Contrast Injection Research Articles

Does Arthrography Improve Accuracy of SPECT/CT for Diagnosis of Aseptic Loosening in Patients with Painful Knee Arthroplasty: A Systematic Review and Metaanalysis.

SPECT/CT combines scintigraphy with a CT scan forming a 3-dimensional reconstruction of bone-tracer uptake patterns. It has become a fundamental component of the work-up of a painful total knee arthroplasty (TKA). The addition of an arthrogram is purported to improve its diagnostic yield. The aim of this study was to assess whether the addition of a concurrent arthrogram to a SPECT/CT enhances its sensitivity and specificity for diagnosing aseptic loosening in a painful total knee replacement. Methods: PubMed, Embase, and Scopus were searched in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included studies compared the results of SPECT/CT with or without an arthrogram against an appropriate reference standard for diagnosing TKA aseptic loosening. The quality of included studies was independently assessed using the QUADAS-2 tool. Results: In total, 160 abstracts were identified by our search strategy. Of these, 6 studies comprising 472 patients met our inclusion criteria. All included studies used operative findings or a period of clinical and radiologic observation as reference standards. The SPECT/CT arthrogram was more sensitive in identifying aseptic loosening of knee prostheses, and it also provided greater specificity for excluding its diagnosis. Conclusion: The amalgamated results of included studies of the use of SPECT/CT demonstrate it is the best test in helping determine aseptic loosening in patients with painful TKAs (specificity, 97% vs. 85%). It is also a more sensitive test (sensitivity, 78% vs. 75%). Considering the potential morbidity of injection of contrast into the prosthetic joint, addition of an arthrogram to SPECT/CT is not beneficial and is potentially harmful.

Interventional real-time molecular MRI for targeting early myocardial injury in a pig model

Myocardial ischemia induces tissue injury with subsequent inflammation and recruitment of immune cells. Besides myocardial tissue characterization, magnetic resonance imaging (MRI) allows for functional assessment using molecular imaging contrast agents. Here, we assessed ischemic cardiac lesions non-invasively directly after ischemia/reperfusion (I/R) in a porcine model by advanced MRI techniques and molecular imaging, targeting the cell adhesion molecule P-selectin functionalized with microparticles of iron oxide (MPIO). We used a closed-chest model of I/R by temporary coronary balloon-occlusion, real time 3T MRI-guided coronary injection of MPIO-based contrast agents, as well as injury, edema and iron-sensitive MRI. Within the first hours after I/R, we found T1 mapping to be most sensitive for tissue injury, with no changes in edema-sensitive MRI. Intriguingly, P-selectin MPIO contrast agent selectively enhanced the ischemic area in iron-sensitive MRI. In conclusion, this approach allows for sensitive detection of early myocardial inflammation beyond traditional edema-sensitive imaging.

Gantry-free cone-beam CT arthrography for diagnosis of scapholunate ligament injuries: accelerating the preoperative work-up in acute wrist trauma.

Combining fluoroscopy and high-resolution cone-beam CT (CBCT) in a multipurpose scanner without a conventional gantry holds the potential for time-saving in musculoskeletal interventions. This study investigated the performance of gantry-free CBCT arthrography in patients with suspected scapholunate ligament (SLL) tears. Fifty-five patients (29 men, 46.0 ± 15.3 years) who underwent preoperative gantry-free CBCT arthrography between June 2021 and March 2024 were analyzed retrospectively. Three radiologists assessed CBCT arthrograms for tears of the palmar and dorsal SLL segments. Surgical reports served as the reference standard for calculating indicators of diagnostic accuracy. Interreader agreement was tested by computing Krippendorff α. Radiation dose and examination time were recorded. Tears of the palmar and dorsal SLL segment were recorded in 25 (45%) and 6 patients (11%), respectively. CBCT arthrography facilitated good sensitivity (range for all readers: 84-92%) and excellent specificity (93-97%) in the assessment of the palmar SLL. For the dorsal SLL, sensitivity (83-100%) and specificity (96-98%) were even higher. Substantial agreement was determined for both the palmar (α = 0.83, 95% CI: 0.74-0.90) and dorsal SLL (0.84, 0.70-0.95). The mean volume CT dose index for CBCT arthrography was 3.2 ± 1.4 mGy. Not requiring patient repositioning, the median time between fluoroscopy-guided contrast injection and CBCT was 3:05 min (2:31-3:50 min). Gantry-free CBCT arthrography allows for excellent accuracy in the preoperative diagnosis of SLL tears with low radiation dose. The ability to alternate between fluoroscopy and CBCT without repositioning facilitates a "one-stop-shop" approach with short examination time. Question Performing fluoroscopy-guided arthrography and high-resolution cone-beam CT without patient repositioning appears advantageous for the preoperative work-up of distal radius fractures with concomitant scapholunate ligament injuries. Findings Gantry-free cone-beam CT arthrography allowed for short examination times and high diagnostic accuracy for either segment of the scapholunate ligament (89-98% versus surgery). Clinical relevance Preoperative assessment of scapholunate instability influences treatment since surgeons can reduce radius fractures and perform osteosynthesis via a dorsal portal to simultaneously stabilize the scapholunate compartment or use an additional dorsal access route for ligament suture and transfixation.

