Acta Radiologica

No quantitative computed tomography (CT) biomarker is actually sufficiently accurate to assess Crohn’s disease (CD) lesion activity, with adequate precision to guide clinical decisions.

To assess the available literature on the use of iodine concentration (IC), from multi-spectral CT acquisition, as a quantitative parameter able to distinguish healthy from affected bowel and assess CD bowel activity and heterogeneity of activity along the involved segments.

A literature search was conducted to identify original research studies published up to February 2022. The inclusion criteria were original research papers (>10 human participants), English language publications, focus on dual-energy CT (DECT) of CD with iodine quantification (IQ) as an outcome measure. The exclusion criteria were animal-only studies, languages other than English, review articles, case reports, correspondence, and study populations <10 patients.

Nine studies were included in this review; all of which showed a strong correlation between IC measurements and CD activity markers, such as CD activity index (CDAI), endoscopy findings and simple endoscopic score for Crohn's disease (SES-CD), and routine CT enterography (CTE) signs and histopathologic score. Statistically significant differences in IC were reported between affected bowel segments and healthy ones (higher P value was P < 0.001), normal segments and those with active inflammation (P < 0.0001) as well as between patients with active disease and those in remission (P < 0.001).

The mean normalized IC at DECTE could be a reliable tool in assisting radiologists in the diagnosis, classification and grading of CD activity.

Evaluation for gastrointestinal leak is a frequent imaging indication, and dual-energy computed tomography (DECT) with oral or rectally administered contrast can be used to improve efficiency and diagnostic confidence.

To assess the value of the DECT iodine overlay (IO) reconstruction as a stand-alone image set compared to routine CT in assessing oral or rectal contrast leak from the gastrointestinal system.

A blinded, retrospective audit study was performed by three readers who each interpreted 50 studies performed for assessment of oral or rectal contrast leak that were acquired using DECT. Each reader independently assessed both the routine CT images and the images of the reconstructed IO for contrast leak in random order with a six-week “wash-out period” between readings. Clinical follow-up provided the reference standard. Readers recorded the presence/absence of a leak, diagnostic confidence, image quality score, and interpretation time for each image set.

Pooled data for overall accuracy in identification of a leak increased from 0.81 (95% confidence interval [CI]=0.74–0.87) for routine CT to 0.91 (95% CI=0.85–0.95) with IO, and the area under the curve (AUC) was significantly higher for IO than routine CT (P = 0.015). Readers required significantly less time to interpret IO than routine CT (median improvement of 12.5 s per image using pooled data; P < 0.001) while maintaining diagnostic confidence and perceived image quality.

Use of DECT IO reconstructions for identification of oral or rectal contrast leak requires less time to interpret than routine CT with improved accuracy and maintained diagnostic confidence and perceived image quality.

Breast cancer mainly affects women aged >50 years; however, younger women may also have advanced breast cancer, so early detection is important.

To collect and review the imaging findings of women aged <30 years with breast cancer to find better diagnostic approaches for the early diagnosis of breast cancer in young women.

In this study, 45 patients aged <30 years with a diagnosis of breast cancer were evaluated. Imaging assessments were performed based on ultrasound, mammography, and magnetic resonance imaging (MRI) findings. Finally, the findings were compared with the pathological results.

Predominant findings in ultrasound included irregular spiculated mass in 59.4%. In mammography, irregular high-density mass (46.5%) and suspicious micro calcification (42.8%) were the most common findings. In MRI, the predominant feature was a heterogeneous enhancing mass with an irregular shape and irregular margin (81%) with a 45% plateau and 36% washout kinetic pattern. In the pathology assessment, invasive ductal carcinoma was the most common finding (84.4%). All three modalities—MRI, ultrasonography, and mammography—are valuable, with sensitivities of 100%, 93.3%, and 90%, respectively.

Ultrasound, mammography, and MRI are highly sensitive and accurate tools for detecting breast cancer lesions in young women. Regular clinical breast examination with breast self-examination, and in suspected cases, ultrasound as the first imaging modality followed by mammography and/or MRI are the preferred diagnostic approach.

Double reading of screening mammograms is associated with a higher rate of screen-detected cancer than single reading, but different strategies exist regarding reader pairing and blinding. Knowledge about these aspects is important when considering strategies for future use of artificial intelligence in mammographic screening.

