medical discoveries merge with the latest computer
technologies to allow radiologists to look inside the human
body with greater detail than ever before. RCND, as
diagnostic imagers, make use of these latest developments in
the diagnosis and treatment of diseases. We hope to update
our referring physicians and patients about some of the
newest radiology techniques and procedures.
If you are a patient, ask your doctor if you may be a
candidate for one of these studies. As always, the risks and
benefits of potential treatments are best discussed with
your own doctor first.
People from around the world come to Medical City and TheNorth
Texas Hospital for Children, for life altering surgery to
repair deformities or birth defects of the skull and face.
The Radiologists of RCND perform 3D Craniofacial Imaging of
these patients to map the underlying bones to help the
internationally known team of plastic surgeons,
neurosurgeons, and craniofacial surgeons and staff of the
Dallas Craniofacial Center to plan their surgical
approaches. Computed tomography (CT) is performed of the
head, and 3D processing produces images such as these which
can be examined in depth to help characterize the skull and
The next generation of CT machines have multiple detectors
and even greater computer speed. A CT scanner can image a
patient with continuous table movement and multiple
similtaneous spiral cuts covering the body in a matter of
image to the left is a 3D reconstruction of a routine
abdomen CT. Utilizing the latest multi-detector CT’s, rapid,
sub-second scanning is a reality, and 300-400 images can be
obtained of the body with a single breath-hold. As the data
set is large, alternative ways of interacting and
interpreting images include 3D real-time data manipulation
by the radiologists. These new paradigms of image
interpretation are a necessity, but the results are also
revolutionary in the way radiologists like those in RCND can
diagnose disease, and more importantly, represent the data
to physicians and patients in a single, yet inclusive photo.
is the visual inspection of the trachea and airways using
a rigid or flexible scope through the nose or mouth, while
the patient is under anesthesia. 3D Virtual bronchoscopy
examines the airways using data obtained from a multislice
CT of the neck and upper chest, targeted to the airway, with
a single breath hold. No anesthesia, No pain. The images to
the right are from such an exam with the viewer proceeding
from the trachea into the left mainstem bronchus, and
finally into the left lower lobe bronchus.
Section of Neuroradiology utilizes the latest
cross-sectional imaging techniques in the imaging of the
Head and Neck. Computed tomography (CT) and MRI provide
anatomic detail, and PET scan, perfusion, diffusion and
functional MRI and spectroscopy can help determine vascular
supply, changes in water content and a patient’s brain
function, in the areas of tumor involvement, stroke or
In addition, different information can be added together to
yield a 3D image of tumor, vessels, and brain function. (see
Functional MRI and Perfusion/Diffusion Imaging).
images are a reconstruction of an actual case showing a neck
mass and its relationship to major vessels and bones. This
information can be used by surgeons to plan tumor extent and
surgical options. The tumor (purple) is close to the major
vessels of the right neck (red), and extends behind the
right jaw (mandible).
Angioplasty is a way of opening a narrowed or closed blood
vessel without having to do major surgery. Instead, a
catheter with a tiny balloon at its tip is inserted into the
vessel—usually one of the coronary arteries supplying the
heart wall or a major artery bringing blood to an arm or
leg. After advancing the catheter until its tip is at the
site of blockage, the balloon is inflated and then deflated
The narrowing or blockage most often is caused by
arteriosclerosis, or hardening of the arteries, when fatty
plaques form on the inner wall of the artery and become
larger, gradually cutting down on free blood flow. Expanding
the balloon stretches the arterial wall and disrupts the
fatty plaques, helping to restore blood flow.
Between 70 percent and 90 percent of angioplasty procedures
use a stent, a hollow thin-walled wire mesh tube, to keep
the vessel open after widening it. Otherwise, because
arteriosclerosis is an ongoing disease, more plaques might
form and again limit blood flow. The stent is placed onto
the balloon and pressed firmly against the artery wall when
inflating it. The balloon then is deflated, leaving the
stent in place to act as a scaffold.
CT and MRI data sets can be reconstructed in three
dimensions, and specifically can yield diagnostic
angiographic images without the pain or risks of traditional
angiography. Possible areas of imaging include MR and CT
angiography of the vessels of the brain, neck, chest,
pulmonary arteties, abdominal aorta, renal vessels, and
peripheral arteries and veins.
radiologists of RCND are experienced in these various
imaging techniques, and work closely with the referral
vascular surgeons, internists, cardiologists and
neurosurgeons in diagnosing vascular diseases and planning
possible traditional or non-invasive treatment. (A) MR
angiogram of the carotid vessels. (B) MR angiogram of the
renal arteries. (C) CT angiogram of the abdomen
demonstrating multiple aneurysms and active bleeding from
the colic artery. (D) MR angiogram of the brain-circle of
Diffusion MRI is a hyper-fast technique for evaluation of
molecular movement of water, which is reduced in some
conditions, namely acute stroke.This technique is nearly
100% accurate in the diagnosis of areas of acute cerebral
patient presented with acute findings suggesting a stroke,
which worsened over a two day period. Imaging demonstrates
an acute stroke in evolution with subsequent extension. (a)
Day 1 diffusion MRI demonstrates a small cortical a
clinical condition worsens, (b) day
2 DWI demonstrates enlargement of the stroke. (c) Perfusion
MRI demonstrates areas of reduced blood flow corresponding
to final infarct size. These scanning techniques provide
valuable information regarding the region of ischemia which
maybe salvageable with thrombolytic therapy.
