Ji Hyun Koo

Sungkyunkwan University, Sŏul, Seoul, South Korea

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Publications (21)23.08 Total impact

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    Ji Hyun Koo · Sang-Hee Choi · Seung Ah Lee · Joon Ho Wang
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    ABSTRACT: The meniscus root plays an essential role in maintaining the circumferential hoop tension and preventing meniscal displacement. Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. However, few studies have directly compared the medial and lateral root tears. To assess the prevalence of meniscal extrusion and its relationship with clinical features in medial and lateral meniscus root tears, we performed a retrospective review of the magnetic resonance imaging (MRI) results of 42 knee patients who had meniscus posterior horn root tears and who had undergone arthroscopic operations. The presence of meniscal extrusion was evaluated and the exact extent was measured from the tibial margin. The results were correlated with arthroscopic findings. Clinical features including patients' ages, joint abnormalities, and previous trauma histories were evaluated. Twenty-two patients had medial meniscus root tears (MMRTs) and twenty patients had lateral meniscus root tears (LMRTs). Meniscal extrusion was present in 18 MMRT patients and one LMRT patient. The mean extent of extrusion was 4.2mm (range, 0.6 to 7.8) in the MMRT group and 0.9mm (range, -1.9 to 3.4) in the LMRT group. Five patients with MMRT had a history of trauma, while 19 patients with LMRT had a history of trauma. Three patients with MMRT had anterior cruciate ligament (ACL) tears, while 19 patients with LMRT had ACL tears. The mean age of the patients was 52 years (range: 29-71 years) and 30 years (range: 14-62 years) in the MMRT and LMRT group, respectively. There was a significant correlation between a MMRT and meniscal extrusion (p<0.0001), and between an ACL tear and LMRT (p<0.0001). A history of trauma was significantly common in LMRT (p<0.0001). LMRT patients were significantly younger than MMRT patients (p<0.0001). Kellgren-Lawrence (K-L) grade differed significantly between MMRT and LMRT group (p<0.0001). Meniscal extrusion is common in patients with MMRTs. However, it is rare in patients with LMRTs, which are more commonly associated with a history of trauma and ACL tears.
    Preview · Article · Oct 2015 · PLoS ONE
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    Ji Hyun Koo · Young Cheol Yoon · Jae Hoon Kim
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    ABSTRACT: To investigate whether quantitative parameters derived from Diffusion-weighted magnetic resonance imaging (DW-MRI) correlate with those of Dynamic contrast-enhanced MRI (DCE-MRI).
    Full-text · Article · Jan 2014
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    ABSTRACT: To retrospectively determine the optimal b value of diffusion-weighted imaging (DWI) for predicting the presence of localized prostate cancer, and to evaluate the utility of DWI under different b values in differentiating between cancers and benign prostatic tissues. Eighty patients with suspected prostate cancer underwent MRI including DWI at 3T, followed by radical prostatectomy. DWI was examined under different b values. Apparent diffusion coefficient (ADC) maps were generated by using b = 0, and other b values of 300, 700, 1000 or 2000 s/mm(2). For predicting the presence of cancers, four different ADC maps were analyzed independently by two blinded readers. ADCs were measured in benign and malignant tissues. For predicting the presence of 110 prostate cancers, the sensitivity and area under the curve (AUC) for an experienced reader was significantly greater at b = 1000 (85% and 0.91) than b = 300, 700 or 2000 s/mm(2) (p < 0.01). For a less-experienced reader, the AUC was significantly greater at b = 700, 1000 or 2000 than b = 300 s/mm(2) (p < 0.01). Mean ADCs of the cancers in sequence from b = 300 to 2000 s/mm(2) were 1.33, 1.03, 0.88 and 0.68 × 10(-3) mm(2)/s, which were significantly lower than those of benign tissues (p < 0.001). The optimal b value for 3T DWI for predicting the presence of prostate cancer may be 1000 s/mm(2).
