Radiologic evaluation of ankle fracture malunions of the fibula.

Ankle fractures involving the distal fibula are common injuries. Malreductions and subsequent malunions of the distal fibula can result in worse clinical outcomes and posttraumatic arthritis. The ability to accurately evaluate and identify malreductions and malunions of the distal fibula is important. A number of different radiographic and CT measurements have been described to assess fibular length and rotation. This review highlights various radiologic measures and discusses their advantages and limitations.

Complications After Renal Mass Biopsy: Frequency, Nature, Timing, and Associated Characteristics.

BACKGROUND. Observation periods after renal mass biopsy (RMB) range from 1 hour to overnight hospitalization. Short observation may improve efficiency by allowing use of the same recovery bed and other resources for RMBs in additional patients. OBJECTIVE. The purpose of this study was to evaluate the frequency, timing, and nature of complications after RMB, as well as to identify characteristics associated with such complications. METHODS. This retrospective study included 576 patients (mean age, 64.9 years; 345 men, 231 women) who underwent percutaneous ultrasound- or CT-guided RMB at one of three hospitals, performed by 22 radiologists, between January 1, 2008, and June 1, 2020. The EHR was reviewed to identify postbiopsy complications, which were classified as bleeding-related or non-bleeding-related and as acute (< 24 hours), subacute (24 hours to 30 days), or delayed (> 30 days). Deviations from normal clinical management (analgesia, unplanned laboratory testing, or additional imaging) were identified. RESULTS. Acute and subacute complications occurred after 3.6% (21/576) and 0.7% (4/576) of RMBs, respectively. No delayed complication or patient death occurred. A total of 76.2% (16/21) of acute complications were bleeding-related. A deviation from normal clinical management occurred after 1.6% (9/551) of RMBs that had no associated postbiopsy complication. Among the 16 patients with bleeding-related acute complications, all experienced a deviation, with mean time to deviation of 56 ± 47 (SD) minutes (range, 10-162 minutes; ≤ 120 minutes in 13/16 patients). The five non-bleeding-related acute complications all presented at the time of RMB completion. The four subacute complications occurred from 28 hours to 18 days after RMB. Patients with, versus those without, a bleeding-related complication had a lower platelet count (mean, 197.7 vs 250.4 × 109/L, p = .01) and greater frequency of entirely endophytic renal masses (47.4% vs 19.6%, p = .01). CONCLUSION. Complications after RMB were uncommon and presented either within 3 hours after biopsy or more than 24 hours after biopsy. CLINICAL IMPACT. A 3-hour monitoring window after RMB before patient discharge (in the absence of deviation from normal clinical management and complemented by informing patients of the low risk of a subacute complication) may provide both safe patient management and appropriate resource utilization.

Parallel Line Sign-A New MRI Sign Associated With Chronic Sacroiliitis: Prevalence, Characteristics, and Associations.

Purpose: The purpose is to demonstrate the existence of the parallel line sign (PLS), a dark line parallel to the sacroiliac joint (SIJ), and determine its prevalence, characteristics, and associations. Methods: 200 consecutive SIJ MRIs referred by rheumatologists were retrospectively reviewed for the presence of the PLS. Presence and extent of imaging features of sacroiliitis (bone marrow edema, fatty infiltration, erosions, sclerosis, and ankylosis) were evaluated. Results: Prevalence of PLS was 11.5% (23/200), with 9 subjects having bilateral PLS, resulting in 32 SIJs showing a PLS. Every PLS involved the synovial portion of the SIJ, and almost all (31/32, 96.9%) involved the iliac (rather than sacral) side of the SIJ. Every PLS occurred with at least one established imaging feature of sacroiliitis. Presence of a PLS was associated with higher prevalence of erosions (78.3% vs 36.7% in those without PLS, P < .001), greater extent of SIJ involvement by erosions (3.6 ± 1.3 vs 2.3 ± 1.1 quadrants of the SIJ involved, P < .001), and higher density of erosions per centimeter (88.9% vs 46.2% with >2 erosions/cm, P = .001). There was higher prevalence of bone marrow edema, fatty infiltration, and sclerosis in those with PLS compared to those without PLS (P = .001, P < .001, and P = .006, respectively). Extent of involvement by any of these features was not significantly different between the two groups (P = .22, P = .16, and P = .46, respectively). Conclusions: The PLS is associated with imaging features of chronic sacroiliitis, especially erosions. Knowledge of the existence of the PLS may help avoid misdiagnosis of an insufficiency fracture and increase confidence in the diagnosis of sacroiliitis.

Rare Bilateral Caudate Infarction in a Patient with a Common Circle of Willis Variant.

A 62-year-old male presented to hospital with acute aphasia. His past medical history was significant for a previous left middle cerebral artery stroke, from which he fully recovered, hypertension, dyslipidemia, coronary artery disease, one episode of atrial fibrillation postoperatively, and thalidomide exposure in utero. Although initially he was thought to be aphasic, on further examination, he demonstrated significant abulia. His level of consciousness was normal, and neurological examination was otherwise unremarkable. A CT angiogram of the head and neck was performed. The patient was not a candidate for acute therapy, as he had established stroke on imaging, and the time of onset was unclear.

Use of a radial artery 'slender' sheath for facilitating transfemoral arterial access for neuroendovascular embolization in a very young infant.

Pediatric neuroendovascular procedures are increasingly performed as several studies have shown the safety of these interventions. In the literature, an upper limit of 4 French catheter size is conventionally used for femoral access in neuroangiography of very young infants. However, this constraint in luminal size may not allow for more complex procedures. We present the previously unreported use of a radial 5 French slender catheter with ultrathin walls for femoral access for aneurysm embolization in a 3-month-old boy presenting with left M2 aneurysm rupture.

