All medical imaging equipment manufactured today is supposed to conform to the DICOM standards. Viewing of the images thus produced cannot be done by ordinary imaging programs available on a regular PC. A special diagnostic medical imaging program is required, known as a DICOM workstation. For commercial use in medical diagnosis, such diagnostic medical imaging programs need to be FDA approved and need a special license. These measures ensure that any application developed for clinical purposes is capable of accurate depiction of high quality medical images.

1. Advances in Diagnostic Medical Imaging
that have transformed Healthcare
Just over a hundred years ago, the advent of X-rays was considered a significant
leap in medical diagnosis. Over the last century, simple radiography has expanded
into a specialized field—diagnostic medical imaging. X-rays have been harnessed
using better technology via digitalized CT scans and new diagnostic medical
imaging techniques, such as the MRI and ultrasound, have emerged. Medical
imaging modalities continue to evolve and refine. As the actual imaging process
progresses, there is a parallel, and equally important, improvement in the handling
of medical images and the associated workflow. In this article, we zoom in on the
most important advances in medical diagnostic imaging that have transformed the
way physicians examine and treat patients.
The DICOM Standard
Medical imaging is used primarily to diagnose diseases as well as to monitor their
progress. It is essential that the images produced are of the highest quality since
they have a direct bearing on patient outcomes. To maintain quality, a set of
standards for medical images was developed jointly by the American Society of
Radiology and the National Electrical Manufacturers Association. It is referred to

2. as the DICOM standards, which stands for Digital Imaging and Communications in
Medicine. Images produced by all medical imaging hardware must conform to the
characteristics described in this standard. Furthermore, there is a specific format
available for storing and sharing medical images—referred to as the DICOM
format.
All medical imaging equipment manufactured today is supposed to conform to the
DICOM standards. Viewing of the images thus produced cannot be done by
ordinary imaging programs available on a regular PC. A special diagnostic medical
imaging program is required, known as a DICOM workstation. For commercial use
in medical diagnosis, such diagnostic medical imaging programs need to be FDA
approved and need a special license. These measures ensure that any application
developed for clinical purposes is capable of accurate depiction of high quality
medical images.
PACS Archiving
With the arrival of digitalized medical diagnostic imaging, the need to develop X-
ray films has markedly declined. However, digital images are still being converted
into ‘films’ with the aid of printers. Imaging films require proper storage under the
right conditions to prevent damage over time. Retrieval of these images from
storage can be a time consuming process and requires dedicated personnel for
record-keeping.
PACS, which stands for Picture Archiving and Communications System, obviates
the need for physical storage and retrieval of films. It is basically a platform for the
virtual storage and retrieval of medical images. PACS makes it possible to handle
enormous volumes of data related to medical images. Any computer that is
connected to a specific PACS server is able to retrieve DICOM images and view
and even modify them. The latest innovation has been the introduction of cloud-
based PACS, where instead of local storage, the PACS is hosted on the internet
and any user connected to the internet, with the right credentials, can access the
images.
Not only has PACS simplified storage and retrieval, it has also made teleradiology
a reality. Today, radiologists need not be present in the same area where images
are being acquired. They can view images from different geographic locations and
provide their expert opinion. Through teleradiology, a single radiologist can
generate reports for images coming in from multiple hospitals. This saves precious
time and resources, and helps to reduce healthcare costs.

3. Real-time Imaging
With the need for developing or printing of films gone, the workflow process for
acquiring and viewing medical images has improved. Real-time imaging is a
concept where there is no time lag between the acquisition of images from the
patient and their viewing by the physician. Radiologists can literally view images
while the patient is still within the scanner.
The faster interpretation of diagnostic medical images leads to immediate
diagnosis, which in turn enables rapid medical intervention. Real-time medical
diagnostic imaging plays a significant role in emergencies. For instance, in trauma
patients, intra-abdominal injury was earlier determined by diagnostic laparoscopy
or peritoneal lavage, both of which were invasive procedures. Today, however, the
standard of care is to use FAST (Focused Abdominal Sonography in Trauma),
which uses a real-time ultrasound to quickly determine whether or not a patient
has suffered an intra-abdominal injury. Real-time ultrasound imaging is also used
to monitor the health of the fetus in utero and assess growth parameters.
Functional Imaging
Most diagnostic medical imaging systems are designed to diagnose anatomical
or structural abnormalities. Modern medical diagnostic imaging, in addition to
that, can also assess abnormalities in tissue and organ function. This includes
detection of abnormalities in physiological processes such as metabolism and
blood flow. Functional imaging is largely achieved through nuclear medicine.
Nuclear medicine is a speciality of radiology which involves injection of molecules
that are ‘tagged’ radioactively into the body. These radioactive molecules may be
preferentially taken up by specific organs for various physiological processes.
After uptake, the organs can emit radiation, which is picked up by external
scanners as ‘hot spots’. For instance, positron emission tomography (PET)
reflects the uptake of radiolabeled glucose by cells. Cells that have increased
metabolic activity, in particular cancer cells, tend to take up more glucose. This
technique is therefore used to identify areas of metastasis within the body.
Another functional imaging technique is the use of thyroid scans, which are used
to detect hyperthyroidism. These scans depend on the uptake of radioactive
iodine by thyroid cells.
Most functional imaging techniques, when used alone, can be difficult to
interpret. This is because although they detect areas of abnormal physiological
activity, it can be difficult to orient these areas anatomically. This may be
overcome by a technique called image fusion. Modern diagnostic medical
imaging programs allow fusion of two or more diagnostic techniques. For instance,
fusion of a PET scan with a CT scan can help identify whether or not there is

