Artifact On an X-Ray

The following question was answered by an expert in the appropriate field:
Q
What does an artifact on an x ray mean? The first x ray (without sedation) showed a mass on the lymph nodes. The next x ray showed everything was fine. The doctor said the first one was an artifact.

A
In basic terms, an "artifact" on a diagnostic x-ray image is an area of the image that may look different from expected, although it is not necessarily something dealing with what is being imaged. An artifact may appear as light or dark spots, lines, fogging, specks, etc. They can be caused by motion, dirt on film, poor chemistry in a film processor, poor contact between the film and the cassette that holds the film, and so on. Types of artifacts may vary with the modality, for example, plain x-ray film, CT, or ultrasound, but the physician who interprets the image tries to make sure that false positive and false negative results are avoided. Ideally, the physician wants an image that contains no artifacts and, in some cases, will ask that a study be repeated to eliminate an artifact. Ken "Duke" Lovins, MS, iCHP Health Physicist

Terjemahannya kira - kira :

Artefak dalam radiografi adalah suatu daerah yang terlihat berbeda dari yang diharapkan yang tidak ada hubungannya dengan objek. Artefak dapat muncul berbentuk titik terang atau gelap, garis, kabut, dan lain-lain. Dapat disebabkan oleh gerakan, kotoran dalam film, kondisi cairan pencucian yang jelek, dan lainnya. Artefak dapat terjadi pada citra x-ray konvensional, CT Scan, dan USG. Dokter yang menginterpretasikan gambar tersebut tidak ingin ada artefak dalam radiograf, beberapa kejadian dokter akan meminta pengulangan foto.