Shu-Huei Shen

Diffusion-weighted single-shot echo-planar imaging with parallel technique in assessment of endometrial cancer.

OBJECTIVE The purposes of this study were to determine the feasibility of diffusion-weighted imaging (DWI) with a single-shot echo-planar sequence and parallel technique for depicting endometrial cancer and to examine the role of this technique in preoperative assessment. SUBJECTS AND METHODS A total of 31 patients were recruited for MRI evaluation of suspicious endometrial lesions found on transvaginal sonography. Twenty-four of the patients were proved to have endometrial cancer (patient group), and seven to have benign diseases (control group). The MRI examinations included diffusion-weighted single-shot echoplanar sequences and contrast-enhanced T1-weighted 3D fat-suppressed spoiled gradient-echo sequences. The apparent diffusion coefficient of endometrial cancer in the patient group and of normal endometrium in the control group were measured on the apparent diffusion coefficient map of each diffusion-weighted image and compared for the two groups. In the patient group, myometrial invasion was evaluated with the two sequences. The diagnostic accuracy rates of each pulse sequence were compared. RESULTS The mean apparent diffusion coefficient of endometrial cancer was 0.864 x 10(-3) mm2/s and that of benign endometrial lesions was 1.277 x 10(-3) mm2/s. The difference between the two groups was significant (p = 0.0058). The diagnostic accuracy for myometrial invasion was 61.9% for DWI and 71.4% for gadolinium-enhanced T1-weighted 3D fat-suppressed spoiled gradient-recalled echo images. In five cases, DWI provided information about tumor extent and depicted the tumor focus, findings that changed preoperative staging. CONCLUSION DWI performed with parallel imaging technique has potential as a method for differentiating benign from malignant endometrial lesions. It also provides valuable information for preoperative evaluation and should be considered part of routine preoperative MRI evaluation for endometrial cancer.

Are There Useful CT Features to Differentiate Renal Cell Carcinoma From Lipid-Poor Renal Angiomyolipoma?

OBJECTIVE This study was an attempt to identify key CT features that can potentially be used to differentiate between lipid-poor renal angiomyolipoma and renal cell carcinoma (RCC). MATERIALS AND METHODS We conducted an analysis of patients who received nephrectomy or renal biopsy from 2002 to 2011 with suspected RCC. We included tumors smaller than 7 cm with a completed three-phase CT examination. A radiologist and a urology fellow, blinded to histopathologic diagnosis, recorded the imaging findings by consensus and compared the values for each parameter between lipid-poor angiomyolipoma, RCC subtypes, and RCC as a group. Multivariate logistic regression analysis was performed for each univariate significant feature. RESULTS The sample in our study consisted of 132 patients with 135 renal tumors, including 51 men (age range, 26-84 years; mean age, 57 years) and 81 women (age range, 29-91 years; mean age, 57 years). These tumors included 33 lipid-poor angiomyolipomas, 54 clear-cell RCC, 31 chromophobe RCC, and 17 papillary RCC. Multivariate analysis revealed four significant parameters for differentiating RCC as a group from lipid-poor angiomyolipoma (angular interface, p = 0.023; hypodense rim, p = 0.045; homogeneity, p = 0.005; unenhanced attenuation > 38.5 HU, p < 0.001), five for clear-cell RCC, two for chromophobe RCC, and one for papillary RCC. Lipid-poor angiomyolipoma and clear-cell RCC showed early strong enhancement and a washout pattern, whereas chromophobe RCC and papillary RCC showed gradual enhancement over time. CONCLUSION Specific CT features can potentially be used to differentiate lipid-poor renal angiomyolipoma from renal cell carcinoma.

Prospective Comparison of Unenhanced Spiral Computed Tomography and Intravenous Urography in the Evaluation of Acute Renal Colic

Background: The purpose of this prospective study was to evaluate the feasibility of replacing intravenous urography (IVU) with unenhanced computed tomography (CT) as the first line diagnostic modality for acute renal colic in the emergency department. Methods: In the 1‐year study period, 82 patients who presented themselves to the emergency room with acute renal colic and who were suspected to have ureteral stones were included. They received both IVU and unenhanced CT on the same day. Results: Sixty‐six patients were proven to have ureteral stone. Four had other urologic pathology (acute pyelonephritis, angiomyolipoma with hemorrhage, ureteropelvic junction stenosis). The remaining 12 had no definite urologic problem. Among the 66 patients with ureteral stone, the sensitivity for detecting ureteral stone was 98.5% for unenhanced CT and 59.1% for IVU. Correct diagnosis could be obtained in most of the patients receiving unenhanced CT, while IVU could provide only limited information about the intra‐abdominal pathology other than urologic system, and as many as 31.7% of the patients needed further imaging examination (sonography, CT, magnetic resonance imaging). In 5 patients, the relationship of the calcified spot and ureter were unclear on axial images. With curved multiplanar reformatted reconstruction, the diagnosis of ureter stone could be confidently made. No side effect (renal toxicity, allergic reaction) from intravenous administration of iodine‐containing contrast medium should be taken into consideration in CT. Besides, the average examination time was 108 minutes for IVU, which was significantly more than the 30 minutes for CT, including the time for curved multiplanar reformatted reconstruction. Conclusion: We consider that unenhanced CT is more effective and efficient than IVU and should replace IVU as the first‐line diagnostic tool for ureteral stone in the emergency department.

