Ishan Kumar

Invasive placental disorders: a prospective US and MRI comparative analysis.

Background Invasive placental disorders are potentially life-threatening. Its diagnosis and evaluation of degree of invasiveness is vital in surgical and treatment planning. Purpose To compare the role of various imaging modalities used in current practice for evaluation of invasive placental disorders, and evaluate the validity of certain imaging signs for prediction of invasive placenta. Material and Methods Twenty-two patients, which were clinically stratified as a risk group for underlying invasive placental abnormality, underwent Doppler sonography and magnetic resonance imaging (MRI). Abnormal placental invasiveness was assessed using various Doppler sonography and MRI signs described in the existing literature. We systematically evaluated the utility of each of these modalities and signs, and compared the roles played by them separately and in combination. All the cases were correlated with surgical and pathological findings. Results Nine patients had surgical and pathological confirmation of placental adhesive disorders, of which eight were predicted correctly by MRI (true positive) while one was misdiagnosed as normal placenta (false negative). All the nine cases were correctly identified by Doppler sonography. MRI was more accurate in predicting bladder invasion, identifying 5/6 cases. Conclusion Both MRI and Doppler sonography are useful for detection of invasive placental disorders. However, MRI is a better predictor of bladder invasion.

Magnetic resonance spectroscopy — Revisiting the biochemical and molecular milieu of brain tumors

Background Magnetic resonance spectroscopy (MRS) is an established tool for in-vivo evaluation of the biochemical basis of human diseases. On one hand, such lucid depiction of ‘live biochemistry’ helps one to decipher the true nature of the pathology while on the other hand one can track the response to therapy at sub-cellular level. Brain tumors have been an area of continuous interrogation and instigation for mankind. Evaluation of these lesions by MRS plays a crucial role in the two aspects of disease management described above. Scope of review Presented is an overview of the window provided by MRS into the biochemical aspects of brain tumors. We systematically visit each metabolite deciphered by MRS and discuss the role of deconvoluting the biochemical aspects of pathologies (here in context of brain tumors) in the disease management cycle. We further try to unify a radiologists perspective of disease with that of a biochemist to prove the point that preclinical work is the mother of the treatment we provide at bedside as clinicians. Furthermore, an integrated approach by various scientific experts help resolve a query encountered in everyday practice. Major conclusions MR spectroscopy is an integral tool for evaluation and systematic follow-up of brain tumors. A deeper understanding of this technology by a biochemist would help in a swift and more logical development of the technique while a close collaboration with radiologist would enable definitive application of the same. General significance The review aims at inciting closer ties between the two specialists enabling a deeper understanding of this valuable technology.

Utility of magnetic resonance imaging in the diagnosis of unsuspected cases of Parsonage-Turner syndrome: two case reports

IntroductionMRI is becoming increasingly important in the evaluation of shoulder pain, especially in the diagnosis of rotator cuff injuries and conditions that mimic them. Parsonage-Turner syndrome is a well-defined clinical entity that presents with acute-onset shoulder pain and weakness, often first recognized on magnetic resonance imaging scans.Case presentationWe studied magnetic resonance imaging features of two Asian men (ages 24 and 31 years) who presented with variable-onset shoulder pain and weakness. Magnetic resonance imaging revealed increased T2-weighted signal intensity of supraspinatus and infraspinatus muscles in both patients.ConclusionMagnetic resonance imaging findings are distinctive, although nonspecific, in cases of Parsonage-Turner syndrome, and knowledge of the imaging and clinical features of this disease enable clinicians to arrive at the correct diagnosis and guide appropriate management.

Congenital facial nerve aplasia: MR depiction of a rare anomaly

We report two infants presenting with unilateral congenital facial palsy since birth. Magnetic resonance imaging (MRI) in both the cases revealed complete unilateral aplasia of facial nerve. To our knowledge, this is the first reported MR depiction of nonsyndromic isolated facial nerve aplasia. Imaging features and the pertinent anatomy is discussed along with a brief review of literature.

Idiopathic Hypertrophic Pachymeningitis â MRI Diagnosis and Follow up

Idiopathic hypertrophic pachymeningitis is a rare entity, posing challenge to the radiologist for a confident prospective diagnosis. The same is of prime importance as in the absence of a definitive treatment, the clinician has to initiate a presumptive therapy based on radiological diagnosis, histopathology not being the pragmatic option in most cases. We present a case which is interesting not only by virtue of the rarity of this disease but also due to the extent of cranial nerves involved and the drastic response to therapy initiated once suspected on MRI. The emphasize of this report is on being mindful of the possibility and early recognition of signs differentiating it from other close and commoner mimickers.

