Post-operative complications of cholecystectomy: what the radiologist needs to know.

Cholecystectomy is one of the most performed surgical procedures. The safety of this surgery notwithstanding, the sheer volume of operations results in a notable incidence of post-cholecystectomy complications. Early and accurate diagnosis of such complications is essential for timely and effective management. Imaging techniques are critical for this purpose, aiding in distinguishing between expected postsurgical changes and true complications. This review highlights current knowledge on the indications for cholecystectomy, pertinent surgical anatomy and surgical technique, and the recognition of anatomical variants that may complicate surgery. The article also outlines the roles of various imaging modalities in identifying complications, the spectrum of possible postsurgical anatomical changes, and the implications of such findings. Furthermore, we explore the array of complications that can arise post-cholecystectomy, such as biliary system injuries, gallstone-related issues, vascular complications, and the formation of postsurgical collections. Radiologists should be adept at identifying normal and abnormal postoperative findings to guide patient management effectively.

MRA for Preoperative Planning and Postoperative Management of Perforator Flap Surgeries: A Review.

Perforator flap magnetic resonance angiography (MRA) has emerged as a widely accepted and preferred modality for perforator flap mapping at several institutions. Autologous perforator flaps are a type of reconstructive microsurgical technique that involves transferring skin and fat from one part of the patient's body to another to replace tissue lost due to trauma, cancer resection, or other reasons. Autologous perforator flaps are based on a specific perforating blood vessel perfusing the transferred tissue. Hence, the surgery relies on the precise identification and mapping of perforating vessels to ensure successful outcomes. With its superior soft tissue contrast and multiplanar imaging capabilities, MRA has shown great potential in providing accurate and detailed visualization of perforator anatomy, size, and course. This review article summarizes the current literature on perforator flap MRA, including its technical considerations, imaging protocols, postprocessing, and reporting, specifically for autologous breast reconstructions. The advantages and limitations of MRA in evaluating perforator flaps are discussed, including its role in preoperative planning, intraoperative guidance, and postoperative assessment. Anatomy, brief surgical technique, specific technical modifications, and reporting of most commonly performed autologous breast flaps are described. Recent advancements in Perforator flap surgery and MRA techniques are discussed. Additionally, we examine the emerging role of artificial intelligence and machine learning in improving the accuracy and efficiency of perforator flap MRA interpretation. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 5.

Cystic dystrophy of the duodenal wall: case report and literature review.

Cystic dystrophy of the duodenal wall (CDDW) is an uncommon pathological condition that may be a cause of symptomatic duodenal mass in some patients. CDDW and closely related conditions that involve the duodenal wall and the pancreatoduodenal groove have gone by a variety names in the literature. Though their pathophysiology is not fully understood, they are thought to be due to the presence of heterotopic pancreatic tissue that undergoes a degenerative process. A multimodal imaging approach paired with biopsy is often employed to rule out malignancy in these patients. This case report provides an account of the radiological and pathological findings that helped lead to the diagnosis of CDDW. A review of relevant literature and a discussion of the presented case are provided.

Migrating pseudolipoma of Glisson's capsule.

Pseudolipomas of Glisson's capsule are rare benign subcapsular liver lesions that typically affect older men. They are composed of degenerating fat that is thought to originate from a detached epiploic appendage. On Computed Tomographic (CT) imaging, pseudolipomas of Glisson's capsule are well-circumscribed and hypoattenuating compared to the hepatic parenchyma. This case report examines three consecutive CT studies in the same patient that show the pseudolipoma migrating to a hepatic subcapsular location over a period of 4.5 months. To our knowledge, this is the first documented case of a pseudolipoma migrating over time and it supports the hypothesis of a migrating epiploic appendage forming a pseudolipoma of Glisson's capsule. A comprehensive review of relevant literature and a discussion of the presented case are provided.

CT-guided cryoablation for post-thoracotomy pain syndrome: a retrospective analysis.

