الله الله بسم بسمالرحمن الرحمن الرحيمالرحيم

Multi-Slice CTMulti-Slice CT Short Notes On Clinical ApplicationShort Notes On Clinical Application

Dr Mohamed El Safwany, MD.

Physical Principles Physical Principles of Multi-Detector of Multi-Detector

CTCT

Intended learning Intended learning outcomeoutcome

The student should learn at the end The student should learn at the end of this lecture principles of of this lecture principles of multidetector CT.multidetector CT.

Multiplied Computed Tomography (MSCT) was introduced in the field of radiology in 1998 resulting in revolution of imaging and addition of a new clinical applications.

The benefits of multi-detector CT relative to single-section CT are significant.

The examination can be done with thinner sections, and much faster resulting in improved resolution and reducing the motion artifacts.

MDCT can cover a distance 8 times longer than single-slice CT.

There are 2 main differences There are 2 main differences between ordinary spiral CT between ordinary spiral CT machines andmachines and MDCTMDCT :- :-

1- It allows the acquisition of multiple axial images with a single gantry rotation.2- It has shorter gantry rotation period making it much faster.

Scanning SpeedScanning Speed MDCTMDCT scanners have gantry scanners have gantry

rotation period of 0.5 sec, rotation period of 0.5 sec, twice the speed of most twice the speed of most conventionalconventional helical scanners. helical scanners.

Therefore, a MDCT scanner Therefore, a MDCT scanner with 4 data channels is up to with 4 data channels is up to 8 8 timestimes faster than a faster than a conventional single-slice CT conventional single-slice CT scanner.scanner.

Clinical ApplicationsClinical Applications

Multisection CT aquires changes in the Multisection CT aquires changes in the planning and staging of patient planning and staging of patient examinations. The scanning time is examinations. The scanning time is reduced for most examinations, requiring reduced for most examinations, requiring adjustments in the administration of adjustments in the administration of intravenous contrast material. The amount intravenous contrast material. The amount of contrast material can be reduced, and of contrast material can be reduced, and different vascular phases can be better different vascular phases can be better visualized. Thin-section scanning allows visualized. Thin-section scanning allows production of high-quality MPR images production of high-quality MPR images

  Coronal reformation image of the Coronal reformation image of the right temporal bone created from an right temporal bone created from an axial multisectionaxial multisection

(a) Coronal MPR image clearly shows (a) Coronal MPR image clearly shows a pin penetrating the posterior a pin penetrating the posterior subtalar joint (arrowheads). (b) subtalar joint (arrowheads). (b) Sagittal MPR image clearly shows Sagittal MPR image clearly shows secondary degenerative changes secondary degenerative changes (arrows). Streak artifacts are (arrows). Streak artifacts are remarkably mild given the large remarkably mild given the large amount of steel. amount of steel.

Thin-section CT of the hip Thin-section CT of the hip (a, b)(a, b) Coronal Coronal (a)(a) and curved oblique and curved oblique sagittal sagittal (b)(b) reformation images reformation images show fine detail. show fine detail. (c)(c) Lateral surface- Lateral surface-rendered image shows the rendered image shows the acetabulum and femur together. acetabulum and femur together.

    (a)(a) Coronal maximum-intensity Coronal maximum-intensity projection image shows the sacrum projection image shows the sacrum with metal appliances. with metal appliances. (b)(b) Curved Curved reformation image shows the reformation image shows the sacroiliac joint surfaces and bone sacroiliac joint surfaces and bone grafts (arrow). grafts (arrow).

(a)(a) Sagittal image shows that the Sagittal image shows that the multisection acquisition will avoid multisection acquisition will avoid dental hardware and the associated dental hardware and the associated artifacts. artifacts. (b, c)(b, c) Coronal Coronal (b)(b) and and sagittal sagittal (c)(c) reformation images show reformation images show mucoperiosteal thickening. mucoperiosteal thickening.

Bone TumorsBone Tumors

(a)(a) Sagittal reformation Sagittal reformation image shows excellent image shows excellent bone detail and the outline bone detail and the outline of the subarachnoid space. of the subarachnoid space. (b, c)(b, c) Corrected-axis MPR Corrected-axis MPR image image (b)(b), which was , which was obtained along the dashed obtained along the dashed line in line in aa, has the same , has the same spatial resolution as an spatial resolution as an original axial imageoriginal axial image

Duodenal carcinoma. Duodenal carcinoma. (a-c)(a-c) Axial Axial (a)(a), , coronal coronal (b)(b), and sagittal , and sagittal (c)(c) images images show a dilated common bile duct (I) show a dilated common bile duct (I) and a duodenal neoplasm (arrows). and a duodenal neoplasm (arrows). (d, e)(d, e) Lateral arterial-phase Lateral arterial-phase (d)(d) and and anterior venous-phase anterior venous-phase (e)(e) maximum- maximum-intensity projection images show intensity projection images show normal vessels. normal vessels.

    Bilateral carotid artery Bilateral carotid artery stenosis. Coronal maximum-stenosis. Coronal maximum-intensity projection image intensity projection image from CT angiography from CT angiography performed from the arch to performed from the arch to the skull base (1.0-mm the skull base (1.0-mm section thickness, 19-cm section thickness, 19-cm longitudinal coverage, 0.5-longitudinal coverage, 0.5-mm longitudinal mm longitudinal reconstruction interval) reconstruction interval) shows severe stenosis of shows severe stenosis of the left internal carotid the left internal carotid artery (arrow). artery (arrow).

Renal artery stenosis in a Renal artery stenosis in a hypertensive patient imaged with CT hypertensive patient imaged with CT angiography angiography

Renal AngiographyRenal Angiography

Endovascular repair of an Endovascular repair of an aortic aneurysm with stent-aortic aneurysm with stent-graftsgrafts

Virtual EndoscopyVirtual Endoscopy

CTCT coronarycoronary angiography is angiography is becoming feasible with the becoming feasible with the availability of faster multiseavailability of faster multisectction ion imaging.imaging.

Multisection CT is superior to single-section Multisection CT is superior to single-section helical CT for nearly all clinical applications. The helical CT for nearly all clinical applications. The superior speed of the former can be used to superior speed of the former can be used to improve the temporal, spatial, and contrast improve the temporal, spatial, and contrast resolution of the images. In addition, resolution of the images. In addition, multisection CT shows promise for clinical multisection CT shows promise for clinical applications that were limited or impossible with applications that were limited or impossible with single-section helical CT, such as cardiac single-section helical CT, such as cardiac imaging, organ perfusion studies, and imaging, organ perfusion studies, and examinations of multiple vascular phases. It also examinations of multiple vascular phases. It also brings isotropic imaging into the CT domain. CT brings isotropic imaging into the CT domain. CT has reached the brink of a new era. has reached the brink of a new era.

Text BookText Book

David Sutton’s RadiologyDavid Sutton’s Radiology Clark’s Radiographic positioning and Clark’s Radiographic positioning and

techniquestechniques

AssignmentAssignment

Two students will be selected for Two students will be selected for assignment.assignment.

QuestionQuestion

State difference between single and State difference between single and multidetector CT?multidetector CT?

Thank YouThank You

30