Validating the safety of low-dose CTPA in pregnancy: results from the OPTICA (Optimised CT Pulmonary Angiography in Pregnancy) Study.

BACKGROUND: Pulmonary embolism (PE) is a leading cause of pregnancy-related mortality. CT pulmonary angiogram (CTPA) is the first-line advanced imaging modality for suspected PE in pregnancy at institutes offering low-dose techniques; however, a protocol balancing safety with low dose remains undefined. The wide range of CTPA doses reported in pregnancy suggests a lack of confidence in implementing low-dose techniques in this group. PURPOSE: To define and validate the safety, radiation dose and image quality of a low-dose CTPA protocol optimised for pregnancy. MATERIALS AND METHODS: The OPTICA study is a prospective observational study. Pregnant study participants with suspected PE underwent the same CTPA protocol between May 2018 and February 2022. The primary outcome, CTPA safety, was judged by the reference standard; the 3-month incidence of venous thromboembolism (VTE) in study participants with a negative index CTPA. Secondary outcomes defined radiation dose and image quality. Absorbed breast, maternal effective and fetal doses were estimated by Monte-Carlo simulation on gestation-matched phantoms. Image quality was assessed by signal-to-noise and contrast-to-noise ratios and a Likert score for pulmonary arterial enhancement. RESULTS: A total of 116 CTPAs were performed in 113 pregnant women of which 16 CTPAs were excluded. PE was diagnosed on 1 CTPA and out-ruled in 99. The incidence of recurrent symptomatic VTE was 0.0% (one-sided 95% CI, 2.66%) at follow-up. The mean absorbed breast dose was 2.9 ± 2.1mGy, uterine/fetal dose was 0.1 ± 0.2mGy and maternal effective dose was 1.4 ± 0.9mSv. Signal-to-noise ratio (SNR) was 11.9 ± 3.7. Contrast-to-noise ratio (CNR) was 10.4 ± 3.5. CONCLUSION: The OPTICA CTPA protocol safely excluded PE in pregnant women across all trimesters, with low fetal and maternal radiation. CLINICAL RELEVANCE: OPTICA (Optimised CT Pulmonary Angiography in Pregnancy) is the first prospective study to define the achievable radiation dose, image-quality and safety of a low-dose CT pulmonary angiogram protocol optimised for pregnancy (NCT04179487). It provides the current benchmark for safe and achievable CT pulmonary angiogram doses in the pregnant population. KEY POINTS: • Despite the increased use of CT pulmonary angiogram in pregnancy, an optimised low-dose protocol has not been defined and reported doses in pregnancy continue to vary widely. • The OPTICA (Optimised CT Pulmonary Angiography in Pregnancy) study prospectively defines the achievable dose, image quality and safety of a low-dose CT pulmonary angiogram protocol using widely available technology. • OPTICA provides a benchmark for safe and achievable CT pulmonary angiogram doses in the pregnant population.

An update on epidural steroid injections: is there still a role for particulate corticosteroids?

Epidural steroid injections (ESIs) play an important role in the multifaceted management of neck and back pain. Corticosteroid preparations used in ESIs may be considered "particulate" or "non-particulate" based on whether they form a crystalline suspension or a soluble clear solution, respectively. In the past two decades, there have been reports of rare but severe and permanent neurological complications as a result of ESI. These complications have principally occurred with particulate corticosteroid preparations when using a transforaminal injection technique at cervical or thoracic levels, and only rarely in the lumbosacral spine. As a result, some published clinical guidelines and recommendations have advised against the use of particulate corticosteroids for transforaminal ESI, and the FDA introduced a warning label for injectable corticosteroids regarding the risk of serious neurological adverse events. There is growing evidence that the efficacy of non-particulate corticosteroids for pain relief and functional improvement after ESI is non-inferior to particulate agents, and that non-particulate injections almost never result in permanent neurological injury. Despite this, particulate corticosteroids continue to be routinely used for transforaminal epidural injections. More consistent clinical guidelines and societal recommendations are required alongside increased awareness of the comparative efficacy of non-particulate agents among specialists who perform ESIs. The current role for particulate corticosteroids in ESIs should be limited to caudal and interlaminar approaches, or transforaminal injections in the lumbar spine only if initial non-particulate ESI resulted in a significant but short-lived improvement.

Complications in image-guided musculoskeletal injections.

