Chang Kyu Seong

MRI in staging advanced gastric cancer: is it useful compared with spiral CT?

PURPOSE During the last decade, rapid progress has been made in MR technology. Our objective was to evaluate the role of MRI in staging advanced gastric cancer (AGC; gastric cancer invading the muscularis propria) and to compare it with that of spiral CT. METHOD We prospectively performed both MR and CT examinations on 26 patients with AGC proven by endoscopic biopsy. Contrast-enhanced CT and nonenhanced MRI with a 1.0 T scanner using FLASH, HASTE, and true-FISP sequences were obtained in each patient after injection of antiperistaltic drug and ingestion of 1 L of tap water. Fifty-two sets of CT and MR images were analyzed by two radiologists in consensus without any information from other images. T and N staging of AGC was determined according to the TNM classification. All patients underwent surgery within 1 week after both examinations. Diagnostic accuracy of each staging of AGC on CT or MRI was evaluated by comparison with the pathologic results. RESULTS MRI was slightly superior to CT in T staging (81 vs. 73%, respectively; p < 0.05). Although MRI had a tendency to overstage the pathologic T2 cancer, positive predictability of T2 stage and sensitivity of T3 stage were high (100%, respectively). Regarding the N staging, CT was slightly superior to MRI (73 vs. 65%; p > 0.05). However, both CT and MRI demonstrated the tendency of understaging in N staging. CONCLUSION Although MRI was superior to spiral CT in T staging, MRI cannot completely replace spiral CT in staging AGC because of its limitation in N staging.

Recurrent uterine cervical carcinoma: spectrum of imaging findings.

Uterine cervical carcinoma is one of the most common malignant tumors occurring in females. After primary treatment, patients are usually followed up with CT or MRI and the findings of these modalities may be the first sign of recurrent disease. Because earlier additional treatment by chemotherapy or radiation therapy may improve the prognosis, the early detection of recurrent cervical carcinoma is clinically important. In this article, we review the CT and MR imaging findings of recurrent uterine cervical carcinoma, and assign them to one of four groups: a) recurrence at the primary site, involving the intrapelvic organs, b) extension to the pelvic side-wall, c) metastases to pelvic and extrapelvic lymph nodes, or d) metastases to distant organs. A further contribution of CT and MR imaging is the detection of hydronephrosis due to ureteral obstruction. The cases in each group are illustrated and discussed, and since an awareness of the spectrum of imaging findings of recurrent cervical carcinoma is likely to lead to its early detection, radiologists should be familiar with the information presented.

Vesicouterine fistula after cesarean section: ultrasonographic findings in two cases.

VUF is a rare condition, representing only 1 to 4% of all cases of urogenital fistula.1,2 The majority of cases of VUF are iatrogenic, occurring mainly after cesarean section, usually a low segment incision.1–4 The diagnosis is most often made by clinical detection of urine or dye passing through an external cervical os or by demonstration of a fistulous tract on HSG or cystography.4 We report ultrasonographic findings in two patients with VUF manifested by double echogenic lines from the endometrial cavity to the posterior wall of the bladder. CASE 1

Vertebroplasty: magnetic resonance findings related to cement leakage risk:

Purpose: To find magnetic resonance (MR) findings predicting cement leakage in patients receiving percutaneous vertebroplasty (PVP) due to osteoporotic compression fractures. Material and Methods: MR was done in 43 patients (age 52–89 years) before PVP (56 vertebrae), which was done via a bipedicular approach with fluoroscopic monitoring. Shortly after the procedure, a non-contrast-enhanced computed tomography (CT) scan was done at the vertebroplasty sites for evaluation of bone cement leakage. The following MR findings of fractured vertebral bodies were retrospectively reviewed for correlation with leakage risk: severity of bone-marrow edema, presence of a T2-weighted low-signal-intensity line, percentage residual vertebral body height, presence of either a vacuum or cystic change within the vertebral body, and presence of a cortical disruption. Results: After PVP, cement leakage was detected in 35 vertebrae (62.5%). Leakage was most frequently observed in the anterior external vertebral venous plexus (46%). Cement leakage rate increased when there was a cortical disruption (P = 0.037), especially at the endplates, while it decreased when there was a vacuum or a cystic change within the fractured vertebra (P = 0.019). Other MR findings were not related to the risk of cement leakage. Conclusion: The risk of cement leakage in PVP increases when MR shows cortical disruption in a fractured vertebral body, especially at the endplates. It decreases when MR shows a vacuum or cystic change within the body.

Interface Vessels on Color/power Doppler Us and Mri: A Clue to Differentiate Subserosal Uterine Myomas from Extrauterine Tumors

Purpose In subserosal myomas, vessels are often demonstrated between the masses and the uterus. This study was performed to assess the usefulness of demonstrating these vessels in differentiating subserosal myomas from extrauterine tumors on color or power Doppler US (CDUS/PDUS) and MRI. Method This retrospective study included 41 patients with subserosal myomas and 27 patients with solid extrauterine tumors. The incidence and shape of these vessels seen on CDUS/PDUS and MRI were compared in the myoma and extrauterine tumor groups. Results The interface vessels were demonstrated in 39 of 41 subserosal myomas (18 on CDUS/PDUS, 14 on MRI, 7 on both), whereas they were seen in only 3 of 27 extrauterine tumors (1 on CDUS/PDUS, 2 on MRI). These three extrauterine tumors were ovarian malignancies that directly invaded the uterus. The shapes of these interface vessels were 7 intervening, 12 crossing, and 20 mixed in the myoma group, whereas they were mixed in all three extrauterine tumor groups. The sensitivity/specificity of this finding in differentiating subserosal myomas and extrauterine tumors was 100/92%, 91/91%, and 95/89%, respectively, with CDUS/PDUS, MRI, and either CDUS/PDUS or MRI. Conclusion Observation of the interface vessels between the uterus and juxtauterine masses seems to be a useful clue in differentiating subserosal myomas from extrauterine tumors.

