Time course of complications after small renal mass biopsy: evaluation of initial follow-up images.

PURPOSE: To retrospectively assess the time course of complications after image-guided small renal mass biopsy using initial follow-up imaging. MATERIALS AND METHODS: A total of 190 masses (mean, 2.1 ± 0.70 cm; range, 0.6-3.8 cm) were assessed using initial computed tomography (43 non-enhanced and 141 enhanced) or magnetic resonance imaging (five non-enhanced and one enhanced) after biopsy. Initial follow-up imaging was classified into two groups (i.e., with or without hematoma) and various factors were compared. RESULTS: The masses were histologically diagnosed in all patients except one. Post-procedural complications included 129 Grade I hematomas, 1 Grade I hemothorax, 9 Grade II hematomas, and 1 Grade IIIa pneumothorax. Residual 28 Grade I and 6 Grade II hematomas and 8 new complications (6 small hematomas, 1 pseudoaneurysm, and 1 arteriovenous fistula) were observed on the initial follow-up imaging obtained at a median of 21 days (3-90 days) after the biopsy. On the initial follow-up imaging, the groups with and without hematoma differed significantly in the following factors: age (P = 0.04), size (P = 0.02), guided images (P < 0.01), hematoma at the end of the procedure (P < 0.01), and days after biopsy (P < 0.01). Although three masses exhibited > 25% shrinkage, no significant change was observed in mass diameter on initial follow-up imaging (mean, 2.1 ± 0.71 cm; P = 0.90). CONCLUSION: Initial follow-up imaging after a biopsy revealed improvements in most of the complications, a few new complications, and an unchanged mass diameter.

Correlation between renal ablation zone in contrast-enhanced CT and non-enhanced MRI during the early period following percutaneous cryoablation.

PURPOSE: To retrospectively evaluate and correlate the contrast-enhanced computed tomography (CECT) and non-enhanced magnetic resonance imaging (MRI) during the early period following renal cryoablation. MATERIALS AND METHODS: Both dynamic CECT and non-enhanced MRI were performed within 4 days following cryoablation in 34 renal tumors in 33 patients. The renal volumes of the unenhanced regions on dynamic CECT (nephrogenic phase, 4 mm thickness) and the regions with signal intensity changes on non-enhanced MRI (fat-suppressed T2-weighted image, 4 mm thickness) were evaluated. Fusion images of the axial, coronal, and sagittal sections of CECT and MRI images were created from the maximum cross-section of the renal tumor, and the match score of each image was visually evaluated on a 5-point scale. RESULTS: The mean renal volume of the unenhanced regions on CECT and those with signal intensity changes on non-enhanced MRI following cryoablation were 29.5 ± 19.9 cm3 (range, 4.3-97.4 cm3) and 30.7 ± 19.8 cm3 (range, 6.7-94.0 cm3), respectively; the difference between them was -1.17 cm3 (95% confidence interval [CI] -2.74, 0.40, P = 0.139). The Pearson's product-moment correlation coefficient (r = 0.975; 95% CI, 0.951, 0.988; P < 0.0001) showed a strong correlation between the volumes. The average match score between CECT and non-enhanced MRI was as high as 4.5 ± 0.5 points (radiologist 1, 4.3 ± 0.5; radiologist 2, 4.7 ± 0.5). Local tumor control rate was 94.1% (32/34 tumors) and recurrence-free survival rate was 82.0% (95% CI: 64.2%, 91.5%) at 5 years. CONCLUSIONS: The region with signal intensity changes on non-enhanced MRI was strongly correlated with the unenhanced region on CECT during the early period following renal cryoablation.

CT evaluation of patent artery after percutaneous cryoablation of renal cell carcinoma.

