Sonography continues to turn less into more

Every modality other than ultrasound has siting requirements, sometimes big ones; cardiac cath labs and angio suites, are examples. But even the largest sonography systems can be wheeled from one room to another. Some can fit in the palm of your hand. There are trade-offs, to be sure. These nano scanners don't have much display space, and the computing engine can't compare to those on cart-based systems. But the market wants portability, the more the better, in some cases.

Not all systems will be reduced to pocket size, but even premium-end carts are getting smaller and lighter. These big kin have the advantages of 3D/4D, advanced measurements and image processing, and specialized transducers. With so much to offer, they'll maintain their popularity for a long time, particularly among radiologists, whose raison d'etre is to deliver expert results. Meanwhile, sonography, long known for its propensity to be many things to many people, will continue to diffuse throughout the medical community.

• Miniaturization speeds adoption. Application-specific integrated circuits, field-programmable gate arrays, and advanced signal-processing algorithms have collapsed the space needed for a diagnostic ultrasound scanner. The specialization of these units for certain applications has also helped. The result has been an unprecedented expansion of sonography.

• Sonography spreads into new areas. Hand-carried units are the emissaries of ultrasound, reaching medical practitioners previously outside the fold, converting them to the use of this technology or convincing dabblers to become committed users. Interventionalists, anesthesiologists, and women's health specialists have clearly responded, adopting the space-saving units. On-the-go radiologists, cardiologists, and techs appreciate the portability. The jury is out on whether specialty units envisioned for emergency medical technologists, critical care, and general practitioners will transform medicine. But the increasing power being crammed into small packages is strengthening the argument.

• 3D/4D comes off defense. Not long ago, advocates of volumetric imaging were struggling to defend its use. Now machines with this capability are everywhere, including some places, such as fetal boutiques specializing in prenatal picture albums, where many medical professionals believe they shouldn't be.

• Image quality remains king. Not a year has passed in the two decades since Acuson came out with the 128-channel scanner that image quality hasn't been the one overriding consideration of practitioners and vendors alike. Improved transducers composed of advanced piezoelectric ceramics and driven by miniaturized electronics and software create images that, in some cases, rival those of CT and MR in anatomic detail. Much of the fine tuning today is done with algorithms that tweak the data to come up with images to the liking of operators, as presets take the guesswork out of knob twisting. Alternatively, some units deliver what experts have determined is the best image, freeing specialists to do the tasks, such as biopsies, that they do best.