To investigate screening outcome, histopathological tumor characteristics, and mammographic features stratified by the first and the second reader in a population based screening program for breast cancer.

The study sample consisted of data from 3,499,048 screening examinations from 834,691 women performed during 1996–2018 in BreastScreen Norway. All examinations were interpreted independently by two radiologists, 272 in total. We analyzed interpretation score, recall, and cancer detection, as well as histopathological tumor characteristics and mammographic features of the cancers, stratified by the first and second readers.

For Reader 1, the rate of positive interpretations was 4.8%, recall 2.3%, and cancer detection 0.5%. The corresponding percentages for Reader 2 were 4.9%, 2.5%, and 0.5% (P < 0.05 compared with Reader 1). No statistical difference was observed for histopathological tumor characteristics or mammographic features when stratified by Readers 1 and 2. Recall and cancer detection were statistically higher and histopathological tumor characteristics less favorable for cases detected after concordant positive compared with discordant interpretations.

Despite reaching statistical significance, mainly due to the large study sample, we consider the differences in interpretation scores, recall, and cancer detection between the first and second readers to be clinically negligible. For practical and clinical purposes, double reading in BreastScreen Norway is independent.

Computed tomography (CT) value studies of cone-beam breast CT (CBBCT) mainly focus on the enhancement value or enhancement rate, and there has been no study on the CT value (Hounsfield units [HU]) of the lesion itself.

To investigate the CT values under contrast-enhanced CBBCT (CE-CBBCT) and non-contrast-enhanced CBBCT (NC-CBBCT) in scanning for the differential diagnosis of benign and malignant breast lesions.

A retrospective analysis was performed on 189 cases of mammary glandular tissues that underwent NC-CBBCT and CE-CBBCT examination. The qualitative CT values of the lesions, standardized Δ(L-A), standardized Δ*(L - G), standardized Δ(L-A) (Post 1st-Pre), and standardized Δ*(L-G) (Post 2nd-Post 1st) between the benign and malignant groups were compared. Prediction performance was evaluated using receiver operating characteristic (ROC) curves.

In total, 58 cases were included in the benign group, 79 cases were included in the malignant group, and 52 cases were included in the normal group. The best diagnostic thresholds of CT values for L (Post 1st-Pre), Δ(L-A) (Post 1st-Pre), and Δ*(L-G) (Post 1st-Pre) were 49.5, 44, and 64.8 HU, respectively. The Δ(L-A) Post-1st rate values of CBBCT had medium diagnostic efficacy (AUC = 0.74, sensitivity = 76.6%, specificity = 69.4%).

CE-CBBCT can improve the diagnostic efficiency of breast lesions compared with NC-CBBCT. The CT values (HU) of lesions do not need to be standardized with fat and can be directly used in clinical differential diagnosis. The first contrast phase (60 s) is recommended to reduce the radiation exposure.

Iodine contrast agent (CA) is widely used in cardiac computed tomography (CT). The CA can increase the organ radiation doses due to the photoelectric effect.

To investigate the impact of CA on radiation dose in cardiac CT by comparing the radiation dose between contrast coronary CT angiography (CCTA) and non-contrast calcium scoring CT (CSCT).

Radiation doses were computationally calculated for 30 individual patients who received CSCT and CCTA in the same exam session. The geometry and acquisition parameters were modeled in the simulations based on individual patient CT images and acquisitions. Doses in the presence and absence of CA were obtained in the aorta, left ventricle (LV), right ventricle (RV), and myocardial tissue (MT). The dose values were normalized by size-specific dose estimate (SSDE). The dose enhancement factors (DEF_SSDE) were calculated as the ratio of doses in CCTA over doses in CSCT.

Compared to the CSCT scans, doses increase in the CCTA scans in the aorta (DEF_SSDE = 2.14 ± 0.20), LV (DEF_SSDE = 1.78 ± 0.26), and RV (DEF_SSDE = 1.31 ± 0.22). A linear relation is observed between the local CA concentrations and the dose increase in the heart; DEF_SSDE = 0.07*I(mg/mL) + 0.80 (R² = 0.8; p < 0.01). The DEF_SSDE in the MT (DEF_SSDE = 0.96 ± 0.08) showed no noticeable impact of CA on the dose in this tissue. In addition, patient variability in the dose distributions was observed.