PURPOSE: The purpose of this retrospective study was to determine the incidence of persistent patent artery after percutaneous cryoablation of renal cell carcinoma (RCC) and the relationship between patent arteries one month after cryoablation and early tumor progression. MATERIALS AND METHODS: One hundred and fifty-nine patients (112 men, 47 women; mean age, 63.6±14.6 [SD] years; age range: 21-91 years) who underwent percutaneous cryoablation for 186 RCCs (mean diameter, 1.9±0.6 [SD] cm; range: 0.7-4.0cm) were retrospectively included. After cryoablation, patients underwent contrast-enhanced computed tomography (CT) with ≤2-mm slice thickness within one week from cryoablation, and at one, three, and six months. The time course of patent artery in the ablated renal parenchyma after cryoablation was the primary endpoint. The relationships between patent arteries one month after cryoablation and treatment effectiveness, tumor vascularity, tumor enhancement one month after cryoablation, tumor subtype, and renal function changes were evaluated as secondary endpoints. RESULTS: CT showed patent arteries in the ablated renal parenchyma within one week in 166 RCCs (89.2%), at one month in 54 RCCs (29.0%), at three months in 8 RCCs (4.3%), and at six months in 2 RCCs (1.1%). The presence of patent artery one month after cryoablation was significantly associated with tumor enhancement at the same time point (P=0.015). There was no association between patent arteries one month after cryoablation and treatment effectiveness (P=0.693). CONCLUSION: Patent arteries in the ablated renal parenchyma are commonly observed on CT examination after percutaneous cryoablation of RCC. However, they gradually disappear and do not require specific treatment.

Contrast examination of central venous access port implanted through internal jugular vein for evaluation of suspected complications.

PURPOSE: We summarized the findings, diagnosis, and outcomes of cases for which contrast examination of central venous access ports (CV-ports) were attempted to detect complications. MATERIALS AND METHODS: Fifty-seven contrast examinations were attempted for 45 patients with 46 CV-ports (median, 162 days after implantation). Contrast examination was performed due to three suspicion catheter fractures or 54 CV-port dysfunctions (combinations of an absence of blood reflux on aspiration and 9 sufficient, 21 insufficient, or 24 impossible drip infusions). RESULTS: Contrast examination was successfully performed in 52 cases and revealed 45 normal findings, 5 pericatheter fibrin sheath formations, and 2 partial catheter fractures. In 23 of 45 cases with normal findings, the resistance to injection was initially mild or moderate but resolved after the CV-port was flushed slowly with heparinized saline solution. Subsequent contrast examination demonstrated normal findings. All fibrin sheath formations disappeared after thrombolytic therapy. Five cases could not undergo contrast examination due to high resistance. After contrast examination, nine of 46 CV-ports were removed or exchanged, while the use of the remaining 37 continued. CONCLUSION: Contrast examination of CV-port allowed the assessment of suspected complications and early treatment.

Computed Tomography-guided Core Needle Biopsy for Renal Tumors: A Review.

Small renal tumors are sometimes challenging to diagnose accurately through imaging alone, and image-guided biopsies are performed when histological diagnoses are needed. Although ultrasound guidance is usually chosen for renal tumor biopsies, computed tomography guidance is preferred for selected cases; e.g., obese patients or when the target is undetectable by ultrasound (as those in the upper pole). In the 14 recently published studies covering ≥50 procedures, computed tomography-guided renal tumor biopsies had a wide range diagnostic yield (67.4%-97.4%). Complications often occurred; however, most were minor and asymptomatic. No biopsy-related deaths and tumor seeding occurred. This study aimed to review the advantages and disadvantages, procedure techniques, diagnostic yields, and complications of core needle biopsies for renal tumors under computed tomography guidance.

Gradual enhancement pattern of tracheobronchial adenoid cystic carcinoma on multiphasic dynamic computed tomography†:†a case series.

Tracheobronchial adenoid cystic carcinoma is a rare malignancy. To the best of our knowledge, its enhancement pattern on multiphasic contrast-enhanced multidetector computed tomography has not been reported. Herein, we report the computed tomography findings of three consecutive cases of tracheobronchial adenoid cystic carcinoma. All lesions presented a gradual enhancement pattern on multiphasic contrast-enhanced computed tomography. We speculate that the gradual enhancement pattern on multiphasic contrast-enhanced computed tomography could potentially serve as a characteristic imaging feature and may therefore be a clue to diagnose tracheobronchial adenoid cystic carcinoma. J. Med. Invest. 67 : 378-381, August, 2020.