Craniosynostosis: Imaging and Surgical Implications.

The purpose of this article is to review the diagnostic imaging findings, differential diagnosis, complications, and postoperative imaging appearance of urethral diverticulum. With increased clinical awareness and advanced imaging techniques, diagnoses of urethral diverticula are more frequent, and radiologists need to be aware of the pre- and postoperative imaging appearances of this disorder.

The purpose of this manuscript is to review the surgical techniques of aortic arch repair, imaging techniques for evaluating the pre- and post-operative aortic arch, and both normal and abnormal post-operative imaging appearances. Aortic arch repair is a technically challenging and rapidly evolving procedure, utilizing a variety of surgical methods that result in variable imaging appearances. Imaging plays an important role in the diagnosis of aortic arch abnormalities, as well as diagnosis of abnormalities in the adjacent ascending and descending aorta. Imaging also plays a key role in post-operative evaluation and surveillance. Familiarity with aortic arch surgical procedures and their expected post-operative imaging appearances is crucial for the radiologist to identify the surgery performed, recognize surgical complications, and avoid imaging pitfalls that may be mistaken for complications.

Surgical resection represents the mainstay treatment and only potentially curative option for gastric carcinoma, and is increasingly performed laparoscopically. Furthermore, other tumours and selected cases of non-malignant disorders of the stomach may require partial or total gastrectomy. Often performed in elderly patients, gastric resection remains a challenging procedure, with significant morbidity (14–43% complication rate) and non-negligible postoperative mortality (approximately 3%). This paper provides an overview of contemporary surgical techniques for non-bariatric gastric resection, reviews and illustrates the expected postoperative imaging appearances, common and unusual complications after partial and total gastrectomy. Albeit cumbersome or unfeasible in severely ill or uncooperative patients, contrast fluoroscopy remains useful to rapidly check for anastomotic patency and integrity. Currently, emphasis is placed on multidetector CT, which comprehensively visualizes the surgically altered anatomy and consistently detects complications such as anastomotic leaks and fistulas, duodenal stump leakage, afferent loop syndrome, haemorrhages, pancreatic fistulas and porto-mesenteric venous thrombosis. Our aim is to help radiologists become familiar with early postoperative imaging, in order to understand the surgically altered anatomy and to differentiate between expected imaging appearances and abnormal changes heralding iatrogenic complications, thus providing a consistent basis for correct choice between conservative, interventional or surgical treatment.Teaching points• Radical gastrectomy is associated with frequent postoperative morbidity and non-negligible mortality.• In cooperative patients fluoroscopy allows checking for anastomotic patency and leaks.• Multidetector CT with / without oral contrast comprehensively visualizes the operated abdomen.• Awareness of surgically altered anatomy and expected postoperative appearances is warranted.• Main complications include anastomotic and duodenal leaks, haemorrhages and pancreatic fistulas.

Tendon and ligament disorders are common indications for ankle surgery. Numerous surgeries and related modifications, ranging from simple repairs and debridement to complex reconstructions with tendon transfers or graft, are available. Knowledge of postoperative imaging appearances of common ankle surgeries is critical to identify complications and aid assessment of clinical treatment failure. This comprehensive review article discusses the surgical indications, techniques, imaging appearances, and complications-specifically those related to minimally invasive or arthroscopic surgery-for various ankle and foot conditions. It includes anatomical (Brostrom type) and nonanatomical lateral ligament repairs for ankle instability. Medial compartment procedures are described, such as peroneal tendon and retinacular repairs, as well as treatments for progressive collapsing flatfoot deformity, formerly known as posterior tibial tendon dysfunction or acquired flatfoot deformity. We also examine posterior compartment procedures, focusing on Achilles tendon repairs. Primary imaging modalities covered are magnetic resonance imaging, ultrasound, computed tomography, and radiographs, including expected postoperative appearances and the usefulness of each modality.

