Long-term CT follow-up of patients with lumbar spondylolysis reveals low rate of spontaneous bone fusion

OBJECTIVES

Knowledge about the long-term outcome of patients with lumbar spondylolysis (LS) is limited. This study assessed the frequency of bone fusion in conservatively treated lumbar spondylolysis with photon counting detector computed tomography.

METHODS

Patients with lumbar spondylolysis diagnosed with CT or MRI were prospectively enrolled and underwent CT 5-10 years after initial imaging. Image assessment included evaluation of Meyerding grade, listhesis size, measurement of the lysis gap, and disc integrity on the lysis level. Comparisons were made between bone fusion as the primary endpoint and sex, body mass index, age at diagnosis, follow-up interval, size of listhesis, Meyerding grade, size of the lysis gap, sports activity, and presence of pain.

RESULTS

A total of 39 patients (26.0 ± 3.1 years, 15 female) with lumbar spondylolysis on 41 levels were included after a mean follow-up period of 9.1 ± 2.2 years. Nine patients (22.0%, four female) showed complete fusion of the lysis gap. Patients with bone fusion of the lysis gap had a significantly lower Meyerding grade (p = 0.01), smaller size of the listhesis (p = 0.019), and smaller anterior and posterior lysis gap size (p = 0.046 and p = 0.011, respectively). Unilateral lyses showed significantly higher fusion rates than bilateral lyses (40.0% vs. 16.1%, p = 0.01). No statistically significant difference was found for pain at follow-up between patients with and without bone fusion (p = 0.253).

CONCLUSION

Bone fusion occurred in about a fifth of conservatively treated lumbar spondylolysis after a follow-up period of 9 years. Factors associated with a successful fusion were a lower Meyerding grade, minimal listhesis, and a small lysis gap.

The value of non-enhanced MRI in the evaluation of patients with suspected idiopathic inflammatory myopathy

INTRODUCTION/AIMS

The performance of magnetic resonance imaging (MRI) for diagnosing suspected idiopathic inflammatory myopathy (IIM) remains controversial. Furthermore, the role of contrast-enhanced magnetic resonance imaging (CE-MRI) sequences is unclear. The aim of this study was to evaluate the sensitivity and specificity of a non-enhanced magnetic resonance imaging (NE-MRI) protocol compared to a CE-MRI protocol in adult patients with confirmed IIM.

METHODS

This study retrospectively enrolled patients with suspected IIM who underwent MRI of the upper thigh between 2008 and 2020. The protocol consisted of a T1-weighted (T1w) sequence, a turbo inversion recovery magnitude (TIRM) sequence and a contrast-enhanced T1-weighted sequence (CE-T1w). After randomly stratifying patients into a group with only the T1w and TIRM sequences available and another group with additional availability of CE-T1w, three blinded readers assessed the presence of IIM based on characteristic imaging features. Confirmation of the diagnosis was determined based on the 2017 ACR/EULAR criteria.

RESULTS

Of the 80 patients (mean age 49.0 ± 21.1 years; 42 female, 38 male) included, 54 (67.5%) had a positive diagnosis of IIM. Cumulated sensitivity and specificity for MRI to detect IIM was 87.1% and 83.3% in the NE-MRI group versus 87.0% and 63.0% in the CE-MRI group. The group differences for sensitivity and specificity were non-significant for each of the three readers, respectively (p ≥ .081).

DISCUSSION

NE-MRI detects suspected IIM with high diagnostic accuracy and performs equivalently to CE-MRI. Therefore, it may be appropriate to omit the use of contrast agents in MRI scans performed for suspected IIM.

Advanced muscle imaging in adolescent elite rowers utilizing diffusion tensor imaging: Association of imaging findings with stroke typology

PURPOSE

Muscular overuse injuries are a common health issue in elite athletes. Changes in the muscular microenvironment can be depicted by Diffusion Tensor Imaging (DTI). We hypothesize that the biomechanics of different stroke typologies plays a role in muscle injury and tested our hypothesis by magnetic resonance imaging (MRI) examination of the lumbar spine muscles of adolescent rowers utilizing DTI.

METHODS AND MATERIALS

Twenty-two male elite rowers (12 sweep, 10 scull rowers) with a mean age of 15.8 ± 1.2 years underwent 3-Tesla MRI of the lumbar spine 6 hours after cessation of training. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were calculated for the erector spinae and multifidus muscle. Student's t-test was used to test differences of DTI parameters between sweep and scull rowers and a Pearson correlation was utilized to correlate the parameters to training volume.

RESULTS

ADC values in the erector spinae and multifidus muscle were significantly higher (p = 0.039) and FA values significantly lower (p < 0.001) in sweep rowers compared to scull rowers. There was no significant association between DTI parameters and training volume (r ≤ -0.459, p ≥ 0.074).

CONCLUSIONS

Our DTI results show that lumbar spine muscle diffusivity is higher in sweep rowers than in scull rowers. Altered muscle diffusivity is suggestive of microscopic tissue disruption and might be attributable to biomechanical differences between stroke typologies.

Prediction of regional lymph node metastasis in intrahepatic cholangiocarcinoma: it's not all about size

OBJECTIVES

Lymph node metastases (LNM) are frequent in patients with intrahepatic cholangiocarcinoma (iCC) and worsen their prognosis even after surgery. Our aim was to investigate the predictive value of lymph node (LN) short axis, the most common discriminator for identifying LNM in tumor-imaging and to develop a predictive model for regional LNM in iCC taking computed tomography (CT) features of extranodal disease into account.

MATERIALS AND METHODS

We enrolled 102 patients with pathologically proven iCC who underwent CT prior to hepatic resection and hilar lymph node dissection (LND) from 2005 to 2021. Two blinded radiologists assessed various imaging characteristics and LN diameters, which were analyzed by bivariate and multivariate logistic regression to develop a prediction model for LNM.

RESULTS

Prevalence of LNM was high (42.4 %) and estimated survival was shorter in LN-positive patients (p = 0.07). An LN short axis diameter of ≥ 9 mm demonstrated the highest predictive power for LNM. Three additional, statistically significant imaging features, presence of intrahepatic metastasis (p = 0.003), hilar tumor infiltration (p = 0.003), and tumor growth along the liver capsule (p = 0.004), were integrated into a prediction model, which substantially outperformed use of LN axis alone in ROC analysis (AUC 0.856 vs 0.701).

CONCLUSIONS

LN diameter alone proved to be a relevant but unreliable imaging-marker for LNM prediction in iCC. Our proposed prognostic model, which additionally considers intrahepatic metastases and hilar and capsular infiltration, significantly improves discriminatory power. Hilar and capsular involvement might indicate direct tumor extension to lymphatic liver structures.