OBJECTIVE: To establish the incidence and define the nature of complications occurring following image-guided musculoskeletal injections at our institution. MATERIALS AND METHODS: All patients undergoing image-guided musculoskeletal injection during the study period (16/3/2016 to 24/01/2020) were included. Departmental records were reviewed to identify all patients describing possible complications following injection, what therapy was required (if any) and what the outcome was. No patients were excluded. Complications were classified as minor or major. Injections were categorised as follows: cervical spine, lumbar facet joint, lumbar nerve root, caudal epidural and 'other'. The complication rate for each individual category of procedure was compared with the combined complication rate for all other categories by constructing contingency tables and using Fisher's exact test. RESULTS: A total of 8226 patients underwent image-guided musculoskeletal injections within the study period. Exactly 100 patients were identified as having reported a complication, producing an overall complication rate of 1.2%. One complication was categorised as 'major', with the patient requiring expedited surgery. The remainder (99 patients) were categorised as having experienced minor complications. The incidence of complications after 'other' injections was significantly greater than for other categories of injection (1.86%, p = 0.028). There was no significant difference in the complication rate for cervical spine (0.93%, p = 0.257), lumbar nerve root (0.85%, p = 0.401), lumbar facet joint (0.67%, p = 0.326) or caudal epidural (1.29%, p = 0.687) injections. 'Other' injections were subsequently further sub-categorised by anatomical site and imaging modality used. Glenohumeral (2.97%, p = 0.0361) and sacro-iliac (3.51%, p = 0.0498) joint injections were associated with a significantly increased risk of complications. There was no difference in the incidence of complications with fluoroscopic or ultrasound guidance. CONCLUSION: In conclusion, image-guided musculoskeletal injections are safe and well-tolerated procedures. Complications are rare, occurring in just 1.2% of patients. 99% of complications are minor, either not requiring intervention or resolving with simple supportive treatment.

Incorporating Cone-Beam CT Into the Diagnostic Algorithm for Suspected Radiocarpal Fractures: A New Standard of Care?

OBJECTIVE. The purpose of this study was to assess the result of adding cone-beam CT to the standard imaging algorithm for patients with suspected radiographically occult traumatic radiocarpal fractures. SUBJECTS AND METHODS. A prospective review was performed on all patients who had cone-beam CT investigation of acute wrist pain after normal initial radiographs. Patients with no identified fractures were clinically reassessed and referred for MRI if concern for a fracture persisted. RESULTS. In all, 117 patients were assessed; 50.4% had fractures identified with a total of 67 radiographically occult fractures. One fracture was identified on MRI that was not seen on cone-beam CT. Cone-beam CT had sensitivity of 98.3% (95% CI, 91.1-100%), specificity of 100% (95% CI, 93.7-100%), positive predictive value of 100%, and negative predictive value of 98.3% (95% CI, 89.1-100%). Accuracy was 99.1% (95% CI, 95.3-100%). CONCLUSION. Incorporating cone-beam CT into routine clinical practice as part of a standardized diagnostic algorithm yielded a 50% fracture detection rate in patients with negative wrist radiographs but ongoing clinical concern for radiocarpal fracture. Cone-beam CT provides more diagnostic information than radiographs at a lower radiation dose than conventional MDCT. Given the poor accuracy of radiographs for acute radiocarpal fractures and the high fracture prevalence in this cohort, we feel that cone-beam CT should be regarded as the new standard of care in the investigation of these patients.

An acute stroke CT imaging algorithm incorporating automated perfusion analysis.

In this paper, we propose a CT imaging algorithm for patients presenting with suspected acute stroke that incorporates automated CT perfusion (CTP) imaging. The algorithm details evaluation of the non-contrast CT (NCCT) for hemorrhage and acute ischemia, calculation of ASPECTS, with performance and interpretation of CTP if appropriate. In particular, we consider the key steps in expeditious interpretation of non-contrast CT and CT angiography in the context of suspected acute ischemic stroke. Given the recent expansion of the "imaging based" treatment window for thrombectomy from 6 to 24 h in the 2018 American Heart Association stroke guidelines, we consider the key criteria in the decision to perform CT perfusion and the patient cohorts in which this might be most helpful. We also describe how imaging findings might be incorporated into the treatment paradigm for suspected with acute ischemic stroke and we allude to some of the most frequently encountered pitfalls associated with CTP which we think will be particularly helpful for radiologists and stroke physicians who are considering adding CT perfusion to their work-up for acute stroke.