PURPOSE Post-thoracotomy pain syndrome is a common condition affecting up to 50% of post-thoracotomy patients. However, percutaneous computed tomography (CT)-guided intercostal nerve cryoablation may provide symptomatic benefit in chronic and/or refractory cases. METHODS A retrospective review of our institution's comprehensive case log from October 2017 to September 2018 for patients who underwent cryoablation was analyzed. Thirteen patients with post-thoracotomy pain syndrome, refractory to medical management, were treated with CT-guided intercostal nerve cryoablation. Most patients had treatment of the intercostal nerve at the level of their thoracotomy scar, two levels above and below. The safety and technical success of this technique and the clinical outcomes of the study population were then retrospectively reviewed. RESULTS Of the patients, 69% experienced significant improvement in their pain symptoms with a median pain improvement score of 3 points (range, -1 to 8 points) over a median follow-up of 11 months (range, 2-18.6 months). Complications included pneumothorax in 8% and pseudohernia in 23% of patients. CONCLUSION CT-guided intercostal nerve cryoablation may be an effective technique in the treatment of post-thoracotomy pain syndrome and requires further study.

Preoperative cross-sectional mapping for deep inferior epigastric and profunda artery perforator flaps.

Perforator flap-based breast reconstruction in a post mastectomy patient requires dissection of the artery-vein bundle (perforators) responsible for perfusion of the subcutaneous fat and skin of the flap. Traditionally, these reconstructions were performed with the transverse rectus abdominis myocutaneous (TRAM) flap, but autologous breast reconstruction using muscle sparing free flaps has become steadily more popular in recent years. Preoperative imaging to locate and evaluate candidate perforators has become an essential step before patients undergo the microsurgical procedure. Preoperative mapping assists with operative planning, reduces operating times, and brings anatomical variations to their attention. Pre-operative imaging also assists in choosing the appropriate donor site for harvesting flaps. Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) have been widely used for this type of preoperative imaging. Both MRA and CTA have their inherent advantages and disadvantages, and the preferred modality for this purpose varies by institution based on factors such as scanner availability, radiologist and surgeon experience, and comfort in interpreting the images. Concerns over excessive exposure to ionizing radiation and poor iodinated contrast agent enhancement of the intramuscular perforator course has made MRA the first-choice imaging modality in many centers. The purpose of the article is to review technique and protocols for the pre-operative CTA/MRA in patients who are being considered for a deep inferior epigastric artery perforator (DIEP) or profunda artery perforator (PAP) flap and to familiarize the reader with the normal and variant anatomic features of the deep inferior epigastric and PAP vessels along with the anatomic and surgical considerations used in the selection of perforator flap donor site for breast reconstruction post mastectomy.

Automating Perforator Flap MRA and CTA Reporting.

Surgical breast reconstruction after mastectomy requires precise perforator coordinates/dimensions, perforator course, and fat volume in a radiology report. Automatic perforator reporting software was implemented as an OsiriX Digital Imaging and Communications in Medicine (DICOM) viewer plugin. For perforator analysis, the user identifies a reference point (e.g., umbilicus) and marks each perforating artery/vein bundle with multiple region of interest (ROI) points along its course beginning at the muscle-fat interface. Computations using these points and analysis of image data produce content for the report. Post-processing times were compared against conventional/manual methods using de-identified images of 26 patients with surgically confirmed accuracy of perforator locations and caliber. The time from loading source images to completion of report was measured. Significance of differences in mean processing times for this automated approach versus the conventional/manual approach was assessed using a paired t test. The mean conventional reporting time for our radiologists was 76 ± 27 min (median 65 min) compared with 25 ± 6 min (median 25 min) using our OsiriX plugin (p < 0.01). The conventional approach had three reports with transcription errors compared to none with the OsiriX plugin. Otherwise, the reports were similar. In conclusion, automated reporting of perforator magnetic resonance angiography (MRA) studies is faster compared with the standard, manual approach, and transcription errors which are eliminated.

Breast Tissue Expanders with Magnetic Ports: Clinical Experience at 1.5 T.

