The usefulness of computed tomographic colonography for evaluation of deep infiltrating endometriosis: comparison with magnetic resonance imaging.

OBJECTIVE: We wanted to assess the diagnostic value and morphologic feature of deep infiltrating endometriosis (DIE), involving rectosigmoid colon, with computed tomography (CT) colonography in comparison with magnetic resonance (MR). METHODS: Fifty patients with DIE, who had undergone CT colonography and MR imaging (MRI) before surgery, were enrolled. Among these 50 patients who underwent laparoscopic surgery with DIE, 37 patients were diagnosed as rectosigmoid involvement of endometriosis (presence of rectal outer wall involvement, endometrial implantation in the rectouterine space, and complete obliteration of cul-de-sac with histologic confirmation). Image findings at CT colonography and MRI were reviewed by 2 radiologists to determine whether there are radiologic features that can help predict rectosigmoid endometriosis. Computed tomography images were analyzed for the luminal alteration of rectosigmoid colon, mural thickening, and mass formation in the rectosigmoid colon, whereas MR images were analyzed for the mass formation in the rectosigmoid colon, fat plane obliteration, between rectum and uterus or vagina, retroversion of uterus, retraction of uterus toward the colon, and detection of endometrial spot in rectovaginal or rectouterine space. Statistical analysis was performed with Pearson χ and receiver operating characteristic curve. RESULTS: With CT colonography, the luminal alteration of rectosigmoid colon was detected with sensitivity of 96.0% and specificity of 48.0% (P < 0.001) in the overall rectosigmoid endometriosis and with sensitivity of 84.0% and specificity of 80.0% (P = 0.005) in the case of DIE with cul-de-sac obliteration. With MR, the sensitivity and specificity for detection of endometriosis of rectosigmoid or rectouterine space were 94.4% and 37.5% (P = 0.013), respectively. Other variables had no statistical significance. The diagnostic accuracy of CT colonography is higher than that of MRI (area under the curve, 0.786 vs 0.691; P < 0.001), for the overall rectosigmoid endometriosis. In the evaluation of complete cul-de-sac obliteration, morphologic change of rectosigmoid colon is identified more accurately with CT colonography than that of MRI (area under the curve, 0.821 vs 0.686; P < 0.001). CONCLUSIONS: Both CT colonography and MRI are highly sensitive to the detection of rectosigmoid endometriosis, but lack specificity. However, the depiction rate of morphologic change in rectosigmoid colon is greater with CT colonography than that of MRI, in the case of cul-de-sac obliteration. The luminal alteration significantly correlates with morphologic change in rectosigmoid endometriosis.

High-intensity focused ultrasound treatment of abnormal vaginal bleeding secondary to uterine myoma.

We describe the use of high-intensity focused ultrasound for acute vaginal bleeding secondary to uterine myoma in 2 young female patients. Both patients had episodes of abnormal vaginal bleeding with severe dysmenorrhea that was not efficiently controlled by medical treatment. After high-intensity focused ultrasound ablation, both vaginal bleeding control and symptom relief were achieved without postinterventional complications. The patients remained free of symptoms during 2 months of follow-up and regained normal menstruation after high-intensity focused ultrasound therapy. High-intensity focused ultrasound treatment is one of the least invasive options for dysfunctional vaginal bleeding and may be an effective and safe alternative to other procedures in women of reproductive age with abnormal vaginal bleeding secondary to uterine myoma.

CT and MR imaging findings of endocrine tumor of the pancreas according to WHO classification.

The pancreatic endocrine tumors are rare neuroendocrine tumors of the pancreas originating from totipotential stem cells or differentiated mature endocrine cells within the exocrine gland. Endocrine tumors are usually classified into functioning and non-functioning tumors and presents with a range of benignity or malignancy. In this article, we present the various CT and MR imaging findings of endocrine tumors of pancreas according to recent WHO classification.

Assessment of malignancy in gliomas by 3T 1H MR spectroscopy .