PurposeThe diagnosis of chronic increased intracranial pressure (IIP)is often based on subjective evaluation or clinical metrics with low predictive value. We aimed to quantify cranial bone changes associated with pediatric IIP using CT images and to identify patients at risk.MethodsWe retrospectively quantified local cranial bone thickness and mineral density from the CT images of children with chronic IIP and compared their statistical differences to normative children without IIP adjusting for age, sex and image resolution. Subsequently, we developed a classifier to identify IIP based on these measurements. Finally, we demonstrated our methods to explore signs of IIP in patients with non-syndromic sagittal craniosynostosis (NSSC).ResultsWe quantified a significant decrease of bone density in 48 patients with IIP compared to 1,018 normative subjects (P < .001), but no differences in bone thickness (P = .56 and P = .89 for age groups 0–2 and 2–10 years, respectively). Our classifier demonstrated 83.33% (95% CI: 69.24%, 92.03%) sensitivity and 87.13% (95% CI: 84.88%, 89.10%) specificity in identifying patients with IIP. Compared to normative subjects, 242 patients with NSSC presented significantly lower cranial bone density (P < .001), but no differences were found compared to patients with IIP (P = .57). Of patients with NSSC, 36.78% (95% CI: 30.76%, 43.22%) presented signs of IIP.ConclusionCranial bone changes associated with pediatric IIP can be quantified from CT images to support earlier diagnoses of IIP, and to study the presence of IIP secondary to cranial pathology such as non-syndromic sagittal craniosynostosis.

Peripheral nerve injury is a complex condition that significantly impacts quality of life and often affects young and active individuals. Accurate classification of injury severity using the Sunderland grading system is essential for distinguishing cases amenable to conservative management from those that require surgical intervention. While lower-grade injuries are typically managed conservatively at first, persistent or severe symptoms frequently necessitate surgery. Surgical approaches vary depending on the underlying cause of the nerve injury, including compressive neuropathies, trauma, and neoplastic lesions, and may involve nerve decompression, transposition, neurolysis, nerve repair techniques, and tumor resection. Imaging evaluation with high-frequency US and MRI is fundamental for postoperative peripheral nerve assessment, allowing direct nerve visualization, evaluation of the surgical site and persistent signs of nerve injury, identification of secondary changes such as muscle denervation, and differentiation between the expected postoperative findings and complications. These complications include perineural fibrosis, neuroma formation, incomplete decompression, nerve graft failure, and surgical site collections. It is crucial for radiologists to understand the spectrum of normal postoperative changes and recognize abnormal findings to avoid misinterpretation, optimize patient care, and guide clinical decision making after peripheral nerve surgery. The authors aim to provide a comprehensive review of the main peripheral nerve surgical procedures, with a focus on the surgical techniques, expected postoperative imaging appearances, and spectrum of potential complications.

Postoperative Imaging of the Knee: Meniscus, Cartilage, and Ligaments

Assessment for elevated intracranial pressure (ICP) helps guide interventional decision-making to treat craniosynostosis. However, noninvasive techniques for measuring ICP are limited. This study assessed whether optic nerve sheath diameter (ONSD) on low-dose computed tomographic (CT) scans is associated with ICP in patients with craniosynostosis. Pediatric patients treated between 2014 and 2023 with craniosynostosis, intraoperative ICP measurements by direct subdural catheterization, and spectral domain-optical coherent tomographic (SD-OCT) data were included. ONSD was retrospectively assessed on preoperative CT scans by a masked neuroradiologist and compared with measures and proxies of ICP. Among the 132 patients included (median age, 6.9 years; interquartile range, 4.7 to 9.5 years), 41 (31.1%) had a syndromic diagnosis. Maximal ONSD was increased in patients with an ICP of 15 mmHg or greater (6.1 mm versus 5.5 mm; P < 0.01) and 20 mmHg or greater (6.3 mm versus 5.6 mm; P < 0.01). Maximal ( r = 0.32; P < 0.001), minimum ( r = 0.26; P = 0.003), and average ( r = 0.29; P < 0.001) ONSD correlated with direct ICP measurements. ONSD and SD-OCT measurements were also correlated (maximum retinal nerve fiber layer, r = 0 .21, P = 0.04; maximum retinal thickness, r = 0.24, P = 0.02). An ONSD max threshold of 5.75 mm demonstrated 65% sensitivity and 64% specificity for detecting ICP of 15 mmHg or greater on optimized receiver operating characteristic curve analysis. Multivariable logistic regression generated an algorithm incorporating ONSD max and age to detect an ICP of 20 mmHg or greater with 64% sensitivity and 80% specificity. ONSD measured on low-dose CT scans detected elevated ICP with moderate accuracy. Precision increased when patient age was taken into consideration. Given the ease of accessing CT scan data, this may be a helpful ICP proxy for clinical decision-making. Diagnostic, II.

