50 Shades of Gray: My Month on Radiology

A day in the life of:

This month I am on my radiology rotation.  Working in a small community hospital, the type of patients we see in the radiology department are your typical “bread and butter” cases. My day consists of about 2 hours worth of self-guided reading or a lecture from my attending where we go over the basic concepts of radiology and we discuss the imaging modalities or review a patient’s images.   The next few hours is a mix of watching the attending radiologist read and dictate an image and doing some hands on procedures. So far in the past couple weeks I have seen esophagrams done under fluroscopy, a type of continuous x-ray imaging, modified barium swallow studies also known as a cookie swallow, and CT guided paracentesis.

Classmates sometimes refer to radiology rotation as “radiation vacation” because it’s a pretty cush set up compared to other inpatient rotations. Typically radiologists work 40 hour weeks, with or without weekend and on-call requirements depending on the hospital. Aside from the relatively easy hours, the work isn’t physically demanding and you can work at your own pace. The work of a radiologist is best described as episodic. Some images are read and dictated in 2 minutes, other more complex cases can take upwards of 30 minutes dissecting one image a cross-section at a time.  Truthfully my biggest only complaint with this rotation is trying to staying awake! The entire work day is spent in a dark room, with comfy chairs and people talking in hushed voices. Those factors combined with my innate inability to read radiographic images make staying actively engaged a feat in itself.

So what is it like to be a radiologist? Radiology is a unique avenue in medicine due to most of their work being “behind the scenes” when it comes to patient care. The general public may be surprised to realize how integral the radiologist is to their treatment. Radiologists are sometimes referred to as the “doctor’s doctor” because instead of working one on one with patients, they collaborate with physicians to piece together what has been identified on an image with the clinical symptoms the patient is experiencing. Neurologists or ED physicians may stop by the radiology suite to discuss the imaging obtained on the 88 year old man with slurred speech and sudden onset weakness. Surgeons may review imaging with the radiologist prior to heading to the OR to determine the safest approach to perform a procedure. Radiologists can confirm the success of a central line placement or identify life-threatening insults such as a tension pneumothorax, a saddle embolism, perforated bowel, or subdural hematoma.  Radiologists are always included into multi-disciplinary meetings to discuss interesting cases and the specialty is ever-changing with the advent of interventional radiology and advancements in the quality of MRI and CT images.

If you school doesn’t require it, I highly recommend you use an elective for a general radiology rotation.Regardless of which specialty you end up in, odds are you will need to have a basic understanding of radiographic imaging. As a clinician you will serve as the link between the radiologist and your patient, so it is up to you to assess whether you agree with the radiologist’s interpretation and to apply his or her recommendations as you see fit. If the schedule allows for it, ask if you can shadow the various techs in the radiology department. Earning an associate’s degree as a radiology technician is typically a 2 year program, and most programs have 9-12 months of hands on training learning how to obtain images. Working one on one with a tech even if just for a day will give you a new appreciation for how valuable these techs are! They have a wealth of knowledge which is not taught in any medical school and has not been discussed on my radiology rotation thus far.

Learning how the images are obtained will make you a better clinician for various reasons. The most obvious reason is, if you’re going to put in an order you should understand what the process entails. As a medical student we are kind of spoiled when it comes to imaging. We suggest a patient gets an abdominal CT during rounds, an order gets sent in on the computer and a day later a report is generated with the findings. I once worked with a resident physician who didn’t even know where the MRI machine was. You don’t want to be that physician. Aside from looking like you know what you’re doing, watching how the imaging is obtained will also make you be able to better communicate with your patients and will allow you to determine if your patient is a good candidate for the imaging modality. If you haven’t seen how small the inner portion of a MRI machine is, you may not think of assessing your patient for claustrophobia. If your patient suffers from dementia and doesn’t take directions well, they may be unable to tolerate a swallow study.