    Full-text · Article · Jan 2013 · Korean journal of radiology: official journal of the Korean Radiological Society
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    ABSTRACT: PURPOSE To compare the metal artifacts and acquisition time among the slice encoding for metal artifact correction (SEMAC) images, SEMAC with dual-source parallel radiofrequency transmission images, and fast spin echo (FSE) images in 3.0T MR imaging. METHOD AND MATERIALS Our institutional review board approved this retrospective study and informed consent was waived. A phantom study was performed by using a titanium alloy pedicle screw. Total of 16 patients (3 men and 13 women) who underwent spine surgery, using pedicle screws, were included for this clinical study. The T1-weighted FSE images, the SEMAC images, and the SEMAC with dual-source parallel RF transmission images were obtained. The SNR was calculated in the phantom study. As a qualitative study, four imaging findings (visibility of the dural sac, visibility of neural foramens, visibility of bone-implant interface, overall artifacts) were evaluated by using five-point scales, independently by two observers. RESULTS In the phantom study, the mean SNR was 71.2, 25.7, and 28.4, and the scan time was 2 minutes 24 seconds, 12 minutes 53 seconds, and 8 minutes 36 seconds for the FSE images, the SEMAC images, and the SEMAC with dual-source parallel RF transmission images, respectively. In the clinical study, FSE images were ranked lower than that of the SEMAC images and the SEMAC with dual-source parallel RF transmission images. Further, the ranking of the SEMAC images and the images of the SEMAC with dual-source parallel RF transmission were not statistically different for all four imaging findings. The mean scan time was 9 minutes 51 seconds and 6 minutes 31 seconds for the SEMAC images and the SEMAC with dual-source parallel RF transmission images, respectively. CONCLUSION SEMAC can reduce metallic artifacts and improve the visualization of anatomical structures around the metal implants. With additional dual source parallel RF transmission technique can reduce the acquisition time of SEMAC images without a loss of SNR and image quality. CLINICAL RELEVANCE/APPLICATION Reduction of acquisition time of SEMAC with additional use of dual source parallel RF transmission technique can help to reduce the possibility of motion artifact and patient’s discomfort.
    No preview · Conference Paper · Nov 2012
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    ABSTRACT: PURPOSE To evaluate the usefulness of slice encoding for metal artifact correction (SEMAC) in patients who have metallic prosthesis after spinal surgery, compared with conventional fast spin-echo technique at 3.0-T MRI. METHOD AND MATERIALS Forty nine patients who have metallic spinal screw were enrolled in this retrospective study. The diameter of the metallic artifact (n=134) was repetitively measured on paired sagittal images of FSE and SEMAC by two independent radiologists. Visualization of periprosthetic bone marrow (n=134) and neural foramen (n=117) were evaluated with three- and four-point scale respectively. Intraobserver reliability and interobserver agreement were assessed. RESULTS The diameter of the metallic artifact was measured significantly larger on FSE images than on SEMAC images (p<0.001). Intraobserver reliability was excellent on both sequences (FSE, 0.921; SEMAC, 0.826). SEMAC images were significantly better than FSE images in terms of visualization of periprosthetic bone marrow (observer 1, p=0.007; observer 2, p<0.001) and neural foramen (observer 1, p<0.001; observer 2, p<0.001). Interobserver agreement was acceptable or excellent on both FSE (bone marrow, 0.714; neural foramen, 0.855) and SEMAC (bone marrow, 0.688; neural foramen, 0.792) images. CONCLUSION SEMAC is an effective method for reducing metal artifact compared with conventional fast spin-echo sequence. CLINICAL RELEVANCE/APPLICATION SEMAC can reduce the metal artifact and make the evaluation around spinal instrumentations much better.