Utility of multiparametric MRI in Caesarean section scar characterization and preoperative prediction of scar dehiscence: a prospective study

Background Post-Caesarean uterine scar rupture during vaginal birth after Caesarean section (VBAC) is a potentially life-threatening complication. Prediction of scar dehiscence and scar rupture is vital in treatment planning and selecting candidates of trial of labor after a Caesarean section (CS). Purpose To assess the accuracy of magnetic resonance imaging (MRI) for evaluation of post-Caesarean uterine scar and to predict scar dehiscence during repeat CS. Material and Methods Thirty patients with a history of at least one previous CS underwent pelvic MRI for assessment of uterine scar during a subsequent gestation, all of whom underwent lower segment Caesarean section (LSCS) subsequently due to one of the established indications of CSs. Thickness, T1, T2 signal intensity ratio (SER), and apparent diffusion coefficient (ADC) value of scar site were charted. The lower uterine segment was assessed and graded intraoperatively and findings were correlated with MRI findings. Results A total of 30 participants were included in this study, of which nine were classified as having an abnormal scar (of various grades) based on surgical observations. T2 SER with a cutoff value of 0.935 showed the highest sensitivity of 100% and scar thickness value of 3.45 mm showed highest specificity of 91% in prediction of abnormal scar. On drawing a receiver operating characteristic (ROC) curve, T2 signal intensity ratio showed the highest area under the curve (AUC) closely followed by scar thickness values. Conclusion MRI derived parameters may be utilized for differentiation of an abnormal post-Caesarean uterine scar from a normal one. Both scar thickness and T2 SER measured on MRI can be used to predict scar dehiscence. However, T2 SER can serve as a more standardized and objective criterion.

Magnetic resonance neurographic confirmation of extensive Plexiform neurofibroma in neurofibromatosis-1 presenting as ambiguous genitalia

Genitourinary involvement of neurofibromatosis is uncommon and genital neurofibromatosis is even rarer. Involvement of clitoris by neurofibroma can lead to clitoromegaly masquerading as a male penis. We report such a case of ambiguous genitalia in a 7-year-old female child presenting with clitoromegaly since birth, in which magnetic resonance imaging (MRI) revealed the presence of extensive neurofibromatosis in the clitoris and lumbosacral regions. We emphasize the central role of MRI in evaluation of hormonal and non-hormonal causes of ambiguous genitalia. We further discuss the merits of including MR neurography in the imaging protocol for comprehensive delineation of neurofibromatosis.

Mandibular arteriovenous malformation: A rare life- threatening condition depicted on multidetector CT angiography

Arteriovenous malformation (AVM) of the mandible is a rare and potentially life-threatening condition which can lead to massive hemorrhage. The following is a description where a large mandibular AVM presented with torrential bleeding following tooth extraction for caries. An orthopantomogram (OPG) was performed which was suggestive of aneurysmal bone cyst or ameloblastoma. A computed tomography (CT) angiography revealed a large mandibular AVM with submandibular extension. It is important for both clinicians and radiologist to be aware of this type of lesion that can have life-threatening complications. It is important to define the anatomical location and the feeder vessels of the entity in detail preoperatively. This communication highlights the common differential and use of multidetector CT (MDCT) angiography along with other imaging modalities to prevent a fatal hemorrhage and arrive at a correct diagnosis.

Discordant Twin Pregnancy with One Malformed Fetus – Color Doppler Follow Up for Expectant Management

Monochorionic twin discordant with congenital anomalies introduce additional burdens to obstetricians in their endeavor to save the normal co-twin. The wide array of treatment options that have been described all incur significant morbidity and none of them are unequivocally optimal. Whether to embrace the antepartum use of aggressive intervention techniques or take the conservative anticipative approach remains a topic of debate and clinical dilemma. In our view, a serial evaluation of the color Doppler parameters in such patients might help us to triage the appropriate candidates for expectant management and lead to reduced rate of overtreated patients. In this study, we describe our experience with monochorionic twinning discordant with fetal acardia and anencephaly managed conservatively through color Doppler surveillance

Comparative accuracy of magnetic resonance morphometry and sonography in assessment of post-cesarean uterine scar

Objective: To compare the diagnostic accuracy of magnetic resonance imaging (MRI) with that of ultrasonography (USG) for the measurement of lower segment cesarean scar during trial of labor after cesarean (TOLAC). Materials and Methods: This was a prospective case-control observational study conducted with a cohort of 30 participants being considered for TOLAC but eventually proceeding to lower segment cesarean section (LSCS) at a university-based teaching institute over a period of 2 years. Measurement of scar thicknesses were done by MRI and USG preoperatively and validated by surgical findings. Comparison of diagnostic accuracy as well as the cut-off values (to differentiate a normal scar from an abnormal scar) was done between the two modalities. Results: Insignificant systematic error between the measurements obtained by the two modalities was noted by a Bland–Altmann analysis. The diagnostic accuracy of USG for differentiating a normal from an abnormal uterine scar was 96.7% while that of MRI was at a slightly lower level of 90%. A strong level of agreement between the two modalities was observed. Conclusion: MRI offers no advantage in diagnostic accuracy for the measurement of LSCS scar thickness during consideration of TOLAC. Advances in Knowledge: Measurement of uterine scar by MRI has a good correlation with that done on USG in the setting of post-cesarean pregnancy. The results hold good both for normal (grades 1 and 2) and abnormal (grades 3) scars. MRI, however, does not offer any added advantage over sonographic scar thickness measurement for the differentiation of a normal (grades 1 and 2) from an abnormal (grade 3) scar.