Correction to: Septal bowing and pulmonary artery diameter on computed tomography pulmonary angiography are associated with short-term outcomes in patients with acute pulmonary embolism.

The above article was published online with an error in an author's last name: It should be Muzikansky (and not Muzikanski). The correct name is presented here. The original article has been corrected.

Septal bowing and pulmonary artery diameter on computed tomography pulmonary angiography are associated with short-term outcomes in patients with acute pulmonary embolism.

PURPOSE: Patients with acute pulmonary embolism (PE) can quickly deteriorate and the condition has high mortality due to right ventricular (RV) failure. Immediately available predictors of adverse outcome are of major interest to the treating physician in the acute setting. The purpose of the present study was to evaluate if easily attainable measurements of RV function from the diagnostic computed tomography pulmonary angiography (CTPA) provide information for fast risk stratification in patients with acute PE. METHODS: We retrospectively evaluated images from CTPA in 261 patients (age median 60 years, 50% females) enrolled in a prospective study. RV and left ventricular (LV) diameters and their ratio, the presence of septal bowing, contrast reflux in the inferior vena cava, and the diameter of the central pulmonary arteries (PA) were measured. The composite outcome was 5-day severe adverse events including death, acute decompensation, or need for emergent treatment. We used Wilcoxon rank sum test and Fischer's exact test to test between groups and multivariate logistic regression for prediction. RESULTS: In multivariate analysis, increased diameter of the main PA (OR = 1.08 per 1 mm increase, p = 0.047) and the presence of septal bowing (OR = 2.23, p = 0.055) were associated with severe adverse events. RV/LV > 1 did not predict severe outcomes (OR = 0.73, p = 0.541). CONCLUSIONS: Two easily attainable parameters of RV function on CTPA, septal bowing and main PA diameter, are associated with short-term adverse outcomes in patients with acute PE. Further study is required to determine whether these findings can be incorporated into clinical treatment algorithms.

Subtraction multiphase CT angiography: A new technique for faster detection of intracranial arterial occlusions.

OBJECTIVE: To describe and evaluate a novel technical development to improve detection of intracranial vessel occlusions using multiphase CT angiography (MPCTA). MATERIALS AND METHODS: The institutional ethics committee approved the study. Fifty patients (30 consecutive distal (M2 or smaller) anterior circulation occlusions, ten M1 occlusions, ten cases without occlusion) presenting with suspected AIS who underwent MPCTA were included. Post-processing of MPCTA studies created "subtraction" and "delayed enhancement" (DE) datasets. Initially, non-contrast CT and MPCTA studies for each patient were evaluated. Readers' confidence, speed and sensitivity of detection of intracranial vessel occlusions were recorded. After an interval of at least 4 weeks, readers were provided with post-processed images and studies were re-evaluated. RESULTS: While the sensitivity of detection of intracranial vessel occlusions was equal for both conventional MPCTA and subMPCTA, the mean time taken to identify a vessel occlusion decreased by 64 % using subMPCTA (16 s vs. 45 s with conventional MPCTA) (p<0.001). In addition, confidence in interpretation improved (from 4.4 to 4.9) using subMPCTA (p<0.001). CONCLUSION: SubMPCTA is a novel technique that aids in identifying small intracranial vessel occlusions in the suspected AIS patient. SubMPCTA increases confidence in interpretation and reduces the time taken to detect intracranial vessel occlusions. KEY POINTS: • SubMPCTA processes MPCTA data to better demonstrate intracranial arterial occlusions. • SubMPCTA increases confidence and speed of interpretation of MPCTA studies. • SubMPCTA may aid in rapidly differentiating acute ischaemic stroke from stroke mimics.

Spine Injectables: What Is the Safest Cocktail?

OBJECTIVE: Spinal injections are common pain management procedures using corticosteroids and local anesthetics. Most corticosteroid preparations are particulate suspensions, such as methylprednisolone acetate and triamcinolone acetonide. In the cervical spine, particulate corticosteroids have been linked to catastrophic complications, including blindness, paralysis, and death. Serious neurologic injuries have also been reported at the thoracic, lumbar, and sacral levels. CONCLUSION: Nonparticulate preparations, such as dexamethasone, are safer but have shorter-lived antiinflammatory effects. Local anesthetics are often mixed with corticosteroids in pain management procedures. Although everyday risks are minimal, injection techniques should take into account neural and cardiac toxicities. In this article, we discuss the potential for serious adverse events associated with injected medications. We review the current literature to make conclusions on medication combinations that balance safety and efficacy.