    No preview · Conference Paper · Nov 2012

  • No preview · Conference Paper · Nov 2012
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    ABSTRACT: PURPOSE To evaluate differences in T2 relaxation time of ankle cartilage at magnetic resonance (MR) imaging according to the status of anterior talofibular ligament (ATFL). METHOD AND MATERIALS Talar trochlear cartilage (TTC) was evaluated in 52 subjects with ankle pain who were categorized according to the status of ATFL; normal (NL) (n = 22, mean age 40), partial tear (PT) (n = 23, mean age 39), or complete tear (CT) (n = 7, mean age 33). TTC was divided into six compartments (medial anterior, medial center, medial posterior, lateral anterior, lateral center, and lateral posterior). Mean T2 value of each compartment was obtained with multi-echo sequence. Data were analyzed with parametric and non-parametric statistical tests. RESULTS Mean T2 values of TTC showed significant difference between three groups; NL, PT, and CT (P < 0.001). T2 value between three ligamentous groups were significantly different in the compartment of medial anterior, lateral anterior, and lateral center (P=0.003, 0.002, 0.002). T2 values of PT and CT groups were significantly higher than that of NL group in the medial anterior (p = 0.015, 0.002) and lateral anterior compartment (p = 0.026, < 0.001). T2 value of CT group was significantly higher than those of NL and PT groups in lateral center compartment (P < .001, 0.031). CONCLUSION T2 value of TTC in patients with ATFL injury was increased at its medial anterior, lateral anterior, and lateral center compartments. CLINICAL RELEVANCE/APPLICATION T2 mapping of the articular cartilage may be clinically useful to select patients that are at risk to develop post-traumatic OA and require ligament repair from those that are not.
    No preview · Conference Paper · Nov 2012
  • Ji Hyun Koo · Ki Jeong Park · Yu Jin Oh · Sang-Hee Choi
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    ABSTRACT: PURPOSE The purpose of our study was to evaluate the normal range of lateral synovial plica of the elbow joint and propose the magnetic resonance (MR) imaging diagnostic criterion of symptomatic lateral synovial plica syndrome. METHOD AND MATERIALS We retrospectively reviewed 13 consecutive patients referred for operation for symptomatic lateral synovial plica syndrome of the elbow joint at our institution between November 2005 and August 2010. Patients who did not have preoperative elbow MR imaging or could not follow up for more than six months were excluded. On coronal and sagittal images, we measured the width of plica and calculated the width of plica-to-the width of radial head ratio which compared to those of normal control group. We evaluated whether there is significant difference between control group and symptomatic patients. Cut-off value of the width of synovial plica was also evaluated. RESULTS In lateral synovial plica syndrome group, the mean widths of plica were 6.2 mm, 6.5 mm respectively on coronal and sagittal images. On control group the mean widths of plica were 3.6 mm, 4.8 mm respectively on coronal and sagittal images. The mean widths of plica-to-radial head ratio were on patient group 0.29, 0.29 on coronal and sagittal images, respectively. The mean widths of plica-to-radial head ratio were on control group 0.16, 0.21on coronal and sagittal images, respectively. The width of plica and the width of plica-to-radial head ratio were significantly higher than those of the control group (p < 0.05). Cut-off value for diagnostic criteria of lateral synovial plica syndrome were 4.4 mm on coronal (sensitivity, 100%, specificity, 76%, positive predictive value, 52%, negative predictive value, 100%, accuracy, 81%) and 5.6 mm on sagittal images (sensitivity, 69%, specificity, 68%, positive predictive value, 36%, negative predictive value, 89%, accuracy, 68%). CONCLUSION In patients who had symptomatic lateral synovial plica syndrome, the width of plica and the width of plica-to-radial head ratio are significantly higher than those of the control group. Cut-off value for diagnostic criteria of synovial plica can be applied for preoperative diagnosis of lateral synovial plica syndrome. CLINICAL RELEVANCE/APPLICATION Cut-off value for diagnostic criteria of synovial plica can be applied for preoperative diagnosis of lateral synovial plica syndrome.
