AI-Accelerated prostate MRI: a systematic review.

BACKGROUND: Prostate cancer ranks among the most prevalent cancers affecting men globally. While conventional MRI serves as a diagnostic tool, its extended acquisition time, associated costs, and strain on healthcare systems, underscore the necessity for more efficient methods. The emergence of AI-acceleration in prostate MRI offers promise to mitigate these challenges. METHODS: A systematic review of studies looking at AI-accelerated prostate MRI was conducted, with a focus on acquisition time along with various qualitative and quantitative measurements. RESULTS: Two primary findings were observed. Firstly, all studies indicated that AI-acceleration in MRI achieved notable reductions in acquisition times without compromising image quality. This efficiency offers potential clinical advantages, including reduced scan durations, improved scheduling, diminished patient discomfort, and economic benefits. Secondly, AI demonstrated a beneficial effect in reducing or maintaining artifact levels in T2-weighted images despite this accelerated acquisition time. Inconsistent results were found in all other domains, which were likely influenced by factors such as heterogeneity in methodologies, variability in AI models, and diverse radiologist profiles. These variances underscore the need for larger, more robust studies, standardisation, and diverse training datasets for AI models. CONCLUSION: The integration of AI-acceleration in prostate MRI thus far shows some promising results for efficient and enhanced scanning. These advancements may fill current gaps in early detection and prognosis. However, careful navigation and collaborative efforts are essential to overcome challenges and maximize the potential of this innovative and evolving field. ADVANCES IN KNOWLEDGE: This paper reveals overall significant reductions in acquisition time without compromised image quality in AI-accelerated prostate MRI, highlighting potential clinical and diagnostic advantages.

Ultra-low-dose cone-beam CT compared to standard dose in the assessment for acute fractures.

PURPOSE: Multi-detector computed tomography (MDCT) is superior in fracture detection than conventional radiography; however, dose is increased. Cone-beam computed tomography (CBCT) offers higher spatial resolution and lower dose than MDCT. Manufacturers offer an ultra-low-dose algorithm. This study compares the diagnostic accuracy of the ultra-low-dose CBCT (ULDCBCT) with that of the standard-dose CBCT (SDCBCT). MATERIALS AND METHODS: In total, 64 patients were scanned with both the SDCBCT and the ULDCBCT protocols. Both studies were reported by two consultant radiologists with fellowship training in emergency radiology separated in time. The reporter recorded a diagnosis of fracture or normal and diagnostic confidence using a 5-point Likert scale. The gold standard was taken as the SDCBCT. Reporters were blinded to the indication and the SDCBCT report. Cases of discrepancy were resolved by consensus. RESULTS: There were 34 fractures and 30 cases had no fracture. Several fractures were missed using the UDCBCT, and there were also several cases of overdiagnosis. ULD was inferior to SD for fracture diagnosis (p < 0.00001). The diagnostic accuracy of ULDCBCT was 82.8% (75.1-88.9 CI). The diagnostic accuracy of plain radiograph was 64% (55.1-75.7% CI). Diagnostic confidence was reduced; the mean confidence for SDCBCT was 4.68 vs 4.12 for ULDCBCT (p < 0.001). The Kappa for interobserver agreement was 0.6. CONCLUSION: ULDCBCT is inferior to SDCBCT in fracture detection and confidence is reduced. For diagnostic studies, the standard dose should be used.

Evaluation of optimised 3D turbo spin echo and gradient echo MR pulse sequences of the knee at 3T and 1.5T.