BACKGROUND: The purpose of this study was to evaluate breast tissue expanders with magnetic ports for safety in patients undergoing abdominal/pelvic magnetic resonance angiography before autologous breast reconstruction. METHODS: Magnetic resonance angiography of the abdomen and pelvis at 1.5 T was performed in 71 patients in prone position with tissue expanders with magnetic ports labeled "MR Unsafe" from July of 2012 to May of 2014. Patients were monitored during magnetic resonance angiography for tissue expander-related symptoms, and the chest wall tissue adjacent to the tissue expander was examined for injury at the time of tissue expander removal for breast reconstruction. Retrospective review of these patients' clinical records was performed. T2-weighted fast spin echo, steady-state free precession and gadolinium-enhanced spoiled gradient echo sequences were assessed for image artifacts. RESULTS: No patient had tissue expander or magnetic port migration during the magnetic resonance examination and none reported pain during scanning. On tissue expander removal (71 patients, 112 implants), the surgeons reported no evidence of tissue damage, and there were no operative complications at those sites of breast reconstruction. CONCLUSION: Magnetic resonance angiography of the abdomen and pelvis in patients with certain breast tissue expanders containing magnetic ports can be performed safely at 1.5 T for pre-autologous flap breast reconstruction perforator vessel mapping. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Pancreatic Cysts in Autosomal Dominant Polycystic Kidney Disease: Prevalence and Association with PKD2 Gene Mutations.

Purpose To define the magnetic resonance (MR) imaging prevalence of pancreatic cysts in a cohort of patients with autosomal dominant polycystic kidney disease (ADPKD) compared with a control group without ADPKD that was matched for age, sex, and renal function. Materials and Methods In this HIPAA-compliant, institutional review board-approved study, all patients with ADPKD provided informed consent; for control subjects, informed consent was waived. Patients with ADPKD (n = 110) with mutations identified in PKD1 or PKD2 and control subjects without ADPKD or known pancreatic disease (n = 110) who were matched for age, sex, estimated glomerular filtration rate, and date of MR imaging examination were evaluated for pancreatic cysts by using axial and coronal single-shot fast spin-echo T2-weighted images obtained at 1.5 T. Total kidney volume and liver volume were measured. Univariate and multivariable logistic regression analyses were conducted to evaluate potential associations between collected variables and presence of pancreatic cysts among patients with ADPKD. The number, size, location, and imaging characteristics of the cysts were recorded. Results Patients with ADPKD were significantly more likely than control subjects to have at least one pancreatic cyst (40 of 110 patients [36%] vs 25 of 110 control subjects [23%]; P = .027). In a univariate analysis, pancreatic cysts were more prevalent in patients with ADPKD with mutations in PKD2 than in PKD1 (21 of 34 patients [62%] vs 19 of 76 patients [25%]; P = .0002). In a multivariable logistic regression model, PKD2 mutation locus was significantly associated with the presence of pancreatic cysts (P = .0004) and with liver volume (P = .038). Patients with ADPKD and a pancreatic cyst were 5.9 times more likely to have a PKD2 mutation than a PKD1 mutation after adjusting for age, race, sex, estimated glomerular filtration rate, liver volume, and total kidney volume. Conclusion Pancreatic cysts were more prevalent in patients with ADPKD with PKD2 mutation than in control subjects or patients with PKD1 mutation. (©) RSNA, 2016 Online supplemental material is available for this article.

Cisterna chyli in autosomal dominant polycystic kidney disease.