abdominal aortic aneurysm (AAA) is a bulge in the aortawhich
can continue to grow like a balloon until it bursts,
becoming a life-threatening emergency. The normal aorta is
2.0-2.3cm in diameter, is aneurysmal when it grows 50% more
than its normal size, and the risk of rupture increases
rapidly when it is greater than 4-5cm.
are more common in men, and caused by cigarette smoking,
atherosclerosis, high blood pressure or infection. Many
aneurysms are without symptoms at the time of diagnosis, but
can undergo rapid or unpredictable growth and rupture. An
aneurysm can be diagnosed by physical exam, and imaged or
monitored with ultrasound, CT, MRI or arteriogram. Repair by
traditional open surgery requires a large incision in the
abdominal wall and clamping of the aorta, cutting it open,
and sewing in an aortic graft bypass.
There is now an alternative to traditional surgery in many
patients. An endovascular endograft can repair the AAA from
the inside of the vessel by using a catheter pre-fitted with
a stent, customize-sized to the individual patient’s
aneurysm. The hospital stay
is shorter, usually 2-3days, rather than a week or more, and
the complications of surgery are fewer. A specially trained
Vascular Surgeon and Interventional-Radiology team uses
X-ray guidance in the operating suite, to position the graft
in the aneurysm through small incisions in the groin
To date, the RCND Radiology and Surgical team at Medical
City Dallas Hospital have placed more endovascular
endografts to repair AAA than any other team in Dallas.
Physicians can call RCND at 972-566-7866, to arrange an
evaluation for your patient to see if the endograft
procedure is appropriate. Images can be evaluated, and
frequently customized packaged stents can be manufactured
from measurements made from a CT scan.
(Images courtesy of Ancure™ Endograft
Functional MRI demonstrates regions of temporary increase of
cerebral blood flow associated with thought processes or
movement. Functional data superimposed on regular MRI images
permits mapping of areas of the brain which can be useful in
pre-surgical planning. In this case, the patient presents
with a cavernous malformation of the brain.
patient was asked to perform a simple motor task while in
the scanner, left hand finger tapping, in order to identify
the area of the brain responsible for hand motion (red
areas). This region was shown to be intimately associated
with the cavernous malformation (white) which was being
considered for surgical resection.
Techniques such as these can help determine which patients
may or may not be eligible for surgery and possible risks
for post-operative paralysis. (Note some plasticity of the
brain with areas of the left motor cortex activated.)
MRI Spectroscopy (MRS) is a special technique used for
characterization of the biochemistry of tumors, infarcts,
and other pathology.
MRS is useful for demonstrating aspects of physiology such
as tumor aggressiveness and anaerobic metabolism.
2D MRS of the brain demonstrates the characteristic internal
biochemical makeup of glioblastoma multiforme, a highly
aggressive brain tumor.
MRI is a special technique for evaluation of microscopic
blood flow in cerebral capillaries and venules. (A)
Calculated MRI perfusion map of a high grade brain
tumordemonstrates areas of increased capillary blood volume
in tumor (red) corresponding to tumor neovascularity. (B)
Perfusion map superimposed on FLAIR image demonstrates area
of tumor with highest malignancy potential to aid biopsy
The osteoporotic spine loses strength and with age a
vertebra (B) can collapse causing loss of height,
compression fractures, and
severe pain. In addition, degenerative disc disease (A)
often has proliferative bone spurs, and sclerosis and
arthritis of the facet joints (D), which together can cause
painful compression of the exiting nerve roots (C).
Percutaneous transpedicular polymethylmethacrylate
vertebroplasty (PTPV) is a therapeutic neuroradiological
procedure in which an acrylic cement is injected into the
partially collapsed vertebral body to stabilize the bone.
Once hardened, the cement prevents further compression
fracture. Most patients have a marked improvement in the
pain associated with this instability.
With fluoroscopic guidance, the facet joints themselves can
be injected with medicines to relieve pain in the arthritic
joints. Also, epidural steroid injections can reduce the
inflammation around the exiting nerve roots, also improving
The Neuroradiologists of RCND are trained to aid in the
treatment of back pain due to these conditions. Ask your
physician if you are a candidate for these procedures.
Contact us for more information.
Large fibroids of the uterus can cause pain and
dysfunctional bleeding, which can lead to a hysterectomy. An
alternate palliative or pre-surgical procedure called
Uterine Fibroid Embolization, now exists which gives a woman
another option for treatment or lessening the risk of
bleeding with directed fibroid removal. Small catheters are
placed in the vessels in the groin and advanced into the
arteries supplying the fibroid tumors of the uterus, and
microparticles injected directly into the fibroid vessels,
interrupting blood flow to the fibroid causing it to shrink
and or be relatively less vascular, making risk of blood
loss during surgical removal less likely. The RCND section
of interventional radiology evaluates women for potential
therapy, and are experienced in this cutting-edge therapy.
Patients can find out more
about specific procedures and the specialty of radiology at radiologyinfo.org,
a site co-sponsored by the American College of Radiology and
The Radiology Society of North America.