    No preview · Conference Paper · Nov 2012
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    ABSTRACT: Our aim was to determine whether sonographically guided radiofrequency ablation with superficial saline injection can minimize thermal injury of the skin without an influence on therapeutic efficacy. Institutional Animal Care Committee approval was obtained. Twelve percutaneous radiofrequency ablation procedures were performed in the thighs of 6 rabbits (control, n = 6, right thigh; experimental, n = 6, left thigh). The ablation with local anesthesia was performed in the most superficial area of the thigh muscle. In the experimental group, 1 mL of saline was injected before the ablation at the tissue layer between the skin and ablated muscle. The duration and energy of the ablation were the same in the control and experimental groups. Rabbits were compared for their gross skin state and histopathologic findings after the ablation. The degree of thermal coagulation of the muscle was similar in both groups at pathologic examination. Grossly, skin redness was mild in the experimental group but moderate in the control group. Of the 6 rabbits, 5 tended to show more frequent histopathologic changes, including an inflammatory reaction, interruption of collagen fibers, injury of the skin adnexa, and fibrosis, in the control group when compared with the experimental group. However, there was no statistically significant difference (all P> .05). One rabbit that underwent ablation at higher energy had a partially dissected epidermis in the control group only. Sonographically guided radiofrequency ablation with a saline injection superficial to a tumor might prevent skin burns and provide equivalent therapeutic efficacy for ablating superficial lesions.
    No preview · Article · Jun 2012 · Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine
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    ABSTRACT: We investigated low dose digital tomosynthesis (DT) for the evaluation of the paranasal sinus (PNS), and compared its diagnostic accuracy with a PNS radiography series (XR). We enrolled 43 patients for whom XR, PNS DT, and OMU CT were performed. We measured effective doses (EDs) of XR, DT, and OMU CT using Monte Carlo simulation software. Two radiologists performed independent observation of both XR and DT. For seven PNSs, they scored anatomic conspicuity of sinuses and confidence on the presence of sinusitis using nine point scales. OMU CT was observed by the third radiologist and the findings were regarded as reference standard. We compared scores for conspicuity and sinusitis confidence between XR and DT. Mean EDs were 29 ± 6 µSv, 48 ± 10 µSv, and 980 ± 250 µSv, respectively, for XR, DT, and CT. Mean scores for conspicuity were 6.3 and 7.4, respectively, for XR and DT. Sensitivity per patient basis for sinusitis detection were 52% and 96%, respectively, for XR and DT in observer 1 (p = 0.001) and 80% and 92% for observer 2 (p = 0.25). Specificities for sinusitis exclusion were 100% for both XR and DT for observer 1 and 89% and 100% for observer 2 (p = 0.50). Accuracies for sinusitis diagnosis were 72% and 98%, respectively, for XR and DT for observer 1 (p = 0.001) and 84% and 95% for observer 2 (p = 0.125). Patient radiation dose from low dose DT is comparable with that of PNS XR. Diagnostic sensitivity of DT for sinusitis was superior to PNS XR.
    Full-text · Article · Mar 2012 · Korean journal of radiology: official journal of the Korean Radiological Society
  • H.N. Jung · M.J. Chung · J.H. Koo · H.C. Kim · K.S. Lee
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    ABSTRACT: To evaluate the performance of digital tomosynthesis (DT) of the chest for detection of lung nodules in patients with colorectal cancer (CRC). The institutional review board approved this study, and all patients provided informed consent. A commercial caesium iodide/amorphous silicon (CsI/a-Si) flat-panel detector system was used to verify the performance of the DT and chest radiography (XR) methods. DT was performed in 142 patients with CRC. All 142 patients underwent chest computed tomography (CT) within a week of DT. As a reference standard, two radiologists reviewed the chest CT in consensus and recorded the presence of pulmonary nodules. Another two radiologists independently observed the DT images and recorded the presence of pulmonary nodules. The status of all lung nodules was assessed either histologically or by follow-up over a period of 1 year. The nodules were classified into metastasis, benign, and uncertain. Statistical analysis of the results was performed. Two hundred and thirty-seven nodules from 142 patients were found at CT. These included 71 proven metastases and 126 benign nodules; 40 nodules were uncertain. Observers detected 83% of all lung nodules and 93% of proven metastases using DT. Among 237 nodules, 147 nodules were larger than 4mm in diameter on the CT images. Observers detected 87% of lung nodules that were larger than 4mm. Despite a reasonably low radiation dose, DT is a sensitive method, and is comparable to chest CT for the detection of lung nodules, particularly metastatic lung nodules in patients with CRC.
