Radiology Coding Alert

Don’t steer far from the alphabetic index for a more specific code.

Being a well-rounded radiology coder means finding your “zone” and working through claims in a timely and efficient manner. It’s for this reason that running into an ICD-10-CM coding snag in the middle of a productive day can be especially frustrating.

That’s why you should always take time to tackle some of these nuanced and extra-detailed ICD-10-CM coding encounters, so you’ll be prepared the next time one tries to interrupt your groove.

Work your way through these two equally challenging examples that will put all you’ve learned as a diagnosis coder to the test.

Let Index, Descriptors Lead the Way

Example: Magnetic resonance imaging (MRI) scan of the left foot yielding an impression of lateral dorsal cutaneous nerve neuritis.

A diagnosis of lateral dorsal cutaneous nerve neuritis is a handful to say out loud, but fortunately the coding process doesn’t prove as daunting so long as you know how to maneuver through the ICD-10-CM index.

First, you’ll want to identify the area affected. If you’re unfamiliar with nerve anatomy in the foot, you could get tripped up by the word cutaneous. In this instance, the term cutaneous is not a supplementary descriptive term, but rather an inherent part of the affected nerve: the lateral dorsal cutaneous nerve. Understanding these kinds of semantics may be important when navigating through the ICD-10-CM in search of key terms and sub terms.

Since neuritis is the underlying condition, that’s where you’ll begin your search in the alphabetic index. Under Neuritis, you should home in on two competing sub terms: peripheral (nerve) and specified nerve NEC. Technically, both of these options are correct. Remember that any words in the index enclosed by parentheses are considered supplementary terms. This means that when applicable, they should be factored into your diagnostic search.

If you didn’t have a more specific diagnostic keyword available, you’d be correct to continue on this route to ultimately report G62.9 (Polyneuropathy, unspecified). However, further down the list, you’re presented with a sub term that offers a slightly better representation of your diagnosis. Choosing “specified nerve NEC” will lead you to your final diagnosis of G58.8 (Other specified mononeuropathies).

With the next diagnostic scenario, you’re going to have to take multiple variables into account in order to reach the correct diagnosis or diagnoses. As you’ll see, when it comes to surgical complications, there are guidelines in place to help lead the way to the most correct code.

Work Within Frame of ICD-10-CM Complications Guidelines

Example: Ultrasound (US) scan following a colonoscopy revealing a diagnosis of hepatic portal vein gas.

You’re now looking at a diagnosis that’s the result of a colonoscopy — otherwise known as a complication. Hepatic portal vein gas is a serious condition that’s a known, albeit rare, side effect of colonoscopies. The diagnosis is somewhat self-explanatory, describing a condition that results from the influx of intestinal gas into the portal venous circulation. As for the coding of this diagnosis, you’ll have to take into account two considerations: the diagnosis itself and the complication.

Since the alphabetic index won’t lead you directly to Gas ⇒ vein, you’ll have to consider alternative approaches. Instead, you’ll have to resort to finding a more generalized diagnosis using the key term Disease. However, you’re not looking for a disease of the liver. Rather, you’re in search of a disease afflicting the hepatic vein. Unfortunately, the index won’t let your search extend beyond Disease ⇒ vein. This results in diagnosis code I87.9 (Disorder of vein, unspecified).

Coder’s note: Even though you may feel inclined to, at the very least, report code I87.8 (Other specified disorders of veins) instead, you’d be bypassing the ICD-10-CM index in doing so. “While the alphabetic index will direct you to the right neighborhood for a code, it is still incumbent upon the coder to review the code in context,” says Sheri Poe Bernard, CPC, of Poe Bernard Consulting in Salt Lake City.

Poe Bernard further explains that the Official Guidelines (I.A.c.9.) state the following:

• “Codes titled ‘other’ or ‘other specified’ are for use when the information in the medical record provides detail for which a specific code does not exist. Alphabetic index entries with NEC in the line designate ‘other’ codes in the Tabular List. These Alphabetic Index entries represent specific disease entities for which no specific code exists so the term is included within an ‘other’ code.”

“In this case, we know the specific diagnosis, but there is no unique code in the classification for describing portal vein gas. Because we have that information, it would be inappropriate to report ‘unspecified,” explains Bernard.

Your coding duties don’t stop here, though. While you understand that the hepatic portal vein gas is a complication of the colonoscopy, you first want to make sure there’s enough documentation to support that. As the ICD-10-CM guidelines explain, that means more than documentation detailing a cause-and-effect relationship. The provider needs to specifically document the condition as a complication of the surgery:

• “It is important to note that not all conditions that occur during or following medical care or surgery are classified as complications. There must be a cause-and-effect relationship between the care provided and the condition, and an indication in the documentation that it is a complication.”

The next step in the process is taking into account the following guideline that elaborates on the sequencing of the complication code and the condition code:

• “When the admission is for treatment of a complication resulting from surgery or other medical care, the complication code is sequenced as the principal diagnosis. If the complication is classified to the T80-T88 series and the code lacks the necessary specificity in describing the complication, an additional code for the specific complication should be assigned.”

As the guidelines explain, you should be reporting the complication code as the primary diagnosis. As you’ll see, you’ll be reporting the appropriate complication diagnosis using a K code, not a T code — but that doesn’t mean you shouldn’t still report the condition as a secondary diagnosis. If you must resort to using a T code to identify the complication, ICD-10-CM guidelines mandate a secondary code. While it’s technically optional in this scenario, you should still make it a point to report the condition as a secondary diagnosis for documentation purposes.

As for the coding, in an ideal world, you’d be able to find the sub term “Colonoscopy” under keyword “Complication(s) (from) (of).” However, in lieu of the specific operation as a sub term, you can reach the next best alternative by looking up Complication(s) (from) (of) ⇒ gastrointestinal ⇒ postoperative ⇒ specified NEC to arrive at K91.89 (Other postprocedural complications and disorders of digestive system).