Incidence, Potential Mechanisms, and Clinical Significance of Cavernous Sinus Air Sign

Background/Objectives: The cavernous sinus air sign, historically linked to trauma or venous sinus thrombosis, has recently been reported in association with retrograde venous air embolism, often without clinical significance. Despite this, its exact prevalence, etiology, and clinical relevance remain unclear. This study aims to systematically evaluate the incidence of the cavernous sinus air sign in patients undergoing CT angiography (CTA) and to assess its potential clinical implications. Methods: We retrospectively analyzed data from patients who underwent CTA between January 2021 and December 2021. The cavernous sinus air sign was defined radiologically as air-density foci within the cavernous sinus, with Hounsfield units lower than those of orbital fat. Key variables included clinical indications for CTA, evidence of venous reflux of contrast media, the laterality of contrast injection, and the presence of brachiocephalic vein stenosis. Comparative analyses were performed to identify factors associated with the occurrence of the cavernous sinus air sign. Results: Among the 2,821 patients evaluated, the cavernous sinus air sign was identified in 35 cases (1.2%). Notably, none of these patients had a history of trauma or venous sinus thrombosis. Follow-up CT imaging was available for 27 of the 35 cases (77.1%), and in all instances, the cavernous sinus air sign resolved spontaneously. A statistically significant association was found between the cavernous sinus air sign and left-sided peripheral intravenous contrast injection, observed in 8.6% of affected patients compared to 1.5% in those without the sign (p = 0.001). Venous reflux into the internal jugular vein was also more frequent in patients with the air sign (34.3% vs. 14.1%, p = 0.001). These findings suggest a mechanical component, likely related to retrograde air embolism, influenced by anatomical and procedural factors. Conclusions: The isolated presence of the cavernous sinus air sign, in the absence of relevant clinical conditions, is most likely a benign, incidental finding associated with retrograde air embolism.

Performance of the CT-Guided C1-C2 Facet (Lateral Atlantoaxial Joint) Injection.

CT-guided C1-C2 facet joint injections are a valuable tool for managing cervicogenic headaches caused by degenerative and inflammatory conditions of the atlantoaxial joint. This video article presents the procedural technique for a CT-guided C1-C2 facet joint injection in a patient with left-sided cervicogenic headache. Despite concerns regarding potential complications such as vascular injury to the vertebral artery and nerve injury to the C2 dorsal root ganglion, careful anatomic planning and imaging guidance allows safe and effective treatment. The injection involves precise needle placement between the vertebral artery and the C2 dorsal root ganglion, followed by contrast injection to confirm positioning and administration of a steroid-anesthetic mixture. Preprocedural imaging and safety precautions such as reviewing the international normalized ratio and platelet levels are essential. While rare adverse events have been reported, this technique remains a valuable option for pain relief in patients unresponsive to conservative therapies.

