Characterization of microcalcification: can digital monitor zooming replace magnification mammography in full-field digital mammography?

The aim of this study was to compare the diagnostic accuracy and image quality of microcalcifications in zoomed digital contact mammography with digital magnification mammography. Three radiologists with different levels of experience in mammography reviewed 120 microcalcification clusters in 111 patients with a full-field digital mammography system relying on digital magnification mammogram (MAG) images and zoomed images from contact mammography (ZOOM) using commercially available zooming systems on monitors. Each radiologist estimated the probability of malignancy and rated the image quality and confidence rate. Performance was evaluated by sensitivity, specificity, positive predictive value, negative predictive value, and receiver operating characteristic (ROC) analysis. All three radiologists rated MAG images higher than ZOOM images for sensitivity with statistical significance (average value, 92% vs. 87%, P < 0.05) and performance by ROC analysis improved with MAG imaging. The confidence rate for diagnosis decision and the assessment of lesion characteristics were also better in MAG images than in ZOOM images with statistical significance (P < 0.0001). Digital magnification mammography can enhance diagnostic performance when characterizing microcalcifications. Images zoomed from digital contact mammography cannot serve as an alternative to direct magnification digital mammography. This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2007-313-E00363).     

Zooming method (× 2.0) of digital mammography vs digital magnification view (× 1.8) in full-field digital mammography for the diagnosis of microcalcifications

The purpose of this study was to determine whether the interpretation of microcalcifications assessed on images zoomed (× 2.0) from digital mammograms is at least equivalent to that from digital magnification mammography (× 1.8) with respect to diagnostic accuracy and image quality. Three radiologists with different levels of experience in mammography reviewed each full-field digital mammography reader set for 185 patients with pathologically proven microcalcification clusters, which consisted of digital magnification mammograms (MAGs) with a magnification factor of 1.8 and images zoomed from mammograms (ZOOM) with a zoom factor of 2.0. Each radiologist rated their suspicion of breast cancer in microcalcific lesions using a six-point scale and the image quality and their confidence in the decisions using a five-point scale. Results were analysed according to display methods using areas under the receiver operating characteristic curves (A_z value) for ZOOM and MAGs to interpret microcalcifications, and the Wilcoxon matched pairs signed rank test for image quality and confidence levels. There was no statistically significant difference in the level of suspicion of breast cancer between the ZOOM and MAG groups (A_z = 0.8680 for ZOOM; A_z = 0.8682 for MAG; p = 0.9897). However, MAG images were significantly better than ZOOM images in terms of visual imaging quality (p < 0.001), and the confidence level with MAG was better than with ZOOM (p < 0.001). In conclusion, the performance of radiologists in the diagnosis of microcalcifications using ZOOM was similar to that using MAGs, although image quality and confidence levels were better using MAGs.Magnification mammography produces better spatial resolution and signal-to-noise ratio than does contact mammography. It is well established as a valuable adjunct to contact mammography, especially for the diagnosis of microcalcifications, despite the additional radiation exposure and increased radiation dose because of the shorter distance between the breast and X-ray source during examination [1–4].However, with respect to full-field digital mammography (FFDM), a few studies using zoomed images from contact mammograms have recently been reported and, as a result, a debate has arisen over whether a digital zooming system of FFDM can replace the magnification view of digital mammography [5–7]. Whereas Fischer et al [5] reported that zoomed images of a digital contact mammogram were equivalent to direct magnification of FFDM for the interpretation of microcalcifications, our previous report suggested that magnification mammography yielded better sensitivity and receiver operating characteristic (ROC) analysis than did zoomed images [7]. However, that study compared images zoomed by a factor of 1.3 with images magnified by a factor of 1.8. Therefore, we wondered whether using a zooming factor comparable to a magnification factor of 1.8 would yield the same results.The purpose of this study was to determine whether the diagnostic accuracy and image quality of microcalcification assessments using images twice zoomed from contact mammograms were equivalent to those obtained using digital magnification mammography by a magnification factor of 1.8.     