Resources I used

  • American College of Radiology Appropriateness Criteria – If you take nothing else from this blog post, pay attention here! This is one resource that I know I will use moving forward regardless of what rotation I am on. Have you ever been in the situation where you sit down to write a plan for a patient you just saw but aren’t entirely sure which imaging is the most appropriate to determine whether your differential diagnosis is correct?
  • Clinical Radiology Made Ridiculously Simple: I used the “Made Ridiculously Simple” series when studying for Step 1, so I was excited to stumble across the “Made Ridiculously Simple” series for the wards. Pros: this book is a good introduction to radiology and those who are novices in reading images. It’s an easy read with simple explanations and plenty of tips to help remember the basics.  Cons: the images aren’t great quality and it doesn’t provide enough detail to master radiology just from this text alone.
  • First Aid Radiology for the Wards: I used this as a supplement to Clinical Radiology Made Ridiculously Simple. I felt the images in First Air were more clear but a lot of the information was pretty redundant when comparing the two books. Just like Clinical Radiology Made Ridiculously Simple, First AId is a quick read and a good introduction to the basic concepts of radiology.
  • Felson’s Principle of Chest Roentgenology: Full disclosure, I did not use this book but it repeatedly came up in discussions of top resources for a radiology rotation that I thought it deserved to make the list! This book strictly discusses how to read chest radiographs. Per the students I know who used this book, it’s a quick read and you’ll look like a total boss next time you are asked to read a CXR (score).


My Top 10 Pimping Questions

  1. What are the 5 densities of radiography darkest to lightest?
    • Air < Fat < Soft Tissue < Calcium < Metal
  2. Are anterioposterior and posterioanterior films equal?
    • No! Since the heart is an anterior structure, AP films artificially magnify the size of the heart shadow and blurs the pulmonary vasculature due to how the beam diverges. This is also exaggerated by the patient being closer to the X-ray source in AP imaging (40” away with the patient supine), versus PA films (72” away with the patient upright). AP films should only be reserved for patients who are unable to position themselves for a PA film.
  3. If a chest radiograph isn’t labeled, how do you tell if it is an AP or PA film?
    • PA is the “standard” for obtaining chest radiographs, so it is a reasonable guess to assume if an image is unlabeled it was obtained as a PA film. If you want to verify how the image was obtained, look at the medial edges of the scapula. In AP films a patient’s arms are typically at their side so the scapula are not retracted and the border can be seen overlaying the lungs bilaterally. In PA films, the patient is positioned with hands on the hips or with the arms hugging the detector plate which rotates the scapula laterally so the borders do not overlap the lungs.
  4. What is silhouette sign?
    • It is the phenomenon that occurs  when two objects of the same radiographic density touch causing  the border between them to be obliterated.  The term “silhouette sign” is a misnomer itself because it actually describes the loss of a silhouette
  5. What is the most sensitive image for diagnosing a pleural effusion?
    • Lateral decubitus. Up to 300mL of fluid can collect in the posterior costophrenic angle before the lateral costophrenic angle, so a PA image may hide a pleural effusion if it is caught early or is relatively small. Since both right and left posterior costophrenic angles are superimposed on a lateral view, it is best to image the patient in the decubitus position which allows the fluid to move to an area where it can be more easily identified on imaging.
  6. What is the “3/6/9 rule” for identifying if a section of bowel is dilated?
    • Normal small bowel diameter is <3cm wide
    • Normal large bowel diameter is <6cm wide
    • Normal cecum and sigmoid diameter is < 9cm wide
  7. A 25 year old woman finds a lump on self-breast exam, is it appropriate to do mammography?
    • In woman younger than 30, ultrasound is preferred over mammography due to younger woman having denser breast tissue.
  8. What is a mach band?
    • A mach band is an optical illusion that occurs when the border between different shades of gray is exaggerated by the human eye. It is important to acknowledge the presence of mach bands because they are a known source of diagnostic error in radiology. For more of an explanation and for some examples, click here.
  9. How much radiation is a patient exposed to with different imaging modalities?
    • Radiation dose depends on type of imaging and the part of the body that is being imaged. Although the exact numbers may vary, it is a good rule of thumb to know that ultrasound and MRI do not use ionizing radiation and x-rays expose you to less radiation than a CT scan.
  10. Can a patient with an implantable device get an MRI?
    • Depends! Most of the prosthetic heart valves and coronary artery stents on the market are approved for use within an MRI. Some of the newer pacemakers and defibrillators are safe for use in MRI with limitations on the length of the scan or which area of the body is being scanned. The fear with use of of MRI on patients with implantable devices is that the magnetic field of the MRI can generate electricity and heat up the metal leads that are implanted within the heart. This could damage heart tissue and create an arrhythmia. As per my radiologist, if there is any question whether a device is “MRI-safe” it is better to use CT imaging which is safe for all implanted devices.

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