An Accelerated Spectroscopic MRI Metabolite Quantification Based on a Deep Learning Method for Radiation Therapy Planning in Brain Tumor Patients

Background: Spectroscopic MRI (sMRI) is a quantitative imaging technique that maps infiltrated tumors in the brain without contrast injections. In a previous study (NCT03137888), sMRI-guided radiation treatment extended patient survival, showing promise for clinical translation. The spectral fitting of individual voxels in an sMRI dataset generate metabolite concentration maps that guide treatment. The established spectral analysis methods use iterative least-squares fitting (FITT) that are computationally demanding. This study compares the performance of NNFit, a neural network-based, accelerated spectral fitting model, to the established FITT for metabolite quantification and radiation treatment planning. Methods: NNFit is a self-supervised deep learning model trained on 50 ms echo-time (TE) sMRI data to estimate metabolite levels of choline (Cho), creatine (Cr), and NAA. We trained the model on 30 GBM patients (56 scans) and tested it on 17 GBM patients (29 scans). NNFit’s performance was compared to the FITT using structural similarity indices (SSIM) and the Dice coefficient. Results: NNFit significantly improved processing speed while maintaining strong agreement with FITT. The radiation target volumes defined by Cho/NAA ≥ 2x were visually comparable, with fewer artifacts in NNFit. Structural similarity indices (SSIM) indicated minimal bias and high consistency across methods. Conclusions: This study highlights NNFit’s potential for rapid, accurate, and artifact-reduced metabolic imaging, enabling faster radiotherapy planning.

"Synthetic" DSC Perfusion MRI with Adjustable Acquisition Parameters in Brain Tumors Using Dynamic Spin-and-Gradient-Echo Echoplanar Imaging.

Normalized relative cerebral blood volume (nrCBV) and percentage of signal recovery (PSR) computed from dynamic susceptibility contrast (DSC) perfusion imaging are useful biomarkers for differential diagnosis and treatment response assessment in brain tumors. However, their measurements are dependent on DSC acquisition factors, and CBV-optimized protocols technically differ from PSR-optimized protocols. This study aimed to generate "synthetic" DSC data with adjustable synthetic acquisition parameters using dual-echo gradient-echo (GE) DSC datasets extracted from dynamic spin-and-gradient-echo echoplanar imaging (dynamic SAGE-EPI). Synthetic DSC was aimed at: 1) simultaneously create nrCBV and PSR maps using optimal sequence parameters, 2) compare DSC datasets with heterogeneous external cohorts, and 3) assess the impact of acquisition factors on DSC metrics. Thirty-eight patients with contrast-enhancing brain tumors were prospectively imaged with dynamic SAGE-EPI during a non-preloaded single-dose contrast injection and included in this cross-sectional study. Multiple synthetic DSC curves with desired pulse sequence parameters were generated using the Bloch equations applied to the dual-echo GE data extracted from dynamic SAGE-EPI datasets, with or without optional preload simulation. Dynamic SAGE-EPI allowed for simultaneous generation of CBV-optimized and PSR-optimized DSC datasets with a single contrast injection, while PSR computation from guideline-compliant CBV-optimized protocols resulted in rank variations within the cohort (Spearman's ρ = 0.83-0.89, i.e. 31%-21% rank variation). Treatment-naïve glioblastoma exhibited lower parameter-matched PSR compared to the external cohorts of treatment-naïve primary CNS lymphomas (PCNSL) (p<0.0001), supporting a role of synthetic DSC for multicenter comparisons. Acquisition factors highly impacted PSR, and nrCBV without leakage correction also showed parameter-dependence, although less pronounced. However, this dependence was remarkably mitigated by post-hoc leakage correction. Dynamic SAGE-EPI allows for simultaneous generation of CBV-optimized and PSR-optimized DSC data with one acquisition and a single contrast injection, facilitating the use of a single perfusion protocol for all DSC applications. This approach may also be useful for comparisons of perfusion metrics across heterogeneous multicenter datasets, as it facilitates post-hoc harmonization.

A Systematic Review of Indocyanine Green Lymphography (ICGL) Imaging for the Diagnosis of Primary Lymphoedema.

This systematic review aims to evaluate the use of Indocyanine Green Lymphography (ICGL) for the investigation of the lymphatics in the lower limbs of primary lymphoedema patients. MEDLINE and EMBASE articles from 01/01/2000 to 01/09/2023 were searched for. A total of 11 studies were included in the review after a two-stage screening process. Data on patient demographics, ICG contrast injection technique, imaging protocols and imaging outcomes were summarised and reviewed in detail. The review highlights the lack of commonality in protocols used. Factors important for good imaging are highly variable, particularly the number of injections, their location and whether they are delivered intradermally or subcutaneously. ICGL has strong potential to become a diagnostic tool to diagnose lymphoedema, due to its non-ionising nature and cost-effectiveness. However due to the lack of thorough phenotyping and genotyping of patients included in the studies, uncertainty still exists as to the value of the described imaging features such as splash, starburst and diffuse dermal rerouting patterns. Future studies, therefore, should aim to explore the diagnostic utility of ICGL for lymphoedema further through the imaging of primary lymphoedema patients with a confirmed genetic diagnosis and using standardised imaging protocols. ICGL is a strong candidate for advancing the diagnosis and understanding of primary lymphoedema, and monitoring response to treatment, but protocol heterogeneity and a lack of consistency in reporting imaging details and patient phenotyping currently hold it back.

