Clinical Computed Tomography

Welcome to the course for the Lab Course on clinical CT, where we will show you the basics of computed tomography, and give you some insights in state-of-the-art clinical and especially spectral CT. This lab course is divided into three parts in presence. For each part you will have prepare before the lab course -- we have prepared a separate manual for each part --, evaluate your data, work with python scripts, answer CT related questions, and summarize your work in a report.

Computed tomography (CT) is a non-destructive X-ray imaging method, which allows to visualize three-dimensional X-ray absorption properties of an object. In part 1, you will learn the basics of computed tomography in a laboratory environment. In the first part of the lab course, you will learn the basics about X-ray imaging and computed tomography using a simple laboratory CT setup. Next to theoretical and experimental basics of X-ray imaging and radiography, you will get an idea how CT reconstruction using filtered backprojection (FBP) works and how typical reconstruction artifacts look like. You can also scan your own samples. Part 1 will take place in the TUM Physics Department in Garching Forschungszentrum.

In part 2, we will focus on clinical CT systems with respect to image quality and dose. Clinical CT systems are a standard diagnostic tool in radiology. The method is fast, comparably cheap, and provides three-dimensional isotropic attenuation of different tissue. CT is not only used in emergency medicine, where a whole body scan can be performed below 20 seconds with state-of-the-art CT systems, but also for different diagnostic questions like staging of cancer patients, determination of kidney stones, or diagnosis of cardio-vascular diseases with the use of contrast agent. However, CT comes at the cost of radiation exposure. In part 2, you will perform measurements at a clinical CT scanner at the TUM Klinikum rechts der Isar in Munich. First, we will measure a test sample to get familiar with the CT scanner. You can also measure again samples of your own. The second topic will cover spatial resolution. Here, you will learn how to determine the spatial resolution of a CT system. The third task is to assess quantitatively noise using phantoms. Moreover, you will assess dose of a scan, which is determined by noise and resolution and essential to be kept at a minimum in patient care.

In part 3, you fill focus on state-of-the-art dual-energy CT (DECT) imaging. DECT, also known as spectral CT, is a computed tomography technique that separates X-ray spectra, allowing for quantitative assessment of materials that have different attenuation properties at different energies. In this part of the BEMP clinical CT lab course, you will learn the basics about DECT using image-based material decomposition on micro CT data as well as a simple simulation of data for projection-based decomposition. Also, you will look into clinical data sets and investigate the diagnostic potential of DECT. Next to theoretical and experimental basics, you will get an idea of how data acquisition, material decomposition in projection space, filtered backprojection (FBP), and algebraic reconstruction (ART) work in combination. You will create your own DECT measurement datasets and simulation data from a digital phantom. This part will also take place at the TUM Klinikum rechts der Isar in Munich.

After successful completion of the module the students are able to:

1. prepare self-dependently an x-ray based radiography and CT experiment
2. operate a clinical CT and perform measurements under supervision
3. perform data record, analysis, and evaluation
4. document the experiments including methods, results, and
discussion fulfilling the requirement for a scientific publication
5. perform literature research

No preconditions in addition to the requirements for the Master’s program in Physics. Lecture PH2001 might be helpful.

The lab course is carried out in groups of usually 3 participants. The groups are working self-dependently as far as possible. A supervisor supports the group in case that questions or problems arise. Students have to prepare for the course by studying introductory material like the manual of each part and additional literature, perform the experiments for each part, work the given Python script tasks. The experimental data has to be analyzed and evaluated. For each part, a report has to be written according to scientific standards. Eventually, the lab course has to be presented in a colloquium followed by a scientific discussion. The first experimental part of this lab course will take place on campus Garching (TUM Physics Department) and the parts two and three will take place at the TUM Klinikum rechts der Isar in Munich.

Moodle course script including manuals and python scripts as well as a PowerPoint (or similar) presentation

see recommended literature on Moodle.

The module is examined by a laboratory assignment in form of a pass/fail requirement. The students perform a three-staged series of experiments on computed tomography, clinical and spectral CT. The lab work contains three stages of experimental as well as theoretical nature and is assessed on the performance in the experimental, on the correct processing of the obtained data and on the presentation of their results. In doing so, students show their ability to perform CT experiments and process as well as evaluate the gained data according to scientific standard.

The laboratory assignment consists of four parts:

1. Preparation (insufficiently prepared participants may be rejected due to safety reasons; to be done for each part).

2. Execution (up to 20 points; to be done for each part; work conscientiously, safely and cleanly, understanding and keeping safety instructions).

3. Report (5-10 pages, up to 20 points; to be done for each part; data quality, correct scientific reporting of results, citations neat, good laboratory practice).

4. ‘Colloquium’: presentation (regarding all three parts) followed by a discussion (duration: 20-30 minutes presentation, up to 60 points). (use of correct technical terminology, comprehension of the results obtained, units of time and reasonable structure of the presentation, manner of presenting the results.)

A total of 66 points must be achieved to pass the laboratory assignment.