Radiology Coding Alert

When radiology coders have to assign CPT Codes for a computed tomography (CT) scan from the diaphragm to the pubis, they sometimes get that sinking feeling but vague orders need not cause a stomach ache.

Written guidelines make it look so easy. They'll tell you to use both 74150 (Computerized axial tomography, abdomen; without contrast material), or 74160 ( with contrast material[s]) or CPT 74170 ( without contrast material, followed by contrast material[s] and further section) and 72192 (Computerized axial tomography, pelvis; without contrast material) or 72193 ( with contrast material[s]), or 72194 (... without contrast material, followed by contrast material[s] and further section) when scanning all the way from diaphragm to pubis. Obviously, the codes chosen for the abdominal and pelvic CT scans would need to "match" with regard to the contrast protocol used, i.e., with, without, or without followed by with contrast.

The American College of Radiology (ACR) provides a standard for these procedures in its Standard for the Performance of Computed Tomography of the Abdomen and Pelvis (for a copy, go to www.acr.org). ACR rules specify 74150 when scanning "upper abdomen" only, and 72192 when scanning the "pelvic area" only. However, in the real world of clinical radiology practice, applying the rule is not so simple.

According to the ACR standard, which draws an imaginary line between abdomen and pelvis, the reference points for a CT of the abdomen extend from the top of the diaphragm to the border of the pelvic bone known as the iliac crest. The reference points for a CT of the pelvis are from the iliac crest to the lower end of the pelvic bone (the ischial tuberosity).

On the harder question of when to do both exams, the ACR standard states, "Often, depending on the clinical circumstances, both the abdomen and pelvis must be examined." And that's the problem. The decision depends on the radiologist's evaluation of clinical circumstances, but as Mark McElroy, CPC, a radiology technician at University Health Services in Augusta, Ga., says, "What's intended to be ordered isn't always what's ordered."

McElroy agrees that the definitions and guidance in the ACR standard support his department's protocols. However, the radiologist still has to respond to vague indications and exam orders from referring physicians who may not be familiar with or aware of CT standards or protocols. The radiologist also remains responsible for clinical evaluation of indications to decide when abdominal and/or pelvic CT is appropriate.

To understand the importance of indications received from the referring physician, as well as the challenge faced by the radiologist trying to do the right exams as efficiently as possible the first time, consider the following case:

A patient is referred from the emergency room with right-lower-quadrant abdominal pain (789.03). The referring ER physician suspects appendicitis and refers to radiology where protocol for evaluation of appendicitis calls for CT pelvis (72192), which is performed with negative results. The patient is admitted and upon further evaluation is sent to radiology again, this time for CT of the abdomen (74150), which results in finding inflammation of the kidney (583.9, Nephritis) and, upon further CT slices, the discovery of a small kidney stone (592.0, Calculus of kidney).

If the radiologist is forced to limit a scan to a portion of the abdominopelvic cavity because a facility interprets the order as "pelvis" or "upper abdomen," an incomplete evaluation may be the result. Vague indications like "abdominal pain" often lead to imaging confusion because the site of the perceived pain is removed from its origin. If the original imaging had included CT of the abdomen to allow correct diagnosis of a kidney stone, an unnecessary hospital admission may have been avoided.

Adding contrast injections into the CT soup only makes things more interesting. Since the RVUs are higher for a CT with contrast than for a CT without contrast, says Cheryl Schad, CPC, CPCM, owner of Schad Medical Management in Mullica Hill, N.J., there may be a temptation to increase the level of service by administering contrast.

For example, she says, if you do a CT of the thorax, chest and pelvis, you'll generally inject once at the thorax. Gravity will direct the dye toward the feet, and as long as the contrast is in the body when the scan is performed it doesn't matter whether it came from one injection or several.

If contrast is administered and the scans are obtained with contrast, then you should code the scans "with contrast." Because contemporary CT scanning equipment can obtain contrast studies of several anatomic areas very quickly, one is not necessarily required to re-administer contrast for each scan.

Another twist may occur if, for example, a radiologist performs a CT abdomen and pelvis without contrast but, as the patient's symptoms progress on that same day, a different radiologist from the same practice does a CT abdomen/pelvis combination with contrast. In some cases with non-Medicare payers, you can code the services separately using modifiers -59 (Distinct procedural service) and -76 (Repeat procedure by same physician). In the case of a denial, you may then use additional documentation to explain why they were done as two different exams.

Under Medicare, you are prohibited from billing for both sessions e.g., 74150, 72192, 74160 and 72193. CCI bundles these codes with a 0 indicator, meaning Medicare will not accept the bundled CPTs even if modifier -59 is used.

According to Schad, your best bet is to code the second study with 76380 (Computerized axial tomography, limited or localized follow-up study). Although the reimbursement will be less than for a CT with contrast, using the limited follow-up will get you something rather than nothing.

The other approach to this scenario works only if communication and protocol channels at your practice are crystal-clear. McElroy notes that the radiologist who performs the second exam has almost certainly seen or referred to the first exam. By getting both radiologists involved, you may be able to combine the studies. The first series becomes the comparison study for coding 74175 (Computed tomographic angiography, abdomen, without contrast material[s], followed by contrast material[s] and further sections, including image postprocessing) and 72191 (Computed tomographic angiography, pelvis, without contrast material[s], followed by contrast material[s] and further sections, including image post-processing).

You may also need to take into account any local medical review policies (LMRPs) published by your carrier. For example, Administar Federal's LMRP on diagnostic CTs states that "when multiple CT scans are performed on the same date of service and on the same patient (e.g., partial pelvic CT in addition to a full abdominal CT), the partial service performed must be significant, reasonable, and necessary for the diagnosis and/or medical management of the patient in order to be eligible for coverage."