PEGylated Ultrasmall Iron Oxide Nanoparticles as MRI Contrast Agents for Vascular Imaging and Real-Time Monitoring.

Accurate imaging evaluations of pre- and post-treatment of cardiovascular diseases are pivotal for effective clinical interventions and improved patient outcomes. However, current imaging methods lack real-time monitoring capabilities with a high contrast and resolution during treatments. This study introduces PEGylated ultrasmall iron oxide nanoparticles (PUSIONPs), which have undergone comprehensive safety evaluations, boasting an r1 value of 6.31 mM-1 s-1, for contrast-enhanced magnetic resonance angiography (MRA). Systematic comparisons against common clinical methods in rabbits reveal that PUSIONPs-enhanced MRA exhibited improved vascular contrast, clearer vascular boundaries, and superior vessel resolution. Moreover, owing to their nanosize, PUSIONPs demonstrate significantly prolonged blood circulation compared to small molecular contrast agents such as Magnevist and Ultravist. This extended circulation enables captivating real-time monitoring of thrombolysis treatment for up to 4 h in rabbit models postsingle contrast agent injection. Additionally, in larger animal models such as beagles and Bama minipigs, PUSIONPs-enhanced MRA also showcases superior contrast effects, boundary delineation, and microvessel visualization, underscoring their potential to transform cardiovascular imaging, particularly in real-time monitoring and high-resolution visualization during treatment processes.

Ultrasound-guided needle positioning confirmation with injection of saline solution for nodal dynamic contrast-enhanced MR-lymphangiography in pediatric patients.

To assess the success rate of confirmation of ultrasound-guided intranodal needle positioning by saline injection for dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) in pediatric patients. Data from children undergoing nodal DCMRL after ultrasound-guided needle positioning into inguinal lymph nodes and validation of the needle position by injection of plain saline solution between 05/2020 and 12/2022 were reviewed. On injection of saline solution, adequate needle position was confirmed by lymph node distension without leakage. Detection rates and lymph node diameters were recorded. Technical success of needle placement was defined as enhancement of ipsilateral iliac draining lymph vessels on DCMRL, while clinical success was based on enhancement of central lymphatics and/or lymphatic pathologies being observed. One hundred sixteen DCMRLwere performed in 90 children (58 male, mean age 6.1 years, range 3 weeks-18 years). In 232/232 groins lymph nodes were identified on ultrasound with a mean diameter of 2.5 mm (smallest diameter 1 mm in n = 24 patients). Due to skin inflammation, no puncture was performed in 2/232 groins. Saline injection showed lymph node distension in 230/230 punctured nodes. On MR contrast injection enhancement of draining lymph vessels was seen in 228/230 nodes. In 1/230 nodes, in-bore needle retraction led to lymphatic enhancement, so a total of 229/230 needle placements were technically successful. One of the 230 DCMRLs was successful with only a unilateral contrast application. Overall, 116/116 DCMRLs were clinically successful. Confirmation of ultrasound-guided needle positioning for nodal DCMRL using saline injection is a reliable technique with a very high success rate in pediatric patients with small lymph nodes. Question Evaluation of ultrasound-guided injection needle positioning for dynamic contrast-enhanced MR-lymphangiography in children requires validation. Findings Confirmation of needle positioning by ultrasound-guided saline injection is a reliable technique with a very high success rate for MR-lymphangiography in pediatric patients. Clinical relevance Intranodal needle position for dynamic contrast-enhanced lymphangiography can be confirmed with a very high success rate using saline injection alone in a pediatric cohort.

Iatrogenic aorto-coronary dissection triggered by contrast injection during coronary evaluation with optical frequency domain imaging.

Iatrogenic aorto-coronary dissection triggered by contrast injection during coronary evaluation with optical frequency domain imaging.

