Infiltrative endometriosis without endometrioma: A case report and imaging findings mimicking a bladder malignancy

Endometriosis affects 10%-15% of women of childbearing age, but the incidence can be as high as 90% in those with chronic pelvic pain. Endometriosis is categorized into ovarian endometriomas, superficial peritoneal implants, and deep infiltrating endometriosis. In this case report a 40-year-old woman gravida 1, para 1 with a history of hysterectomy in Mexico presented with chronic abdominal pain and severe hematuria. Magnetic resonance imaging revealed an infiltrative pelvic mass involving the bladder concerning for a neoplasm that demonstrated subtle hyperintense components on T1-weighted images. The diagnosis of infiltrative endometriosis was established following cystoscopy and tissue sampling. This case highlights the importance of considering endometriosis in the differential for patients with pelvic masses, and recognizing potential features that could suggest the diagnosis.     

Endometriosis: radiologic-pathologic correlation.

Endometriosis is an important gynecologic disorder primarily affecting women during their reproductive years. Pathologically, it is the result of functional endometrium located outside the uterus. It may vary from microscopic endometriotic implants to large cysts (endometriomas). The physical manifestations are protean, with some patients being asymptomatic and others having disabling pelvic pain, infertility, or adnexal masses. Symptoms do not necessarily correlate with the severity of the disease. Ultrasonographic (US) features are variable and can mimic those of other benign and malignant ovarian lesions. Low-level internal echoes and echogenic wall foci are more specific US features for endometriomas. Magnetic resonance imaging improves diagnostic accuracy, with endometriotic cysts typically appearing with high signal intensity on T1-weighted images and demonstrating "shading" on T2-weighted images. The ovaries are the most common sites affected, but endometriosis can also involve the gastrointestinal tract, urinary tract, chest, and soft tissues. Small implants and adhesions are not well evaluated radiologically; therefore, laparoscopy remains the standard of reference for diagnosis and staging. Both medical and surgical treatment options are available depending on the patient's specific case.     

MR urography for suspected upper tract urothelial carcinoma

The key components of the MR urography protocol for suspected upper tract urothelial carcinoma are coronal T2-weighted hydrographic sequences without contrast agent and coronal gadolinium-enhanced T1-weighted 3D-spoiled gradient-recalled echo in nephrographic and pyelographic phases. Upper tract urothelial carcinomas can be categorized into papillary tumor, flat tumor, and infiltrative tumor based on the growth pattern and extent. Papillary lesions appear as small filling defects of soft tissue signal on T2-weighted hydrographic and T1-weighted pyelographic phase images. On nephrographic phase images, the lesions show homogeneous enhancement. A flat tumor appears as a segmental area of diffuse thickening and enhancement of the urinary tract wall on nephrographic phase images. Infiltrative tumor often appears as a large heterogeneously enhancing mass. MR urography is a promising alternative for CT urography in the evaluation of upper tract urothelial carcinoma, especially when the patient has a contraindication to iodinated contrast material.     

Benign and malignant mimickers of infiltrative hepatocellular carcinoma: tips and tricks for differential diagnosis on CT and MRI

Hepatocellular carcinoma (HCC) may have an infiltrative appearance in about 8–20% of cases. Infiltrative HCC can be a challenging diagnosis and it is associated with the worst overall survival among HCC patients. Infiltrative HCC is characterized by the spread of multiple minute nodules throughout the liver, without a dominant one, ultimately resulting into macrovascular invasion. On CT and MRI, infiltrative HCC appears as an ill-defined, large mass, with variable degree of enhancement, and satellite neoplastic nodules in up to 52% of patients. On MRI, it may show restriction on diffusion weighted imaging, hyperintensity on T2- and hypointensity on T1-weighted images, and, if hepatobiliary agent is used, hypointensity on hepatobiliary phase. Infiltrative HCC must be differentiated from other liver diseases, such as focal confluent fibrosis, steatosis, amyloidosis, vascular disorders of the liver, cholangiocarcinoma, and diffuse metastatic disease. In cirrhotic patients, the identification of vascular tumor invasion of the portal vein and its differentiation from bland thrombosis is of utmost importance for patient management. On contrast enhanced CT and MRI, portal vein tumor thrombosis appears as an enhancing thrombus within the portal vein, close to the main tumor and results into vein enlargement. The aim of this pictorial review is to show CT and MRI features that allow the diagnosis of infiltrative HCC and portal vein tumor thrombosis. A particular point of interest includes the tips and tricks for differential diagnosis with potential mimickers of infiltrative HCC.     