Hypoechoic Normal Renal Sinus and Renal Pelvis Tumors Sonographic Differentiation

Objective. To evaluate the sonographic findings of an unusually hypoechoic renal sinus that mimics a tumor in the renal pelvis or renal sinus. Methods. Sonographic scans of 7 patients with an unusually hypoechoic portion in the renal sinus were reviewed retrospectively. Computed tomography, excretory urography, or both confirmed all sinuses as normal. Five consecutive cases of renal pelvis tumors, which were detected on sonography initially in same period, were also reviewed to determine the differences between the 2 conditions. All cases were transitional cell carcinomas of the renal calyces. The images were analyzed for location, shape, margin, presence of posterior sonic attenuation, and associated findings such as caliectasis. Results. Sonographic findings noted in patients with hypoechoic normal renal sinuses were irregular and poorly defined margins (n = 7), a central and symmetric location in the renal sinus (n = 6), the presence of posterior sonic attenuation with nonvisualization of the posterior border of the lesion (n = 7), an unaffected peripheral hyperechoic renal sinus (n = 7), and traversing hilar vessels in the lesion on color Doppler sonography (n = 7). In contrast, renal pelvis tumors had a relatively well‐defined margin (n = 4), an eccentric location in the renal sinus (n = 2), a partially or completely obliterated hyperechoic renal sinus (n = 2), a visible posterior margin (n = 5), no posterior shadowing (n = 5), vessel displacement by the mass on color Doppler sonography (n = 5), and associated caliectasis (n = 1). Conclusions. By being familiar with the sonographic characteristics of a hypoechoic renal sinus, it can be differentiated from renal pelvis tumors, and unnecessary diagnostic workups can be avoided.

MR findings of renal cortical necrosis.

Purpose Evaluating the MR findings of renal cortical necrosis was the purpose of this study. Method Eight series of T1-/T2-weighted (n = 8) and contrast-enhanced T1-weighted (n = 4) MR images in six patients with renal cortical necrosis diagnosed by renal biopsy (n = 4) or on clinical grounds (n = 2) were reviewed. In those who had follow-up MRI (n = 2) or comparable CT (n = 3), interval changes of MR findings and comparison with CT images were done. Results Swollen kidney with dark signal intensity rim involving the inner cortex and column of Bertin was noted on T2-and T1-weighted images. It was more conspicuous on T2-weighted images. The lesion did not enhance and was differentiated from uninvolved renal parenchyma. In the follow-up MRI, thickened dark signal intensity was more prominent and proved to be calcification or fibrosis. Conclusion MRI, especially T2-weighted and contrast-enhanced T1-weighted imaging, was helpful in evaluating renal cortical necrosis.

Krukenberg tumor findings at color and power Doppler US ; Correlation with findings at CT, MR imaging, and pathology case reports

We report on the findings at color and power Doppler US in 2 cases of Krukenberg tumor. Power Doppler US may suggest a Krukenberg tumor when it shows a relatively prominent vascular signal along the wall of well-demarcated intramural cysts in a solid ovarian mass

Prospective Analysis on the Relation between Pain and Prostate Volume during Transrectal Prostate Biopsy

Objective We wanted to assess the relationship between pain and the prostate volume during transrectal ultrasound (TRUS) guided biopsy. Materials and Methods Between July and September 2006, 71 patients scheduled for TRUS biopsy of the prostate were considered for inclusion to this study. These patients underwent periprostatic neurovascular bundle block with lidocaine prior to biopsy. Pain was assessed using a Visual Analogue Scale (VAS) during periprostatic neurovascular bundle block (VAS 1), during biopsy (VAS 2), and 20 minutes after biopsy (VAS 3). The mean pain scores were analyzed in the large prostate group (prostate volume > 40 cc) and the small prostate group (prostate volume ≤ 40 cc). P values < 0.05 were considered significant. Results The mean prostate volume was 42.2 cc (standard deviation: 8.6). The mean pain scores of VAS 1, 2 and 3 were 4.70 ± 1.61, 3.15 ± 2.44 and 1.05 ± 1.51, respectively. In the large prostate group, the mean pains scores of VAS 1, 2 and 3 were 4.75 ± 1.76, 3.51 ± 2.76 and 1.29 ± 1.70, respectively, whereas in the small prostate group, the means pain scores were 4.66 ± 1.46, 2.77 ± 2.0, and 0.80 ± 1.26, respectively. Although there were no statistical differences of VAS 1, the larger prostate group revealed higher pain scores of VAS 2 and 3 compared with the small prostate group (p < 0.05). Conclusion Patients with larger prostate volumes tend to feel more pain during and after TRUS guided prostate biopsy. Our findings suggest that additional analgesic strategies may be necessary when the patients with larger prostate undergo TRUS guided prostate biopsy.

Detection of Segmental Branch Renal Artery Stenosis by Doppler US: A Case Report

In stenosis of a segmental branch or among multiple renal arteries, Doppler sampling of intrarenal arteries in the upper, mid and lower poles demonstrates strikingly different waveform patterns that might otherwise be overlooked. We report a case of segmental branch renal artery stenosis in which a pulsus parvus et tardus waveform was observed in a segmental branch of a renal artery. In this case, systematic analysis of Doppler waveforms of intrarenal arteries at more than three different locations facilitated a rapid and confident diagnosis of segmental branch renal artery stenosis.