Is lower-dose digital fluorography diagnostically adequate compared with higher-dose digital radiography for the diagnosis of fallopian tube stenosis?

Purpose: In an effort to reduce patient radiation dose during selective fallopian tube catheterization, the diagnostic adequacy of fluoroscopic images was compared with digital radiographic images in both a phantom study and a clinical study. Methods: For the phantom study polyethylene tubes with inner diameters of 1.30, 0.95, 0.80, 0.57, and 0.45 mm were used. Randomly selected tubes with/without stenoses, recorded by digital radiographic and last-image hold fluoroscopic images, were presented to five blinded radiologists, and receiver-operating characteristic (ROC) analyses were performed. For the clinical study tubal visualization as well as detectability of stenoses and occlusions were analyzed in 14 women using a 2-way analysis of variance for nonrepeated measures. Results: The phantom study showed no significant differences between the two imaging techniques for 0.57-mm-diameter and larger tubes; in contrast, fluoroscopic images provided significantly lower detectability of stenoses in 0.45-mm-diameter tubes (p < 0.05). The clinical study showed inferior tubal visualization and diagnostic performance for fluoroscopic images. Conclusions: Although fluoroscopic images have inferior diagnostic capability in detection of tubal stenoses and occlusions, these images may be adequate for documenting tubal patency with spill into the peritoneal cavity.     

Dual-energy contrast-enhanced digital breast tomosynthesis – a feasibility study

Contrast-enhanced digital breast tomosynthesis (CE-DBT) is a novel modality for imaging breast lesion morphology and vascularity. The purpose of this study is to assess the feasibility of dual-energy subtraction as a technique for CE-DBT (a temporal subtraction CE-DBT technique has been described previously). As CE-DBT evolves, exploration of alternative image acquisition techniques will contribute to its optimisation. Evaluation of dual-energy CE-DBT was conducted with Institutional Review Board (IRB) approval from our institution and in compliance with federal Health Insurance Portability and Accountability Act (HIPAA) guidelines. A 55-year old patient with a known malignancy in the right breast underwent imaging with MRI and CE-DBT. CE-DBT was performed in the medial lateral oblique view with a DBT system, which was modified under IRB approval to allow high-energy image acquisition with a 0.25 mm Cu filter. Image acquisition occurred via both temporal and dual-energy subtraction CE-DBT. Between the pre- and post-contrast DBT image sets, a single bolus of iodinated contrast agent (1.0 ml kg^–1) was administered, followed by a 60 ml saline flush. The contrast agent and saline were administrated manually at a rate of ∼2 ml s^–1. Images were reconstructed using filtered-back projection and transmitted to a clinical PACS workstation. Dual-energy CE-DBT was shown to be clinically feasible. In our index case, the dual-energy technique was able to provide morphology and kinetic information about the known malignancy. This information was qualitatively concordant with that of CE-MRI. Compared with the temporal subtraction CE-DBT technique, dual-energy CE-DBT appears less susceptible to motion artefacts.Breast tumour growth and metastasis are accompanied by the development of new blood vessels that have an abnormally increased permeability [1]. As a result, the absorption of vascular contrast agents in malignant breast tissue is often different to that in benign and normal tissues. Today, contrast-enhanced MRI (CE-MRI), which uses a gadolinium chelate as a vascular contrast agent, is the standard for vascular imaging of breast cancers [2–7]. Breast lesion characterisation with CE-MRI relies on a combination of the analysis of the morphological features of the lesion and the vascular enhancement kinetics.Preliminary studies have demonstrated that contrast-enhanced digital breast tomosynthesis (CE-DBT) using an iodinated vascular contrast agent has the potential to demonstrate morphology and vascular enhancement information concordant with that of CE-MRI [8]. As the clinical uses of CE-MRI continue to expand, investigation into a potential alternative such as CE-DBT (which is projected to be less costly and more widely available than MRI) may also increase in importance.Two CE X-ray imaging techniques have been proposed: temporal and dual-energy subtraction. In temporal subtraction breast X-ray imaging, one pre-contrast and one (or more) post-contrast time-points are acquired using a spectrum predominantly above the K-edge of iodine (33.2 keV) [9–12]. Pre- and post-contrast images are then subtracted logarithmically, yielding iodine-enhanced images. In dual-energy subtraction, post-contrast images are acquired in pairs at energies that closely bracket the K-edge of iodine [13–16]. At each time point, iodine-enhanced images are calculated by weighted logarithmic subtraction of the low- and high-energy (LE and HE) images.The objective of this study was to assess the feasibility of applying a dual-energy subtraction technique to CE-DBT. In addition, we sought to compare the quality of the images obtained with a dual-energy CE-DBT technique with those obtained via temporal subtraction CE-DBT.     