Long-term effects of linear versus macrocyclic GBCAs on gene expression in the central nervous system of mice

BackgroundWe examined chronic gadolinium retention impact on gene expression in the mouse central nervous system (CNS) after injection of linear or macrocyclic gadolinium-based contrast agents (GBCAs).MethodsFrom 05/2022 to 07/2023, 36 female mice underwent weekly intraperitoneal injections of gadodiamide (2.5 mmol/kg, linear), gadobutrol (2.5 mmol/kg, macrocyclic), or saline. Mice were sacrificed on day 29 or 391 after a 1-year washout. Assessments included magnetic resonance imaging (MRI), mechanical hyperalgesia tests, and inductively coupled plasma mass spectrometry to measure gadolinium levels. Ribonucleic acid (RNA) sequencing and bioinformatic analyses identified differentially expressed genes (DEGs), with validation by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot (WB).ResultsPost-gadodiamide, MRI showed increased signal intensity in the deep cerebellar nuclei (pre, 0.997 ± 0.006 versus post, 1.086 ± 0.013, p < 0.001). Mechanical hyperalgesia tests indicated transient sensory changes. After 1-year, gadolinium retention was noted in the brain (5.92 ± 0.32 nmol/kg) and spinal cord (1.23 ± 0.66 nmol/kg) with gadodiamide, compared to saline controls (0.06 ± 0.02 nmol/kg in brains and 0.28 ± 0.06 nmol/kg in spinal cords). RNA sequencing identified 17 shared DEGs between brain and spinal cord in the gadodiamide group on day 391, with altered Hmgb2 and Sgk1 expression confirmed by qRT-PCR and WB. Reactome pathway analysis showed enrichment in neuroinflammation pathways. No DEGs were detected in brains on day 29.ConclusionChronic gadolinium deposition from repeated linear GBCA but not macrocyclic administration causes significant gene expression alterations in the mouse CNS, particularly affecting neuroinflammation pathways.Relevance statementThis study examined the long-term impact of chronic gadolinium retention on gene expression in the mouse CNS, uncovering significant changes associated with neuroinflammation pathways after repeated administration of linear GBCA, but not with macrocyclic GBCA. These findings highlight the importance of further research on the long-term safety of linear GBCA in medical imaging.Key PointsChronic gadolinium retention alters gene expression in the mouse central nervous system.Significant neuroinflammatory pathway changes were observed after linear gadodiamide exposure.MRI showed increased signal intensity in deep cerebellar nuclei after gadodiamide injection.Graphical

Comparison of 3D BFFE and 3D TRANCE on pulmonary artery imaging with two T-SLIP placement strategies.

3D BFFE and TRANCE can provide a visualization of pulmonary vessels without injection of contrast agent. T-SLIP can observe a large area of vessels using an arterial spin labeling technique. 3D BFFE and TRANCE with two T-SLIP placement strategies were compared on pulmonary artery imaging. Ten male and thirteen female healthy volunteers were recruited in the present study. Each subject underwent non-contrast-enhanced pulmonary MRA. Four protocols were involved in the present study as follows: 3D BFFE with T-SLIP covering vena cava (VC) and right atrium and ventricle (RV), respectively; 3D TRANCE with T-SLIP covering VC and RV, respectively. The SNR were measured at eight ROIs, while CNR were measured at five ROIs. The number of visualized branch and image quality were analyzed by two radiologists. The differences of metrics among different imaging strategies were compared. SNR and CNR were compared between two T-SLIP placement strategies using a paired t-test. The branches number and image quality were compared between two T-SLIP placement strategies using a rank-sum test. The agreement of subjective assessment was conducted using a Kappa test. There were significant differences at all ROIs between TRANCE and BFEE with T-SLIP on RV (all P values <0.01). TRANCE with T-SLIP on RV exhibited a higher CNR at all five ROIs compared with BFFE with T-SLIP on RV. TRANCE with T-SLIP on RV performed better on the number of observed branches and image quality compared with BFFE with T-SLIP on RV. 3D TRANCE with T-SLIP on RV can provide a higher SNR and image quality among four MR protocols, and thus may be a potential non-contrast enhanced technique in the visualization of pulmonary artery.