The purpose of this study was to assess clinical 1H MR spectroscopy (MRS) as a noninvasive method for evaluating brain tumor malignancy at 3T high-field system. Using 3T MRI/MRS system, localized water-suppressed single-voxel technique in patients with brain tumor (i.e., gliomas) was employed to evaluate spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cr) and lactate. On the basis of Cr, these peak areas were quantitated as a relative ratio. The variation of metabolite measurements of the designated region in 10 normal volunteers was less than 10%. Normal ranges of NAA/Cr and Cho/Cr ratios were 1.67+/-018 and 1.16+/-0.15, respectively. NAA/Cr ratio of gliomas was significantly lower than that of the normal tissues (P= .005), but Cho/Cr ratio of gliomas was significantly higher (P= .001). Cho/Cr ratio of high-grade gliomas was significantly higher than that of low-grade gliomas. The present study demonstrated that the neuronal degradation or loss was observed in all gliomas. Higher-grade glioma was correlated with higher Cho/Cr ratio, indicating a significant dependence of Cho levels on malignancy of gliomas. Our results suggest that clinical 1H MR spectroscopy could be useful to predict tumor malignancy.

The renal sinus: pathologic spectrum and multimodality imaging approach.

Various pathologic conditions can occur in the renal sinus, primarily originating in the constituents of the renal sinus, and the renal sinus can be secondarily involved by surrounding renal parenchymal and adjacent retroperitoneal lesions. Lipomatosis and cysts are common renal sinus lesions with little clinical significance, but differentiation from other pathologic conditions is important. Renal vascular lesions such as renal artery aneurysm or arteriovenous fistula can mimic other parapelvic or peripelvic lesions at excretory urography, but their vascular nature is evident at color Doppler ultrasonography, contrast material-enhanced computed tomography (CT), and magnetic resonance (MR) imaging. Although most tumors originating in the renal pelvis are transitional cell carcinoma or squamous cell carcinoma, renal parenchymal tumors such as renal cell carcinoma or benign multilocular cystic nephroma have a tendency to grow into the renal sinus. Rare tumors of mesenchymal origin can develop in the renal sinus, but their imaging findings are nonspecific. The observation of renal sinus fat is important for detecting a small tumor located in that area and determining the exact tumor stage. Multiplanar CT or MR images can allow exact evaluation of the extent of complex renal sinus disease.

Proton MR spectroscopic changes in Parkinson's diseases after thalamotomy.

To investigate whether there are significant changes in regional brain metabolism in patients with Parkinson's disease before and after thalamotomy using proton magnetic resonance spectroscopy (1H MRS). Fifteen patients underwent 15 stereotactic thalamotomies for control of medically refractory parkinsonian tremor. Single-voxel 1H MRS was carried out on a 1.5 T unit using stimulated-echo acquisition mode (STEAM) sequence (TR/TM/TE, 2000/14/20 ms). Spectra were obtained from substantia nigra, thalamus and putamen areas with volumes of interests (7-8 ml) in patients before and after the surgery. Metabolite ratios of NAA/Cho, NAA/Cr and Cho/Cr were calculated from relative peak area measurements. We evaluated alterations of metabolite ratios in brain metabolism in Parkinson's disease patients with clinical outcome following thalamotomy. NAA/Cho ratios showed generally low levels in substantia nigra and thalamus in Parkinson's disease patients with clinical improvement following thalamotomy. In 80% (12/15) patients, decreased NAA/Cho ratios were observed from the selected voxels in substantia nigra after thalamic surgery (P<0.05). The ratios were also significantly decreased in thalamus in 67% (10/15) patients with clinical improvement (P<0.05). Our results suggest that NAA/Cho ratio may be a valuable criterion for evaluation of Parkinson's disease patients with the clinical improvement following surgery. 1H MRS may be a useful utility for the aid in better understanding the pathophysiologic process in Parkinson's disease patients on the basis of the variation of NAA/Cho ratio.

Metabolic alterations in Parkinson's disease after thalamotomy, as revealed by 1H MR spectroscopy.