Are digital images good enough? A comparative study of conventional film-screen vs digital radiographs on printed images of total hip replacement

The aim of this study was to evaluate the inter- and intra-observer variability and to find differences in diagnostic safety between digital and analog technique in diagnostic zones around hip prostheses. In 80 patients who had had a total hip replacement (THR) for more than 2 years, a conventional image and a digital image were taken. Gruens model of seven distinct regions of interest was used for evaluations. Five experienced radiologists observed the seven regions and noted in a protocol the following distances: stem–cement; cement–bone; and stem–bone. All images were printed on hard copies and were read twice. Weighted kappa, _w, analyses were used. The two most frequently loosening regions, stem–cement region 1 and cement–bone region 7, were closely analyzed. In region 1 the five observers had an agreement of 86.75–97.92% between analog and digital images in stem–cement, which is a varied _w 0.29–0.71. For cement–bone region 7 an agreement of 87.21–90.45% was found, which is a varied _w of 0.48–0.58. All the kappa values differ significantly from nil. The result shows that digital technique is as good as analog radiographs for diagnosing possible loosening of hip prostheses.     

Measurement of breast density with digital breast tomosynthesis—a systematic review

Digital breast tomosynthesis (DBT) has gained acceptance as an adjunct to digital mammography in screening. Now that breast density reporting is mandated in several states in the USA, it is increasingly important that the methods of breast density measurement be robust, reliable and consistent. Breast density assessment with DBT needs some consideration since quantitative methods are modelled for two-dimensional (2D) mammography. A review of methods used for breast density assessment with DBT was performed. Existing evidence shows Cumulus has better reproducibility than that of the breast imaging reporting and data system (BI-RADS®) but still suffers from subjective variability; MedDensity is limited by image noise, whilst Volpara and Quantra are robust and consistent. The reported BI-RADs inter-reader breast density agreement (k) ranged from 0.65 to 0.91, with inter-reader correlation (r) ranging from 0.70 to 0.93. The correlation (r) between BI-RADS and Cumulus ranged from 0.54–0.94, whilst that of BI-RADs and MedDensity ranged from 0.48–0.78. The reported agreement (k) between BI-RADs and Volpara is 0.953. Breast density correlation between DBT and 2D mammography ranged from 0.73 to 0.97, with agreement (k) ranging from 0.56 to 0.96. To avoid variability and provide more reliable breast density information for clinicians, automated volumetric methods are preferred.Breast cancer accounts for approximately 23% of all cancers in females and is the most frequent cause of cancer deaths in females worldwide.^1–3 The exact aetiology of the disease is complex, but many risk factors have been documented in the literature amongst which is breast density.^4–7 Breast density refers to the proportion of the breast that is composed of fibroglandular tissue. Breasts with high density contain more epithelial and stromal cells and collagen, which are significant for tumorigenesis as well as tissue-specific progenitor cells that are at risk of transformation to cancer cells.^8,9 Studies have shown that breast density is a strong, modifiable and measureable risk factor for breast cancer.^10–13 Additionally, the masking effect from breast density reduces the performance of screening mammography and limits early detection and treatment of breast cancer.¹⁴ Encouragingly, breast density is reducible, and its reduction has been shown to mitigate breast cancer risk.¹³ Therefore, mammographic breast density measurement can be used for breast cancer risk prediction and personalization of breast cancer prevention and control strategies, such as the selection of females who may require breast density reduction interventions. It may also be used for selection of more appropriate imaging pathways for earlier detection of breast cancer.