Origin of the Term ALADA
The acronym ALADA stands for “as low as diagnostically acceptable.” It emerged in the mid-2010s as a refinement of the well-known radiation safety principle ALARA (“as low as reasonably achievable”). The term first gained formal recognition in 2014, when Dr. Jerrold T. Bushberg proposed ALADA at the National Council on Radiation Protection and Measurements (NCRP) annual meeting[1]. Bushberg – a medical physicist and prominent member of the American Association of Physicists in Medicine (AAPM) – introduced ALADA as a variation of ALARA, emphasizing that radiation dose should be minimized while still achieving an image of adequate diagnostic quality[1]. This proposal was intended to stress optimization in medical imaging: rather than simply lowering dose endlessly, one should lower it only to the point that the image remains diagnostically acceptable (i.e. useful for diagnosis)[2]. The concept quickly entered discussions in radiology and dental imaging circles, given growing concern that aggressive dose reduction under ALARA might sometimes compromise image quality and diagnostic efficacy[3]. In fact, a 2015 editorial in Imaging Science in Dentistry explicitly advocated “time to move from ALARA to ALADA” for dental cone-beam CT (CBCT), highlighting that two decades after CBCT’s introduction, it was important to balance dose reduction with sufficient image quality for diagnosis[3][4].
What does ALADA mean? In essence, ALADA carries the same spirit as ALARA – keeping patient radiation exposure as low as possible – but with an explicit caveat: do not reduce the dose so far that the resulting image is nondiagnostic. In other words, the lowest acceptable dose is one that still yields a clinically useful image[2]. This term arose to remind practitioners that “pretty” or ultra-clear images are not always necessary if they come at the cost of higher dose; instead, the goal is an image that is just good enough for diagnosis, and no better (hence minimum necessary dose)[5]. ALADA thus highlights optimization (the second tenet of radiation protection, after justification) in a more practical way: “the lowest dose necessary to produce diagnostic-quality images”[6]. Notably, radiologists had long implicitly understood this — for example, standard definitions of ALARA in diagnostic radiology already imply using the lowest dose that still achieves the required image quality[6]. ALADA simply puts this nuance front and center in the terminology. It has sometimes been phrased as “ALARA, but not beyond the point of diagnostic adequacy.”
Early Appearances in Dental Radiology
The dental radiology community was among the first to embrace and formalize ALADA. With the expansion of dental cone-beam CT (CBCT) in the 2000s and 2010s, concerns grew about unnecessary radiation in dentistry, especially for children. Dental radiologists and organizations began using ALADA to guide practitioners toward appropriate, indication-based imaging protocols. For instance, the “Image Gently in Dentistry” campaign (launched in late 2014 as part of the Alliance for Radiation Safety in Pediatric Imaging) explicitly built its recommendations around keeping exposures “as low as diagnostically acceptable”[7][8]. The campaign’s six-step plan for pediatric dental X-ray safety emphasized that radiographs must be justified and then performed with the minimum dose that still yields a diagnostic image, in line with ALADA[7]. Likewise, the FDI World Dental Federation’s policy statement on radiation safety instructs that “optimization is the concept that a radiograph should be of sufficient diagnostic quality, keeping the dose to the patient as low as diagnostically acceptable (ALADA)”[9]. In practical terms, this means dentists are urged to use techniques such as smaller fields-of-view, pulsed exposures, faster image receptors, and patient-specific settings to reduce dose without sacrificing the clarity needed to make a diagnosis[9][10]. The American Academy of Oral and Maxillofacial Radiology (AAOMR) and the American Dental Association (ADA) have also stressed similar principles in their guidelines – essentially an endorsement of ALADA under the umbrella of ALARA – when advising on the use of dental radiographs and CBCT. By 2015, dental imaging literature routinely mentioned ALADA; for example, Jaju et al. (2015) argue that with modern CBCT improvements, “it is time to move from ALARA to ALADA,” cautioning against obtaining unnecessarily high-quality (and high-dose) “beautiful” images when lower-dose, diagnostically acceptable images will suffice[5][11].
It’s worth noting that the ALADA concept even evolved further in the dental community. In 2017 a European pediatric dental imaging consortium (the DIMITRA project) proposed ALADAIP, meaning “as low as diagnostically acceptable, being indication-oriented and patient-specific.” This extension adds that exams should be tailored to the clinical indication and the patient’s individual characteristics, reinforcing personalized optimization on top of the ALADA principle[12]. The move from ALARA to ALADA – and then to ALADAIP for children – reflects the dental radiology community’s commitment to minimizing dose while maintaining diagnostic benefit. In summary, dental experts have strongly endorsed ALADA in practice: all unnecessary exposure should be eliminated, but never at the expense of the diagnostic information that justified taking the radiograph in the first place[9][7].