4. metastasis, and can also precisely identify the anatomical zones in which
metastasis has occurred.
Post-processing Techniques
Post-processing techniques refer to interventions applied to diagnostic medical
images after the images have been acquired from the patient. Post-processing
techniques are usually done using an advanced diagnostic medical imaging
program. They provide the radiologist with information that is not available by just
looking at the original images. Some of the most useful post-processing techniques
used in medical diagnostic imaging are as follows:
• 3D reconstruction: A critical drawback of medical diagnostic imaging is
that it is two-dimensional in nature. Nevertheless, recent technology allows
images to be viewed as three dimensional objects, by taking multiple image
slices and stacking them together. This allows better anatomical orientation
and is easier to interpret. It also helps to understand the relationship
between various structures. Another form of 3D reconstruction
is multiplanar reconstruction. In this, the radiologist can take the 3D object,
rotate it at will, and slice at any given angle, different from the originally
acquired slices. These techniques help the radiologist virtually view the
anatomical structure as if they were physically holding and slicing it, giving
them an unmatched level of accuracy.
• Intensity projections: This is based on the premise that different structures
within the body will absorb and reflect different amounts of radiation, which
would be reflected in their CT numbers. In maximum intensity projections
(MIP), only regions that have the highest CT numbers are displayed. MIP is
most useful in CT angiography, where it helps to distinguish large blood
vessels from other anatomical structures. In minimum intensity projections
(MINIP), only the regions that have the lowest CT numbers are displayed.
MINIP is extremely useful in lung parenchyma diseases, which present as
hypo-attenuated CT values. For instance, in patients with constrictive
obstructive bronchiolitis, CT changes are extremely subtle. Using MINIP can
make these changes more conspicuous.

5. Some Disruptive Technologies for the Future of Medical
Imaging
Artificial Intelligence
Artificial intelligence (AI) is an exciting front that is slowly making inroads into
medical diagnostic imaging. Artificial intelligence is the ability of machines to make
cognitive decisions, such as learning and problem solving. By feeding computers
deep learning algorithms, they can learn to distinguish between various digital
patterns and can thus aid in diagnosis. A team of researchers at Stanford
University, for instance, has developed such an algorithm for chest X-rays. The
researchers claim that by using this algorithm, computers can recognize the
presence or absence of pneumonia better than radiologists. The radiology team at
UCSF meanwhile is partnering with GE to develop a series of algorithms that can
help distinguish between normal and abnormal chest X-rays. Another medical
application, called Viz, helps screen multiple images across several hospital
databases for large vessel obstructions (LVO), which are indicative of imminent
stroke. If an LVO is detected, the software can alert both the stroke specialist and
the patient’s primary care physician to ensure that the patient receives prompt
treatment.
Integration of Imaging Systems
While PACS stores medical images, other medical information is stored in different
systems. For instance, health information systems (HIS) store information related
to the patient’s medical history, clinical details, and laboratory investigations.
Radiology information systems (RIS) manage imaging data apart from the actual
images, such as referrals, requisitions, billing details and interpretations. All these
information systems are separate from each other. Yet, in dealing with a patient, a
physician must often have all these details together on hand to make a diagnosis
and plan treatment. Integrating all information systems into a single medical record
that can be accessed through a single server can help streamline workflow and
improve both accuracy and throughput.
What are the Challenges as Medical Diagnostic Imaging
continues to evolve?
• Rising healthcare costs: As diagnostic medical imaging continues to stride
ahead, each new development comes at a cost. The cost of the technology
itself, the cost of research and the cost of implementation are finally reflected
as one parameter—the increased cost of healthcare to the patient. Perhaps,
this is why developing nations still rely on manual X-ray imaging and

6. manually developed films for diagnosis of basic diseases, and reserve
advanced imaging techniques for more complex health conditions. Still, if
everyone is to benefit from advances in diagnostic medical imaging, efforts
must be made to keep the cost of new medical technologies at affordable
levels.
• Protection of patient data and privacy: As diagnostic medical imaging
relies more heavily on web-based technologies, patient information gets
uploaded and stored online. There is some basic protection in place, in that
only specific user accounts which are owned by physicians and hospitals can
access PACS servers. When images are exported for purposes of teaching or
research, there is an option to anonymize data that could be used to identify
patients. Even so, there have been concerns about data breach and loss of
patient privacy. There is an urgent requirement for policy measures to be
taken that will ensure protection of medical imaging data on PACS servers.
Advanced Diagnostic Medical Imaging at your fingertips—
with PostDICOM!
PostDICOM helps you and your practice keep pace with the ever-evolving
landscape of advanced diagnostic imaging. This robust, yet easy-to-use diagnostic
medical imaging program is a modern DICOM image viewer with several advanced
features. PostDICOM offers a cloud-based PACS platform and is supported on
multiple operating systems including Windows, Mac OS, Linux and Android. It
allows you to access your DICOM files anywhere, from any device. PostDICOM
has sophisticated post-processing tools that enable superior diagnosis and
treatment planning. While our PACS is cloud-based, patient data is completely
secure. We keep patient data separated by geographical regions, all data is
encrypted, and secure SSL systems are used for communication. Images can be
anonymized before uploading to the PACS server. PostDICOM is free to download
with all features—and you receive 50 GB of cloud storage free! Storage can be
upgraded at a nominal cost. To harness the power of advanced medical imaging,
visit postdicom.com and get your free viewer today!