Using cone-beam CT as a low-dose 3D imaging technique for the extremities: initial experience in 50 subjects.

PURPOSE: To prospectively evaluate a dedicated extremity cone-beam CT (CBCT) scanner in cases with and without orthopedic hardware by (1) comparing its imaging duration and image quality to those of radiography and multidetector CT (MDCT) and (2) comparing its radiation dose to that of MDCT. MATERIALS AND METHODS: Written informed consent was obtained for all subjects for this IRB-approved, HIPAA-compliant study. Fifty subjects with (1) fracture of small bones, (2) suspected intraarticular fracture, (3) fracture at the site of complex anatomy, or (4) a surgical site difficult to assess with radiography alone were recruited and scanned on an extremity CBCT scanner prior to FDA approval. Same-day radiographs were performed in all subjects. Some subjects also underwent MDCT within 1 month of CBCT. Imaging duration and image quality were compared between CBCT and radiographs. Imaging duration, effective radiation dose, and image quality were compared between CBCT and MDCT. RESULTS: Fifty-one CBCT scans were performed in 50 subjects. Average imaging duration was shorter for CBCT than radiographs (4.5 min vs. 6.6 min, P = 0.001, n = 51) and MDCT (7.6 min vs. 10.9 min, P = 0.01, n = 7). Average estimated effective radiation dose was less for CBCT than MDCT (0.04 mSv vs. 0.13 mSv, P = .02, n = 7). CBCT images yielded more diagnostic information than radiographs in 23/51 cases and more diagnostic information than MDCT in 1/7 cases, although radiographs were superior for detecting hardware complications. CONCLUSION: CBCT performs high-resolution imaging of the extremities using less imaging time than radiographs and MDCT and lower radiation dose than MDCT.

Frequency of nonthromboembolic imaging abnormalities in pregnant women referred for computed tomography pulmonary arteriography.

PURPOSE: The study sought to determine the frequency of nonthromboembolic imaging abnormalities in pregnant women referred for computed tomography pulmonary arteriography (CTPA). MATERIALS AND METHODS: CTPA studies on 100 consecutive pregnant women performed over a 5-year period were reviewed independently by 2 radiologists, with conflicts resolved by consensus. Age range was 18-43 years (mean 28 years). The presence or absence of pulmonary embolism and of nonthromboembolic imaging abnormalities was recorded. These were graded as A if the abnormalities were thought to provide potential alternative explanations for acute symptoms, B if findings were incidental that required clinical or radiologic follow-up, and C if the findings did not require further action. RESULTS: Pulmonary embolism was seen in 5 women. In 2 of these additional findings of consolidation and infarction were seen. Ninety-five women did not have pulmonary embolism. Eleven women (12%) had grade A abnormalities; 6 cases of consolidation, 2 cases of lobar collapse, and 3 cases of heart failure with pleural effusions. One woman had a grade B abnormality due to the presence of pulmonary nodules. Ten women had incidental grade C abnormalities. CONCLUSION: Pulmonary embolism occurs in 5% of pregnant women referred for CTPA. In pregnant women without embolism on CTPA, potential alternative causes for patient symptoms are seen on CT in 12% of cases.

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 artefact 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, standardization, 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 article reveals overall significant reductions in acquisition time without compromised image quality in AI-accelerated prostate MRI, highlighting potential clinical and diagnostic advantages.

An evaluation of the practice of image-guided lumbar puncture.

OBJECTIVE: The purpose of this study was to evaluate the technical success and complication rates of image-guided lumbar puncture (IGLP) and to evaluate for differences in approach employed to help establish the optimum technique. METHODS: A retrospective search of the hospital picture archiving and communications system was performed to identify all IGLPs that had taken place over a 5-year period. Radiology reports and the electronic medical record were examined to identify technical parameters and complications associated with each procedure. RESULTS: The technical success rate was 96% (219/228). 69.4% (n = 161) had a previously failed bedside attempt. The rate of complications was 0.01% (n = 2). No major complications were observed. There was no difference in the rates of failure (2.4% vs 3.6%, p = 0.68) or complications (0.008% vs 0.012%, p = 1) between interlaminar and interspinous approaches. CONCLUSION: IGLP is a safe procedure with a high rate of technical success. Where a difficult bedside attempt is anticipated, it is reasonable to forego this and proceed directly to IGLP. ADVANCES IN KNOWLEDGE:: This paper helps to confirm what is already assumed about a common radiological procedure. This is important as there has been a shift from bedside technique to most lumbar punctures being performed via image guidance.