Radiology Community’s Perspective
In the broader medical radiology field, ALARA remains a foundational principle, but ALADA has been recognized as a valuable clarification for diagnostic imaging. Radiologists and medical physicists agree that optimization of dose means achieving the “lowest dose necessary for a diagnostically adequate study.” In fact, many radiology textbooks and training materials now mention ALADA alongside ALARA when discussing dose optimization. For example, a radiology safety text notes that keeping exposures ALARA inherently implies using the lowest dose that still produces a diagnostic-quality image, sometimes referred to as ALADA[6]. In practice, this perspective has always guided imaging protocols: radiologists want images that answer the clinical question, and any additional image quality beyond that is a luxury that might not justify additional dose. Thus, while the acronym ALADA may not be as ubiquitously cited in general radiology as ALARA, the underlying concept is very much accepted and taught. Radiology professional bodies like the American College of Radiology (ACR) continue to emphasize justification of imaging and optimization of dose. The ACR’s Appropriateness Criteria and Imaging 2.0 initiatives, as well as the Image Wisely campaign (geared toward adult imaging), all align with “avoid unnecessary radiation, but do obtain whatever imaging is needed for proper diagnosis.” This is essentially an endorsement of ALADA in principle. Notably, the NCRP itself – which informs radiology practice – signaled in 2014 that a shift from ALARA to ALADA should be considered for medical imaging to underscore the importance of image quality in dose reduction strategies[13][2]. In everyday radiology, one sees this balance in action: protocols for CT, fluoroscopy, etc., are tuned to use the lowest dose that still yields clear visualization of the anatomy/pathology of interest. Radiologists caution against “dose heroics” – reducing dose to the point that images become nondiagnostic is counterproductive and could lead to missed diagnoses[5]. Thus, the radiology community’s position is inherently aligned with ALADA: radiation should be minimized, but never below the threshold that compromises diagnostic confidence[2]. In summary, radiologists support ALADA as a useful articulation of the optimization principle, even if ALARA remains the more commonly referenced term in general. The key is that image quality requirements set the floor for how low the dose can go.
AAPM’s Position and Involvement
The American Association of Physicists in Medicine (AAPM) has been deeply involved in promoting dose optimization concepts like ALADA. As mentioned, it was an AAPM leader (Dr. Bushberg) who initially coined ALADA in 2014 to address medical imaging practices[1]. The AAPM fully supports the ALARA principle, and by extension it supports ALADA as a nuanced application of ALARA in diagnostic radiology. In fact, AAPM presentations and publications around that time echoed the ALADA message. For example, at the 2014 AAPM Annual Meeting, experts stressed that for CT scans, “the medical benefit should be clear and dose [kept] ALADA (As Low As Diagnostically Acceptable)”[14]. This statement encapsulates AAPM’s view: patients should not be exposed to radiation unless it’s justified by clear clinical benefit, and even then every scan should use the minimum dose that still achieves the needed diagnostic information[14]. The AAPM’s involvement in initiatives like Image Gently (pediatric imaging) and Image Wisely (adult imaging) further demonstrates its commitment to these principles. Through these campaigns (in partnership with radiology organizations), AAPM has helped develop educational materials that explicitly mention keeping doses as low as diagnostically necessary. Moreover, the AAPM’s own journal articles and task group reports on imaging optimization align with ALADA’s philosophy, often implicitly. For instance, when discussing techniques like automatic exposure control, iterative image reconstruction, or pediatric protocol adjustments, the emphasis is always on finding the dose level that yields acceptable image noise and clarity for the task at hand, and not exceeding that.
It’s important to note that ALADA is not a replacement for ALARA in regulations or official policy, but rather a complementary concept. The AAPM and NCRP did not discard “reasonably achievable” – instead, ALADA was proposed to emphasize to practitioners what “reasonably achievable” should mean in practice. The AAPM continues to endorse ALARA as a general principle across all uses of radiation, while embracing ALADA in the context of diagnostic imaging quality control[15][6]. In practical terms, AAPM’s position is that every imaging exam should be justified (benefit outweighs risk) and optimized. Optimization, as AAPM experts clarify, means you adjust scanning parameters and technologies so that the patient receives the lowest possible dose that still yields images of sufficient quality for diagnosis[15]. If lowering the dose further would undermine the ability to interpret the exam, then that dose would not be “diagnostically acceptable.” This approach is now standard in AAPM’s training of medical physicists who manage imaging protocols.
In summary, AAPM supports the ALADA concept as it dovetails with long-standing dose optimization goals. The term first appeared around 2014 in AAPM/NCRP discussions[1], and since then it has been championed especially in dental and pediatric radiology contexts. Both the radiology community and AAPM stress that patient exposures should be “as low as diagnostically acceptable” – reducing unnecessary radiation while ensuring diagnostic efficacy is maintained[2][9]. By focusing on diagnostic acceptability, radiologists and medical physicists together ensure that safety measures do not compromise the very purpose of the imaging exam.
Sources:
- Bushberg, J.T. et al., NCRP 50th Annual Meeting (2014) – Introduction of the ALADA concept as a variation of ALARA[1].
- Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology (2015) – “Image Gently in Dentistry” campaign guidelines emphasizing ALADA for pediatric dental imaging[7][8].
- FDI World Dental Federation Policy on Radiation Safety (2019) – Definition of optimization as keeping dose “as low as diagnostically acceptable” in dental radiography[9].
- Jaju, P.P. & Jaju, S. (2015) Imaging Sci Dent 45:263-265 – Letter: “Time to move from ALARA to ALADA” in dental CBCT[3][4].
- RadiologyKey (educational resource) – Explanation that ALARA’s optimization means using the lowest dose necessary for diagnostic-quality imaging, also referred to as ALADA[6].
- ITI (International Team for Implantology) Academy Module (2020) – Noting NCRP 2014’s recommendation to shift from ALARA to ALADA for dose optimization in CBCT, and stating ALADA = As Low As Diagnostically Acceptable without compromising image quality[13][2].
- AAPM Presentation (2014) – Slide stating “medical benefit should be clear and dose [kept] ALADA (As Low As Diagnostically Acceptable)” in the context of CT scans[14].
- DIMITRA Project Position Statement (2017, via Pediatric Radiology) – Extension of ALADA to ALADAIP for pediatric imaging, underlining patient-specific and indication-oriented optimization[12].
[1] [7] [8] [10] The Image Gently in Dentistry campaign: promotion of responsible use of maxillofacial radiology in dentistry for children – Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
[6] Radiation Protection | Radiology Key
[9] Radiation Safety in Dentistry | FDI
[12] Principles of radiological protection and application of ALARA … – PMC
[14] Slide 1
http://amos3.aapm.org/abstracts/pdf/90-25494-339462-107960.pdf