^5,13 Utilization of breast density for these purposes requires robust and consistent methods for its assessment.Breast density depicted by the radio-opaque areas on a mammogram can be assessed using qualitative and quantitative (semi-automated and automated) methods.^15–17 Qualitative methods assign breast density grades based on visual assessment of the relative proportions of dense tissue, fat and prominence of ducts and include breast imaging reporting and data system (BI-RADS®), visual analogue scale and Wolfe, Tabar and Boyd assessment methods.^15,18,19 Semi-automated methods use segmentation and thresholding techniques to quantify the percentage of dense tissue on a mammogram and include planimetry and interactive thresholding methods such as Cumulus and Madena.^20,21 Automated methods use mathematical, statistical and physical modelling to calculate breast density; such automated methods include computerized texture-based techniques, calibration approaches and dual X-ray absorptiometry.^22–24 Others are automated thresholding approaches, such as Autodensity and MedDensity,^25,26 and three physical model-based techniques: standard mammographic form (SMF), Volpara and Quantra.^27–29 Irrespective of the method of measurement, breast density has been shown to be a potent risk factor for breast cancer.Many studies on mammographic breast density measurement are based on film–screen mammography and digital mammography (DM), which produce two-dimensional (2D) images of a three-dimensional (3D) breast. Qualitative methods have been shown to be poorly reproducible with these modalities; they have wide inter-reader agreement with Kappa (k) values ranging from 0.37 to 0.91.^26,30 Quantitative methods have better reproducibility with these modalities; however, there are concerns that quantitative area measurement of breast density as percentage mammographic density (PMD) is not representative of the tissue at risk of breast cancer, and that it is more reasonable to measure the volume of only the fibroglandular tissue, which is more related to the dense tissue at risk instead of PMD.^16,31 Another concern is that volumetric breast density measurement with 2D mammography is limited owing to the absence of depth information in such mammograms;³¹ methods estimating mammographic breast density with 2D mammography attempt to take into account variation in breast tissue thickness by modelling; however, with all models, there are assumptions made that may not be necessarily correct for an individual patient.Digital breast tomosynthesis (DBT) has gained acceptance as a tool for imaging of the symptomatic breast and as an adjunct to DM in screening.^32,33 Breast density assessment with DBT needs some consideration since quantitative methods are modelled for 2D mammography. DBT is a 3D imaging modality utilizing the concept of conventional tomography but a limited angle of tube movement (11–60^°) to acquire depth information from the breast (Figure 1a,b).³⁴ With the removal of anatomical noise (superimposed skin and subcutaneous tissue) in DBT images, quantitatively assessed breast density is expected to be lower than DM. On the other hand, more dense tissue becomes apparent to a subjective reader and qualitatively assessed breast density with DBT is expected to be higher relative to DM. It is therefore important to have a standardized robust, reliable and reproducible assessment method to avoid variability in breast density measurement as this will impact on clinical decision-making for females undergoing breast screening. There are several contending methods (Figure 2), each of which has its own merits; this review briefly examines the links between breast density and breast cancer. It also examines methods that have been used for measurement of mammographic breast density with DBT to ascertain which can be considered the best approach.Open in a separate windowFigure 1.Principles of digital breast tomosynthesis: (a) tube rotations relative to the detector and (b) acquired image slices. Image courtesy of Hologic Inc.; Bedford, MA © 2011. All rights reserved.Open in a separate windowFigure 2.Methods of breast density measurement. BI-RADS®, breast imaging reporting and data systems; SMF, standard mammographic form.     

