MRI T2 mapping assessment of T2 relaxation time in desmoid tumors as a quantitative imaging biomarker of tumor response: preliminary results

ObjectivesBecause size-based imaging criteria poorly capture biologic response in desmoid-type fibromatosis (DF), changes in MRI T2 signal intensity are frequently used as a response surrogate, but remain qualitative. We hypothesized that absolute quantification of DF T2 relaxation time derived from parametric T2 maps would be a feasible and effective imaging biomarker of disease activity.MethodsThis IRB-approved retrospective study included 11 patients with DF, managed by observation or systemic therapy, assessed by 3T MRI. Tumor maximum diameter, volume, and T2-weighted signal intensity were derived from manual tumor segmentations. Tumor:muscle T2 signal ratios were recorded. Two readers measured tumor T2 relaxation times using a commercial T2 scanning sequence, manual ROI delineation and commercial calculation software enabling estimation of reader reliability. Objective response rates based on RECIST1.1 and best responses were compared between size-based and signal-based parameters.ResultsMedian patient age was 52.6 years; 8 subjects were female (73%). Nine patients with longitudinal assessments were followed for an average of 314 days. Median baseline tumor diameter was 7.2 cm (range 4.4 - 18.2 cm). Median baseline T2 was 65.1 ms (range 40.4 - 94.8 ms, n=11); median at last follow-up was 44.3 ms (-32% from baseline; range 29.3 - 94.7 ms, n=9). T2 relaxation times correlated with tumor:muscle T2 signal ratios, Spearman p=0.78 (p<0.001). T2 mapping showed high inter-reader reliability, ICC=0.84. The best response as a percentage change in T2 values was statistically significant (mean -17.9%, p=0.05, paired t-test) while change in diameter was not (mean -8.9%, p=0.12).ConclusionsAnalysis of T2 relaxation time maps of DF may offer a feasible quantitative biomarker for assessing the extent of response to treatment. This approach may have high inter-reader reliability

Sclerosing angiomatoid nodular transformation of the spleen: multimodality imaging findings and pathologic correlate

Sclerosing angiomatoid nodular transformation of the spleen is a recently recognized benign vascular lesion, characterized microscopically by multiple angiomatoid nodules embedded within a fibrosclerotic stroma. Although its imaging manifestations have been limited in the radiologic literature, features such as low-level increased fluorodeoxyglucose activity on a positron emission tomographic scan, near-complete blending in with normal splenic parenchyma on a delayed-phase image, and the presence of radiating scarring on a magnetic resonance image may suggest the diagnosis. We report here the computed tomographic, magnetic resonance imaging, and positron emission tomographic findings of sclerosing angiomatoid nodular transformation, along with gross and microscopic pathological correlation

Survival to the age of 87 years in a woman with unoperated tetralogy of Fallot

Tetralogy of Fallot is the most common cyanotic congenital heart defect, affecting approximately 2700 infants per year born in the United States. The natural history of the tetralogy reflects the adverse physiologic consequences of the underlying structural abnormalities, with only approximately 3% of uncorrected patients surviving past age 40. In this case report, we report an 87-year-old woman with unoperated tetralogy of Fallot, who we believe to be the oldest and only second octogenarian described in the literature

Value added: functional MR imaging in management of bone and soft tissue sarcomas

MRI plays a crucial role in the initial diagnosis, treatment planning, and long-term management of bone and soft tissue sarcomas. Technological advances have enabled improvements in both delineation of anatomic detail, and in functional imaging techniques that interrogate tissues at the cellular level. This bears particular relevance in sarcomas as morphological parameters alone do not necessarily correlate with treatment response and prognosis. Here, we describe recent developments in advanced MRI techniques, including chemical-shift MRI, diffusion-weighted imaging (DWI), MR spectroscopy (MRS), and dynamic contrast enhanced (DCE) MRI. Chemical-shift MRI allows robust discrimination of marrow infiltrating neoplasms from benign red marrow. DWI reveals tumor cellularity, and aids in distinguishing benign and malignant tumors along with the assessment of treatment response. MRS is technically challenging in the musculoskeletal system, but shows promise as a means to noninvasively assess metabolic aberrations in a variety of sarcomas. DCE is particularly suited to treatment response evaluation, in which traditional size-based assessment criteria may underestimate efficacy in clinical trials. Functional MRI techniques offer novel imaging biomarkers that effectively complement conventional MRI in the assessment of bone and soft tissue sarcomas at all stages of patient care

Pleomorphic hyalinizing angiectatic tumor: imaging findings

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare soft tissue tumor of low malignant potential, which most often arises in the lower extremities. To the best of our knowledge, there have been no prior descriptions of the imaging features of this neoplasm. In this case series, we report the imaging findings in three patients. Two patients had a lower extremity subcutaneous PHAT, while the third patient had an intramuscular upper extremity PHAT. While imaging features are variable, a diagnosis of PHAT should be considered when encountering an enhancing, subcutaneous tumor with ill-defined margins, particularly in the extremity

Incidental minimal atypical lobular hyperplasia on core needle biopsy: correlation with findings on follow-up excision

Atypical lobular hyperplasia (ALH), often an incidental finding in breast core biopsies, is largely considered to be a risk factor for carcinoma rather than a direct precursor. However, management of ALH is controversial. We review our experience with incidental minimal ALH on core biopsy, and correlate with excision and follow-up results. We evaluated all cases of ALH on core biopsy from 1999 to 2009 from our institution, focusing on cases with < or =3 foci of ALH (minimal), paired excision, and no other lesion on the core biopsy that by itself would require excision. Cases with discordant clinical/radiologic impressions, suggesting that a suspicious lesion had been missed on biopsy, were excluded. Therefore, the excisions were performed because of the diagnosis of ALH. Of 56 cases with ALH on biopsy and paired excision, 42 showed minimal ALH. On excision, 26 had residual ALH and 13 were benign. Three cases had other atypical lesions: lobular carcinoma in situ (2 cases) and mild atypical ductal hyperplasia separate from the biopsy site (1 case). On follow-up, only 1 patient developed subsequent ALH in the same breast. No other ipsilateral lesions were later diagnosed (mean follow-up 3.2 y). No case with ALH on biopsy had a lesion on excision requiring further treatment, suggesting that these patients can be managed more conservatively. Furthermore, no patients were diagnosed with a higher grade lesion in the same breast on follow-up. We propose that, if there is close radiologic correlation and follow-up, minimal incidental ALH on core biopsy (< or =3 foci) does not require excision

Apparent diffusion coefficient map of a case of extramedullary plasmacytoma

Plasmacytomas are rare tumors, which arise from the monoclonal proliferation of malignant plasma cells. They may affect either the bony skeleton or rarely the soft tissues, the latter being referred to as extramedullary or extraosseous. We report a case of an extramedullary plasmacytoma that presented as a soft tissue mass involving the muscles of the left leg, in a patient who was previously treated for multiple myeloma. We describe the MR Imaging characteristics of the tumor and highlight the usefulness of diffusion-weighted imaging with apparent diffusion coefficient mapping