The recommended treatment for craniosynostosis, is cranial vault expansion to prevent increased intracranial pressure and optimize developmental outcomes. Some patients complain about postoperative headaches and occasionally require revision to treat increased intracranial pressure. This study examines whether specific factors are associated with an increased risk of postoperative headaches or intracranial hypertension. This retrospective cohort included patients with craniosynostosis from 1995 and 2010. Primary outcomes included headaches and delayed intracranial hypertension. Logistic regression was used to evaluate the associations with clinical characteristics. The cohort included 383 patients, of whom 127 (33 percent) complained of headaches. The positive predictive value of a headache indicating intracranial hypertension was only 9.4 percent among all patients and 6.7 percent among patients with nonsyndromic craniosynostosis. Headaches occurring in the morning, more than once per week, and associated with nausea, vomiting, or decreased activity level were most likely to be associated with delayed intracranial hypertension. Only 21 patients (6 percent) required revision surgery, and these patients were more likely to have syndromic craniosynostosis (OR, 5.6; 95 percent CI, 2.1 to 14.9), Chiari malformation (OR, 5.8; 95 percent CI, 1.7 to 19.5), or secondary craniosynostosis (additional sutures fused on the 2-year postoperative CT scan) (OR, 5.4; 95 percent CI, 2.2 to 13.5). Headaches are common after cranial vault remodeling but are not very predictive of who will need revision surgery for intracranial hypertension. Patients with specific headache characteristics, syndromic craniosynostosis, secondary synostosis, and Chiari malformations have the highest risk of developing delayed intracranial hypertension. Risk, III.

Imaging evaluation of post pancreatic surgery

The menisci play an important biomechanical role in axial load distribution of the knees by means of hoop strength, which is contingent on intact circumferentially oriented collagen fibers and meniscal root attachments. Disruption of the meniscal root attachments leads to altered biomechanics, resulting in progressive cartilage loss, osteoarthritis, and subchondral edema, with the potential for development of a subchondral insufficiency fracture. Identification of meniscal root tears at magnetic resonance (MR) imaging is crucial because new arthroscopic surgical techniques (transtibial pullout repair) have been developed to repair meniscal root tears and preserve the tibiofemoral cartilage of the knee. An MR imaging classification of posterior medial meniscal root ligament lesions has been recently described that is dedicated to the posterior root of the medial meniscus. An arthroscopic classification of meniscal root tears has been described that can be applied to the anterior and posterior roots of both the medial meniscus and the lateral meniscus. This arthroscopic classification includes type 1, partial stable root tears; type 2, complete radial root tears; type 3, vertical longitudinal bucket-handle tears; type 4, complex oblique tears; and type 5, bone avulsion fractures of the root attachments. Knowledge of these classifications and the potential contraindications to meniscal root repair can aid the radiologist in the preoperative reporting of meniscal root tear types and the evaluation of the tibiofemoral cartilage. As more patients undergo arthroscopic repair of meniscal root tears, familiarity with the surgical technique and the postoperative radiographic and MR imaging appearance is important to adequately report the imaging findings. ©RSNA, 2016.

Intracranial hypertension may be idiopathic or due to multiple etiologies. Some bone dysplasias and chronic shunt overdrainage syndrome may sometimes lead to intracranial hypertension associated with craniocerebral disproportion due to thickening of cranial diploe. The internal cranial expansion procedure has been used for patients with intracranial hypertension, whether or not associated with craniocerebral disproportion. Its purpose is to increase the intracranial volume by drilling down the inner table. This technique enables the craniocerebral disproportion to be improved and intracranial hypertension reduced. In other etiologies of intracranial hypertension with non-thickened diploe, internal cranial expansion may not be enough to resolve the hypertension. For these cases we propose a modification of the technique by expanding the cranial vault outwards; external cranial expansion. We describe this technique as used in a pediatric patient who presented with chronic headache, tonsillar ectopia, and sleep apnea syndrome. This patient also had a multisuture craniosynostosis, a non-thickened diploe, and intracranial hypertension.

Hydrocephalus is variously associated with syndromic craniosynostosis (CS), while it is randomly encountered in nonsyndromic CS. But actually, the ventriculomegaly in CS is less described. In this study, the authors aim to establish whether ventriculomegaly is common in patients with CS, in both syndromic and nonsyndromic. Retrospective measurements of Evans index (EI) were taken from thin-section computed tomography scans of 169 preoperative CS patients to assess cerebral ventricular volume. EI >0.3 indicates ventricular enlargement. A total of 169 CS patients who underwent computed tomography scan from February 2018 to December 2021 were retrospectively evaluated, including 114 males and 55 females. The average age at diagnosis was 16 months (range: 1-103mo). Among them, 37 with syndromic CS, including 17 ventricular megaly patients, had an EI >0.3 (46.0%), and 4 of them had intracranial hypertension and needed ventriculoperitoneal shunt treatment before cranial vault remolding. One hundred and thirty-two had nonsyndromic CS (100 single-suture CS, 32 multisuture CS), and 26 of them had an EI of 0.3 or greater (19.7%). Ventrocular megaly is common among patients with CS. Early craniotomy may stabilize ventricular dilation.