Should previous mammograms be digitised in the transition to digital mammography?

Breast screening specificity is improved if previous mammograms are available, which presents a challenge when converting to digital mammography. Two display options were investigated: mounting previous film mammograms on a multiviewer adjacent to the workstation, or digitising them for soft copy display. Eight qualified screen readers were videotaped undertaking routine screen reading for two 45-min sessions in each scenario. Analysis of gross eye and head movements showed that when digitised, previous mammograms were examined a greater number of times per case (p = 0.03), due to a combination of being used in 19% more cases (p = 0.04) and where used, looked at a greater number of times (28% increase, p = 0.04). Digitising previous mammograms reduced both the average time taken per case by 18% (p = 0.04) and the participants’ perceptions of workload (p < 0.05). Digitising previous analogue mammograms may be advantageous, in particular in increasing their level of use.     

Indeterminate breast lesions: Can contrast enhanced digital mammography change our decisions?

Objective

To assess the efficiency of dual energy contrast enhanced mammography in the assessment of the indeterminate breast lesions (BIRADS 3 and BIRADS 4).

A pilot study evaluating the “STATSCAN” digital X-ray machine in paediatric polytrauma

A pilot study evaluating the use in paediatric polytrauma of the STATSCAN, a low-radiation dose, fan-beam digital radiography unit (Lodox Systems, Sandton, South Africa). Over 3 months, 23 polytrauma patients treated at the Emergency Unit of the Red Cross Children’s Hospital in Cape Town, South Africa, were imaged on the STATSCAN. Image quality, diagnostic equivalence and clinical efficiency were compared with a computed radiography (CR) system (Fuji FCR 5000, Fuji Photo Film, Tokyo, Japan). The STATSCAN antero-posterior bodygram correlated well technically and diagnostically with CR, showing 96% of the fractures in the cohort. It allowed superior visualisation of the trachea and main bronchi and imaging was, on average, 13% faster than CR. The STATSCAN could play an important role in paediatric polytrauma. The clinical significance of its superior demonstration of the trachea and main bronchi requires further evaluation.     

Does digital acquisition reduce patients' skin dose in cardiac interventional procedures? An experimental study

OBJECTIVE: It is necessary to reduce the exposure doses from both fluoroscopy and angiocardiography. Pulsed fluoroscopy clearly reduces patients' exposure. By contrast, whether digital acquisition reduces patients' exposure is not clear. This study simulated the skin radiation doses of patients in cardiac catheterization laboratories with various radiography systems used in percutaneous transluminal coronary angioplasty to determine whether digital acquisition reduces patient exposure as compared with cine film recording. MATERIALS AND METHODS: The entrance surface doses with cineangiography and fluoroscopy of acrylic phantoms were compared for 11 radiography systems at seven facilities; each performs more than 100 cardiac intervention procedures per year. The entrance surface dose for an acrylic plate (20 cm thick) was measured using a skin-dose monitor. RESULTS: The maximum dose exceeded the minimum dose by 6.44 times for cineangiography and by 3.42 times for fluoroscopy. The entrance surface dose with acrylic plate was lower with digital-only acquisition (mean +/- SD, 3.07 +/- 0.84 mGy/sec) than with film recording (6.00 +/- 3.04 mGy/sec). By contrast, the entrance surface frame dose, after correction for the cine frame rate, tended to be higher with digital acquisition than with film recording (0.210 +/- 0.053 vs 0.179 +/- 0.058 mGy/frame, respectively). CONCLUSION. The entrance surface dose was approximately 50% less with digital-only acquisition than with film recording. However, after correcting the dose for cine frame rate, filmless acquisition did not in itself reduce the exposure. For the surface dose to be reduced for cardiac interventional radiography, even with digital filmless radiography systems, a low recording speed is necessary for angiocardiography.     

Does the digital signature of the DICOM standard meet the requirements of German law?