Evaluation of image quality of diffusion weighted readout segmentation of long variable echo-trains MR pulse sequence for lumbosacral nerve imaging at 3T.

Background: Limited magnetic resonance (MR) pulse sequences facilitate lumbosacral nerve imaging with acceptable image quality. This study aimed to evaluate the impact of parameter modification for Diffusion Weighted Image (DWI) using Readout Segmentation of Long Variable Echo-trains (RESOLVE) sequence with opportunities for improving the visibility of lumbosacral nerves and image quality. Methods: Following ethical approval and acquisition of informed consent, imaging of an MR phantom and twenty healthy volunteers (n=20) was prospectively performed with 3T MRI scanner. Acquired sequences included standard two-dimensional (2D) turbo spin echo sequences and readout-segmented echo-planar imaging (EPI) DWI-RESOLVE using three different b-values b-50, b-500 and b-800 s/mm2. Signal-to-noise ratio (SNR), apparent diffusion coefficient (ADC) and nerve size were measured. Two musculoskeletal radiologists evaluated anatomical structure visualisation and image quality. Quantitative and qualitative findings for healthy volunteers were investigated for differences using Wilcoxon signed-rank and Friedman tests, respectively. Inter and intra-observer agreement was determined with κ statistics. Results: Phantom images revealed higher SNR for images with low b-values with 206.1 (±10.9), 125.1 (±45.2) and 59.2 (±17.8) for DWI-RESOLVE images acquired at b50, b500 and b800, respectively. Comparable results were found for SNR, ADC and nerve size across normal right and left sided for healthy volunteer images. The SNR findings for b-50 images were higher than b-500 and b-800 images for healthy volunteer images. The qualitative findings ranked images acquired using b-50 and b-500 images significantly higher than corresponding b-800 images (P<0.05). Inter and intra-observer agreements for evaluation across all b-values ranged from 0.59 to 0.81 and 0.83 to 0.92, respectively. Conclusions: The modified DWI-RESOLVE images facilitated visualization of the normal lumbosacral nerves with acceptable image quality, which support the clinical applicability of this sequence.

Breast Shielding Combined With an Optimized Computed Tomography Pulmonary Angiography Pregnancy Protocol: A Special Use-Case for Shielding?

OBJECTIVES: To determine the impact of breast shields on breast dose and image quality when combined with a low-dose computed tomography pulmonary angiography (CTPA) protocol for pregnancy. METHODS: A low-dose CTPA protocol, with and without breast shields, was evaluated by anthropomorphic phantom and 20 prospectively recruited pregnant participants from January to October 2019. Thermoluminescent dosimeters measured surface and absorbed breast dose in the phantom and surface breast dose in participants. The Monte-Carlo method estimated the absorbed breast dose in participants. Image quality was assessed quantitatively by regions of interest analysis and subjectively by the Likert scale. Doses and image quality for CTPA alone were compared with CTPA with breast shields. RESULTS: Mean surface and absorbed breast dose for CTPA alone were 1.3±0.4 and 2.8±1.5 mGy in participants, and 1.5±0.7 and 1.6±0.6 mGy in the phantom. Shielding reduced surface breast dose to 0.5±0.3 and 0.7±0.2 mGy in the phantom (66%) and study participants (48%), respectively. Absorbed breast dose reduced to 0.9±0.5 mGy (46%) in the phantom.Noise increased with breast shields at lower kV settings (80 to 100 kV) in the phantom; however, in study participants there was no significant difference between shield and no-shield groups for main pulmonary artery noise (no-shield: 34±9.8, shield: 36.3±7.2, P =0.56), SNR (no-shield: 11.2±3.7, shield: 10.8±2.6, P =0.74) or contrast-to-noise ratio (no-shield: 10.0±3.3, shield: 9.3±2.4, P =0.6). Median subjective image quality scores were comparable (no-shield: 4.0, interquartile range: 3.5 to 4.4, shield: 4.3, interquartile range: 4.0 to 4.5). CONCLUSION: Combining low-dose CTPA with breast shields confers additional breast-dose savings without impacting image quality and yields breast doses approaching those of low-dose scintigraphy, suggesting breast shields play a role in protocol optimization for select groups.