Various causal mechanisms of familial nonsyndromic craniosynostosis have been presented. One hypothesis suggests that overproduction of bone at the suture is the primary origin of craniosynostosis, which affects brain and cranial growth secondarily through altered intracranial pressure (Primary Suture Fusion Model). Other hypotheses suggest that decreased cranial base growth or abnormal brain growth are the primary cause of craniosynostosis (Cranial Base, Brain Parenchyma Models, respectively). This study was designed to investigate which model best describes neurocranial changes associated with craniosynostosis in a rabbit model through multivariate path analysis. Serial magnetic resonance imaging scans and intracranial pressure measurements were obtained at 10, 25, and 42 days of age from 18 rabbits: six controls, six with delayed-onset synostosis, and six with early-onset synostosis. Five variables were collected from each rabbit: calvarial thickness at the affected suture, cranial base length, brain volume, cerebrospinal fluid volume, and intracranial pressure. This data set was used to test causal pathway relationships generated by the proposed models. Goodness of fit was measured by experimental group for each model. Primary Suture Fusion Model best explained the variables in both delayed-onset and early-onset synostotic rabbits (Goodness of fit = 93%, 97%, respectively). Cranial Base Model (Goodness of fit = 94%) best explained the data in control rabbits. Results suggest that the primary site of craniosynostosis in craniosynostotic rabbits is most likely the synostosed suture. Other cranial vault anomalies are most likely secondary compensatory changes. Results of the present study may provide insight regarding the causal pathway of craniosynostosis.

Sulfonylurea-receptor-1(SUR1) and its associated transient-receptor-potential cation channel subfamily-M (TRPM4) channel are key contributors to cerebral edema and intracranial hypertension in traumatic brain injury (TBI) and other neurological disorders. Channel inhibition by glyburide is clinically promising. ABCC8 (encoding SUR1) single-nucleotide polymorphisms (SNPs) are reported as predictors of raised intracranial pressure (ICP). This project evaluated whether TRPM4 SNPs predicted ICP and TBI outcome. DNA was extracted from 435 consecutively enrolled severe TBI patients. Without a priori selection, all 11 TRPM4 SNPs available on the multiplex platform (Illumina:Human-Core-Exome v1.0) were genotyped spanning the 25 exon gene. A total of 385 patients were analyzed after quality control. Outcomes included ICP and 6 month Glasgow Outcome Scale (GOS) score. Proxy SNPs, spatial modeling, and functional predictions were determined using established software programs. rs8104571 (intron-20) and rs150391806 (exon-24) were predictors of ICP. rs8104571 heterozygotes predicted higher average ICP (β = 10.3 mm Hg, p = 0.00000029), peak ICP (β = 19.6 mm Hg, p = 0.0007), and proportion ICP >25 mm Hg (β = 0.16 p = 0.004). rs150391806 heterozygotes had higher mean (β = 7.2 mm Hg, p = 0.042) and peak (β = 28.9 mm Hg, p = 0.0015) ICPs. rs8104571, rs150391806, and 34 associated proxy SNPs in linkage-disequilibrium clustered downstream. This region encodes TRPM4's channel pore and a region postulated to juxtapose SUR1 sequences encoded by an ABCC8 DNA segment containing previously identified relevant SNPs. There was an interaction effect on ICP between rs8104571 and a cluster of predictive ABCC8 SNPs (rs2237982, rs2283261, rs11024286). Although not significant in univariable or a basic multivariable model, in an expanded model additionally accounting for injury pattern, computed tomographic (CT) appearance, and intracranial hypertension, heterozygous rs8104571 was associated with favorable 6 month GOS (odds ratio [OR] = 16.7, p = 0.007951). This trend persisted in a survivor-only subcohort (OR = 20.67, p = 0.0168). In this cohort, two TRPM4 SNPs predicted increased ICP with large effect sizes. Both clustered downstream, spanning a region encoding the channel pore and interacting with SUR1. If validated, this may guide risk stratification and eventually inform treatment-responder classification for SUR1-TRPM4 inhibition in TBI. Larger studies are warranted.