Fibrosing inflammatory pseudotumors involving the skull base: MR and CT manifestations with histopathologic comparison.

PURPOSETo describe the MR and CT features of fibrosing inflammatory pseudotumors of the skull base region, and to document the MR signal intensity of the lesions with histopathologic comparison.METHODSWe reviewed the MR and CT studies of five patients with pathologically proved fibrosing inflammatory pseudotumor involving the skull base. Unenhanced spin-echo T1- and T2-weighted and contrast-enhanced T1-weighted MR images were obtained at 0.5 T in three patients and at 1.5 T in two patients. MR findings were correlated with histopathologic findings in all five cases, and the enhancement pattern was compared with CT findings in three cases.RESULTSIn three cases, the cavernous sinus was involved unilaterally, with adjacent extracranial infiltrative masses. In one case, both orbits, the cavernous sinuses, and the tentorium were involved with diffuse infiltrative lesions. One patient had an infiltrative nasopharyngeal mass; and in all five patients, MR images showed localized involvement of the skull base, with bone marrow replaced by tumor. The soft-tissue lesions were hypointense on T2-weighted images in all five cases and showed homogeneous contrast enhancement. Histopathologic studies revealed scanty inflammatory cell infiltration with densely fibrotic background in all cases. The hypointensity of the lesions on T2-weighted images seemed to be related to the degree of fibrosis.CONCLUSIONFibrosing inflammatory pseudotumor shows characteristic MR findings of infiltrative lesion with bone destruction and hypointensity on T2-weighted images. The lack of mobile protons due to the fibrotic background and/or high cellularity of the lesions may be the reason for their hypointensity and weaker enhancement on MR images.     

CT and MR imaging of solitary extramedullary plasmacytoma of the nasal tract

BACKGROUND AND PURPOSE: Solitary extramedullary plasmacytoma (SEP) is rare. The purpose of this study was to determine the CT and MR imaging features of SEP of the nasal tract. METHODS: We retrospectively reviewed three CT and two MR images of three histologically proved cases in two men and one woman aged 43-66 years. RESULTS: The plasmacytomas predominantly involved the nasopharynx in two cases and the nasal cavity in one. Two of the tumors were bulky solid masses, whereas the third showed infiltrative features. They were predominantly masses or infiltrative lesions with soft-tissue attenuation on CT scans. The lesions were isointense and hyperintense on T1- and T2-weighted MR images, respectively. The tumors revealed moderate-to-marked contrast enhancement and may have been associated with lytic bone destruction. CONCLUSION: The imaging features of SEP are nonspecific. However, this entity should be included in the differential diagnosis of tumors in the nasopharynx and nasal cavity.     

Beyond the boundaries-endometriosis: typical and atypical locations

Endometriosis is characterized by the presence of endometrial glands and stroma in an ectopic location outside the endometrial cavity. This condition affects women during their reproductive years. Ovaries are by far the commonest location of endometriosis and have peculiar imaging features. However, the imaging diagnosis of extraovarian endometriosis is difficult to make both clinically and radiologically. The purpose of this article is to review the imaging features of endometriosis at typical and atypical sites on different modalities and to describe the commonly encountered complications. Atypical sites for endometriosis include the gastrointestinal tract, urinary tract, soft tissues, and chest. Depending on the site, they can present with varied symptoms, including bowel obstruction, melena, hematuria, dysuria, dyspnea, and swelling in the soft tissues, respectively. The endometriotic implant in the extraovarian location is a challenging diagnosis. It is important to be aware of the sites, radiologic appearances, and complications of ovarian and extraovarian endometriosis while evaluating a woman in the reproductive age group with appropriate symptomatology. Endometriosis at extraovarian locations is a challenging diagnosis clinically and radiologically. Clinical symptomatology with characteristic imaging features in the appropriate patient population is helpful in reaching the diagnosis. Precise diagnosis regarding presence, location, and extent of endometriosis is useful for preoperative evaluation and surgical planning of endometriosis.     

