Korean Journal of Radiology最新文献

Objective: To evaluate the impact of adding CT to ultrasound (US) for nodal assessment in patients with papillary thyroid microcarcinoma (PTMC), particularly in those with US-node-negative disease.

Materials and methods: This single-center retrospective study included consecutive patients with PTMC (≤1 cm on US) who underwent both US and CT for PTMC staging between August 2016 and January 2020, and subsequently underwent surgery including neck dissection. The number of patients with clinical N1 and pathological N1 disease was assessed. The diagnostic performance of US, CT, and combined US + CT (positive if either was positive) for macroscopic lymph node metastasis (LNM) (i.e., metastatic tumor foci >2 mm) was evaluated. Cases with discordant nodal staging between US and CT were identified. The diagnostic utility of CT was also assessed in a subgroup of patients with node-negative findings on US.

Results: Among 982 patients (mean age ± standard deviation, 47.3 ± 11.5 years; 774 female), pathological analysis confirmed cervical LNM in 377 patients, including macroscopic, microscopic, and size-unknown LNM in 187, 175, and 15 patients, respectively. The addition of CT to US improved sensitivity for detecting macroscopic LNM compared to US alone (68.4% [128/187] vs. 26.7% [50/187]; P < 0.001), while maintaining high specificity despite a significant decrease (90.9% [709/780] vs. 97.2% [758/780]; P < 0.001). Discordant nodal staging between US and CT regarding macroscopic LNM was observed in 149 cases (15.2% [149/982]), with 131 patients (87.9% [131/149]) being upstaged by CT. In patients with node-negative US findings, CT detected US-undetected macroscopic LNM in 78 patients (8.7% [78/895]) and exhibited a sensitivity of 56.9% (78/137) and specificity of 93.5% (709/758) for macroscopic LNM.

Conclusion: The integration of CT with US improved sensitivity for detecting macroscopic LNM in patients with PTMC, identifying those who would otherwise be inappropriately considered candidates for active surveillance based solely on US findings. This may assist in refining patient management.

Although pediatric thyroid cancer is rare, it has characteristics distinct from those of adult thyroid cancer. Thyroid nodules in children present a higher risk of malignancy, more frequent lymph node and distant metastases, and distinct molecular profiles compared to adults. Despite a more aggressive initial presentation, the long-term prognosis for children is excellent, with paradoxically low mortality rates, even in patients with distant metastases. Therefore, it is questionable whether ultrasound-based risk-stratification systems primarily developed for adults can be directly applied to children. The 2021 Korean Thyroid Imaging Reporting and Data System (K-TIRADS) introduced pediatric-specific biopsy cut-offs and risk-adapted considerations, improving sensitivity, specificity, and overall accuracy. Nevertheless, challenges remain in achieving better diagnostic performance. Specific considerations must also be noted when evaluating pediatric thyroid nodules, such as the diffuse sclerosing subtype of papillary thyroid cancer and intrathyroidal ectopic thymus. Overdiagnosis and age-related heterogeneity further complicate risk assessment and management. Future guidelines could adopt stratified approaches based on patient age and sonographic mimickers, with additional integration of molecular profiling and artificial intelligence-assisted decision support. This review summarizes the current state of ultrasonographic evaluation of pediatric thyroid nodules, including the 2021 K-TIRADS, and discusses future refinements for pediatric-specific ultrasound risk-stratification systems.

Objective: Evidence remains limited regarding whether Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) or modified RECIST (mRECIST) more reliably assesses treatment response in patients with hepatocellular carcinoma (HCC) receiving atezolizumab plus bevacizumab (Atezo/Bev). This study aimed to evaluate response patterns based on RECIST 1.1 and mRECIST, analyze inter-reader agreement, and assess their prognostic value for overall survival (OS) in patients with HCC receiving first-line Atezo/Bev.

Materials and methods: This retrospective study included patients with HCC treated with first-line Atezo/Bev between June 2020 and December 2022 at a tertiary center. Patients with at least one hypervascular hepatic target lesion were eligible. Two radiologists independently assessed treatment responses using RECIST 1.1 and mRECIST. Inter-reader agreement was evaluated using Cohen's kappa coefficient. Time-dependent Cox regression analysis was performed, with radiologic response and progression treated as time-varying covariates. Prognostic discrimination was evaluated using Harrell's concordance index (C-index).

Results: A total of 207 patients were included (171 men; median age, 63 years; median follow-up, 10.7 months [range, 0.8-46.4 months]; median OS, 10.7 months [95% confidence interval, 9.2-12.8 months]). mRECIST identified more responders than RECIST 1.1 (54.6% vs. 16.9%). RECIST 1.1 demonstrated excellent inter-reader agreement, whereas mRECIST showed substantial agreement (weighted kappa, 0.89 vs. 0.79). A significantly higher rate of dissociated responses was observed with mRECIST than with RECIST 1.1 (14.0% vs. 4.3%, P < 0.001). Both RECIST 1.1- and mRECIST-based responses and progression were independently associated with OS. Models incorporating RECIST 1.1 demonstrated slightly higher C-index values than those incorporating mRECIST (RECIST 1.1: 0.68 for response and 0.75 for progression; mRECIST: 0.65 and 0.70, respectively).