    No preview · Article · Sep 2011 · Clinical Radiology
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    ABSTRACT: To evaluate the difference in diagnostic performance of hydro-stomach computed tomography (CT) to detect early gastric cancer (EGC) between blinded and unblinded analysis and to assess independent factors affecting visibility of cancer foci. Two radiologists initially blinded and then unblinded to gastroscopic and surgical-histological findings independently reviewed hydro-stomach CT images of 110 patients with single EGC. They graded the visibility of cancer foci for each of three gastric segments (upper, middle and lower thirds) using a 4-point scale (1: definitely absent, 2: probably absent, 3: probably present, and 4: definitely present). The sensitivity and specificity for detecting an EGC were calculated. Intraobserver and interobserver agreements were analyzed. The visibility of an EGC was evaluated with regard to tumor size, invasion depth, gastric segments, histological type and gross morphology using univariate and multivariate analysis. The respective sensitivities and specificities [reviewer 1: blinded, 20% (22/110) and 98% (215/220); unblinded, 27% (30/110) and 100% (219/220)/reviewer 2: blinded, 19% (21/110) and 98% (216/220); unblinded, 25% (27/110) and 98% (215/220)] were not significantly different. Although intraobserver agreements were good (weighted κ = 0.677 and 0.666), interobserver agreements were fair (blinded, 0.371) or moderate (unblinded, 0.558). For both univariate and multivariate analyses, the tumor size and invasion depth were statistically significant factors affecting visibility. The diagnostic performance of hydro-stomach CT to detect an EGC was not significantly different between blinded and unblinded analysis. The tumor size and invasion depth were independent factors for visibility.
    Preview · Article · Feb 2011 · World Journal of Gastroenterology
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    ABSTRACT: Esophagopleural fistulas after esophageal diverticulectomy are very rare complications. Many treatment options have been reported, and the appropriate method should be chosen according to the individual's clinical status. The authors introduce a new treatment method of esophagopleural fistulas using an AMPLATZER vascular plug (AGA Medical Corporation, Plymouth, Minnesota), coils, and Histoacryl glue (B. Braun, Melsungen AG, Germany), thus avoiding extensive surgery or covered stent insertion.
    No preview · Article · Dec 2010 · Journal of vascular and interventional radiology: JVIR
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    ABSTRACT: PURPOSE The importance of small pulmonary nodules detected on chest radiography (XR) and CT varies substantially according to their size and characterization. Thus RECIST 1.1 recommended that plain radiography should be used for lung nodules larger than 2 cm in diameter. Recent advances in volumetric X-ray digital tomosynthesis (DT) may enable the detection of small lung nodules. With this potential it’s imperative to understand nodule measurement accuracy and its implications on nodule follow-up and management. This accuracy was proved in phantom study but not yet in clinical condition. Thus the purpose of this study was to evaluate the accuracy of measuring the size of each nodule with both XR and DT compared to CT in real clinical conditions. METHOD AND MATERIALS 61 lung nodules (diameter 4 – 20 mm on CT) were selected from 51 patients who had chest CT, XR, and DT within a week. We assessed characteristics (location, marginal sharpness) and coronal diameters (longest diameter on the plane with maximum nodule size) of each nodule on coronal CT as a reference. Two readers independently measured each nodule on XR and DT. We analyzed overall and individual performance and variability. RESULTS The mean diameters of the nodules were 12.3 ± 5.0 mm, 12.5 ± 5.1 mm, and 13.3 ± 5.5 mm, on coronal CT, DT, and XR, respectively. Inter-observer correlation coefficients were .95, .92, and .79 on CT, DT, and XR, respectively. DT (R = .97, P < .01) was correlated better than XR (R = .79, P < .01) with CT . Mean difference of diameter (ΔD) between DT and CT was 0.1 ± 1.2 mm (P = .20, paired T-test)). ΔD of XR was 0.7 ± 3.0 mm (P < .01). For anterior nodules, ΔD were not significant in both DT (0.2 ± 1.4 mm, P = .40) and XR (0.3 ± 2.3 mm, P = .46). For posterior nodules, ΔD was not significant in DT (0.8 ± 1.1 mm, P = .92) but significant in XR (2.0 ± 1.5 mm, P < .01). Variations of difference were not different between well (0.0 ± 1.1 mm) and poorly marginated nodules (0.3 ± 1.4 mm) on DT (P = .18, Levene test), or between left (0.3 ± 1.2 mm ) and right (0.0 ± 1.2 mm) lungs on DT (P = .39). CONCLUSION DT was well correlated and not significantly different than CT for lung nodule size measurement in clinical conditions. DT is comparable to CT for accuracy of lung noulde size. CLINICAL RELEVANCE/APPLICATION With digital tomosynthesis, the size of small lung nodules can be accurately determined, which may improve patient management and follow-up.