INTRODUCTION: To investigate the impact of parameter optimisation for novel three-dimensional 3D sequences at 1.5T and 3T on resultant image quality. METHODS: Following institutional review board approval and acquisition of informed consent, MR phantom and knee joint imaging on healthy volunteers (n = 16) was performed with 1.5 and 3T MRI scanners, respectively incorporating 8- and 15-channel phased array knee radiofrequency coils. The MR phantom and healthy volunteers were prospectively scanned over a six-week period. Acquired sequences included standard two-dimensional (2D) turbo spin echo (TSE) and novel three-dimensional (3D) TSE PDW (SPACE) both with and without fat-suppression, and T2∗W gradient echo (TrueFISP) sequences. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured for knee anatomical structures. Two musculoskeletal radiologists evaluated anatomical structure visualisation and image quality. Quantitative and qualitative findings were investigated for differences using Friedman tests. Inter- and intra-observer agreements were determined with κ statistics. RESULTS: Phantom and healthy volunteer images revealed higher SNR for sequences acquired at 3T (p-value <0.05). Generally, the qualitative findings ranked images acquired at 3T higher than corresponding images acquired at 1.5T (p < 0.05). 3D image data sets demonstrated less sensitivity to partial volume averaging artefact (PVA) compared to 2D sequences. Inter- and intra-observer agreements for evaluation across all sequences ranged from 0.61 to 0.79 and 0.71 to 0.92, respectively. CONCLUSION: Both 2D and 3D images demonstrated higher image quality at 3T than at 1.5T. Optimised 3D sequences performed better than the standard 2D PDW TSE sequence for contrast resolution between cartilage and joint fluid, with reduced PVA artefact. IMPLICATIONS FOR PRACTICE: With rapid advances in MRI scanner technology, including hardware and software, the optimisation of 3D MR pulse sequences to reduce scan time while maintaining image quality, will improve diagnostic accuracy and patient management in musculoskeletal MRI.

Assessment of RAdiopaque Patient IDentification Stickers (RAPIDS) for patient-scan correlation in a mass casualty incident.

PURPOSE: To qualitatively assess the legibility of radiopaque patient identification stickers and their effect on image quality. These stickers are intended for use as a part of a patient registration and identification pack utilized in a mass casualty incident (MCI), to prevent errors in correlating patients with their diagnostic imaging and reports. METHODS: Four different prototype designs of stickers with radiopaque identification numbers which are legible on radiographs and CT were created. These were affixed to head and thorax phantoms and scanned using standard imaging protocols. Images were reviewed qualitatively for legibility and the presence of image degradation due to the radiopaque sticker materials using Likert scales by four radiologists and four emergency physicians. RESULTS: All four prototypes were confidently legible on forehead, shoulder and sternum on CT on topogram and reconstructed images. Sticker positioning over the temple resulted in unreliable legibility on topogram. All prototypes were confidently legible on shoulder and sternum on CT and radiographs. Significant image degradation was reported on radiographs with sticker position over the sternum. The preferred anatomic position was the forehead. CONCLUSION: In a mass casualty incident, radiopaque patient identification stickers affixed to injured patients may help to ensure confidence in the correlation between patients and their imaging. Tested prototypes were found to be easily legible without substantial degradation of image quality. Preferred anatomical position and construction material was established. Consideration should be given to addition of such radiographic identity aides to MCI patient registration packs.

Mass casualty incidents-are you ready? A major incident planning template for diagnostic radiology.

Mass casualty incidents (MCIs) create a large number of casualties in a short period of time. Diagnostic radiology plays an important role in major incident responses but is often underrepresented during major incident planning (MIP) and simulation. Surveys suggest radiologists are unfamiliar with their role during an MCI. We aimed to identify key topics for radiology MIP, familiarize radiologists with their role during an MCI and identify areas for future research. The terms "radiology" and "mass casualty incident" were entered into the advanced search builder on PubMed. Abstracts from this primary search were reviewed and papers selected for inclusion. Additional studies of interest were identified upon review of reference sections of relevant articles and from the related article tab on PubMed. MCI and trauma guidelines were reviewed. Key factors that caused issues during prior MCIs were identified including staff alert mechanisms, patient identification strategies, patient tracking, scan ordering and result communication. Limitations of local imaging resources and capacity should be identified and inform plans for the utilization of diagnostic radiology in the MCI setting. Simulation can help identify areas for improvement and familiarize staff with their roles. Further development of reliable MCI alert technology and patient identification strategies are needed as well as prospective validation of trauma CT selection criteria to identify patients who will benefit most from CT. Radiology should take part in MIP to address key issues encountered during prior MCIs and in MCI simulation to optimize major incident response.

Trapezium fracture: a common clinical mimic of scaphoid fracture.