PURPOSE: After observing prominent cisterna chyli in several patients with autosomal dominant polycystic kidney disease (ADPKD), we investigated the potential association of cistern chyli enlargement with ADPKD. MATERIALS AND METHODS: Retrospective, cross-sectional analysis of abdominal and pelvic MRI at 1.5 Tesla (T) in 70 ADPKD patients (male 44.3%, 20-83 years, median = 53 years) were compared with 70 age and gender matched control subjects without ADPKD, cirrhosis, or cholestasis. Cisterna chyli diameter was measured on axial single shot fast spin echo (SSFSE) images at the level of T12-L2 and evaluated by multivariable regression models with covariates including estimated glomerular filtration rate (eGFR), total kidney volume (TKV), renal cyst fraction (cyst volume/kidney volume), and liver volume. RESULTS: Subjects with ADPKD had larger median cisterna chyli diameter compared with those without ADPKD (6.1 mm versus 3.4 mm, P < 0.0001). The prevalence of cisterna chyli enlargement more than the median (3.4 mm), was greater in ADPKD than in controls (99% versus 51%, P < 0.0001). On univariate analysis, cisterna chyli diameter was inversely correlated with eGFR (r = -0.41; P < 0.0001) and directly correlated with TKV (r = 0.57; P < 0.0001), total renal cyst fraction (r = 0.61; P < 0.001), and liver volume (r = 0.17; P = 0.040). Multivariable linear regression modeling found a significant association of cisterna chyli diameter with ADPKD diagnosis (B = 2.14; 95% confidence interval [CI]: 0.05-4.23; P = 0.04). Logistic regression analysis confirmed the association of ADPKD with an enlarged cisterna chyli diameter (odds ratio = 68.4; 95%CI: 8.9-524, P < 0.0001). CONCLUSION: Enlarged cisterna chyli is highly prevalent in ADPKD patients but not in age and gender-matched controls.

Autologous breast reconstruction: preoperative magnetic resonance angiography for perforator flap vessel mapping.

BACKGROUND: Selection of a vascular pedicle for autologous breast reconstruction is time consuming and depends on visual evaluation during the surgery. Preoperative imaging of donor site for mapping the perforator artery anatomy greatly improves the efficiency of perforator selection and significantly reduces the operative time. In this article, we present our experience with magnetic resonance angiography (MRA) for perforator vessel mapping including MRA technique and interpretation. METHODS: We have performed over 400 MRA examinations from August 2008 to August 2013 at our institution for preoperative imaging of donor site for mapping the perforator vessel anatomy. Using our optimized imaging protocol with blood pool magnetic resonance imaging contrast agents, multiple donor sites can be imaged in a single MRA examination. Following imaging using the postprocessing and reporting tool, we estimated incidence of commonly used perforators for autologous breast reconstruction. RESULTS: In our practice, anterior abdominal wall tissue is the most commonly used donor site for perforator flap breast reconstruction and deep inferior epigastric artery perforators are the most commonly used vascular pedicle. A thigh flap, based on the profunda femoral artery perforator has become the second most used flap at our institution. In addition, MRA imaging also showed evidence of metastatic disease in 4% of our patient subset. CONCLUSION: Our MRA technique allows the surgeons to confidently assess multiple donor sites for the best perforator and flap design. In conclusion, a well-performed MRA with specific postprocessing provides an accurate method for mapping perforator vessel, at the same time avoiding ionizing radiation.

Morphine three-dimensional T1 gadoxetate MR cholangiography of potential living related liver donors.

PURPOSE: To assess low-dose morphine for distension and improved visualization of intrahepatic bile ducts on T1 MR cholangiography (MRC) in preoperative imaging of potential liver donors. MATERIALS AND METHODS: Sixty-nine consecutive potential living related liver donors (mean age, 39 years; age range, 20 to 59 years) referred for pre-transplant MRI evaluation were evaluated without (n=30) or with (n=39) intravenous morphine injection (0.04 mg/kg). Morphine was injected pre-MRI while establishing intravenous access to allow ∼1 h for biliary distension before T1 MRC. Three radiologists reviewed intrahepatic biliary branch order visualization, common bile duct (CBD) diameter, and overall image quality. In 25 patients undergoing liver donation surgery, T1 MRC findings were correlated with intraoperative findings. This retrospective study was approved by the institutional review board. RESULTS: Biliary visualization was improved post-morphine administration with biliary duct branch order visualization score of 3.2 and 3.3 at 45 and 60 min, respectively, compared with 2.7 without morphine (P<0.002); CBD diameter measured 5.3 and 5.5 versus 4.1 mm (P<0.005), and overall image quality score was 2.4 and 2.6 versus 1.8 (P<0.0006). Operative notes confirmed T1 MRC findings in 6/11 donors without morphine and 14/14 donors with morphine. CONCLUSION: Intravenous low-dose morphine distends and improves visualization of bile ducts on T1 gadoxetate MRC.