Differentiation of brain tumor-related edema based on 3D T1rho imaging

Background and purposeCerebral edema associated with brain tumors is an important source of morbidity. Its type depends largely on the capillary ultra-structures of the histopathologic subtype of underlying brain tumor. The purpose of our study was to differentiate vasogenic edema associated with brain metastases and infiltrative edema related to diffuse gliomas using quantitative 3D T1 rho (T1ρ) imaging.Materials and methodsPreoperative MR examination including whole brain 3D T1ρ imaging was performed in 23 patients with newly diagnosed brain tumors (9 with metastasis, 8 with lower grade glioma, LGG, 6 with glioblastoma, GBM). Mean T1ρ values were measured in regions of peritumoral non-enhancing T2 signal hyperintensity, excluding both enhancing and necrotic or cystic component, and normal-appearing white matter.ResultsMean T1ρ values were significantly elevated in the vasogenic edema surrounding intracranial metastases when compared to the infiltrative edema associated with either LGG or GBM (p = 0.02 and <0.01, respectively). No significant difference was noted between T1ρ values of infiltrative edema between LGG and GBM (p = 0.84 and 0.96, respectively).ConclusionOur study demonstrates the feasibility and potential diagnostic role of T1ρ in the quantitative differentiation between edema related to intracranial metastases and gliomas and as a potentially complementary tool to standard MR techniques in further characterizing pathophysiology of vasogenic and infiltrative edema.     

浸润性肾盂癌 MRI 诊断价值

目的：分析并评价浸润性肾盂癌的 MRI 影像学特征,以提高对其诊断与鉴别诊断的能力。方法回顾性分析病理证实为浸润性肾盂癌的21例患者资料,所有患者均接受 MRI 平扫及 DWI 检查,其中3例进行 PWI 检查。结果21例浸润性肾盂癌中心均位于肾脏集合系统,肾脏轮廓大多无明显变化。病灶在 MRI 平扫上大多呈稍长 T1稍短 T2信号,5例病灶呈混杂 T1混杂 T2信号,病灶在 DWI 均呈高信号。3例行 PWI 扫描呈轻-中度强化。3例行肾 AMRA 检查显示肾动脉受包绕推挤,4例伴有静脉癌栓形成,11例伴有腹膜后淋巴结转移,3例伴有肾上腺转移。1例伴有输尿管尿路上皮癌,2例伴有膀胱癌。结论MRI 具有多参数成像能力及较高的软组织分辨率,可清晰显示病灶部位及周围关系,对浸润性肾盂癌诊断及鉴别诊断具有较高的价值。     

Infantile fibromatosis in childhood: findings on MR imaging and pathologic correlation

AIM: The objective of this study was to analyse the MR imaging findings of infantile fibromatosis of childhood and to correlate them with histopathological features. MATERIALS AND METHODS: Seven patients with histologically proven infantile fibromatosis were included in this study. The findings on MR images were retrospectively evaluated and then correlated with the pathological features. Findings on MR imaging evaluated included signal intensity, extent of hyperintense area on T2-weighted images, margins of the lesion, the degree and pattern of enhancement and the presence of fatty tissue. Pathological features evaluated included cellularity, collagenization, and myxoid change. A five point scale was used for the evaluation of the extent of hyperintense area on MR imaging, and each of pathological features. RESULTS: On T1-weighted images, the lesions were iso-intense in two patients; iso- and hypointense in three; and iso-, hypo- and hyperintense in two. On T2-weighted images, iso-, hypo- and hyperintense areas were mixed in all patients, the hyperintense area being the largest portion of the lesion. The margins of the lesions were infiltrative in four patients (57%), smooth in two (29%) and mixed in one (14%). Enhancement was marked in five patients (72%) and diffuse in five (71%). Regardless of the hyperintense signal intensity on T2-weighted images, the grades of each pathologic feature were variable. CONCLUSION: Infantile fibromatosis on MR imaging causes an enhancing mass, that is largely hyperintense on T2-weighted images. Areas of high signal intensity on T2-weighted images corresponded to variable grades of cellularity, collagenization, or myxoid change.     