PURPOSE: Fractures of the trapezium are rarely diagnosed on plain radiographs after acute wrist trauma. High-resolution cross-sectional imaging identifies fractures of the trapezium as the most common radiographically occult carpal bone fracture. We review the fracture frequency, mechanisms and patterns of trapezium fractures. METHODS: Cone beam CT was performed in patients with suspected radiographically occult radiocarpal fracture following acute injury. The frequency of carpal bone fractures was assessed and compared. RESULTS: Ninety-three radiographically occult wrist fractures were identified in 166 patients with acute trauma and negative radiographs. The trapezium was the most frequently fractured carpal bone, making up 20.4% of wrist fractures. Seventy-nine percent of trapezium fractures involved the volar ridge. The scaphoid was the clinically suspected fractured bone at initial assessment in 84% of patients with trapezium fractures. CONCLUSION: Fractures of the trapezium in acute wrist trauma are much more common than described in the literature. If initial radiographs are negative, a fracture of the trapezium is more likely to be present than one of the scaphoid, despite high levels of clinical suspicion for scaphoid injuries. Awareness of the types and mechanisms of trapezium fracture is important. Cross-sectional imaging should be considered in all cases of post-traumatic wrist pain with negative radiographs.

Improved Detection of Anterior Circulation Occlusions: The "Delayed Vessel Sign" on Multiphase CT Angiography.

BACKGROUND AND PURPOSE: Multiphase CTA, a technique to dynamically assess the vasculature in acute ischemic stroke, was primarily developed to evaluate collateral filling. We have observed that it is also useful in identifying distal anterior circulation occlusions due to delayed anterior circulation opacification on multiphase CTA, an observation we term the "delayed vessel sign." We aimed to determine the usefulness of this sign by comparing multiphase CTA with single-phase CTA. MATERIALS AND METHODS: All 23 distal anterior circulation occlusions during a 2-year period were included. Ten M1-segment occlusions and 10 cases without a vessel occlusion were also included. All patients had follow-up imaging confirming the diagnosis. Initially, the noncontrast CT and first phase of the multiphase CTA study for each patient were blindly evaluated (2 neuroradiologists, 2 radiology trainees) for an anterior circulation occlusion. Readers' confidence, speed, and sensitivity of detection were recorded. Readers were then educated on the "delayed vessel sign," and each multiphase CTA study was re-examined for a vessel occlusion after at least 14 days. RESULTS: There was significant improvement in the sensitivity of detection of distal anterior circulation vessel occlusions (P < .001), overall confidence (P < .001), and time taken to interpret (P < .001) with multiphase CTA compared with single-phase CTA. Readers preferred MIP images compared with source images in >90% of cases. CONCLUSIONS: The delayed vessel sign is a reliable indicator of anterior circulation vessel occlusion, particularly in cases involving distal branches. Assessment of the later phases of multiphase CTA for the delayed vessel sign leads to a significant improvement in the speed and confidence of interpretation, compared with single-phase CTA.

Current and Emerging Therapies in Multiple Sclerosis: Implications for the Radiologist, Part 2-Surveillance for Treatment Complications and Disease Progression.

An understanding of the new generation of MS drugs in conjunction with the key role MR imaging plays in the detection of disease progression, opportunistic infections, and drug-related adverse effects is of vital importance to the neuroradiologist. Part 1 of this review outlined the current treatment options available for MS and examined the mechanisms of action of the various medications. It also covered specific complications associated with each form of therapy. Part 2, in turn deals with the subject of pharmacovigilance and the optimal frequency of MRI monitoring for each individual patient, depending on his or her unique risk profile. Special attention is given to the diagnosing of progressive multifocal leukoencephalopathy in patients treated with natalizumab as this is a key area in which neuroradiologists can contribute to improved patient outcomes. This article also outlines the aims of treatment and reviews the possibility of "no evidence of disease activity" becoming a treatment goal with the availability of more effective therapies. Potential future areas and technologies including image subtraction, brain volume measurement and advanced imaging techniques such as double inversion recovery are also reviewed. It is anticipated that such advancements in this rapidly developing field will improve the accuracy of monitoring an individual patient's response to treatment.

Current and Emerging Therapies in Multiple Sclerosis: Implications for the Radiologist, Part 1-Mechanisms, Efficacy, and Safety.

