Diagnostic impact of multiplanar reformations in multislice CT of laryngeal and hypopharyngeal carcinomas. Rofo 175 1079-1085... 

Wang D, Zhang W, Xiong M, Xu J (2001) Laryngeal and hypopharyngeal carcinoma comparison of helical CT multiplanar reformation, three-dimensional reconstruction and virtual laryngoscopy. Chin MedJ (Engl) 114 54-58... 

Three-dimensional data sets can be examined using different 2D and3D reconstruction techniques, starting with multiplanar reformations along three orthogonal axes and in oblique planes. 

Fig. 16.2. a Sagittal multiplanar reformation of the esophagus showing a neoplastic stricture (arrow) located at the lower third of the esophagus, b Virtual endoscopy view showing endoluminal appearance of the lesion (arrow) within esophageal lumen... 

Initially MRC should be read in the multiplanar reformation mode, scrolling through the contrast-enhanced 3D data set in all three orthogonal planes. Whenever a mass protruding from the colonic wall is detected, the identical part of the colon should be analysed on the pre-contrast scan. Increase in signal intensity within the mass can aid in differentiating between residual stool particles and colorectal lesions while colorectal lesions always show strong enhancement, residual stools never show any contrast uptake (Fig. 17.8b,c). 

The assessment of a spiral CT data set further enables postprocessing of the source data and images. Multiplanar reformation of the images allows demonstration of the tracheobronchial stenoses in... 

Current and Future Image Display Techniques 2D Multiplanar Reformation (2D MPR) 74 3D Endoscopic Fly-Through 75 3D Transparency View (Edge-Enhanced View)... 

After years of diligent use of 2D multiplanar reformation (2D MPR) as a primary review with 3D to problem solve, the success of the study of Pickhardt et al. (Pickhardt et al. 2003), aided by improved computer graphics, eclipsed the field in 2003 to demonstrate that 3D as a primary review was not only feasible but may be better. Unfortunately, there has been somewhat of a binary debate of whether 2D vs 3D is better, rather than an understanding of how to apply each of these techniques cohesively in the appropriate setting. 

Fig. 15.1a-d. Dualsource CT coronary angiography in a 49-year-old man with a single episode of atypical chest pain. Scanning was performed with in the step-and-shoot mode (mean heart rate 66 bpm). Curved multiplanar reformations of the right coronary artery (a), left anterior descending artery (b), and the left circmnflex artery. (c,d see next page)... 

Maximum intensity projections or volume rendering techniques may be helpful to show the location of a coronary stent (Fig. 17.2). For the clinical evaluation of the coronary artery stent lumen, multiplanar reformations (MPR) of the data volume are needed. MPR are obtained in at least two orientations, longitudinal and perpendicular to the stent axis, to properly assess for the presence and, if positive, the degree of a stenosis. 

Fig. 20.6a,b. A 52-year-oldmale patient. The multiplanar reformation (MPR) in a short-axis view clearly depicts the extent of an inferior myocardial infarction and shows mild wall thinning in a (arrow). In the same patient, the original axial image... 

Fig. 2.1.6a,b. Multiplanar reformations from 3D CT data sets allow precise assessment of electrode positioning. Note the perfectly centred placement ofthe multi-tined RFA electrode in the coronal (a) and sagittal view (b) in a colorectal cancer metastasis (the hooks are not yet fully delpoyed)... 

Axial, coronal, sagittal reformations 4-mm thickness (3-6 mm, depending on image noise) Interactive multiplanar reformations optional for equivocal and difficult cases... 

The bi-phasic contrast-enhanced scan during the arterial-dominant (15-25 s post injection) and the portal-venous (50-70 s post injection) perfusion phase after bolus-like contrast administration is widely accepted as standard for the optimised display of the complex vascularization of the liver and potential hepatic lesions. Thin-slice data acquisition by modern multi-slice scanners allows isotropic multiplanar reformations with equivalent representations as known from MR. Moreover, CT-arterioportography, also in comparison to modern MR, became less important not least due to the relatively high rate of false positive findings (Vogl et al. 2003). 

Fig. 5.2.12. Coronal multiplanar reformation CT section of a double-lung transplantation recipient in inspiration (left) and expiration (right). Whereas lung density in inspiration is normal, expiration shows extensive basal air trapping...

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