Evaluation of the extent of ketamine-induced uropathy: the role of CT urography

Background With growing ketamine abuse, ketamine-induced uropathy (KIU) has become more prevalent in recent years. This research evaluates the presence, distribution and extent of KIU in the upper and lower urinary tracts by retrospectively reviewing CT urography (CTU) images. Methods Patients diagnosed with KIU who underwent CT scanning from 1 January 2006 to 31 December 2011 were recruited. The CT protocols included three-phase CTU in six patients, split-bolus CTU in 17, two-phase CT in one and unenhanced CT in three. The CT images were retrospectively reviewed by two radiologists. Results A total of 27 patients participated in this study. The common CT findings included diffuse bladder wall thickening (88.9%), small bladder volume (66.7%) and perivesical inflammation (44.4%). Twelve patients (44.4%) were diagnosed with hydronephrosis, including three patients with unilateral hydronephrosis and nine with bilateral hydronephrosis. Of these patients, nine had ureteral wall thickening (33.3%) and two (7.4%) had ureterovesical junction involvement (ie, they had hydronephrosis but no ureteral wall thickening). One patient had a ureteral obstruction because of a ureter stone. The correlation between upper urinary tract involvement and grading of the interstitial cystitis was statistically non-significant (p=0.33). Four patients (14.8%) had a vesicovaginal fistula which could be detected in the excretory phase only. Conclusions Upper urinary tract involvement is common in patients with KIU. CTU might aid evaluation of the extent of KIU and prompt adequate management.

Differentiating Colonic Diverticulitis from Colon Cancer: The Value of Computed Tomography in the Emergency Setting

Background: The purpose of this study was to establish practical diagnostic criteria to differentiate colonic diverticulitis from colon cancer by computed tomography (CT) in the emergency department (ER). Methods: Helical CT scans of 40 patients admitted to the ER with the clinical diagnosis of diverticulitis and 14 patients diagnosed with colon cancer were retrospectively reviewed. In total, 18 imaging parameters were analyzed and were compared between the 2 groups of patients. Results: Thirteen parameters were found to be statistically significant for the diagnosis of colonic diverticulitis in excluding colon cancer: pericolic infiltration (p < 0.001); presence of lymph nodes (p < 0.001); inflamed diverticula (p = 0.001); non‐inflamed diverticula (p = 0.001); degree of enhancement (p = 0.001); intestinal obstruction (p = 0.001); involved wall thickness (p = 0.005); lymph node size (p = 0.007); fascial thickening (p = 0.009); pattern of enhancement (p = 0.012); involved length (p = 0.014); free air (p = 0.035); and abscess formation (p = 0.042). Among these parameters, the most valuable imaging findings for diverticulitis were the presence of non‐inflamed diverticulum, inflamed diverticulum, mild degree of enhancement, and small lymph node size. Three were found to have high specificity but low sensitivity: target enhancement pattern; abscess formation; and free air. When colonic obstruction is present, colon cancer is more likely than diverticulitis. Conclusion: Specific CT criteria help to differentiate colonic diverticulitis from colon cancer. CT scan with intravenous contrast administration would be the best noninvasive imaging modality in the ER for the accurate diagnosis and appropriate management of such disease.

Bilateral Xanthogranulomatous Pyelonephritis

Xanthogranulomatous pyelonephritis is an uncommon form of chronic bacterial pyelonephritis characterized by the destruction of renal parenchyma and the presence of granulomas, abscesses, and collections of lipid-laden macrophages (foam cells) replacing the renal parenchyma. This case report illustrates the clinical course of bilateral diffuse xanthogranulomatous pyelonephritis with a subtle manifestation in contrast to those typically presenting with fever, flank pain or urinary tract infection. The patient therefore received supportive treatment for 18 months without hemodialysis, instead of the curative treatment, bilateral nephrectomy, which would have caused immediate loss of residual renal function and dependence on hemodialysis.