Imaging for the diagnosis and follow-up of patients with suspected or confirmed multiple sclerosis is a common scenario for many general radiologists and subspecialty neuroradiologists. The field of MS therapeutics has rapidly evolved with multiple new agents now being used in routine clinical practice. To provide an informed opinion in discussions concerning newer MS agents, radiologists must have a working understanding of the strengths and limitations of the various novel therapies. The role of imaging in MS has advanced beyond monitoring and surveillance of disease activity to include treatment complications. An understanding of the new generation of MS drugs in conjunction with the key role that MR imaging plays in the detection of disease progression, opportunistic infections, and drug-related adverse events is of vital importance to the radiologist and clinical physician alike. Radiologists are in a unique position to detect many of the described complications well in advance of clinical symptoms. Part 1 of this review outlines recent developments in the treatment of MS and discusses the published clinical data on the efficacy and safety of the currently approved and emerging therapies in this condition as they apply to the radiologist. Part 2 will cover pharmacovigilance and the role the neuroradiologist plays in monitoring patients for signs of opportunistic infection and/or disease progression.

Contrast monitoring techniques in CT pulmonary angiography: An important and underappreciated contributor to breast dose.

OBJECTIVE: The aims of our study were to evaluate the contribution of contrast-monitoring techniques to breast dose in pregnant and non-pregnant women, and to investigate the effect of a reduced peak kilovoltage (kV) monitoring scan protocol on breast dose and Computed Tomography Pulmonary Angiography (CTPA) diagnostic quality. MATERIALS AND METHODS: Single center retrospective study of 221 female patients undergoing a reduced kV 80kV contrast-monitoring CTPA protocol compared to 281 patients using the conventional 120kV contrast-monitoring protocol (Siemens Somatom Definition AS+). 99 pregnant patients analyzed separately. ImPACT dosimetry software was used to calculate dose. Group subsets were evaluated to assess CTPA diagnostic quality. RESULTS: The contrast-monitoring component of a CTPA study constituted 27% of the overall breast dose when using a standard 120kV protocol compared to only 7% of the overall breast dose in the 80kV study group. The dose to the breast from the contrast-monitoring component alone was reduced by 79% in the non-pregnant patients (0.36mGy±0.37 versus 1.7mGy±1.02; p<0.001), and by 88% in the pregnant population (0.25mGy±0.67 versus 2.24mGy±1.61; p<0.001). There was no statistical difference in CTPA diagnostic quality or timing. CONCLUSION: Despite a short scan length and relatively small DLP, contrast-monitoring techniques (test-bolus or bolus-tracked) set at 120kV can account for 27% of the overall breast dose accrued from a CTPA study. By decreasing the kilovoltage of the contrast-monitoring component, a significant reduction in breast dose for pregnant and non-pregnant female patients can be achieved without affecting CTPA quality or timing.

Injectable corticosteroid preparations: an embolic risk assessment by static and dynamic microscopic analysis.

BACKGROUND AND PURPOSE: Transforaminal CS injections have been associated with severe adverse CNS events, including brain and spinal cord infarction. Our purpose was to describe the static and dynamic microscopic appearances of CS preparations, with an emphasis on their potential to cause adverse central nervous system events by embolic mechanisms during transforaminal injection. MATERIALS AND METHODS: Pharmaceutical preparations of nondilute injectable CSs were used after appropriate mixing: MPA (40 mg/mL), TA (40 mg/mL), and DSP (8 mg/2 mL). For dynamic imaging, a novel methodology was devised to replicate the flow of crystals within spinal cord arterioles. In addition, CS preparations were mixed with plasma to assess for changes in crystal size, morphology, and tendency to aggregate. RESULTS: The CS preparations MPA and TA are composed of crystals of varying sizes. MPA crystal size range was 0.4-26 µm (mean, 6.94 µm), TA crystal size range 0.5-110 µm (mean, 17.4 µm), and DSP did not contain any significant crystals or particles. There was no change in the crystal morphology or propensity to aggregate after mixing with local anesthetic. After mixing with plasma, the crystals also were unchanged; however, there was a significant reduction in the size of aggregates. On dynamic imaging, these aggregates were proved to maintain their integrity and to act as potential embolization agents. CONCLUSIONS: MPA and TA have a substantial risk of causing infarction by embolization if inadvertently injected intra-arterially at the time of TFESI. DSP is completely soluble and microscopically has no potential to obstruct arterioles. When performing cervical TFESI procedures, the administration of insoluble CSs should be avoided.

MRI of injuries to the first interosseous cuneometatarsal (Lisfranc) ligament.