Whole-body MRI in neurofibromatosis: incidental findings and prevalence of scoliosis.

OBJECTIVE: To demonstrate incidental findings and scoliosis on whole-body MRI (WBMRI) in patients with neurofibromatosis type 1 and 2 (NF1 & NF2, respectively), and schwannomatosis. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained for this prospective HIPAA-compliant study. A total of 247 subjects (141 with NF1, 55 with NF2, 51 with schwannomatosis; 132 women (53.5%); mean age, 41 years, range, 18-97 years) underwent WBMRI using coronal STIR (TR/TE: 4190/111 ms, TI: 150 ms) and T1-weighted images (TR/TE: 454/10 ms), 10-mm slice thickness, imaging time ~40 min. Images were reviewed for the presence of incidental findings, outside of nerve sheath tumors. The presence of scoliosis was recorded and curve morphology was assessed and quantified. RESULTS: Incidental findings other than scoliosis were recorded in 104/247 (42%) patients, most often affecting the musculoskeletal system (65/247 patients, 26%). We found 16/247 (6.5%) significant incidental findings likely to affect clinical management, including avascular necrosis of bone in eight patients (five with NF2), eight insufficiency fractures, and four non-neurogenic neoplasms (Hodgkin's lymphoma, liposarcoma, dermoid cyst, large uterine myoma requiring excision). Scoliosis was seen in 50/247 patients (20%), including 8/55 with NF2 (15%) and 11/51 with schwannomatosis (22%). CONCLUSIONS: Incidental findings in the neurofibromatoses frequently involve the skeleton. Given the relatively high incidence of unsuspected osteonecrosis and stress fractures, close attention to the skeleton on WBMRI is advised. In addition, knowledge of common incidental findings can help clinicians prepare patients who undergo WBMRI for potential unexpected findings.

A biomechanical approach to MRI of acute knee injuries.

OBJECTIVE: MRI is routinely performed to evaluate acute complex knee injuries. This article will review the fundamental biomechanical forces underlying the most important and common injuries and correlate MRI findings with specific traumatic mechanisms. CONCLUSION: MRI findings can reveal the traumatic mechanisms in many acute knee injuries. By applying a biomechanical approach in MRI interpretation, it is possible to use easily detected lesions, such as osseous contusion and ligament rupture, to predict subtle but important abnormalities that might otherwise be missed. This systematic focused analysis enables a more accurate and rapid interpretation of knee MR studies.

Postoperative imaging of the elbow, wrist, and hand.

There are many bone and soft tissue injuries to the elbow, wrist, and hand that are treated surgically. The operative techniques can be complicated and their indications may change. This article reviews the common injuries at the elbow, wrist, and hand, the indications for surgical management, the current and previous operative techniques used, the expected postoperative appearance on different imaging modalities, and the important potential complications of each technique.

Role of positron emission tomography--computed tomography in head and neck cancer.

Head and neck squamous cell carcinoma (HNC) is the sixth most common cancer worldwide. In the United States, it accounts for approximately 2% of all cancers and 2% of cancer deaths. The introduction of integrated positron emission tomography and computed tomography (PET/CT) has revolutionized imaging by permitting improved and more accurate anatomic localization of functional abnormalities in the complex territory of the head and neck region, and PET/CT has become a standard clinical imaging modality in patients with HNC. The main indications for PET/CT in HNC are in pretherapy staging, detection of unknown primaries, and monitoring of therapy response or disease surveillance. Although PET/CT is a promising tool in diagnosis and surveillance of HNC, there is lack of consensus as to its use, accuracy, and implications for patient management. The existing literature on the role of PET/CT in the management of HNC is reviewed, and a summary of the current debate is provided. Second primary cancers are the main cause of death among HNC patients with early disease, and the presence of distant metastases greatly impairs the survival of patients with advanced HNC. Therefore, early detection of second primary and metastatic tumors is imperative for optimizing survival outcome. However, given the lack of randomized, prospective trials addressing the role of PET/CT after chemoradiotherapy, the ideal function of PET/CT in disease surveillance has yet to be defined.