OBJECTIVE: To determine, using proton magnetic resonance spectroscopy (1H MRS) whether thalamotomy in patients with Parkinson's disease gives rise to significant changes in regional brain metabolism. MATERIALS AND METHODS: Fifteen patients each underwent stereotactic thalamotomy for the control of medically refractory parkinsonian tremor. Single-voxel 1H MRS was performed on a 1.5T unit using a STEAM sequence (TR/TM/TE, 2000/14/20 msec), and spectra were obtained from substantia nigra, thalamus and putamen areas, with volumes of interest of 7-8 ml, before and after thalamotomy. NAA/Cho, NAA/Cr and Cho/Cr metabolite ratios were calculated from relative peak area measurements, and any changes were recorded and assessed. RESULTS: In the substantia nigra and thalamus, NAA/Cho ratios were generally low. In the substantia nigra of 80% of patients (12/15) who showed clinical improvement, decreased NAA/Cho ratios were observed in selected voxels after thalamic surgery (p < 0.05). In the thalamus of 67% of such patients (10/15), significant decreases were also noted (p < 0.05). CONCLUSION: Our results suggest that the NAA/Cho ratio may be a valuable criterion for the evaluation of Parkinson's disease patients who show clinical improvement following surgery. By highlighting variations in this ratio, 1H MRS may help lead to a better understanding of the pathophysiologic processes occurring in those with Parkinson's disease.

Temporal evolution of multidetector CT findings after endoscopic submucosal dissection in patients with early gastric cancer: correlation with endoscopy.

OBJECTIVE: To assess changes over time in imaging findings retrospectively by multidetector CT (MDCT) with two-dimensional (2D) multiplanar reconstruction and three-dimensional (3D) CT gastrography (CTG), after endoscopic submucosal dissection (ESD) in patients with early gastric cancer (EGC), and to correlate 3D CT images with endoscopic appearance. MATERIALS AND METHODS: In this retrospective study, a total of 84 patients underwent ESD and were followed up with MDCT. Fifteen patients underwent CT twice, and 3 patients underwent CT 3 times. A total of 105 CTs were included in this study and 43 CTs contained 3D CTGs. Two radiologists in consensus interpreted CT images for lesion detectability, presence and characteristics of ulcer, focal wall thickening, perigastric fat infiltration, and overlying enhancing layer in 2D images. The presence of ulcer or subtle mucosal nodularity, ulcer mound, and fold convergence were analysed in 3D CT images. We also assessed the time interval between ESD and CT and analysed the temporal evolution of CT findings. The sensitivity, specificity, and overall accuracy of 3D CTG were assessed regarding endoscopic features as the gold standard. RESULTS: The mean interval between ESD and follow up CT was 76.9 days (median, 62; range, 2-223). No tumour recurrence in any lesion was found on follow-up endoscopic biopsy and also lymph node or distant metastasis was not observed on CT exams in the follow-up period. The lesion detectability in a total of 105 post-ESD 2D CT images was 42.0% (44/105), and 93.2% (41/44) of the detected lesions were visualizable 2 months after ESD. Focal wall thickening was observed during the entire follow-up period in all patients. Perigastric fat infiltration was observed in 4 lesions within 1 week of ESD. Overlying enhancing layer appeared in 27 lesions without temporal evolution. On a total of 43 post-ESD 3D CTG, lesion detectability was 76.7% (33/43), and lesions could be visualized for a longer period than by 2D CT images (223 days versus 99 days). Three-dimensional imaging features revealed ulcer, ulcer mound, and fold convergence. Ulcer mounds disappeared first (median, 12.5 days; range, 2-14 days after ESD), ulcers appeared up to 4 months after ESD (median, 14 days; range, 2-174 days after ESD) and fold convergence continued to the end of the study (median, 74 days; range, 2-223 days after ESD). We found that sensitivity, specificity, and overall accuracy of 3D CTG were 70.0%, 92.9%, 83.3% for ulcer, 28.6%, 100%, 71.4% for ulcer mound, and 71.4%, 100%, 75% for fold convergence regarding endoscopy, respectively. CONCLUSION: On follow-up 2D or 3D CT images after ESD, early findings were of perigastric fat infiltration, ulcer, and surrounding oedema. Focal wall thickening and fold convergence continued to be observed late in the study. The overlying enhancing layer did not show temporal evolution.

Correlations of dynamic contrast-enhanced magnetic resonance imaging with morphologic, angiogenic, and molecular prognostic factors in rectal cancer.