The DICOM standard offers the possibilities to generate electronic signatures, valid according to German laws. This enhances the reliability of the correlation between image and patient data. However, only so called qualified electronic signatures--conveniently issued by an accredited supplier--are permissible and not rejectable as evidence in German jurisdiction and are completely equivalent to the handwritten signatures. These qualified electronic signatures can be executed only by individuals, whereas the former are not applicable to technical apparatus like image generating modalities. In consequence, a modality is able to provide its pictures with a "common or advanced signature" solely. This limits the use of the digital signature of the DICOM standard for further applications, e.g. the verifiability within the teleradiology.     

How good is the ACR accreditation phantom for assessing image quality in digital mammography?

RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate the American College of Radiology (ACR) accreditation phantom for assessing image quality in digital mammography. MATERIALS AND METHODS: Digital images were obtained of an ACR accreditation phantom at varying mAs (constant kVp) and varying kVp (constant mAs). The average glandular dose for a breast with 50% glandularity was determined for each technique factor. Images were displayed on a 5 mega-pixel monitor, with the window width and level settings individually optimized for viewing the fibers, specks, and masses in the ACR phantom. Digital images of the ACR phantom were presented in a random manner to eight observers, each of whom indicated the number of objects visible in each image. RESULTS: Intraobserver variability was greater than interobserver variability for the detection of fibers and specks, but the reverse was true for the detection of masses. As the mAs increased, the number of fibers visible increased from less than one at 5 mAs to all six being visible at 80 mAs. The corresponding number of visible specks increased from 12 to 24, and the number of visible masses increased from 1.25 to about four. Above 26 kVp, object visibility was constant with increasing x-ray tube voltage. Reducing the x-ray tube voltage to 24 kVp, however, reduced the number of visible fibers from six to five, the number of visible specks from 24 to 21.1, and the number of visible masses from four to 3.1. Observer performance was approximately constant for average glandular doses greater than 1.6 mGy, so that the range of lesion detectability in the ACR phantom occurs at doses lower than those normally encountered in clinical practice. CONCLUSION: The current design of the ACR phantom is unsatisfactory for assessing image quality in digital mammography.     

The dynamic range of digital radiographic systems: dose reduction or risk of overexposure?

OBJECTIVES: To investigate the range of diagnostically acceptable digital radiographs and film as a function of exposure time, as well as the relationship to dose reduction and consequences for dental practice. METHODS: Five systems for intraoral radiography were used to take a series of radiographs, with increasing exposure times, of five different dry bone specimens. Seven observers evaluated the 25 series of radiographs. The observers had to determine which radiographs of each series were acceptable for dental diagnostics and which radiograph of each series they preferred. RESULTS: For Ektaspeed Plus film, the exposure time for the preferred radiograph was 0.52 s, with a range of diagnostically acceptable radiographs from 0.23-1.02 s. The preferred radiograph of the solid-state systems required less radiation than film (Sirona, 0.13 s; MPDx 0.35 s). The exposure range of these systems is narrow. In contrast, the exposure range of the phosphor plate systems is very wide. The preferred radiograph of the phosphor plate systems required high exposure (Digora, 1.21 s; Gendex DenOptix, 1.16 s). CONCLUSIONS: All digital systems require less exposure than film for diagnostically acceptable radiographs, but this is less obvious for preferred radiographs. Solid-state systems alert the dentist when a too long exposure time is used by a lack of image quality; phosphor plate systems, however, produce good quality radiographs even at high exposure times, which may result in an unnecessarily high dose.     

Walking on thin ice! Identifying methamphetamine “drug mules” on digital plain radiography

Objective:

The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of identifying methamphetamine (MA) internal payloads in “drug mules” by plain abdominal digital radiography (DR).

Methods:

The study consisted of 35 individuals suspected of internal MA drug containers. A total of 59 supine digital radiographs were collected. An overall calculation regarding the diagnostic accuracy for all “drug mules” and a specific evaluation concerning the radiological appearance of drug packs as well as the rate of clearance and complications in correlation with the reader''s experience were performed. The gold standard was the presence of secured drug packs in the faeces.