Pancreatic tuberculosis revealed by a mass with neoplastic appearance: a case report

Introduction. Pancreatic tuberculosis is an extremely rare form of extrapulmonary tuberculosis. This condition can be challenging to diagnose due to its rarity, nonspecific symptoms and radiological features that may mimic a neoplastic origin. Case report. A 46-year-old immunocompetent patient with no past history of tuberculosis exposure presented with spontaneously resolving jaundice over the past month, accompanied by nonspecific fever episodes and general fatigue with no other associated digestive symptoms. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) scans revealed a poorly defined, partially necrotic mass in the pancreatic head with heterogeneous hypodensity and enhancement after contrast injection. Additionally, there were nodal and hilar macro-nodal lesions with necrotic appearances, as well as peripancreatic lymphadenopathy. The patient was scheduled for an endoscopic ultrasound (EUS) examination, which revealed the presence of a heterogeneous lesion with areas of necrosis in the posterosuperior aspect of the head and isthmus of the pancreas, accompanied by perilesional and coeliac lymphadenopathies with necrotic centres. EUS-guided tissue sampling allowed the diagnosis of pancreatic tuberculosis, with both histological examination and GeneXpert MTB/RIF testing rapidly positive for Mycobacterium tuberculosis, followed by culture on solid Loewenstein–Jensen medium. The patient responded well to antitubercular chemotherapy. Conclusion. Pancreatic tuberculosis, though rare, should be considered in cases of pancreatic masses, especially in endemic regions. Tissue samples with necrosis should be tested for M. tuberculosis using GeneXpert and Loewenstein–Jensen culture. This work highlights the GeneXpert MTB/RIF test as highly sensitive, specific and fast, making it ideal for diagnosing extrapulmonary tuberculosis, particularly when smear results are negative.

Application value of split-bolus contrast injection combined with dual-energy CT scanning technology in pediatric CTU imaging.

To explore the clinical value of combining split-bolus contrast injection with dual-energy CT(DECT) scanning technology in pediatric computed tomography urography (CTU) imaging. A total of 128 children aged 0-17years were prospectively selected and randomly assigned to three groups: A, B, and C. For Group A, a high-pitch flash mode was employed, where a single bolus of contrast agent was followed by four-phase scanning (noncontrast, cortex, medulla, and excretory phases). In Group B, a dual-energy scanning mode was used with a split-bolus injection technique (50% of the contrast agent was administered initially, followed by the remaining 50% after 37-43s), and the children underwent two-phase scanning (corticomedullary and excretory phases). In Group C, dual-energy scanning was similarly used with a split-bolus injection technique (65% contrast agent was administered initially, followed by the remaining 35% after 37-43s), along with two-phase scanning (corticomedullary and excretory phases). Virtual noncontrast (VNC) images were obtained from the corticomedullary phase images using iodine subtraction techniques for Groups B and C. The image quality and radiation dose across the groups were compared and analysed. When the CT values of the renal cortex, erector spinae muscles, and standard deviation (SD) values were compared between Group A's cortical phase and Groups B and C's corticomedullary phases, the order was Group B > Group C > Group A (P < 0.05). The comparison of the cortical CNR and SNR between Group A's cortical phase and Groups B's and C's corticomedullary phases (cortices) revealed that Group C > Group B > Group A (P < 0.05). The comparison of the medullary CNR and SNR between Group A's medullary phase and Groups B and C's corticomedullary phases (medulla) showed that Group A > Group C > Group B (P < 0.05). The scores for the VNC images in Groups B and C were lower than those for the true noncontrast (TNC) images in Group A (P > 0.05). In the subjective evaluations of the corticomedullary and excretory phase images, Group B > Group C > Group A (P < 0.05). The comparison of radiation doses revealed that Group B < Group C<Group A (P < 0.05). A significant correlation was found between BMI and the effective radiation dose (P < 0.01), with a correlation coefficient of 0.62. The combination of split-bolus contrast injection and DECT enhances image quality in pediatric CTU while reducing radiation dosage.

Comparing Peristaltic and Direct-Drive Contrast Injection Systems for Thoracic Computed Tomography (CT): Effects on Dose, Image Quality, and Pathology.