PURPOSE: To investigate the correlations between parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and prognostic factors in rectal cancer. MATERIALS AND METHODS: We studied 29 patients with rectal cancer who underwent gadolinium contrast-enhanced, T1-weighted DCE-MRI with a three Tesla scanner prior to surgery. Signal intensity on DCE-MRI was independently measured by two observers to examine reproducibility. A time-signal intensity curve was generated, from which four semiquantitative parameters were calculated: steepest slope (SLP), time to peak (Tp), relative enhancement during a rapid rise (Erise), and maximal enhancement (Emax). Morphologic prognostic factors including T stage, N stage, and histologic grade were identified. Tumor angiogenesis was evaluated in terms of microvessel count (MVC) and microvessel area (MVA) by morphometric study. As molecular factors, the mutation status of the K-ras oncogene and microsatellite instability were assessed. DCE-MRI parameters were correlated with each prognostic factor using bivariate correlation analysis. A p-value of <0.05 was considered significant. RESULTS: Erise was significantly correlated with N stage (r=-0.387 and -0.393, respectively, for two independent data), and Tp was significantly correlated with histologic grade (r=0.466 and 0.489, respectively). MVA was significantly correlated with SLP (r= -0.532 and -0.535, respectively) and Erise (r=-0.511 and -0.446, respectively). MVC was significantly correlated with Emax (r=-0.435 and -0.386, respectively). No significant correlations were found between DCE-MRI parameters and T stage, K-ras mutation, or microsatellite instability. CONCLUSION: DCE-MRI may provide useful prognostic information in terms of histologic differentiation and angiogenesis in rectal cancer.

Effect of microbubble contrast agent during high intensity focused ultrasound ablation on rabbit liver in vivo.

OBJECTIVE: To evaluate the effect of a microbubble contrast agent (SonoVue) during HIFU ablation of a rabbit liver. MATERIALS AND METHODS: HIFU ablations (intensity of 400W/cm(2) for 4s, six times, with a 5s interval between exposures) were performed upon 16 in vivo rabbit livers before and after intravenous injection of a microbubble contrast agent (0.8ml). A Wilcoxon signed rank test was used to compare mean ablation volume and time required to tissue ablation on real-time US. Shape of ablation and pattern of coagulative necrosis were analyzed by Fisher's exact test. RESULTS: The volume of coagulative necrosis was significantly larger in the combination microbubble and HIFU group than in the HIFU alone group (P<0.05). Also, time to reach ablation was shorter in the combination microbubble and HIFU group than in the HIFU alone group (P<0.05). When analyzing the shape of tissue ablation, a pyramidal shape was more prevalently in the HIFU alone group compared to the combination microbubble and HIFU group (P<0.05). Following an analysis of the pattern of coagulative necrosis, non-cavitary necrosis was found in ten and cavitary necrosis in six of the samples in the combination microbubble and HIFU group. Conversely, non-cavitary necrosis occurred in all 16 samples in the HIFU alone group (P<0.05). CONCLUSION: HIFU of in vivo rabbit livers with a microbubble contrast agent produced larger zones of ablation and more cavitary tissue necrosis than without the use of a microbubble contrast agent. Microbubble contrast agents may be useful in tissue ablation by enhancing the treatment effect of HIFU.

Image quality improvement after implementation of a CT accreditation program.

OBJECTIVE: The purpose of this study was to evaluate any improvement in the quality of abdominal CTs after the utilization of the nationally based accreditation program. MATERIALS AND METHODS: Approval was obtained from the Institutional Review Board, and informed consent was waived. We retrospectively analyzed 1,011 outside abdominal CTs, from 2003 to 2007. We evaluated images using a fill-up sheet form of the national accreditation program, and subjectively by grading for the overall CT image quality. CT scans were divided into two categories according to time periods; before and after the implementation of the accreditation program. We compared CT scans between two periods according to parameters pertaining to the evaluation of images. We determined whether there was a correlation between the results of a subjective assessment of the image quality and the evaluation scores of the clinical image. RESULTS: The following parameters were significantly different after the implementation of the accreditation program: identifying data, display parameters, scan length, spatial and contrast resolution, window width and level, optimal contrast enhancement, slice thickness, and total score. The remaining parameters were not significantly different between scans obtained from the two different periods: scan parameters, film quality, and artifacts. CONCLUSION: After performing the CT accreditation program, the quality of the outside abdominal CTs show marked improvement, especially for the parameters related to the scanning protocol.

Metastatic gastric linitis plastica from bladder cancer mimicking a primary gastric carcinoma: a case report.

Primary gastric carcinoma is the most common cause of linitis plastica. Less frequently, metastatic gastric cancer from the breast, omental metastases and non-Hodgkin lymphoma involving the stomach have been reported to show similar radiographic findings as for linitis plastica. A metastatic gastric cancer from bladder cancer is extremely rare. We present an unusual case, the first to our knowledge, of gastric linitis plastica that resulted from a metastatic urothelial carcinoma of the bladder.