    No preview · Conference Paper · Nov 2010
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    ABSTRACT: PURPOSE To determine the optimal b value of 3-T diffusion-weighted MR imaging (DWI) in the prediction of localized prostate cancer, and to evaluate the utility of DWI under different b values in differentiating between the cancers and benign prostatic tissue. METHOD AND MATERIALS 80 consecutive patients with suspected prostate cancer underwent T2-weighted imaging (T2WI) and DWI at 3T using a phased-array coil, followed by radical prostatectomy. DWI was examined with single-shot echo-planar imaging sequence under different b values. Apparent diffusion coefficient (ADC) maps were generated by two b values (i.e., b= 0 and another b value of 300, 700, 1000 or 2000 s/mm2). For predicting the cancer location, the prostate was divided into 10 regions and based on the anatomical details of T2WI, ADC maps at b= 300 (ADC1), 700 (ADC2), 1000 (ADC3) and 2000 (ADC4) s/mm2 were analyzed independently by two blinded readers (experienced and less-experienced) using a five-point scale and the results were compared. ADC values were measured in benign and malignant tissues in the peripheral zone (PZ) or transition zone (TZ). The results at ADC maps of each b value were correlated with step-section histopathologic findings. RESULTS For predicting 102 prostate cancers, the sensitivity in the experienced reader was significantly greater at ADC3 (84.9%) than at ADC1 (35.1%), ADC2 (78%) or ADC4 (74.1%) (P< 0.01). However, the specificity was similar at all b values, with at least 92%. In the experienced reader, the area under the curve (Az) in order from ADC1 to ADC4 was 0.689, 0.877, 0.91 and 0.866, respectively and that of ADC3 showed a significant difference as compared with the others. In the less-experienced reader, the Az value of ADC2 (0.646), ADC3 (0.652) or ADC4 (0.636) was significantly greater than that of ADC1 (0.589) (P< 0.01). The mean ADC value of the cancers in order from ADC1 to ADC4 was 1.34 ± 0.33, 1.03 ± 0.23, 0.83 ± 0.21 and 0.68 ± 0.15 × 10-3mm2/s, respectively, which were significantly lower than that of benign PZ or TZ (P< 0.001). CONCLUSION For predicting the prostate cancer, the optimal b value for 3-T DWI was found to be 1000 s/mm2. Furthermore, 3-T DWI under different b values could differentiate the cancers and benign prostate tissue. CLINICAL RELEVANCE/APPLICATION With the application of the optimal b value of 1000 s/mm2, 3-T DWI using a phased-array coil can improve the diagnostic performance for the evaluation of prostate cancer.