MRI appearances of bladder endometriosis

Endometriosis is characterized by endometrial tissue in ectopic foci outside the uterus. Involvement of the urinary tract is rare, with the bladder being most commonly affected in these cases. Radiologically these lesions, which are usually small, may be difficult to distinguish from intrinsic bladder neoplasia. Four cases of vesical endometriosis are presented with the MRI features that suggest the diagnosis.     

Paraffinoma of the knee

We present the case of a 90-year-old man with a swollen, painful knee and a history of paraffin injections. Radiography showed soft tissue streaky and nodular calcifications without erosions. MR imaging showed globular areas of low signal intensity on T1- and T2-weighted images which became even more hypointense on STIR sequences, and an infiltrative hypointense region containing areas of high signal on T1-weighted, T2-weighted and STIR images. Biopsy confirmed soft tissue foreign body granulomata, fibrous reaction and areas of inflammation. We believe this to be the first report of MR imaging of paraffinoma outside the breast.     

Bone marrow disorders: characterization with quantitative MR imaging

Thirty patients with various hematologic disorders and 15 healthy control subjects underwent quantitative magnetic resonance (MR) imaging of the lumbar spine with spin-echo techniques. Images of patients with infiltrative bone marrow disorders showed significantly more prolonged T1 times than those of control subjects (P less than .001). It was not possible to distinguish different diffuse infiltrative bone marrow disorders on the basis of T1 values. Aplastic anemia could be distinguished from normality because of significantly shortened T1 (P less than .001). A significant correlation was seen between T1 and bone marrow cellularity (r = .74, P less than .001). T2 was of no value in the characterization of bone marrow disorders. Quantitative MR imaging dose not improve the diagnostic potential of bone marrow imaging in the detection of diffuse marrow infiltrates.     

MRI and histological evaluation of the infiltrative growth pattern of myxofibrosarcoma

Objective   Myxofibrosarcoma often shows abnormal signal infiltration along the fascial plane on magnetic resonance imaging (MRI). The objective was to describe this MRI characteristic of myxofibrosarcoma with pathologic findings for comparison. Materials and methods  Clinical, histological, and imaging data for 21 patients with myxofibrosarcoma were reviewed retrospectively. Results  Seventeen tumors showed a diffuse infiltrative pattern on MRI. All tumors with diffuse infiltrative growth pattern showed borderless extension of atypical cells with moderate nuclear atypia to the muscle fascia. Notably, the remaining four patients with focal growth pattern on MRI also demonstrated infiltrative growth pattern histologically suggesting that myxofibrosarcoma shows an infiltrative growth property even in the lack of infiltrative growth pattern on MRI. Conclusion  Most myxofibrosarcoma show an infiltrative growth pattern histologically. Orthopedic oncologist should pay careful attention to accurately assess tumor extension. It seems prudent to resect the entire area of abnormal signal extension seen on MRI whenever possible to obtain an adequate surgical margin of myxofibrosarcoma.     

Can unenhanced multiparametric MRI substitute gadolinium-enhanced MRI in the characterization of vertebral marrow infiltrative lesions?

Purpose

To assess the diagnostic effectiveness of unenhanced-multiparametric magnetic resonance imaging (mp MRI) as an alternative to gadolinium (Gad)-enhanced MRI in the characterization of vertebral marrow infiltrative lesions.