Intradiploic Cerebrospinal Fluid Cyst Following Occipital Encephalocele Surgery in Patient with Dandy-Walker Malformation.

Intradiploic cerebrospinal fluid cysts are rare entities that have been reported to occur following trauma and surgery. We present a case of a 53-year-old female patient with an incidental intradipoloic cerebrospinal fluid cyst in communication with a Dandy-Walker malformation, likely related to a remote history of childhood surgery for occipital encephalocele.

High Prevalence of Pneumothorax on PET-CT Studies Performed in Lung Cancer Patients Following Post-Transthoracic Needle Biopsy Mandates Careful Scrutiny.

In our practice, FDG PET-CT studies are frequently performed within days of transthoracic needle biopsy, often revealing presence of pneumothorax (PTX), a "critical finding" that should be reported expeditiously. In our experience, prevalence of PTX at PET-CT performed 1 day following biopsy is greater than 40%. Of these, approximately a third are not visible on the postprocedure chest radiography, as in a case we describe. A high level of vigilance is therefore recommended to identify PTX in patients who have undergone recent transthoracic needle biopsy, even when no PTX is present immediately following the biopsy procedure.

Utility of T1-weighted MRI as a predictor of liver lesion visibility on ultrasound: A clinical tool to determine feasibility of ultrasound-guided percutaneous interventions.

PURPOSE: To determine the utility of fat-suppressed T1-weighted gradient recalled echo (FS-T1W-GRE) MRI to predict visibility of focal liver lesions (FLL) on abdominal ultrasound (US). MATERIALS AND METHODS: With IRB approval, between 2010 and 2013, 109 patients (28.4% females, age 66.9±10.9years) with 177 FLL (hepatocellular carcinoma=132, metastases=44, other=1) underwent MRI and prospective, radiologist-performed treatment-planning US (to determine eligibility for US-guided ablation). MRI examinations were reviewed by a blinded radiologist who assessed: a) size and location of FLL, b) presence of hepatic steatosis on dual-echo T1W-GRE, and c) quantitative signal intensity of FLL relative to liver on FS-T1W-GRE. Associations between MR imaging findings and visibility on US were assessed using independent t-tests and the chi-squares test. RESULTS: 69.5% (123/177) FLL were identified with US and 30.5% (54/177) were not visible. Size of FLL on MRI was associated with visibility on US (p<0.0001) with no association between FLL visibility on US and segmental or subcapsular location (p=0.29 and p=0.25, respectively). 20.2% (22/109) patients had hepatic steatosis on MRI, which was not associated with non-visibility of FLL on US (p=0.67). 38.4% (68/177) FLL were isointense to liver on FS-T1W-GRE which was associated with non-visibility on US (p=0.036) particularly in non-steatotic livers (p=0.014). CONCLUSION: FLL size and isointensity of FLL to liver parenchyma on FS-T1W-GRE MRI are associated with non-visibility on US, particularly in non-steatotic livers. These results have implications when planning US-guided percutaneous interventions of FLL detected with MRI.

Adopting new gamma cameras and reconstruction algorithms: Do we need to re-establish normal reference values?

BACKGROUND: The impact of adopting new single photon emission computed tomography (SPECT) cameras and new reconstruction algorithms on left ventricular (LV) volumes has not been well established. We sought to understand the impact of hardware and software changes on normal LV reference ranges. METHODS: Consecutive patients who underwent stress Tc-99m tetrofosmin 8-frame gated SPECT MPI were screened. Patients with a history of myocardial infarction, coronary revascularization, abnormal MPI, or known LV dysfunction/reduced ejection fraction were excluded. A total of 1953 consecutive normal patients, with rest LV end-diastolic volume (EDV) and end-systolic volume (ESV) measurements were analyzed. After stratifying according to sex, LV volumes indexed to body surface area were compared across the different gamma cameras. RESULTS: In a normal population, measurements with CZT were different from those obtained by the dual-headed NaI gamma cameras for LV EDVi (men: 53.6 ± 10.4 vs 48.3 ± 10.2 mL/m(2) and women: 43.3 ± 8.9 vs 37.8 ± 9.3 mL/m(2); P < 0.001) and LV ESVi (men: 21.7 ± 7.0 vs 16.9 ± 6.2 mL/m(2) and women: 13.4 ± 5.3 vs 10.6 ± 4.7 mL/m(2); P < 0.001). Inter- and intra-observer reliability for all measures was excellent. These findings were verified in a prospectively collected cohort. A sub-analysis of LV measurements comparing new resolution recovery and standard reconstruction software revealed no significant differences in LV measures. CONCLUSION: This study demonstrates that normal references ranges of LV volumes vary between SPECT cameras and confirms the need for establishing reference values that are camera specific.

Cross-sectional imaging, with surgical correlation, of patients presenting with complications after remote bariatric surgery without bowel obstruction.

Both restrictive and malabsorptive types of bariatric surgery may be associated with short- and long-term complications. The lack of small bowel obstruction is not necessarily indicative of a normal study, as a variety of non-obstructed complications exist. These include stenosis at the gastrojejunostomy, leaks, abscesses, hemorrhage, internal hernias, and gastric band erosions. Radiologists should be familiar with these complications for early diagnosis and intervention before symptoms become life threatening. An understanding of the intraoperative appearances of these complications may improve imaging descriptions and add value to radiological consults for surgeons. This review provides surgical correlations to the imaging features of post-bariatric complications without obstruction of the bowel.