    No preview · Conference Paper · Nov 2010
  • J.H. Koo · J.H. Shin · B.K. Han · E.Y. Ko · S.S. Kang
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    ABSTRACT: Objective. The purpose of our study was to provide sonographic findings of cystic nodules, which can mimic malignancies, after fine-needle aspiration (FNA) and to determine the differential points from malignancies. Methods. We retrospectively reviewed the sonographic findings of 33 lesions in 32 patients who had FNA for predominantly cystic nodules or cysts and showed suspicious findings during sonographic follow-up, as well as findings of 47 surgically confirmed papillary thyroid carcinomas (PTCs) in 45 consecutive patients. We evaluated the size, shape, presence of shadowing and a halo, margin, echogenicity, and presence of echogenic dots for each nodule. The final diagnosis of cystic nodules was confirmed by FNA, surgery, or follow-up sonography. Results. Of the 33 cystic lesions, 31 (94%) were adequate with benign results, and 2 (6%) were inadequate specimens at the initial FNA. There were no malignancies in the cystic nodules at follow-up. The average interval between the initial FNA and suspicious sonographic findings was 26 months (range, 1-92 months). The average size of the suspicious nodules was 0.8 cm (range, 0.3-1.8 cm). Cystic nodules after aspiration were similar to PTCs in their sonographic findings, but the former frequently showed shadowing and a halo (85% versus 21%; P < .0001). With further follow-up, 29 lesions (88%) showed additional decreases in size. Conclusions. Benign cystic nodules after aspiration can have suspicious malignant features. However shadowing and a halo associated with malignant features are characteristic findings of cystic nodule shrinkage. Awareness of these findings and correlation with the FNA history can aid in preventing unnecessary FNA.
    No preview · Article · Oct 2010
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    ABSTRACT: The purpose of our study was to provide sonographic findings of cystic nodules, which can mimic malignancies, after fine-needle aspiration (FNA) and to determine the differential points from malignancies. We retrospectively reviewed the sonographic findings of 33 lesions in 32 patients who had FNA for predominantly cystic nodules or cysts and showed suspicious findings during sonographic follow-up, as well as findings of 47 surgically confirmed papillary thyroid carcinomas (PTCs) in 45 consecutive patients. We evaluated the size, shape, presence of shadowing and a halo, margin, echogenicity, and presence of echogenic dots for each nodule. The final diagnosis of cystic nodules was confirmed by FNA, surgery, or follow-up sonography. Of the 33 cystic lesions, 31 (94%) were adequate with benign results, and 2 (6%) were inadequate specimens at the initial FNA. There were no malignancies in the cystic nodules at follow-up. The average interval between the initial FNA and suspicious sonographic findings was 26 months (range, 1-92 months). The average size of the suspicious nodules was 0.8 cm (range, 0.3-1.8 cm). Cystic nodules after aspiration were similar to PTCs in their sonographic findings, but the former frequently showed shadowing and a halo (85% versus 21%; P < .0001). With further follow-up, 29 lesions (88%) showed additional decreases in size. Benign cystic nodules after aspiration can have suspicious malignant features. However, shadowing and a halo associated with malignant features are characteristic findings of cystic nodule shrinkage. Awareness of these findings and correlation with the FNA history can aid in preventing unnecessary FNA.
    No preview · Article · Oct 2010 · Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine
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    ABSTRACT: This study was designed to compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance imaging (MRI) with gadobenate dimeglumine-enhanced MRI for preoperatively detecting hepatocellular carcinoma (HCC). Eighteen consecutive patients (17 men and one woman, age range: 31-73 years) with 22 HCCs underwent examinations with gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI on a 3.0-Tesla unit. The diagnosis of HCC was established after surgical resection and pathological conformation. Three observers independently reviewed each MR image in a random order on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for the detection of HCC was assessed by performing an alternative free-response receiver operating characteristic (ROC) analysis. The sensitivity and positive predictive values were evaluated. The average value of the area under the ROC curve (Az) for gadoxetic acid enhanced MRI (0.887) was not significantly different from the Az (0.899) for gadobenate dimeglumine-enhanced MRI (p > 0.05). The overall sensitivities of gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI were 80% and 83%, respectively, with no significant difference (p > 0.05). The differences of the positive predictive values for the two contrast agents for each observer were not statistically significant (p > 0.05). The diagnostic performance of gadoxetic acid-enhanced MRI and gadobenate dimeglumine-enhanced MRI for preoperatively detecting HCC is quite similar.