Patients and methods

A prospective evaluation of fifty-six patients with suspected or untreated vertebral metastases undergoing MRI of the spine at 1.5 T was carried out. Two groups of sequences were assigned and compared for the characterization of marrow infiltrative lesions: group [A] unenhanced-mp MRI (including T1-weighted, T2-weighted, short time inversion recovery (STIR), diffusion weighted imaging (DWI) and in/opposed phase sequences) and group [B] gadolinium-enhanced MRI (including T1-weighted, T2-weighted, STIR and T1-weighted fat-suppressed gadolinium-enhanced sequence). Qualitative and quantitative image analysis was performed and compared. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for both imaging techniques were calculated.

Results

There was no statistical significant difference between unenhanced-multiparametric MRI and gadolinium-enhanced MRI as regards their diagnostic performance in differentiating benign from malignant vertebral marrow infiltrative lesions (p > 0.05) with calculated sensitivity (94% vs. 97%), specificity (92% vs. 88%), positive predictive value (94% vs. 91%), negative predictive value (92% vs. 95%) and (93% vs. 93%) accuracy.

Conclusion

Unenhanced-multiparametric MRI is compatible with gadolinium-enhanced MRI in reliable characterization of marrow infiltrative lesions. The routine MRI protocol of cancer patients should be altered to accommodate the evolving MRI technology and cost effectively substitute the need for a gadolinium enhanced scan.     

Cervical epidural lipoblastomatosis: changing MR appearance after chemotherapy

Lipoblastomatosis is a locally infiltrative tumor of embryonic fat. We describe the MR appearance of cervical lipoblastomatosis with epidural extension. The initial MR study showed features of a soft-tissue mass; a subsequent MR examination, performed after chemotherapy, depicted the lesion as a typical lipoma of high signal intensity on T1-weighted images and of intermediate signal on T2-weighted sequences.     

弥散张量成像技术在星形细胞肿瘤中的应用价值初探

目的：评价MRI弥散张量成像技术在星形细胞肿瘤中的应用价值。材料和方法：采用GE1.5T超导MR成像系统，对16例1-2级星形细胞肿瘤及15例3-4级星形细胞肿瘤进行了MRI检查，检查序列包括T1WI、T2WI、FLAIR、弥散张量序列（diffusion tensor imaging，DTI）及增强后T1WI。结果：正常脑白质纤维在不同解剖平面，如半卵圆中心、内囊、胼胝体、视放射、锥体束、锥体交叉及内外侧丘系等，各向异性分数图（FA）均为高信号，白质纤维受到破坏后表现为低信号，而这些表现在常规T1WI、T2WI及FLAIR图上未能清楚显示。结论：DT1可以无创性检查脑白质纤维，用于脑肿瘤诊断及术前手术方案的制定。     

Renal pseudoenlargement in patients with neoplasms

Renal pseudoenlargement due to compression of the kidneys by adjacent enlarged viscera and/or soft tissue masses is an important entity to consider in patients with known primary neoplasm, especially leukemia and lymphoma, who demonstrate enlarged kidneys on urography. This benign condition and its radiographic differentiation from infiltrative renal disorders will be discussed.     

Use of nutritional support formula as a gastrointestinal contrast agent for MRI.

The objective of this study was to evaluate the potential utility of a nutritional support formula to serve as a practical means of enhancing the gastrointestinal tract on abdominal MR images. Nutritional support formula (Ensure Plus) was administered to 29 patients prior to abdominal MRI. Standard T1-weighted and T2-weighted pulse sequences were performed, in addition to fat suppression and inversion recovery sequences in selected patients. Images in these patients were evaluated for degree and uniformity of gastrointestinal tract enhancement and delineation of the bowel wall and pancreas. Results were compared with those obtained in 10 control patients. Marked enhancement of gastric contents was present in nearly all patients who received nutritional support formula on both T1-weighted and T2-weighted sequences, with mild to moderate enhancement of small bowel and colon in most patients. Although gastrointestinal and respiratory motion artifacts often limited bowel wall delineation, excellent delineation of the gastric wall and pancreas was provided. Phantom experiments demonstrated that gastrointestinal tract enhancement with nutritional support formula is due to the paramagnetic trace elements, corn syrup, and lipid material it contains. Such a formula requires no preparation, is safe, inexpensive, palatable, readily available, and represents a practical means of enhancing the gastrointestinal tract on MRI.