Introduction To compare thoracic vasculature opacification between the direct-drive and the peristaltic drive contrast injection systems and the effect on quantitative and qualitative image quality during computed tomography. Method A retrospective chart review of 88 patients who underwent chest computed tomography (CT) following a direct-drive injector before 2016 (Group A) or a peristaltic injector after 2016 (Group B). Both protocols employed 80mL of iodinated contrast media volume. Quantitative measurements of the thoracic vascular opacification, contrast-to-noise ratio (CNR), effective radiation dose, and arterial venous contrast ratio (AVCR) for each vessel were computed and compared. The measured values of vascular opacification, CNR, and dose length product (DLP) were assessed utilizing paired t-test and Pearson's correlation. Receiver operating characteristic(ROC), visual grading characteristics (VGC), and Cohen's kappa methodology were measured. Results There was no significant difference in the mean opacification of the chest vasculature (p > 0.05). The CNR in Group B was significantly lower than in Group A (p < 0.05) except for the brachiocephalic artery, proximal descending aorta, and the right pulmonary artery. Arterial venous contrast ratio at all anatomic levels demonstrated no statistical significance between groups. There were no differences in ROC, VGC, or kappa values between groups. Conclusion When comparing two contrast media injection systems in chest CT, there was no qualitative difference in image quality or pathology detection. However, quantitatively, direct-drive injectors provided higher CNR. Direct-drive contrast injectors also provided a superior quantitative image quality of chest vasculature compared to peristaltic injectors.

Determining the Diagnostic Value of DWIBS in the Diagnosis of Breast Lesions Compared to Dynamic Contrast-Enhanced MRI: A Retrospective Observational Study

Background: Diffusion-weighted imaging with background body signal suppression (DWIBS) is a new imaging tool for the diagnosis of breast lesions. This study aims to compare DWIBS with contrast-enhanced magnetic resonance imaging (CE-MRI) sequences. Materials and Methods: Eighty consecutive patients underwent both CE-MRI and DWIBS images. DWIBS was assessed qualitatively and quantitatively using the apparent diffusion coefficient mapping. A threshold of 1.44 × 10-3 mm2/s was considered as a cutoff value between malignant and benign lesions. CE-MRI images were evaluated based on a combination of kinetic and morphological information and reported using Breast Imaging Reporting and Data System lexicon. Statistical analysis was performed for both sequences based on pathologic findings as a gold standard. Results: Fifty-five out of 80 lesions (69%) were benign, and 25 malignant lesions (31%) have been reported. The sensitivity, specificity, positive predictive value, and negative predictive value for CE-MRI were 100, 38, 42, and 100%, respectively, and those for DWIBS were 77, 70, 53, and 87%, respectively. By comparing DWIBS and CE-MRI data, no statistically significant difference was reported. Conclusion: DWIBS can be used as an effective alternative for breast CE-MRI in cases of contradictions of IV contrast injection.

Triphasic Computed Tomography for Characterization of Liver Lesions Identified on Ultrasonography

Background: Liver disease is the leading cause of death in Pakistan and Asia. Liver carcinoma is the most prevalent cancer in the world. Identification of cancer at an early stage can help in better management of the disease and improved prognosis. Computed tomography can perform scans at different phases after contrast is administered. It is the most effective tool for the diagnosis of tumors and different types of lesions. Our objective of the study was to characterize the liver lesions identified on ultrasonography and differentiate between benign and malignant lesions at Bilal Hospital Rawalpindi. Methods: This cross-sectional quantitative study was conducted at Bilal Hospital, Rawalpindi, Pakistan, to evaluate liver lesions using triphasic CT. Data from 50 reports were analyzed, focusing on hepatic lesions, hepatomegaly, cirrhosis, and portal hypertension identified through ultrasonography. Patients over 30 were included, while those under 30, pregnant, contrast-allergic, or with abnormal renal function tests were excluded. Triphasic CT scans were performed with a 64-slice scanner, capturing arterial, portal venous, and delayed phases after contrast injection. Radiologists reported the scans, and data were analyzed using SPSS-25, ensuring patient consent, confidentiality, and privacy. Results: In this study, 28% of patients had benign liver lesions, with focal nodular hyperplasia (14%) being the most common, followed by hepatic cysts (4%) and hemangiomas (10%). Malignant lesions were observed in 62% of patients, with hepatocellular carcinoma (36%) being the most prevalent, followed by secondary metastases (10%), cholangiocarcinoma (8%), and focal hepatic lesions (8%). The most frequently observed condition was hepatocellular carcinoma. Conclusions: The study concludes that there is a significant prevalence of both benign and malignant liver lesions in patients over 30 years, with hepatocellular carcinoma being the most common malignancy and focal nodular hyperplasia, the most frequent benign lesion. The findings emphasize the crucial role of triphasic CT in accurately diagnosing and differentiating liver lesions, aiding in effective treatment planning.