    Preview · Article · Jun 2010 · Korean journal of radiology: official journal of the Korean Radiological Society
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    ABSTRACT: PURPOSE The aim of this study was to evaluate the performance of low dose (LD) digital tomosynthesis (DTS) of the chest for detecting lung lesions and estimating disease activity in patients with pulmonary tuberculosis. METHOD AND MATERIALS DTS was performed with a commercial CsI/a-Si flat panel detector system. We tuned the parameters of DTS and established lesser dose condition for chest scan. The entrance surface dose of this protocol was 0.3 mGy, and effective dose was 0.05 mSv on RANDO phantom. Effective dose of volume thin section chest CT (vHRCT) of our institute was 3.4 mSv on same phantom. LD DTS was performed in 37 patients with pulmonary tuberculosis. Synthetic coronal planar images were reconstructed with 5 mm interval. Reconstructed images fully covered from anterior skin to back of chest. All of 37 patients underwent vHRCT within a week from DTS. Involved lobes by lung lesions such as bronchiolitis, nodules, consolidation, and bronchiectasis on DTS were recorded. Number and location of cavities were recorded, also. Thereafter, these records were matched and compared to the findings of vHRCT. RESULTS Extents of lung lesion patterns were well matched between LD DTS and vHRCT. Inter-modality agreements were analyzed using Kappa statistical analysis (.690 for bronchiolitis, .614 for nodules, .653 for consolidation, and .775 for bronchiectasis). Total 51 cavities were found in 23 patients on vHRCT. Plane chest radiography revealed 18 cavities and two false lesions (sensitivity 35%, specificity 86%). LD DTS revealed 45 cavities and three false lesions (sensitivity 88%, specificity 79%). CONCLUSION Low dose digital tomosynthesis of the chest gave minimal radiation to the patient compared to chest CT. In spite of very low radiation dose, DTS is a sensitive modality comparable to chest CT to detect lung lesions and to estimate disease activity in patients with pulmonary tuberculosis. CLINICAL RELEVANCE/APPLICATION Pulmonary tuberculosis is common in young population.Low dose digital tomosynthesis is safe and accurate alternate of chest CT for evaluating pulmonary tuberculosis especially in these young patients.
    No preview · Conference Paper · Dec 2009
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    ABSTRACT: We aimed to retrospectively compare CT, PET, and histopathologic (the extent of bronchioloalveolar carcinoma [BAC] components) findings of solitary pulmonary nodular (SPN) adenocarcinomas of the lung to determine their value as prognostic determinants. We reviewed CT and PET characteristics of tumors and pathologic specimens from 65 consecutive patients who underwent surgical resection for SPN adenocarcinomas. Nodule size and TDR (tumor shadow disappearance rate) were assessed from CT scans, and maximum standardized uptake value (SUVmax) of tumors was measured at PET. On pathologic examination, BAC, non-BAC, and central fibrous scar ratios were quantified. Prognosis was evaluated by noting disease recurrence during a minimum 12-month follow-up period after curative resection. The interrelationships between TDR, SUVmax, BAC, and non-BAC ratio were studied, and relationships between recurrence and various variables were analyzed. The median follow-up time was 33 months, and seven patients (11%) developed disease recurrence after surgical resection. TDR at CT and SUVmax at PET correlated well with pathologic BAC and non-BAC ratios. Between subgroups with and without recurrence, there were significant differences in SUVmax and BAC and non-BAC ratios. Based on univariate survival analyses, pathologic BAC and non-BAC ratios were risk factors significantly related to recurrence, but only high non-BAC ratio remained as an independent factor associated with recurrence in the multivariate analysis (hazard ratio [HR]=0.956, P=0.013). Among the factors examined, pathologic non-BAC ratio is the only independent risk factor for poor prognosis in patients with SPN adenocarcinomas.
    No preview · Article · Apr 2009 · Lung cancer (Amsterdam, Netherlands)