A linear causal relation exists between local CA concentration and increase in radiation dose in cardiac CT. For the same CT exposure, dose to the heart is on average 55% higher in contrast cardiac CT.

The reference protocol for the quantification of coronary artery calcium (CAC) should be updated to meet the standards of modern imaging techniques.

To assess the influence of filtered-back projection (FBP), hybrid iterative reconstruction (IR), and three levels of deep learning reconstruction (DLR) on CAC quantification on both in vitro and in vivo studies.

In vitro study was performed with a multipurpose anthropomorphic chest phantom and small pieces of bones. The real volume of each piece was measured using the water displacement method. In the in vivo study, 100 patients (84 men; mean age = 71.2 ± 8.7 years) underwent CAC scoring with a tube voltage of 120 kVp and image thickness of 3 mm. The image reconstruction was done with FBP, hybrid IR, and three levels of DLR including mild (DLR_mild), standard (DLR_std), and strong (DLR_str).

In the in vitro study, the calcium volume was equivalent (P = 0.949) among FBP, hybrid IR, DLR_mild, DLR_std, and DLR_str. In the in vivo study, the image noise was significantly lower in images that used DLR_str-based reconstruction, when compared images other reconstructions (P < 0.001). There were no significant differences in the calcium volume (P = 0.987) and Agatston score (P = 0.991) among FBP, hybrid IR, DLR_mild, DLR_std, and DLR_str. The highest overall agreement of Agatston scores was found in the DLR groups (98%) and hybrid IR (95%) when compared to standard FBP reconstruction.

The DLR_str presented the lowest bias of agreement in the Agatston scores and is recommended for the accurate quantification of CAC.

Postpartum dyspnea is commonly observed, but its cause is often unknown.

To investigate postpartum dyspnea, we compared lung iodine mapping (LIM) using dual-energy computed tomography (DECT) between postpartum women and women suspected of having pulmonary thromboembolism (PTE).

In this retrospective study, 109 women of reproductive age (50 postpartum women, 59 women unrelated to pregnancy) underwent DECT between March 2009 and August 2020. Among the postpartum women, 23 patients were excluded due to late-onset dyspnea (n=20: >48 h after delivery) or the presence of PTE (n=3). A total of 86 patients were divided into three groups (27 postpartum women [postpartum group], 19 women with PTE [PTE group], and 40 women without PTE [non-PTE group]). Quantitation was applied to a decreased LIM value (LIM₅; defined as <5 HU) and the relative value of LIM₅ to whole LIM volume (%LIM₅). LIM defects were classified into five patterns (0 = none, 1 = wedge-shaped, 2 = reticular/liner, 3 = diffuse granular/patchy, 4 = massive defects) based on a consensus between two readers.

There were significant differences in the LIM₅ and %LIM₅ values among the three groups. The LIM₅ and %LIM₅ were largest in the PTE group, and postpartum women showed intermediate values between the non-PTE and PTE groups. Wedge-shaped defects were prominent in the PTE group, and diffuse granular/patchy defect was a typical feature in the postpartum group.

Postpartum women with dyspnea showed granular/patchy defects on DECT with a median quantitative value between the PTE and non-PTE groups.

Quantitative analyses of computed tomography (CT) images using computer-aided detection (CAD) are correlated with visual assessments and pulmonary function test findings and might be useful for predicting the prognosis of patients with idiopathic pulmonary fibrosis (IPF).

To evaluate the association between the quantitative analysis of long-term follow-up CT of IPF and the progression and prognosis.

A total of 48 patients with IPF who received over one year of follow-up CT were included in this study. The results of quantitative analyses (emphysema, ground-glass attenuation [GGA], consolidation, reticulation, and honeycombing) using a CAD software program of initial and follow-up CT findings were evaluated, and the association with the progression of the total lesion of IPF and prognosis using Spearman's rank correlation and Cox regression analyses was considered.

Results of quantitative analyses of consolidation, reticulation, honeycombing, and the total lesion on initial CT were correlated with progressive changes in the total lesion of IPF per year (r = 0.4375, 0.4128, 0.4649, and 0.4095, respectively). The results of quantitative analyses of honeycombing (hazard ratio [HR] = 1.40, 95% confidence interval [CI] = 1.03−1.89, P = 0.0314) and GGA (HR = 0.85, 95% CI = 0.72−0.99, P = 0.0384) at initial CT were prognostic factors according to a multivariate Cox regression analysis.

