Contribution of dynamic contrast enhancement and diffusion-weighted magnetic resonance imaging to the diagnosis of malignant cervical lymph nodes

Intravoxel incoherent motion diffusion-weighted imaging for discrimination of benign and malignant retropharyngeal nodes

PURPOSE

Anatomical imaging criteria for the diagnosis of malignant head and neck nodes may not always be reliable. This study aimed to evaluate the diagnostic value of conventional diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM) DWI in discriminating benign and malignant metastatic retropharyngeal nodes (RPNs).

METHODS

IVIM DWI using 14 b-values was performed on RPNs of 30 patients with newly diagnosed metastatic nasopharyngeal carcinoma (NPC) and 30 patients with elevated plasma Epstein-Barr virus (EBV)-DNA without NPC who were part of an EBV-based NPC screening program. Histogram measurements of the two groups were compared for pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion volume fraction (f) and apparent diffusion coefficient (ADC) using the Mann-Whitney U test. Area under the curves (AUCs) of significant measurements were calculated from receiver-operating characteristics analysis and compared using the DeLong test.

RESULTS

Compared with metastatic RPNs, benign RPNs had lower ADC_mean (0.73 vs 0.82 × 10^-3 mm²/s) and D_mean (0.60 vs 0.71 × 10^-3 mm²/s) and a higher D*_mean (35.21 vs 28.66 × 10^-3 mm²/s) (all p < 0.05). There was no difference in the f measurements between the two groups (p = 0.204 to 0.301). D_mean achieved the highest AUC of 0.800, but this was not statistically better than the AUCs of the other parameters (p = 0.148 to 0.991).

CONCLUSION

Benign RPNs in patients with EBV-DNA showed greater restriction of diffusion compared with malignant metastatic RPNs from NPC. IVIM did not show a significant advantage over conventional DWI in discriminating benign and malignant nodes.

Preoperative computed tomography evaluation of the paranasal sinuses: what should the physician know? - pictorial essay

The introduction of functional endoscopic sinus surgery in the 1980s brought about a drastic change in the treatment of patients with rhinosinusitis, improving quality of life through the removal of pathological processes or anatomical variations that obstruct the drainage pathways of the paranasal sinuses. However, despite the routine use of computed tomography in the anatomical evaluation of the paranasal sinuses, most radiological reports still do not provide sufficient information to guide the surgical planning. The objective of this pictorial essay was to demonstrate, through computed tomography, the main anatomical variations of the paranasal sinuses, the recognition of which is fundamental for preoperative planning, in order to avoid treatment failure and iatrogenic complications.

Changes in temporomandibular joint anatomy, changes in condylar translation, and their relationship with disc displacement: magnetic resonance imaging study

Objective

To assess changes in the articular surfaces of the temporomandibular joint (TMJ) and in condylar translation, as detected by magnetic resonance imaging (MRI), determining whether such changes correlate with disc displacement.

Materials and Methods

We retrospectively analyzed the MRI scans of 2076 TMJs of 1038 patients with symptoms of temporomandibular disorder. We attempted to determine whether articular disc deformity and changes in condylar translation, as well as changes in the articular surfaces of the condyle, glenoid fossa, and articular eminence, correlated with disc displacement.

Results

Disc displacement with reduction was associated with changes in the shape of the articular eminence. Disc displacement without reduction was most strongly associated with disc deformity, condylar degeneration, glenoid fossa degeneration, and effusion. Neither decreases nor increases in condylar translation were associated with disc deformity, degenerative bone changes, or disc displacement.

Conclusion

Changes in the shape of the articular eminence seem to predispose to progression of internal derangement of the TMJ.

Agreement between diagnostic imaging methods for the evaluation of lymphadenopathies in HIV-infected/AIDS patients

Objective

To assess the percent agreement between diagnostic imaging modalities for the evaluation of lymphadenopathies in HIV-infected/AIDS patients.

Materials and Methods

This was an open, comparative, prospective study of diagnostic imaging methods for lymphadenopathy evaluation. We evaluated 30 patients (19 men and 11 women). All underwent ultrasound and computed tomography (CT). Twenty of the patients also underwent magnetic resonance imaging (MRI). We determined the percent agreement between two examiners using the various imaging methods to evaluate lymphadenopathies.

Results

CT had the highest percent agreement, at 93.3%, with a kappa coefficient of 0.85, corresponding to 28 of the 30 examinations. When we compared the percent agreement between the two examiners and between CT and ultrasound, examiner 1 had an observed rate of 80.0%, with a kappa of 0.49, corresponding to 24 of the 30 examinations, whereas examiner 2 had a rate of 70.0%, with a kappa of 0.31, corresponding to 21 of the 30 examinations. Between MRI and CT, the percent agreement for examiner 1 was 50.0%, with a kappa of −0.18, corresponding to 10 of the 20 examinations, whereas that for examiner 2 was 85.0%, with a kappa of 0.69, corresponding to 17 of the 20 examinations. For MRI and ultrasound, examiner 1 had a percent agreement of 70.0%, with a kappa of 0.20, corresponding to 14 of the 20 examinations, and examiner 2 had a percent agreement of 75.0%, with a kappa of 0.38, corresponding to 15 of the 20 examinations.

Conclusion

This study indicates that intermethod agreement is highly dependent on the way in which the research is conducted, rather than on the level of experience of the examiner.