The aim of the study was to check if the subtendons of the Achilles tendon can be identified in vivo on MRI in the midportion of the tendon. The relation of the plantaris tendon to the Achilles tendon was also examined. A retrospective study of 200 MRI of ankle joints including the Achilles tendon was conducted. Statistical analysis of the correlation between the possibility of identifying the subtendons and the side, gender, presence of the central soleus tendon and plantaris tendon variation was performed. The inter-observer agreement between two reviewers in their evaluation of the subtendons was assessed using kappa statistics. The subtendon from the lateral head of the gastrocnemius muscle was identified in 65% (k = 0.63) and was located in the anterior part of the Achilles tendon. The subtendon from the soleus muscle was recognized in 12% (k = 0.75) comprising anterior part of the tendon. In 6% the subtendon from the medial head of the gastrocnemius muscle was identified (k = 0.58). The central soleus tendon was identified in 85% of cases. Statistical analysis shows the weak correlation of the presence of the central soleus tendon and the possibility of identifying the subtendon from the soleus muscle. The plantaris tendon was directly related to the insertion of the Achilles tendon in 42.5%. Identification of the subtendons of the Achilles tendon on MRI is challenging, and most often it is only possible to find the subtendon of the lateral head of the gastrocnemius muscle.

Background A majority of renal tumors are incidentally detected and may therefore have been previously radiologically overlooked. Purpose To investigate the frequency of previously radiologically overlooked renal cell carcinoma (RCC), identify tumor characteristics and imaging factors that contribute to misdiagnoses and to investigate its consequences. Material and Methods All RCCs identified in a regional cancer registry over one year were retrieved (n = 87). All preceding radiological examinations were re-analyzed for overlooked RCCs. Results RCCs had been previously overlooked in 18 (21%) of the 87 patients (on 26 examinations: computed tomography [CT] = 16, magnetic resonance imaging [MRI] = 5, urography = 3, ultrasound = 2) or 18 (43%) of the 42 patients who had earlier radiological examinations. Overlooked RCCs were smaller than non-overlooked RCCs (median = 23 mm; range = 10–45 mm vs. 65 mm; range = 13–207 mm) (P < 0.0001), more frequently located in upper pole, 50% vs. 26% (P = 0.0836), and more frequently homogenous, 50% vs. 9% (P = 0.0003). There was no difference in exophytic growth (60% vs. 60%) (P = 0.74). Overlooked RCCs displayed poorer visualization on CT/MRI in all image planes (axial, coronal, sagittal) compared to non-overlooked tumors (P = 0.004, P = 0.001, P < 0.0001, respectively). Overlooked tumors had interval size progression of median 12 mm (range = 0–65 mm) to clinical detection (median = 1033 days). Conclusions RCCs are frequently overlooked at imaging in the clinical routine. Overlooked tumors were smaller and displayed poorer visualization in all image planes compared to non-overlooked tumors. Substantial delay to clinical diagnosis and variable size progression was noted. Careful attention to the kidneys in multiple image planes seems warranted, irrespective of clinical indication.

Background Peroneal split tears are an underrated cause of ankle pain. While magnetic resonance imaging (MRI) is useful for diagnosis, split tears are challenging to identify. The aim of the study was to investigate the association of peroneus brevis split rupture with abnormalities of the superior peroneal retinaculum (SPR), anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), joint effusion, morphology of the malleolar groove, presence of the bone marrow oedema and prominent peroneal tuberculum. Methods Ankle MRI cases were assessed by independent observers retrospectively in two groups: one with peroneus brevis split tears (n = 80) and one without (control group, n = 115). Two observers evaluated the soft tissue lesions, and three graded the bone lesions. Fisher’s exact test and Pearson correlation were used for analysis. The Bonferroni-Holm method (B-H) was used to adjust for multiple comparisons. Results Only bone marrow edema in the posterior part of the lateral malleolus was significantly (p < 0.05) more common in the split tear group after applying B-H. SPR total rupture was seen only in the experimental group. No differences in incidence of ATFL and CFL lesions or other SPR lesions were noticed (p < 0.05). Conclusion Bone marrow edema in the posterior part of the lateral malleolus is associated with peroneus split tears on MRI.