The quantitative analysis of honeycombing using a CAD software program of CT findings may be useful for predicting the progression and prognosis of patients with IPF.

In recent years, many studies have proven that percutaneous thermal ablation is an effective second-line treatment method with low complication rates in early-stage non-small cell lung carcinoma and lung metastases. Radiofrequency ablation and microwave ablation are commonly used for this purpose.

To evaluate the factors affecting the success of the percutaneous thermal ablation treatment with technical success, complication rates, and long-term follow-up results in metastatic lung lesions.

Computed tomography (CT)-guided percutaneous ablation was performed for 70 metastatic lung lesions in 35 patients (22 men, 13 women; mean age = 61.34 years; age range = 41–75 years). Radiofrequency ablation was performed in 53/70 (75.7%) lesions and microwave ablation in 17/70 (24.3%) lesions.

The technical success rate was 98.6%. Median overall survival, progression-free survival, and local recurrence-free survival of the patients were 33.9 months (range=25.6–42.1 months), 12 months (range=4.9–19.2 months), and 24.2 months (range=8.2–40.1 months), respectively. One- and two-year overall survival rates were 84% and 74%, respectively. Median progression-free survival times were 20.3 months and 11.4 months, respectively, according to the number of metastatic lung lesions being single and multiple, and the difference was statistically significant (P = 0.046). According to the number of lesions ≤3 and >3, the difference was also found statistically significant (P = 0.024) (14.3 months and 5.7 months, respectively).

In conclusion, CT-guided percutaneous thermal ablation is a safe and effective treatment method in metastatic lung lesions. The number of lesions is the most important factor in predicting treatment success.

The radiological and surgical anatomy of the frontal sinus should be well-known in all age groups to successfully manage frontal sinus diseases and reduce the risk of complications in sinus surgery.

To define frontal sinus and frontal cells according to the International Frontal Sinus Anatomy Classification (IFAC) criteria in pediatrics and adults.

A total of 320 frontal recess regions of 160 individuals (80 pediatric, 80 adults) who underwent a computed tomography (CT) scan of the paranasal sinus (PNS) were included in the study. Agger nasi cells, supra agger cells, supra agger frontal cells, suprabullar cells, suprabullar frontal cells, supraorbital ethmoid cells, and frontal septal cells were evaluated in the CT analysis.

The incidence rates of the investigated cells were determined to be 93.1%, 41.9%, 60.0%, 76.3%, 58.5%, 18.8%, and 0% in the pediatric group, respectively, and 86.3%, 35.0%, 44.4%, 54.4%, 46.9%, 19.4%, and 3.4% in the adult group, respectively. Considering the unilateral and bilateral incidence of the cells, agger nasi cells were highly observed bilaterally in both the pediatric group (89.87%) and the adult group (86.48%).

Our study results show that IFAC can be used as a guide to increase the chance of surgical treatment in the pediatric and adult groups and that the prevalence of frontal cells can be determined radiologically and contributes to the generation of estimations of the prevalence of frontal cells.

Scalp arteriovenous malformations (AVMs), or cirsoid aneurysms of the scalp, usually present with troublesome symptoms and cosmetic disfigurement. Endovascular/percutaneous embolization has evolved as a sole treatment method or adjunct to surgical excision in the management of scalp AVMs with an excellent outcome.

To discuss minimally invasive techniques for treating scalp AVMs as well as to highlight the role of embolization before surgery.

This is a retrospective study of 50 patients with scalp AVM who underwent embolization (percutaneous/endovascular) during 2010–2019 at a tertiary care center. n-butyl cyanoacrylate (n-BCA) was used as an embolizing agent in all the cases and the patients were followed up at three- and six-month intervals with Doppler evaluation.

A total of 50 patients were included in the study. The occipital region was the most common location; 82% were Schobinger class II lesions and 18% were class III lesions. Thirteen patients had small-sized AVMs and 37 patients had large-sized AVMs. Post-embolization surgery was performed in 36 patients. Of the patients, 28 underwent percutaneous embolization, 20 underwent endovascular embolization, and two underwent both to achieve complete embolization of the lesion. The number of percutaneous procedures increased in the latter half of the study period as the safety and efficacy of the technique were established. No major complications were seen in this study.