OBJECTIVE: The objective of this study was to assess the utility of MRI in diagnosing injury to the first interosseous cuneometatarsal (Lisfranc) ligament and to additionally determine the associated patterns of traumatic soft tissue and osseous injury. MATERIALS AND METHODS: Fifteen patients (16 feet) who were referred for MRI evaluation of the Lisfranc ligament, and had operative exploration or examination under anesthesia, were included for analysis. Standard non-contrast MRI foot imaging was performed in all cases. Evaluation of the following components was performed: the dorsal and plantar bundles of the Lisfranc ligament, the plantar tarsal metatarsal ligaments, soft tissue edema and fluid, and bone marrow edema and fractures. Surgical reports were regarded as the reference standard in all cases. RESULTS: Seven of 10 cases of grade 3 Lisfranc ligament injuries at surgery were correctly graded at MRI. No cases of surgically proven complete Lisfranc ligament tears (grade 3) were interpreted as normal at MRI. All Lisfranc ligament sprains (grade 2 or 3) at surgery were detected at MRI. Two of six cases reported as grade 1 injuries at MRI were normal at surgery. No cases of surgically proven normal or sprained Lisfranc ligaments were interpreted as grade 3 tears on MRI. Four of six of our cases of normal or sprained Lisfranc ligaments demonstrated fractures; while the minority of complete Lisfranc ligament tears (3/10) contained fractures. CONCLUSION: MRI is reasonably accurate at detecting traumatic injury to the Lisfranc ligament. However, in clinically suspected cases of traumatic Lisfranc ligament injury, true positive rate for sprain is low.

Disc displacement patterns in lumbar anterior spondylolisthesis: contribution to foraminal stenosis.

PURPOSE: To describe the particular disc displacement pattern seen at MRI in patients with spondylolisthesis, and its potential contribution to foraminal stenosis. METHODS: 38 patients with symptomatic lumbar anterior spondylolisthesis and 38 sex and aged matched control patients with herniated disc disease, at corresponding disc space levels, were included for study. In each case note was made of the presence, absence and direction of disc displacement and also the presence and location of neural contact with the displaced disc. RESULTS: In 33 of 38 (86.8%) patients in the spondylolisthesis group, the vertical disc displacement was upward. In the control group only 3 patients (7.8%) had upward vertical disc displacement. 19 patients (53%) from the spondylolisthesis group had exit foraminal nerve root contact, compared to 7 patients (18.4%) from the control group. 27 control patients (71%) had contact within the lateral recess, compared to only 6 patients (17%) with spondylolisthesis. Differences for upward displacement were significant (p<0.05). CONCLUSION: Disc displacement in patients with spondylolisthesis is predominately in a cephalad and lateral direction. Although this disc displacement pattern can occur in patients without spondylolisthesis, its incidence is much greater in the subset of patients with concomitant spondylolisthesis. In the setting of acquired osseous narrowing of the exit foramen, this described pattern of disc displacement superiorly and laterally in spondylolisthesis increases the susceptibility of spondylolisthesis patients to radicular symptoms and accounts for the exiting nerve root being more commonly affected than the traversing nerve root.

Ultrasound-guided percutaneous drainage of meniscal cysts: preliminary clinical experience.

AIM: To evaluate the efficacy of ultrasound-guided percutaneous drainage of symptomatic meniscal cysts. MATERIALS AND METHODS: Patients with lateral knee joint tenderness and swelling and confirmed meniscal cyst on magnetic resonance imaging (MRI) were consecutively enrolled for ultrasound-guided percutaneous cyst aspiration. Cysts were injected with local anaesthetic and steroid before completion of procedure. All 18 patients (all male, average age 33 years) were subsequently followed up (average time 10 months) and meniscal cyst symptoms assessed by questionnaire. Fischer's exact test used to analyse the data. RESULTS: In every case the procedure was well tolerated, and each patient indicated that they would be willing to have a repeat procedure in the future. Ten patients reported complete resolution of symptoms secondary to therapeutic cyst aspiration and had resumed participation in high-performance sport. Two patients reported a satisfactory sustained response, reporting only occasional "twinges of pain". In the remaining six patients, symptoms returned after an initial pain-free period. The pain-free period ranged from 1-8 weeks. In this study, patient outcome did not significantly correlate with any meniscal cyst characteristic. CONCLUSION: Ultrasound-guided percutaneous aspiration of meniscal cysts is a well-tolerated, simple, and safe procedure. In this small patient series, it was associated with positive early results with favourable outcomes in the mid to long-term. It should be considered in patients unsuitable for surgical debridement or as an interim therapy if surgery is delayed or postponed.