Prenatal Diagnosis of Pulmonary Sequestration by Ultrasound and Magnetic Resonance Imaging

A 36-year-old multigravida, G2P1, underwent routine ultrasound scan at 22+1 weeks of gestation, which revealed a single normally growing fetus with left intrathoracic mass and left displacement of the cardiac apex. The left intrathoracic wedge-shaped hyperechogenic mass, measuring 32 x 25 mm in size, was situated at the lower portion of the left lung. A combination of color and power Doppler ultrasound allowed visualization of a vessel arising from the descending aorta, which supplied the mass. The diagnosis of extralobar pulmonary sequestration was made. Magnetic resonance imaging (MRI) was also performed and revealed a well-defined mass with homogeneous high-signal intensity when compared with normal lung tissue in the left upper lung field, which was compatible with pulmonary sequestration. The pulmonary mass was followed up by color and power Doppler every 2 weeks. The peak velocity of 11.85 cm/sec and the diameter of the feeding artery of 1.19 mm gradually decreased and disappeared 8 weeks later. The intrathoracic mass disappeared 10 weeks later at 32+1 gestational weeks. Repeat MRI also revealed spontaneous regression of the mass in favor of resorption of sequestration. The fetus was delivered at 38+1 gestational weeks. A male newborn weighing 2,520 g was spontaneously delivered with an Apgar score of 8 at 1 minute and 9 at 5 minutes. In our patient, it is suggested that progressive decreases in the peak velocity of the feeding vessel heralded the spontaneous regression of pulmonary sequestration not associated with hydrops/hydrothorax.

Prognostic factors of primary resected retroperitoneal soft tissue sarcoma: Analysis from a single asian tertiary center and external validation of gronchi's nomogram.

Surgery is the potentially curative treatment for retroperitoneal sarcoma (RS), but complete resectability is frequently a challenge. This study aimed to characterize the clinical features, prognostic factors and treatment outcomes.

Parallel second stent placement for refractory ureteral stent malfunction in malignant ureteral obstruction.

PURPOSE To review retrospectively the outcome of placement of a parallel second ureteral stent in patients with urinary obstruction secondary to a malignancy. MATERIALS AND METHODS During the period 2005-2008, the medical records of patients with ureteral obstruction from an abdominal malignancy were reviewed. Patients who experienced malfunction of the first ureteral stent subsequently underwent either initial stent exchange (control group) or a parallel second ureteral stent placement. The outcomes of both groups were evaluated in terms of stent function at 1 week, 1 month, and 3 months after the procedure. Several clinical and imaging parameters were also compared between the two groups. RESULTS The stent malfunction rate increased more rapidly in the control group. In 1 week, the malfunction rate was 29.4% in the parallel ureteral stent group and 56.7% in the control group. By the end of the third month, the malfunction rate was 72.7% in the parallel ureteral stent group and 100% in the control group. The creatinine level after the procedure was significantly lower in the parallel ureteral stent group (P = 0.004). The incidence of symptomatic urinary tract infection (UTI) was around 30% in both groups (P = 1.000). CONCLUSIONS Parallel second ureteral stent placement has a high technical success rate. For terminally ill patients who have a malignancy and an occluded ureteral stent, the technique can effectively relieve obstruction and prolong the function of the stent.

Percutaneous cryoablation for inoperable malignant lung tumors: midterm results.

OBJECTIVE To retrospectively analyze the efficacy and short- to mid-term survival rate of cryoablation for malignant lung tumors. METHODS Percutaneous CT-guided cryoablation for 45 malignant lung tumors in 26 patients during 41 sessions from 2009 to 2013 were performed. Follow up CT-scan were used to determine local tumor progression. Survival rate, local tumor control rate and associated risk factors were analyzed. RESULTS The immediate during and short-term complications with CTCAE grade 2 or upper include pneumothorax (15%), pleural effusion (20%), pulmonary hemorrhage (24%), pneumonitis (15%), hemothorax (15%), hemoptysis (10%), pain (20%), bronchopleural fistula (n=1), and empyema (n=2). Life-threatening bleeding or hemodynamic instability was not observed. There was no procedural-related mortality. Overall survival rate of 1, 2, 3 years are 96%, 88%, 88%. For curative intent, local tumor control (LTC) rate of 1, 2, 3 years are 75%, 72%, 72%. CONCLUSION Cryoablation for malignant lung tumors is effective and feasible in local control of tumor growth, with good short- to mid-term survival rate, as an alternative option for inoperable patients.