Embolization of scalp AVMs is a safe and effective technique and can be used in isolation for small lesions and as an adjunct procedure to surgery for large-sized lesions.

The calcaneal vascular remnant, first described by Fleming et al. in 2005, is a benign intramedullary lesion of the calcaneus with a vascular origin.

To determine the prevalence and magnetic resonance imaging (MRI) characteristics of incidental calcaneal vascular remnant on routine ankle MRI.

We retrospectively reviewed 457 ankle MRI scans for the presence of calcaneal vascular remnant. MRI was considered positive when a focal cyst-like area was seen on a T2-weighted sequence, and a low signal intensity was identified on a T1-weighted image beneath the calcaneal sulcus. Patients with calcaneal vascular remnants were further evaluated for age, gender, right or left foot location, size, and lesion characteristics.

The prevalence of incidental calcaneal vascular remnant was 21.7% on our consecutive ankle MR examinations. The average lesion size was 5.5 mm. No statistically significant difference was noted in the frequency of lesion detection between gender, age, and side of the lesions (P > 0.05). Multilobulated lesions were detected predominantly in women (P = 0.013) and classic type lesions were detected predominantly in men (P = 0.036).

This report is the first to determine the prevalence and MRI characteristics of calcaneal vascular remnants. Detecting and reporting this lesion on routine MRI is essential to avoid confusion with other pathologic entities.

The optimal treatment for some symptomatic, benign osteopathy lesions is yet to be identified.

To investigate the clinical efficiency of cementoplasty in managing symptomatic, benign osteopathy.

Between June 2006 and January 2020, we retrospectively enrolled 31 patients (10 men, 21 women; mean age = 46.5 ± 16.6 years; age range = 20–85 years), accounting for 34 treatment sites, who underwent percutaneous osteoplasty (14 treatment sites) and percutaneous vertebroplasty (20 treatment sites) with digital subtraction angiography (DSA) or DSA combined with computed tomography (CT). All the participants experienced different degrees of clinical symptoms with benign osteopathy lesions. The technical success of the procedure and occurrence of complications were recorded. Follow-up examinations were conducted to assess the treatment outcome using the MacNab criteria.

All the participants had a diagnosis of benign osteopathy lesions before or after the cementoplasty. Surgery was successfully completed in all patients. Cement distributions were diffuse and homogeneous, with the complication of cement leakage occurring in 17.6% (6 of 34) of the lesions. The leakage occurred in the intervertebral disc (n = 1), the intra-articular space (n = 1), and the surrounding soft tissue (n = 4). Analysis of the treatment outcome using the MacNab criteria revealed that all patients showed improvement in their clinical symptoms to some extent and in the quality of life.

Cementoplasty is an effective treatment for symptomatic, benign osteopathy, with the advantage of favorable clinical outcomes, and low complication rate.

The consistency of pituitary adenomas affects the course of surgical treatment.

To evaluate the diagnostic capabilities of radiomics based on T1-weighted (T1W) and T2-weighted (T2W) magnetic resonance imaging (MRI) in conjunction with two machine-learning (ML) techniques (support vector machine [SVM] and random forest classifier [RFC]) for assessing the consistency of pituitary adenomas.

The institutional database was retrospectively scanned for patients who underwent surgical excision of pituitary adenomas. Surgical notes were accepted as a reference for the adenoma consistency. Radiomics analysis was performed on preoperative coronal 3.0T T1W and T2W images. First- and second-order parameters were calculated. Inter-observer reproducibility was assessed with Spearman's Correlation (ρ) and intra-observer reproducibility was evaluated with the intraclass correlation coefficient (ICC). Least absolute shrinkage and selection operator (LASSO) was used for dimensionality reduction. SVM and RFC were used as ML methods.

A total of 52 patients who produced 206 regions of interest (ROIs) were included. Twenty adenomas that produced 88 ROIs had firm consistency. There was both inter-observer and intra-observer reproducibility. Ten parameters that were based on T2W images with high discriminative power and without correlation were chosen by LASSO. The diagnostic performance of SVM and RFC was as follows: sensitivity = 95.580% and 92.950%, specificity = 83.670% and 88.420%, area under the curve = 0.956 and 0.904, respectively.

Radiomics analysis based on T2W MRI combined with various ML techniques, such as SVM and RFC, can provide preoperative information regarding pituitary adenoma consistency with high diagnostic accuracy.