Conclusion: RECIST 1.1 is more reproducible and prognostically valuable for guiding treatment decisions in patients with HCC receiving first-line Atezo/Bev. However, this does not invalidate the use of mRECIST as a biological tumor response marker.

Objective: To evaluate the diagnostic performance of magnetic resonance spectroscopy (MRS) in discriminating fumarate hydratase-deficient (FH-d) uterine leiomyomas (ULs) from FH-preserved ULs.

Materials and methods: This study consisted of three stages, with independent cohorts recruited for each stage: 1) sample-size estimation was retrospectively performed on UL specimens (diameter ≥3 cm; age, 20-40 years) from our database with immunohistochemistry (IHC) for 2-succinocysteine (2-SC) as the reference, without genetic testing, 2) MRS sequence optimization in confirmed FH germline mutation participants with ultrasound-detected ULs (diameter ≥3 cm), without IHC analysis, and 3) prospective diagnostic test accuracy was evaluated in consecutive participants with ultrasound-detected ULs (diameter ≥3 cm; age, 20-40 years), using IHC for 2-SC for determining the FH status and subsequent genetic testing in those with positive 2-SC results to identify whether FH mutations were germline or somatic in origin. The choline and fumarate peaks in MRS were classified as positive, negative, or technical failure (TF). TFs were analyzed separately and excluded from the primary diagnostic accuracy calculations. T1-, T2-, and diffusion-weighted images were interpreted as hyperintense or hypointense. The enhancement rate and apparent diffusion coefficient were also acquired. Diagnostic performance was compared between MRS and various magnetic resonance imaging (MRI) features.

Results: The optimal MRS parameters for the fumarate peak were echo time (TE) = 140 ms and an average of 256. Among the 360 prospective participants, 37 were confirmed to have FH-dULs. MRS showed positive fumarate peaks in 35 of 37 FH-dULs. After excluding six TFs, the positive fumarate peak on MRS showed 94.6% (35/37) sensitivity, 99.7% (316/317) specificity, and 99.2% (351/354) accuracy, all of which were significantly superior to those of other MRI features (P ≤ 0.002).

Conclusion: A positive fumarate peak on MRS may be a useful imaging biomarker for diagnosing FH-dULs.

Spontaneous intracranial hypotension is a neurologic condition that is caused by a spinal cerebrospinal fluid (CSF) leak. The resulting CSF hypovolemia can manifest as a variety of clinical symptoms, with orthostatic headache being the most common. Although this disease has been recognized for decades, modern understanding of the types of causative spinal CSF leaks, diagnostic imaging tests to localize these leaks, and treatment options has evolved substantially in recent years. In this focused review article, we will provide an overview of the current diagnosis and treatment of spontaneous intracranial hypotension. We will emphasize recent improvements in understanding the pathophysiology of spinal leaks, developments in myelographic techniques to localize CSF leaks, and new treatment options for each type of leak.

Objective: To evaluate the performance of the left atrial time-to-peak (TTP) derived from time-resolved magnetic resonance angiography (TR-MRA) as a noninvasive indicator of left atrial pressure (LAP) in patients with atrial fibrillation (AF).

Materials and methods: This retrospective study included 92 patients who underwent cardiac TR-MRA and catheter-based LAP measurements prior to catheter ablation for AF between January 2021 and December 2022. TR-MRA-derived TTP was measured in the left atrium using contrast-enhanced time-signal intensity curves. Catheter-based LAP measured during sinus rhythm served as the reference standard, with high LAP defined as ≥15 mmHg. Univariable and multivariable linear regression analyses were performed, with LAP as the dependent variable and echocardiographic parameters as covariates. The diagnostic performance of TTP for high LAP was evaluated using receiver operating characteristic (ROC) curve analysis.

Results: Among the 92 patients (mean age ± standard deviation, 60 ± 10 years; 70 male), 70 (76.0%) had low LAP, and 22 (23.9%) had high LAP. Mean TTP was significantly longer in patients with high LAP than in those with low LAP (25.1 ± 6.9 s vs. 16.9 ± 5.7 s, P < 0.001). In multivariable linear regression analysis, TTP remained independently associated with LAP (β = 0.46, P < 0.001). ROC analysis demonstrated good discriminative performance of TTP for identifying high LAP, with an area under the curve of 0.834 (95% confidence interval, 0.742-0.904). Using a TTP cutoff of >19.6 seconds, the sensitivity and specificity for identifying elevated LAP levels were 81.8% (18/22) and 75.7% (53/70), respectively.

Conclusion: TR-MRA-derived TTP showed a significant independent association with invasively measured LAP. It may serve as a reliable noninvasive imaging marker for identifying high LAP in patients with AF undergoing catheter ablation.