PARK AVENUE - Radiologists
PARK AVENUE Manhattan's Premier Radiology Practice

Low Dose Radiation

Park Avenue Radiologists, PC continues to install the latest multidetector CT technology on an ongoing basis to provide the highest quality CT scans with advanced applications for angiography and cardiac studies, virtual colonoscopy and other 3D applications.

CT stands for Computed Tomography or "CAT" for Computerized Axial Tomography. CT Scans are used to study and diagnose conditions in virtually every part of the body. Many conditions can be ruled out as the result of a CT scan allowing patients to avoid surgery and other invasive medical treatments.

The National Lung Screening Trial (NLST) in the United States has been stopped after 8-year results showed that screening heavy smokers with low-dose helical computed tomography (CT) significantly reduced deaths from lung cancer, compared with screening with chest x-rays. The trial has involved more than 53,000 current and former heavy smokers 55 to 74 years of age. Individuals were randomized to undergo screening annually for 3 years with either CT or chest x-rays, and were then followed for another 5 years. READ MORE

Cancer Risk Overestimated With Radiation From CT Scans: Although it has risen slightly in recent years, the risk of developing cancer from a computed tomography (CT) scan is still lower than was previously thought. Within a year or 2 — the amount of radiation delivered by a CT scan will decrease 10 to 100 fold. READ MORE


As with all radiological procedures patients should inform the technologist if there is any chance of pregnancy or if you are nursing.

  • For most studies patients need not even undress. Most exams take less than 30 minutes.
  • Studies with contrast (*) require the patient to fast for 3 hours prior to the test. Do not eat, drink 3 hours before your appointment.
  • Studies of the abdomen and pelvis with contrast require patients to drink oral contrast after they arrive at the office for their appointment.
  • You will be asked to complete a detailed questionnaire regarding your medical history and the reason your doctor sceduled your appointment.
  • If you have had a severe allergic (food or medicine) in the past, have asthma or a prior reaction to a contrast material during previous CT scan or X-ray please advise the office at the time of scheduling.

Please alert our staff if you have renal / kidney problems.

* Certain studies require patients to drink a contrast medium while others require a contrast via injection; some require both. Contrast media is used to as required for optimizing imaging studies and as prescribed by the referring physician. NON-IONIC CONTRAST MEDIA IS USED EXCLUSIVELY at Park Avenue Radiologists, PC. Patients having an abdomen or pelvic CT Scan should allow an additional 30 minutes to drink the oral contrast prior to the beginning of the scan.

How does it work?

A CT scan is an x-ray that produces computer images of a particular body part and helps diagnose conditions a regular X-Ray cannot or previously required exploratory surgery. During a CT scan the patient lies on the table while an X-ray tube rotates around the body. A computer program is than used to project images on a monitor. The images which show a cross-section of body tissues and organs are then studied by the radiologist.

What will I have to do?

During the exam the patient will be asked to lie still on the examination table. In many cases it is not even necessary for the patients to undress. For certain procedures the technician may ask you to hold your breath. If you require a contrast injection the process will be explained to you and any questions you may have will be answered.

As one of the first outpatient facilities in Manhattan to install the latest generation of multi slice CT scanners, we have the experience as well as the technology to achieve the highest quality noninvasive imaging of the coronary arteries.

Coronary CTA is becoming part of standard screening evaluations in high risk patients. The ability to visualize the vessel wall as well as the vessel lumen represents a unique advantage of CTA over conventional catheter angiography. Moreover, CT angiography has no risk of stroke, acute MI or other morbidities of catheter angiography.

The new multidetector CT scanner maximizes the sensitivity for small lesions due to its volumetric image acquisition with near isotropic imaging; due to the high number of detectors, image resolution is nearly identical in all 3 dimensions. This represents a significant advance over helical single detector or older multidetector units. Studies are evaluated on a dedicated 3D workstation with proprietary vessel imaging software, providing a virtual image of the arteries similar to what a surgeon would see during a bypass.

The examination is performed in less than 10 minutes and does not require sedation. After placing ECG leads on the chest an initial scan is performed to assess for calcification in the coronary arteries. Then a standard intravenous injection is performed. In those patients with an elevated resting heart rate, a beta blocker may be prescribed to bring the heart rate below 80 beats per minute. The scan itself requires approximately 10 seconds for image acquisition.

Park Avenue Radiologists offers virtual colonscopy on our state of the art multislice Siemens Sensation CT unit.

CT colonoscopy has an established role in screening for colon carcinoma, recommended for all patients over age 50. Patients no longer need to undergo the discomfort of a barium enema or undergo invasive procedures for mere screening. Our new scanner maximizes the sensitivity for small lesions due to its volumetric image acquisition with near isotropic imaging; due to the high number of detectors image resolution is nearly identical in all 3 dimensions. This represents a significant advance over helical single detector or older multidetector units. Studies are evaluated on a dedicated workstation with 3d ‘fly through’ imaging software, providing a virtual image of the colon similar to what gastroenterologists see at colonoscopy.

The examination is performed in less than 5 minutes without need for injection or other invasive procedure. Patients need to follow the simple bowel preparation and air is insufflated; the scan itself takes 8-10 seconds and is performed in a single breath hold.

Prior to implant surgery a Dental Scan is required to plan for placement of the implants and determine bone quality.

Park Avenue Radiologists, PC performs CT Dental Scans on our 16 multi-slice CT scanner. The procedure is simple, takes only a few minutes, has minimal radiation exposure and requires no preparation by the patient.

CT Images of the mandible (lower jaw) and/or maxilla (upper jaw) are taken. The data derived from the scan is then reformatted using specialized software (Simplant). Measurements of each tooth and an analysis of surrounding tissue and bone quality are provided. These images and measurements assist dentists and oral surgeons with planning placement of implants prior to surgery.

Dental Scans are generally not covered by medical insurance companies and Park Avenue Radiologists does not participate in dental plans. However, in some cases reimbursement is made directly to patients. We will provide you with a receipt in order that you may file a claim with your carrier.

If you would like additional information on these procedures we recommend visiting the Computed Tomography (CT or CAT) section of

Referring Physician Access