The extent of renal angiomyolipoma (AML) volume reduction after renal transcatheter arterial embolization (TAE) varies between patients, with no predictive measure available.

To determine whether the serum lactate dehydrogenase (LDH) concentration shortly after TAE correlates with the extent of tumor shrinkage.

In a cohort of 36 patients undergoing prophylactic renal TAE for unruptured renal AML, we retrospectively acquired data from patient medical records, including serum LDH before and within 7 days after TAE and the tumor volume before and 12–36 months after TAE. The relationship between the serum level of LDH and reduction in tumor volume was evaluated using Spearman correlation analysis.

The median LDH concentration was significantly higher after TAE than before (909.0 U/L vs. 186.5 U/L). This early post-TAE serum LDH level and LDH index (post-TAE LDH / pre-TAE LDH) correlated significantly and positively with the absolute decrease in tumor volume (both P < 0.0001). We observed no significant correlation between the relative tumor volume reduction and serum LDH level or LDH index.

Serum LDH elevation occurs shortly after TAE and correlates with the extent of absolute decrease in AML volume at 12–36 months after TAE. Further large-scale studies are warranted to confirm the predictive role of post-TAE serum LDH level and LDH index in tumor shrinkage in patients with unruptured renal AML.

Cervical cancer (CC) is the second most common cancer in women worldwide. Diffusion-weighted imaging (DWI) plays an important role in the diagnosis of CC, but the conventional techniques are affected by many factors.

To compare reduced-field-of-view (r-FOV) and full-field-of-view (f-FOV) DWI in the diagnosis of CC.

Preoperative magnetic resonance imaging (MRI) with r-FOV and f-FOV DWI images were collected. Two radiologists reviewed the images using a subjective 4-point scale for anatomical features, magnetic susceptibility artifacts, visual distortion, and overall diagnostic confidence for r-FOV and f-FOV DWI. The objective features included the region of interest (ROI) signal intensity of the cervical lesion (SI_lesion) and gluteus maximus muscle (SI_gluteus), standard deviation of the background noise (SD_background), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). The differences of measured apparent diffusion coefficient (ADC) values between the two examinations in pathological grades and FIGO tumor stages were compared.

A total of 200 patients were included (170 with squamous cell carcinoma and 30 with adenocarcinoma). The scores of anatomical features, magnetic susceptibility artifacts, visual distortion, and overall diagnostic confidence for r-FOV DWI were significantly higher than those for f-FOV DWI. There was no difference in SNR and CNR between r-FOV DWI and f-FOV DWI. There were significant differences in ADC values between the two groups in all comparisons (P < 0.05).

Compared with f-FOV DWI, r-FOV DWI might provide clearer imaging, fewer artifacts, less distortion, and higher image quality for the diagnosis of CC and might assist in the detection of CC.

The risk of gadolinium (Gd)-based contrast agent (GBCA)-induced nephrogenic systemic fibrosis (NSF) in patients with end-stage renal disease (ESRD) and the efficacy of prophylactic hemodialysis (HD) for protection against NSF are not well understood or summarized in the literature.

To determine the risk for NSF related to frequency and time per dialysis session after Gd-magnetic resonance imaging (MRI) by emphasizing the safety of Gd-MRI in patients with ESRD.

This retrospective observational study identified all GBCA injections for MRI examinations performed at two tertiary referral hospitals between 2005 and 2020. All clinical data, including dialysis records and medical history, were investigated for each patient through 2021. The end of follow-up coincided with the last hospital visit.

Overall, 1129 patients with ESRD underwent 1461 Gd-MRI scans (41.5% gadoterate, 39.4% gadobutrol, and 7.7% gadoxetate); a total of 958 patients with 1229 (84.1%) examinations underwent HD on the day of the MRI study, within 2.1 ± 2.0 h (range = 0.2–15.7 h) immediately after Gd exposure. In 53.4% of scans, frequent HD had been performed urgently and then twice more on consecutive days to prophylactically avoid NSF. No cases of NSF were identified during the follow-up period (mean = 81.7 ± 50.5 months) regardless of dose of HD.

No cases of NSF were reported in 1461 Gd-MRI examinations of 1129 inpatients with ESRD on HD. Our findings support the lack of benefit of frequent prophylactic HD being performed urgently within 4 h of the receipt of GBCA.