Sonographic diagnosis of a round ligament cyst in the inguinal area.

We report a case of a 37-year-old female with a mesothelial cyst of the round ligament presenting as a palpable mass. The mass appeared sonographically as a fusiform structure with several cystic anechoic areas and was misdiagnosed preoperatively as herniation of the right ovary.

Sonography of various cystic masses of the female groin.

OBJECTIVE: The purpose of this presentation is to review the pathologic spectrum of cystic masses that may involve the female groin region, with a correlation of the lesions with their sonographic appearance. METHODS: We reviewed the sonographic findings of palpable groin masses showing a cystic pattern in female patients. The groin region is best depicted with a high-frequency (7.5- to 12-MHz) linear array transducer. Color Doppler sonography and an extended field of view are helpful in the differential diagnosis of variable groin masses. RESULTS: There are various cystic masses involving the female groin, such as round ligament cysts, varicosities of the round ligament, inguinal herniation of the ovary, cystic lymphangiomas, epidermal inclusion cysts, abscesses, and pseudoaneurysms. CONCLUSIONS: Sonography with color Doppler imaging is helpful for the differential diagnosis of the pathologic spectrum of cystic masses involving the female groin.

18F-fluorodeoxyglucose positron emission tomography in patients with recurrent ovarian cancer: in comparison with vascularity, Ki-67, p53, and histologic grade.

The aim of this study was to assess the correlation between 18F-fluorodeoxyglucose positron emission tomography (FDG PET) positivity of tumor recurrence and vascularity, Ki-67, p53, and histologic grade in patients with ovarian cancer. Nineteen patients with recurrent ovarian cancer underwent FDG PET before second-look surgery. Archival paraffin-embedded tissue materials were used to assess histologic grade including architectural pattern, mitotic activity, and nuclear pleomorphism; intratumor microvessel density (MVD); Ki-67; and p53. Univariate analysis was used to evaluate the correlation between FDG PET positivity and each biomarker. Stepwise logistic regression analysis was used to determine the best parameter to explain FDG PET positivity. MVD revealed significant positive correlation with FDG PET positivity (p=0.0341). There was no significant correlation between FDG PET positivity and Ki-67 or p53 (p=0.4040, p=0.6027). Mitotic activity yielded statistically significant positive correlations with FDG PET positivity (p=0.0448) although histologic grade revealed no positive correlation (p=1). Stepwise logistic regression analysis revealed MVD to be the strongest parameter for FDG PET positivity (OR=0.696, 95% CI 0.487-0.993, p=0.0458). In conclusion, FDG PET positivity revealed positive correlation with MVD and mitotic activity. MVD was the strongest parameter in predicting positive tumor recurrence on FDG PET.

Evaluation of joint effusion in rabbits by color Doppler, power Doppler, and contrast-enhanced power Doppler ultrasonography.

PURPOSE: The aim of this prospective study was to evaluate the diagnostic value of power Doppler ultrasonography (PDUS) and contrast-enhanced PDUS (CEPDUS) in the depiction and characterization of experimentally induced arthritis in the rabbit. MATERIALS AND METHODS: Thirty rabbits were divided into three groups consisting of one control group (saline injection group) and two experimental groups: a suppurative arthritis group and a chemically induced synovitis group. The same amount (1 ml) of each agent was directly injected into the right hip joint. Serial color Doppler ultrasound (CDUS), PDUS, and CEPDUS images were obtained before and after injection. RESULTS: We observed that all of the infected knees in the suppurative arthritis group with Staphylococcus aureus demonstrated an increased signal on PDUS after inoculation. A minimal power Doppler signal was presented in the chemically induced synovitis group with talc injection, but none of the control knees demonstrated any increased signals. CEPDUS was the most sensitive imaging modality for evaluating the increase of blood flows in suppurative arthritis and was subsequently followed by PDUS and CDUS. CONCLUSION: The increased signals obtained with PDUS represent increased local blood flows; therefore, this technique can be used for evaluating the degree of inflammation. Furthermore, using the contrast agent enhances the sensitivity of PDUS, and it can even be useful for differentiating borderline cases.

Breast MRI findings after modified radical mastectomy and transverse rectus abdominis myocutaneous flap in patients with breast cancer.

