Digital Volumetric Tomography (DVT): Information & DVT Specialists

Digital volume tomography (DVT) is a cross-sectional imaging technique, similar to conventional computed tomography (CT). The cross-sectional images are converted into a detailed 3D image using a computer.

The procedure was originally developed for dentistry and has been in use there since 1997. Initially, DVT was known as dental volume tomography or digital panoramic X-ray. Just ten years later, 80 percent of all dental practices already had a DVT machine.

Since then, DVT has been further developed. It is also used in oral and maxillofacial surgery as well as in otolaryngology.

Before the examination, the patient must provide information about any pre-existing medical conditions and metal implants in their body.

The actual examination is then performed by specially trained radiology technicians (MTRA). The patient is given a radiation protection apron and, in most cases, special thyroid protection as well. Depending on the device and the clinical indication, the CBCT is performed while the patient is sitting, lying down, or standing.

In dentistry, the patient sits or stands. Their head is secured using a chin rest, a headband, and a bite block to prevent movement during the scan. The staff then leaves the room and initiates the scan from a control panel outside the X-ray room.

In DVT, a three-dimensional X-ray beam is combined with a flat-panel detector. This produces images with high detail and minimal distortion within seconds. The X-ray tube and the image detector rotate synchronously around the patient’s head. The X-rays are reflected by the bones and surrounding tissue, measured, and converted into images.

Approximately 400 individual images are captured, from which the computer reconstructs a virtual 3D object.

Digital volume tomography is fundamentally very similar to computed tomography. However, DVT uses a cone-shaped beam, whereas the beam in a standard CT scan is fan-shaped.

There are also differences in terms of radiation exposure: A DVT involves ten times less radiation exposure than a CT scan. Nevertheless, the exposure is higher than with a standard X-ray examination. Therefore, the use of digital volume tomography must always be carefully considered.

In some cases, low-resolution images are sufficient for diagnosis, allowing the radiation dose to be reduced.

There are many situations in which a DVT is indicated. Dentists and oral surgeons, for example, often rely on this technique when

• planning to place dental implants,
• perform root canal treatment, or
• assess the exact spatial relationship between the wisdom teeth and the inferior alveolar nerve.

Digital volume tomography enables

• the precise localization of root canals,
• determining bone volume, and
• the detection of diseases of the maxillary sinus.

In otolaryngology, DVT is suitable for diagnosis as well as for preparing surgical procedures involving the ears and paranasal sinuses.

DVT also allows for a reliable distinction between sinusitis originating from a tooth and that originating from the nasal mucosa.

The following specialists use digital volume tomography particularly frequently:

• Dentists
• Oral and maxillofacial surgeons
• Ear, Nose, and Throat (ENT) specialists
• Neuroradiology
• Radiation oncology

Digital volume tomography is also increasingly being used

• in orthopedics,
• for rheumatic diseases, and
• even in sleep medicine (for example, for diagnosing severe snoring or sleep apnea)

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DVT is particularly well-suited for imaging bony structures. These are captured more accurately with digital volume tomography than with conventional computed tomography. However, the imaging of soft tissue is less high-contrast than with a standard CT scan.

Digital volume tomography offers a key advantage for patients: Unlike with a CT scan, they do not have to enter a narrow tube. Many people therefore find a CT scan very stressful.

The entire DVT examination usually takes only a few minutes. The results are available—just like with an X-ray—in a very short time.

Furthermore, DVT ensures maximum safety during surgeries in challenging areas. These include, for example, the jaw area and the ears. The treating physician can plan surgical procedures down to the smallest detail and typically perform them using minimally invasive techniques.

Detailed planning also increases the chances of the best possible treatment outcome.

Unfortunately, DVT also has disadvantages. The radiation exposure is higher compared to a standard X-ray. For this reason, digital volume tomography should only be used after careful consideration.

Furthermore, DVT devices are sensitive to metal objects, such as implants. Areas containing metal appear black. Metal objects also reduce the overall quality of the examination results. Additionally, metal objects can mimic pathological structures where healthy tissue is actually present.

Digital volume tomography has been in proven use for over 20 years. Nevertheless, it is still a relatively new imaging technique. As a result, the costs of DVT are not yet covered by statutory health insurance plans.

Especially in complicated cases and when the diagnosis is unclear, it may well be worth it for the patient to cover the costs themselves. Before surgery, the surgeon can assess the surgical site more accurately. This reduces the risk of complications during and after the procedure.

The price for digital volume tomography consists of two components:

• the cost of acquiring the image and
• the cost of analyzing the data.

Depending on the size of the area to be imaged, the costs can therefore vary significantly. On average, patients can expect to pay between 100 and 300 euros.