Results:

There were 16 true-positive “drug mules” identified. DR of all drug carriers for Group 1 (forensic imaging experienced readers, n = 2) exhibited a sensitivity of 100%, a mean specificity of 76.3%, positive predictive value (PPV) of 78.5%, negative predictive value (NPV) of 100% and a mean accuracy 87.2%. Group 2 (inexperienced readers, n = 3) showed a lower sensitivity (93.7%), a mean specificity of 86%, a PPV of 86.5%, an NPV of 94.1% and a mean accuracy of 89.5%. The interrater agreement within Group 1 was 0.72 and within Group 2 averaged to 0.79, indicating a fair to very good agreement.

Conclusion:

DR is a valuable screening tool in cases of MA body packers with huge internal payloads being associated with a high diagnostic insecurity. Diagnostic insecurity on plain films may be overcome by low-dose CT as a cross-sectional imaging modality and addressed by improved radiological education in reporting drug carriers on imaging.

Advances in knowledge:

Diagnostic signs (double-condom and halo signs) on digital plain radiography are specific in MA “drug mules”, although DR is associated with high diagnostic insecurity and underreports the total internal payload.For the past decade, significant worldwide manufacturing of amphetamine-type stimulants has been reported to the United Nations Office on Drugs and Crime, Vienna, Austria, with a predominance of methamphetamine (MA) and its derivatives, which are also known as “syabu” or “ice”, throughout East and South East Asia.¹ In this region, the use of this synthetic drug is more prevalent than that of cocaine or heroin, which are more common in relatively developed areas, such as Europe and the USA.² During the course of this development, an increase in the number of drug carriers being intercepted by law enforcement at the borders of Malaysia has been observed. Drug carriers or “drug mules” are generally referred to as a human harbouring internal illicit drug packet(s). Internal body concealment of illegal drugs is one of the methods used to smuggle this illicit drug across the border.^3,4 “Drug mules” are generally known as body packers.^5,6 However, for correct terminology, one should differentiate between the terms body packer, body pusher and body stuffer. A body packer swallows a large amount of specially prepared drug packets to smuggle the packets in their gastrointestinal tract across a national border.^5,6 A body pusher hides a few containers in easily accessible body cavities, such as the rectum or vagina. Body stuffers, including traffickers and users, ingest intentionally small amounts of loosely wrapped drug pellets (typically initially hidden in the mouth), usually immediately before an unexpected encounter with law enforcement.^5–10The generally accepted radiological examination is a plain abdominal radiograph in the supine projection.^4–6 This technique is widely available at a low cost and is a simple method of detecting drug-filled packets within the alimentary tract. Radiation exposure to the patient is relatively moderate. In the literature, the detection rate for drug-filled packets is highly variable, and sensitivities from 58.3% to 90% have been reported.^4,5,11 Hence, plain abdominal radiography is a flawed screening method for identifying “drug mules”. Examining the bowel for foreign bodies, such as drug containers with variable sizes and radiodensities, is problematic, even for an experienced radiologist because the drug-filled packets may have an appearance similar to that of stool and gas and may be superimposed. Specific appearances described in the literature, such as the “double-condom”, “halo” and “rosette” signs, may be diagnostic for drug packages but are not necessarily so.^{4–6,11–13} Other modalities employed worldwide for the identification of body packers include CT, ultrasound, MRI and low-dose linear slit digital radiography (LSDR or LODOX®; Lodox Systems, Johannesburg, South Africa).^4,5,14–18Recent research has mainly concentrated on cocaine and heroin drug trafficking, which occurs predominantly in Western countries.^{3,4,6,7,11,14,19} There is little research on the accuracy of plain abdominal radiography in MA drug carriers, although there has been a significant increase of MA in Asia, accompanied by draconian legal measures in cases of drug trafficking.^1,2 The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of plain abdominal digital radiography (DRL) for identifying the internal payloads of MA in “drug mules”.