PURPOSE: To evaluate the MRI findings in breast cancer patients who had undergone a modified radical mastectomy (MRM) and a transverse rectus abdominis myocutaneous (TRAM) flap. MATERIALS AND METHODS: MRI was performed on 20 patients who had been diagnosed with breast cancer and had undergone an MRM and TRAM flap. The results were examined in terms of MRI's ability to detect the flap and assess possible postoperative changes and recurrence. In addition, MRI images of the opposite breast were analyzed. Follow-up examinations were carried out on 11 patients, and all changes were assessed. RESULTS: The flap was clearly visualized by MRI in all of the patients. The signal intensity of the flap was equivalent to that of fat. The contact zone between the TRAM flap and the mastectomy site was enhanced after contrast infusion. Postoperative changes, such as skin thickening (n=20), edema (n=2), fluid collection (n=3), hematoma (n=1), and fat necrosis (n=3), were detected. In two patients, artificially inserted fat tissue was identified. On the MRI of the opposite breast, enhancing lesions were detected in seven patients. In one patient with this finding, ductal carcinoma in situ was diagnosed. On the follow-up MRI, a decrease in skin thickening, fat necrosis, and hematoma was detected. CONCLUSION: MRI is an effective method for lesion detection and evaluation of postoperative changes after MRM and TRAM flap, as well as for evaluation of the opposite breast.

CT and MRI findings of sex cord-stromal tumor of the ovary.

OBJECTIVE: The purpose of this article was to research the clinical and imaging features of sex cord-stromal tumors of the ovary to help in specific diagnosis of ovarian tumors. Sex cord-stromal tumors of the ovary are rare ovarian neoplasms, which arise from stromal cells and primitive sex cords in the ovary. The common types are granulosa cell tumors, fibrothecomas, sclerosing stromal tumors, and Sertoli-Leydig cell tumors. They account for most of the hormonally active ovarian tumors. They have characteristic imaging features in each type of the tumor. CONCLUSION: Clinical and radiologic clues are helpful in differential diagnosis from the more common epithelial tumors; sex cord-stromal tumors primarily are treated surgically and have generally good prognosis.

CT and MR imaging of ovarian tumors with emphasis on differential diagnosis.

Ovarian tumors are classified on the basis of tumor origin as epithelial tumors (serous and mucinous tumors, endometrioid and clear cell carcinomas, Brenner tumor), germ cell tumors (mature and immature teratomas, dysgerminoma, endodermal sinus tumor, embryonal carcinoma), sex cord-stromal tumors (fibrothecoma; granulosa cell, sclerosing stromal, and Sertoli-Leydig cell tumors), and metastatic tumors. Epithelial tumors are primarily cystic and, when malignant, are associated with varying proportions of a solid component. Papillary projections are a distinctive feature of epithelial tumors. Profuse papillary projections are highly suggestive of borderline (low-malignant-potential) or malignant tumor. Ovarian teratomas demonstrate lipid material at computed tomography and magnetic resonance (MR) imaging. Malignant germ cell tumors manifest as a large, complex abdominal mass that contains both solid and cystic components. Tumor markers are helpful in diagnosis. The radiologic appearance of sex cord-stromal tumors varies from small solid masses to large multicystic masses. Granulosa cell tumors are usually large multicystic masses with solid components. Fibrothecoma, sclerosing stromal tumor, and Sertoli-Leydig cell tumors are usually solid masses. Fibromas have very low signal intensity on T2-weighted MR images. Certain radiologic findings predominate for each type of tumor. Knowledge of these key features of ovarian tumors provides the criteria for making a specific diagnosis or substantially narrowing the differential diagnosis.

Infantile scrotal pyocele simulating missed testicular torsion on sonography.

We present the case of a neonate with idiopathic infantile pyocele. Scrotal sonography revealed a complex fluid collection within the left scrotal sac containing septations and a fluid-fluid level. The dependent region of the collection had moderate echogenicity, the slightly hypoechoic testis was not well defined, and the scrotal wall was thickened. Color Doppler sonography revealed mild hypervascularity in the thickened scrotal wall but no vascularity inside the testis. The sonographic findings suggested missed testicular torsion, but surgery revealed a pyocele, for which no source was identified. Radiologists should be aware that idiopathic infantile pyocele can mimic the Doppler sonographic findings in missed testicular torsion.