Inside the MRI: Why It Takes So Long—and What’s Actually Happening
Ever wondered why MRI scans take 30 to 60 minutes—or more? What feels like stillness is actually a highly complex imaging process happening in real time.
Curious about how MRI scans really work? Discover how this advanced technology blends physics, precision, and patient care—and how technologists guide every step of the scan.
To an outside observer, an MRI scan can seem uneventful. The patient lies still, the machine makes loud knocking or whirring sounds, and time ticks by. But behind the scenes, a cascade of high-speed calculations and physical interactions are shaping one of the most detailed medical images modern science can produce.
Magnetic Resonance Imaging (MRI) takes longer than other scans because of its incredible precision. Unlike X-rays or CT scans, which rely on quick bursts of radiation, MRI uses powerful magnets and radiofrequency pulses to interact with the hydrogen atoms in the body. And each of those interactions takes time to build, refine, and layer into a final image.
🔍 Insights
The average MRI scan is actually a series of scans—each one focusing on a different plane, body part, or contrast setting. The more detail the doctor needs, the longer the scan becomes.
Here’s What’s Really Happening During the Scan
Once a patient is positioned, the scanner begins collecting data. The MRI technologist selects a sequence—a set of instructions that tells the machine which tissues to highlight, how deep to scan, and how fast to collect signals. Then, using a combination of magnetic gradients and radio pulses, the scanner “excites” atoms in the body and listens for the response.
The sounds you hear—thumping, banging, clicking—are the gradients switching on and off rapidly as the machine changes its focus. Each sound corresponds to a specific step in collecting information.
And yes, patients need to stay very still—not just because of the magnets, but because even tiny movements can distort the signal and blur the image. That’s one of the reasons MRI technologists are trained to make patients comfortable and calm before the scan begins.
Why Some Scans Take Longer Than Others
- • Multi-sequence scans (e.g., brain, spine) require multiple sets of data
- • High-resolution settings take longer to capture each slice
- • Use of contrast agents adds both prep and scanning time
- • Repeat scans may be needed if a patient moves
- • Metal screening or safety checks may extend setup time
📝 What To Learn About Scan Timing
- How different sequences affect time and image clarity
- How to reduce patient anxiety and improve cooperation
- Why noise levels and stillness are so critical to image quality
- How to balance image quality with speed for optimal results
- What protocol variations exist across different body regions
Every Minute Matters
To patients, the experience might feel like a long wait. But to the technologist, every minute is packed with decisions—about how to capture the right sequence, check alignment, monitor comfort, and adapt on the fly. MRI isn’t slow—it’s strategic.
If you’re fascinated by what happens inside the machine, and you enjoy working with both people and technology, Magnetic Resonance Imaging might offer the perfect career path.
Find Out More
Want to be part of the team behind those powerful scans? Explore our Magnetic Resonance Imaging (MRI) program, or Request Information.
Katherine R. Lieber, Director of Enrollment Technology at Midwestern Career College, is a technology and digital strategy leader who has driven student engagement and content innovation across industries. Her expertise in enrollment technology, marketing, and data-driven storytelling ensures that prospective students connect with the right career insights.