Reliability of post-contrast deep learning-based highly accelerated cardiac cine MRI for the assessment of ventricular function.

The total examination time can be reduced if high-quality two-dimensional (2D) cine images can be collected post-contrast to minimize non-scanning time prior to late gadolinium-enhanced imaging. This study aimed to assess the equivalency of the pre-and post-contrast performance of 2D deep learning-based highly accelerated cardiac cine (DL cine) imaging by evaluating the image quality and the quantification of biventricular volumes and function in the clinical setting. Thirty patients (20 men, mean age 53.7 ± 17.8 years) underwent cardiac magnetic resonance on a 1.5 T scanner for clinical indications, and pre- and post-contrast DL cine images were acquired with a short-axis view. Image-quality was scored according to three main criteria: the blood-to-myocardial contrast, endocardial edge delineation, and presence of motion artifacts throughout the cardiac cycle. Biventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and left ventricular mass (LVM) were analyzed and compared between the pre- and post-contrast DL cine images. The actual median time of 2D DL cine acquisition was 38.4 ± 9.1 s. There were no significant differences in the image quality scores between pre- and post-contrast DL cine images (p > 0.05). In the volume and functional analysis, there was no significant difference in terms of biventricular EDV, ESV, SV, EF, and LVM (p > 0.05). The performance of 2D DL cine is equivalent before and after contrast injection for the assessment of image quality and ventricular function in the clinical setting.

Diagnostic capabilities of cardiac computed tomography in the preoperative diagnosis of hypertrophic cardiomyopathy

BACKGROUND: A comprehensive approach to studying hypertrophic cardiomyopathy with diagnostic equipment and the latest scanning methods will ensure quality control and effective treatment of patients with this condition. The implementation of innovative technologies and computer calculation using next-generation scanners may become relevant and promising in studying various phenotypes of left ventricular remodeling in combination with abnormalities of the chordopapillary apparatus of the mitral valve and myocardial structure. AIM: To examine the diagnostic capabilities of computed tomography in the preoperative examination of various hypertrophic cardiomyopathy phenotypes. MATERIALS AND METHODS: The retrospective data analysis included 47 patients with hypertrophic cardiomyopathy (mean age, 52±7 full years) before surgical correction. computed tomography was performed using our protocol with automatic bolus tracking in the left atrium with a 90 HU threshold and biphasic contrast injection to assess the heart chambers and coronary arteries anatomy and mitral valve morphology. Moreover, to assess myocardial structure remodeling, iodine dual-energy computed tomography maps obtained with delayed contrast enhancement were analyzed. All patients with hypertrophic cardiomyopathy were classified by morphological types. The anatomy of chordopapillary apparatus was evaluated in each case. RESULTS: This study demonstrated variability in hypertrophic cardiomyopathy phenotypes, which were conventionally divided into five morphological categories, but not restricted by them. Among the patients, 26 (55%) had diffuse septum hypertrophic cardiomyopathy, 5 (11%) had midventricular hypertrophic cardiomyopathy, 2 (4%) had midventricular obstruction and apical aneurysm, 8 (18%) had focal basal septum hypertrophic cardiomyopathy, 4 (8%) had concentric hypertrophic cardiomyopathy, and the remaining 4 (8%) had apical hypertrophic cardiomyopathy. Most patients were diagnosed with chordopapillary abnormalities of the mitral valve, categorized by papillary muscle number and position, and the ratio of chords to muscles. In 10 (21%) patients, data on the myocardial bridge of a coronary artery were obtained, whereas 3 (14%) of them had dynamic stenosis. All patients had focal iodine uptake on dual-energy computed tomography maps. An extracellular volume increase was observed in 10 out of 13 (76%) patients. As shown by dual-energy computed tomography, the mean extracellular volume of the left ventricular myocardium was 30.58% (95% confidence interval, 27–34%). CONCLUSION: Our scanning protocols developed with computed tomography scanners of various generations enable to evaluate the specific morphological patterns of hypertrophic cardiomyopathy in a single study and provide a detailed interpretation of the geometry of cardiac valves and chambers, left ventricular function, state of the coronary bed, and structural changes of the left ventricular myocardium.